WO2013161054A1 - Wireless base station, wireless terminal, wireless communication system, and communication control method - Google Patents
Wireless base station, wireless terminal, wireless communication system, and communication control method Download PDFInfo
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- WO2013161054A1 WO2013161054A1 PCT/JP2012/061362 JP2012061362W WO2013161054A1 WO 2013161054 A1 WO2013161054 A1 WO 2013161054A1 JP 2012061362 W JP2012061362 W JP 2012061362W WO 2013161054 A1 WO2013161054 A1 WO 2013161054A1
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/04—TPC
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/04—Wireless resource allocation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
- H04W88/08—Access point devices
- H04W88/085—Access point devices with remote components
Definitions
- the present invention relates to a radio base station, a radio terminal, a radio communication system, and a communication control method.
- CoMP scenario 4 remote radio heads (RRH, overhanging stations) 200-1 and 200-2 are arranged in a radio area 400 of eNodeB (eNB, radio base station) 100, as illustrated in FIG. A system configuration is assumed in which the eNB 100 and each of the RRHs 200-1 and 200-2 are connected by a high-speed interface such as an optical fiber.
- eNodeB eNodeB
- UEs 300-1 to 300-7 are located in the radio area 400 of the eNB 100, and UEs 300-3 and 300-4 are located in the radio area 500-1 of the RRH 200-1. . Furthermore, UEs 300-5 to 300-7 are located in the radio area 500-2 of the RRH 200-2. Also, in CoMP scenario 4, by sharing the cell ID between the eNB 100 and each of the RRHs 200-1 and 200-2, load reduction of mobility control, sharing of cell-specific resources, and the like are achieved.
- each of the UEs 300-1 to 300-7 transmits a Sounding Reference Symbol (SRS) as an example of a known signal for estimating the quality of an uplink radio channel to the eNB 100 and the RRHs 200-1 and 200-2.
- SRS Sounding Reference Symbol
- the uplink transmission power control when each UE 300-1 to 300-7 transmits the SRS is offset to the Transmission Power Control (TPC) of the Physical Uplink Shared Channel (PUSCH). It is specified to be performed according to the following control equation (1) having the added shape.
- Is a subframe Is the transmission power of SRS, Is the maximum transmit power, Is an offset value from the transmission power of PUSCH, Is the number of PUSCH allocation resources, Is the PUSCH received power target value, Is the path loss coefficient, Is a propagation loss (path loss) between the UE 300-1 to 300-7 and the serving base station, Represents the power adjustment coefficient of PUSCH, respectively.
- the above control equation (1) is intended to compensate for the path loss of the serving cell.
- the following control expression (2) is proposed in 3GPP contribution “R1-113328” and the like.
- the above control equation (2) is intended to receive the SRS in the entire CoMP set, and has the advantage that the reception quality of UpLink (UL, uplink) can be obtained by more eNBs 100, RRHs 200-1, 200-2. There is.
- the UEs 300-1 to 300-7 are allocated radio resources for transmitting SRS from the eNB 100, and transmit SRSs using the allocated radio resources.
- each UE 300-1 to 300-7 is assigned radio resources that can be identified by different base sequences, cyclic shifts (CS), and comb teeth, and applies frequency hopping to the assigned radio resources.
- SRS is transmitted.
- radio resources defined by a combination of frequency and time (timing) are allocated to each UE.
- radio resources # 1 to # 7 represent radio resources allocated to the UEs 300-1 to 300-7, respectively.
- CoMP scenario 4 since a common cell ID is used by eNB 100 and each RRH 200-1 and 200-2, there is one base sequence.
- the eNB 100 can only identify SRSs from 16 UEs.
- CoMP scenario 4 when the number of UEs increases, even when considering the difference in SRS transmission timing, the case of transmitting SRS in the same band and the same timing Can happen enough.
- SRS interference may occur.
- a plurality of UEs transmit SRS using the same radio resource, or when a plurality of UEs transmit SRS using radio resources at least partially overlapping each other, an SRS collision occurs and interference occurs. May occur.
- an object of the present invention is to suppress interference of known signals.
- the present invention is not limited to the above-described objects, and is an operation and effect derived from each configuration shown in the embodiment for carrying out the invention described below, and also exhibits an operation and effect that cannot be obtained by conventional techniques. It can be positioned as one of the purposes.
- the other signal so that a known signal transmitted by a wireless terminal located in a wireless area of another wireless base station different from the own station among the plurality of wireless terminals is received by a wireless base station other than the own station.
- a processing unit that controls transmission power of a wireless terminal located in the wireless area of the wireless base station, and at least a known signal transmitted by a wireless terminal located in the wireless area of the own station among the plurality of wireless terminals It is possible to use a radio base station that includes a receiving unit.
- radio resources at least partially overlapping each other are allocated to a plurality of radio terminals including the own station.
- radio resources that are at least partially overlapping among a plurality of radio resources used when transmitting a known signal are allocated to a plurality of radio terminals.
- a known signal transmitted by a wireless terminal located in a wireless area of another wireless base station different from the own station among the plurality of wireless terminals is received by a wireless base station other than the own station.
- a radio base station that controls transmission power of a radio terminal located in the radio area of the other radio base station, and a transmission power that is located in the radio area of the other radio base station and controlled by the radio base station It is possible to use a wireless communication system that includes a wireless terminal that transmits the known signal using a wireless communication device.
- a fourth plan for example, in a radio base station, radio resources at least partially overlapping each other among a plurality of radio resources used when transmitting a known signal to a plurality of radio terminals Among the plurality of wireless terminals, a known signal transmitted by a wireless terminal located in a wireless area of another wireless base station different from the own station is transmitted by a wireless base station other than the own station.
- the transmission power of a radio terminal located in the radio area of the other radio base station is controlled to be received, and the controlled transmission power is controlled in a radio terminal located in the radio area of the other radio base station.
- a communication control method can be used in which the known signal is transmitted using the.
- FIG. (A) And (B) is a figure which shows an example of the transmission format of an instruction
- (A) And (B) is a figure which shows an example of the transmission format of a notification signal. It is a figure which shows an example of operation
- FIG. 3 is a diagram illustrating an example of the configuration of a radio communication system according to one embodiment.
- the radio communication system 6 shown in FIG. 3 illustratively includes an eNB 1 that is an example of a radio base station, extended stations (RRH) 2-1 and 2-2, and a plurality of user apparatuses (UE) 3-1 to 3-7.
- eNB 1 that is an example of a radio base station
- RRH extended stations
- UE user apparatuses
- RRHs 2-1 and 2-2 when RRHs 2-1 and 2-2 are not distinguished, they are simply expressed as RRH2, and when UEs 3-1 to 3-7 are not distinguished, they are simply expressed as UE3.
- the numbers of RRH2 and UE3 are not limited to the numbers illustrated in FIG.
- the eNB 1 provides a radio area 4 such as a cell or a sector, and can perform radio communication with the UEs 3-1 to 3-7 located in the radio area 4.
- the RRH 2-1 provides a radio area 5-1, and can perform radio communication with the UEs 3-3 and 3-4 located in the radio area 5-1.
- the RRH 2-2 provides a radio area 5-2 and can perform radio communication with UEs 3-5 to 3-7 located in the radio area 5-2.
- the eNB 1 and the RRHs 2-1 and 2-2 are connected by a high-speed interface such as an optical fiber and can communicate with each other.
- a high-speed interface such as an optical fiber
- the interface between the eNB 1 and the RRHs 2-1 and 2-2 is not limited to an optical fiber, and for example, an X2 interface or a wireless backhaul may be used.
- CoMP technology can be used.
- the eNB 1 directly receives a signal transmitted from the UE 3 to the local station 1 and transmits a signal transmitted from the UE 3 to the other station 2 via a high-speed interface such as an optical fiber.
- a high-speed interface such as an optical fiber.
- the RRH 2 directly receives a signal transmitted from the UE 3 to the own station 2 and receives a signal transmitted from the UE 3 to the other station 1 via a high-speed interface such as an optical fiber, and combines the received signals. By doing so, uploading of data can be speeded up.
- each UE 3 receives a signal transmitted from the eNB 1 to the local station 3 and receives a signal transmitted from the RRH 2 to the local station 3.
- DL downlink
- each UE 3 is pre-assigned from eNB 1 or RRH 2 radio resources for transmitting a known reference signal (SRS) for estimating the quality of an uplink radio channel, and uses the assigned radio resources for SRS. Send. Note that this SRS is not a target of the synthesis process in CoMP.
- SRS known reference signal
- the same radio resource may be allocated to different UEs 3 in duplicate.
- UE 3-1 and UE 3-7 performs transmission power control according to the following control equation (2)
- UE 3-7 transmits the SRS to the eNB 1 and the RRH 2-2 using the same radio resource while transmitting the SRS to the eNB 1 using the resource.
- the eNB 1 may collide with the SRS transmitted from the UE 3-1 and the SRS transmitted from the UE 3-7, and there is a possibility that SRS interference occurs.
- SRS interference occurs, the eNB 1 cannot appropriately estimate the uplink channel quality and may not be able to perform efficient CoMP. Therefore, in this example, as illustrated in FIG. 4, first, the eNB 1 or the RRH 2 assigns radio resources for SRS transmission to each UE 3, and the same radio resource is duplicated in different UE 3. Detect whether it was assigned or not.
- step S10 When it detects that the same radio resource is assigned to different UEs 3 (duplication of SRS radio resources) (step S10), eNB1 or RRH2 detects at least one of UEs 3 to which the same radio resource is assigned. Then, switching of transmission power control is instructed (step S11).
- the UE 3 instructed to switch the transmission power control performs, for example, transmission power control according to the following control equation (1) so that the SRS reaches only the serving cell (step S12), and the SRS is determined based on the determined transmission power. Is transmitted (step S13).
- step S14 when eNB1 or RRH2 detects that the duplication of SRS radio resources has been resolved (step S14), among UE3s that have been assigned the same radio resource, to UE3 that has instructed step S11. Then, switching of transmission power control is instructed (step S15). UE3 instructed to switch transmission power control performs transmission power control according to the following control equation (2), for example, so that the SRS reaches all reception points in the CoMP set (step S16). The SRS is transmitted with the determined transmission power (step S17).
- FIG. 5 is a diagram illustrating an example of the configuration of eNB1. Since RRH2 has the same configuration as eNB1, description of the configuration example of RRH2 is omitted.
- the eNB 1 illustrated in FIG. 5 exemplarily includes an antenna 11, a duplexer 12, a reception unit 13, a channel estimation unit 14, a control signal demodulation / decoding unit 15, a data signal demodulation / decoding unit 16, and a reception quality calculation.
- a unit 17 and a scheduler 18 are provided.
- eNB1 illustrated in FIG. 5 exemplarily includes a data signal generation unit 19, a control signal generation unit 20, a reference signal generation unit 21, a data signal encoding modulation unit 22, and a control signal encoding modulation unit 23.
- an assigning unit 24 and a transmitting unit 25 exemplarily includes a transmitting unit 25.
- the antenna 11 functions as a reception antenna that receives a radio signal from the UE 3 and also functions as a transmission antenna that transmits a radio signal to the UE 3. That is, the antenna 11 of this example has a configuration in which the reception antenna and the transmission antenna are shared by the duplexer 12. Note that FIG. 5 merely shows an example of the configuration of the eNB 1. For example, when the duplexer 12 is not used, the eNB 1 may have a transmission antenna and a reception antenna individually.
- the receiving unit 13 extracts a reference signal (SRS), a control signal, and a data signal from uplink radio signals such as PUSCH and Physical-Uplink-Control-Channel (PUCCH) transmitted from the UE 3 received by the antenna 11.
- SRS reference signal
- PUCCH Physical-Uplink-Control-Channel
- the reference signal, control signal, and data signal extracted by the reception unit 13 are output to the channel estimation unit 14, the control signal demodulation / decoding unit 15, and the data signal demodulation / decoding unit 16, respectively.
- the receiving unit 13 functions as an example of a receiving unit that receives at least a known signal such as SRS transmitted by the wireless terminal 3 located in the wireless area of the local station 1 among the plurality of wireless terminals 3.
- the channel estimation unit 14 calculates a channel estimation value using the reference signal extracted by the reception unit 13.
- the channel estimation value calculated by the channel estimation unit 14 is output to the control signal demodulation / decoding unit 15, the data signal demodulation / decoding unit 16, and the reception quality calculation unit 17, respectively.
- the control signal demodulation / decoding unit 15 performs demodulation processing and decoding processing on the control signal extracted by the reception unit 13 using the channel estimation value calculated by the channel estimation unit 14.
- the control information obtained by the control signal demodulation / decoding unit 15 is output to the data signal demodulation / decoding unit 16 and the scheduler 18, respectively. Further, ACKnowledgement (ACK) indicating that the decoding result is normal or Negative ACKnowledgement (NACK) indicating that the decoding result is abnormal may be output to the scheduler 18.
- ACK acknowledgement
- NACK Negative ACKnowledgement
- the data signal demodulation / decoding unit 16 performs demodulation processing and decoding processing on the data signal extracted by the reception unit 13 using the channel estimation value calculated by the channel estimation unit 14.
- the data obtained by the data signal demodulation / decoding unit 16 is output to the scheduler 18. Further, ACK indicating that the decoding result is normal or NACK indicating that the decoding result is abnormal may be output to the scheduler 18.
- the reception quality calculation unit 17 uses the channel estimation value calculated by the channel estimation unit 14 to calculate reception quality such as a signal-to-interference ratio (SIR). Information regarding the reception quality calculated by the reception quality calculation unit 17 is output to the scheduler 18.
- the scheduler 18 sends a signal generation request to the data signal generation unit 19, the control signal generation unit 20, and the reference signal generation unit 21 based on each input information. Further, the scheduler 18 sends scheduling information indicating radio resource allocation for each signal to the allocation unit 24 based on each input information.
- the data signal generator 19 generates a data signal based on the signal generation request from the scheduler 18.
- the data signal encoding / modulating unit 22 performs encoding processing and modulation processing on the data signal generated by the data signal generating unit 19.
- the encoded and modulated data signal obtained by the data signal encoding / modulating unit 22 is output to the assigning unit 24.
- the control signal generation unit 20 generates a control signal based on the signal generation request from the scheduler 18.
- the control signal encoding / modulating unit 23 performs encoding processing and modulation processing on the control signal generated by the control signal generating unit 20.
- the encoded and modulated control signal obtained by the control signal encoding / modulating unit 23 is output to the allocating unit 24.
- the reference signal generation unit 21 generates a reference signal based on the signal generation request from the scheduler 18.
- the allocating unit 24 uses the scheduling information instructed by the scheduler 18 for the data signal from the data signal encoding and modulating unit 22, the control signal from the control signal encoding and modulating unit 23, and the reference signal from the reference signal generating unit 21.
- Wireless resources are allocated.
- the radio resources include, for example, transmission / reception power, transmission / reception frequency (channel), transmission / reception timing, and the like as examples of communication resources used for transmission / reception of radio signals.
- the transmission unit 25 transmits a data signal, a control signal, and a reference signal via the antenna 11 using the radio resource allocated by the allocation unit 24.
- the scheduler 18 performs radio resource allocation control. For example, as shown in FIG. 6, when the scheduler 18 starts radio resource allocation control (step S20), the scheduler 18 calculates the number of uplink radio resources that the UE 3 can use for transmission of SRS (step S21). Note that the number of uplink radio resources includes, for example, the number of resource blocks (RB, resource blocks) defined by the channel and transmission timing.
- RB resource blocks
- the scheduler 18 calculates the number of UEs 3 to which uplink radio resources for SRS transmission are allocated (step S22). Then, it is determined whether or not the number of UE3 is larger than the number of uplink radio resources (step S23). When it is determined that the number of UE3 is equal to or less than the number of uplink radio resources (No route of step S23), the scheduler 18 allocates different radio resources to each UE 3 (step S25), and ends the radio resource allocation control (step S26).
- the scheduler 18 will allocate the same radio resource to any of the plurality of UE3.
- the scheduler 18 in this example assigns the same radio resource to the UEs 3 having different radio areas in the same area (step S24), and ends the radio resource allocation control (step S26). Thereby, it is possible to prevent the SRS from the UE 3 to which the same radio resource is assigned in duplicate from colliding and interfering in the eNB 1 and the RRH 2 by the transmission power switching control of this example described later.
- the scheduler 18 locates radio resources at least partially overlapping among the plurality of radio resources in the radio areas of the radio terminal 3 and other radio base stations 2 located in the radio area of the own station 1. It can be assigned to the wireless terminal 3.
- the scheduler 18 performs transmission power switching control. For example, as shown in FIG. 7, when the scheduler 18 starts transmission power switching control (step S30), the scheduler 18 determines whether or not the same radio resource is allocated to different UEs 3 (step S31). If there is no radio resource duplication (No route in step S31), the transmission power switching control is terminated (step S34).
- the scheduler 18 determines whether or not each UE 3 to which the same radio resource is assigned is an application target of CoMP (step S32). .
- the scheduler 18 ends the transmission power switching control (Step S34). .
- step S32 when it is determined that any of the UEs 3 to which the same radio resource is allocated is a CoMP application target (Yes route in step S32), the scheduler 18 Instructing UE 3 residing in a radio area provided by another station different from the radio area provided by own stations 1 and 2 to switch transmission power control (TPC) (step S33), the transmission power switching control is terminated (step S34).
- TPC transmission power control
- the scheduler 18 performs the following transmission power re-switching control after performing the process of step S33. For example, as shown in FIG. 8, when the scheduler 18 starts transmission power re-switching control (step S40), it is determined whether or not the situation where the same radio resource is allocated to different UEs 3 has been resolved. Determination is made (step S41).
- the scheduler 18 uses the radio provided by the own stations 1 and 2 among the UEs 3 to which the same radio resource is allocated.
- a UE 3 located in a radio area provided by another station different from the area is instructed to switch transmission power control (TPC) (step S43), and the transmission power re-switching control is terminated (step S43). Step S44).
- the scheduler 18 determines whether or not at least one of the UEs 3 to which the same radio resource is allocated is not subject to CoMP application. Is determined (step S42). Here, if it is determined that at least one of the UEs 3 to which the same radio resource is assigned is not subject to CoMP application (Yes route in step S42), the scheduler 18 has been assigned the same radio resource. In addition, among the UEs 3, the transmission power control (TPC) is switched for the UEs 3 located in the wireless areas provided by other stations different from the wireless areas provided by the own stations 1 and 2. An instruction is given (step S43), and transmission power re-switching control is terminated (step S44).
- TPC transmission power control
- Step S44 when it is determined that each of the UEs 3 to which the same radio resource is allocated is a CoMP application target (No route in Step S42), the scheduler 18 ends the transmission power re-switching control (Step S44).
- a transmission power control (TPC) switching instruction and a transmission power control (TPC) switching instruction will be described in detail.
- the scheduler 18 When the TPC switching instruction shown in step S33 and the TPC re-switching instruction shown in step S43 are performed, the scheduler 18 generates an instruction signal for instructing the control signal generation unit 20 to switch the TPC. Request that.
- the instruction signal is configured as, for example, a flag that can take two values “1” and “0”.
- the scheduler 18 sets the instruction signal to “1” to cause the UE 3 to perform TPC according to the following control equation (1) from the following control equation (2).
- the scheduler 18 allocates radio resources at least partially overlapping each other among the plurality of radio resources used when transmitting a known signal such as SRS to the plurality of radio terminals 3, Among the plurality of wireless terminals 3, a known signal transmitted by a wireless terminal 3 located in a wireless area of another wireless base station 2 different from the local station 1 is received by the wireless base station 2 except the local station 1.
- a processing unit that controls the transmission power of the wireless terminal 3 located in the wireless area of the other wireless base station 2.
- step S43 the scheduler 18 sets the instruction signal to “0” to cause the UE 3 to perform TPC according to the following control equation (1) to the following control equation (2).
- the scheduler 18 transmits a radio terminal 3 located in a radio area of another radio base station 2 when different radio resources among a plurality of radio resources are allocated to a plurality of radio terminals.
- the transmission power of the radio terminal 3 located in the radio area of the other radio base station 2 can be controlled so that the known signal is received at least by the own station 1 and the other radio base station 2.
- the instruction signal may be stored and transmitted in downlink control information such as DCI (Downlink Control Information): A-CQI (Channel Quality Indicator) as shown in FIG. 9A, for example.
- DCI Downlink Control Information
- A-CQI Channel Quality Indicator
- the instruction signal is added as a new field (srs-ConfigTPC) to a control signal in an upper layer such as SoundingRS-UL-Config of Radio ⁇ ⁇ ⁇ resource control information elements. May be sent.
- FIG. 10 is a diagram illustrating an exemplary configuration of UE3.
- the UE 3 shown in FIG. 10 exemplarily includes an antenna 31, a duplexer 32, a reception unit 33, a channel estimation unit 34, a control signal demodulation / decoding unit 35, a data signal demodulation / decoding unit 36, and a reception quality calculation.
- the unit 37 is provided.
- 10 exemplarily includes a data signal generation unit 38, a control signal generation unit 39, a reference signal generation unit 40, a data signal encoding modulation unit 41, and a control signal encoding modulation unit 42.
- an allocating unit 43, a switching control unit 44, a transmission power determining unit 45, and a transmitting unit 46 exemplarily includes a Wi-Fi Protected Access (WPA)
- a transmission power determining unit 45 a transmitting unit 46.
- the antenna 31 functions as a reception antenna that receives radio signals from the eNB1 and RRH2, and also functions as a transmission antenna that transmits radio signals to the eNB1 and RRH2. That is, the antenna 31 of this example has a configuration in which the reception antenna and the transmission antenna are shared by the duplexer 32. Note that FIG. 10 merely shows an example of the configuration of the UE 3. For example, when the duplexer 32 is not used, the UE 3 may have a transmission antenna and a reception antenna individually.
- the receiving unit 33 extracts a reference signal, a control signal, and a data signal from downlink radio signals, such as Physical31Downlink Shared Channel (PDSCH) and Physical Downlink Control Channel (PDCCH) transmitted from eNB1 and RRH2 received by the antenna 31. .
- the reference signal, control signal, and data signal extracted by the reception unit 33 are output to the channel estimation unit 34, the control signal demodulation / decoding unit 35, and the data signal demodulation / decoding unit 36, respectively.
- the channel estimation unit 34 calculates a channel estimation value using the reference signal extracted by the reception unit 33.
- the channel estimation value calculated by the channel estimation unit 34 is output to the control signal demodulation / decoding unit 35, the data signal demodulation / decoding unit 36, and the reception quality calculation unit 37, respectively.
- the control signal demodulation / decoding unit 35 uses the channel estimation value calculated by the channel estimation unit 34 to perform demodulation processing and decoding processing on the control signal extracted by the reception unit 33.
- the control information obtained by the control signal demodulation / decoding unit 35 is output to the data signal demodulation / decoding unit 36, the control signal generation unit 39, the allocation unit 43, and the switching control unit 44, respectively.
- ACK indicating that the decoding result is normal or NACK indicating that the decoding result is abnormal may be output to the control signal generation unit 39.
- the data signal demodulation / decoding unit 36 performs demodulation processing and decoding processing on the data signal extracted by the receiving unit 33 using the channel estimation value calculated by the channel estimation unit 34.
- the data obtained by the data signal demodulation / decoding unit 36 is output to the control signal generation unit 39. Further, ACK indicating that the decoding result is normal or NACK indicating that the decoding result is abnormal may be output to the control signal generation unit 39.
- the reception quality calculation unit 37 calculates reception quality such as SIR using the channel estimation value calculated by the channel estimation unit 34. Information regarding the reception quality calculated by the reception quality calculation unit 37 is output to the control signal generation unit 39.
- the data signal generation unit 38 generates a data signal.
- the data signal encoding / modulating unit 41 performs encoding processing and modulation processing on the data signal generated by the data signal generating unit 38.
- the encoded and modulated data signal obtained by the data signal encoding / modulating unit 41 is output to the assigning unit 43.
- the control signal generation unit 39 generates a control signal based on various information from the control signal demodulation / decoding unit 35, the data signal demodulation / decoding unit 36, and the reception quality calculation unit 37.
- the control signal encoding / modulating unit 42 performs encoding processing and modulation processing on the control signal generated by the control signal generating unit 39.
- the encoded and modulated control signal obtained by the control signal encoding / modulating unit 42 is output to the allocating unit 43.
- the reference signal generation unit 40 generates a reference signal.
- the allocating unit 43 receives the data signal from the data signal encoding / modulating unit 41, the control signal from the control signal encoding / modulating unit 42, and the reference signal from the reference signal generating unit 40 from the control signal demodulation / decoding unit 35.
- Radio resources are allocated based on the control information.
- the radio resources include, for example, transmission / reception frequencies (channels), transmission / reception timings, and the like as examples of communication resources used for transmission / reception of radio signals. For example, when the number of UE3 is larger than the number of radio resources that can be allocated in eNB1 and RRH2, UE3 allocates the same radio resource as other UE3 as the radio resource used for SRS transmission.
- the switching control unit 44 switches transmission power control (TPC) in the UE 3 based on the control information input from the control signal demodulation / decoding unit 35. Specifically, for example, when the control information input from the control signal demodulation / decoding unit 35 includes the instruction signal set to “1” as the above-described instruction signal, the switching control unit 44 uses the following control expression (2 ) To transmit power control according to the following control equation (1). When the control information input from the control signal demodulation / decoding unit 35 includes the instruction signal set to “0” as the above-described instruction signal, the switching control unit 44 transmits transmission power according to the following control expression (1). Control is switched to transmission power control according to the following control equation (2).
- the transmission power determination unit 45 determines the transmission power of the UE 3 according to the transmission power control method after switching by the switching control unit 44. More specifically, the transmission power determination unit 45 determines the transmission power for the SRS according to the transmission power control equation after switching by the switching control unit 44. That is, the transmission power determination unit 45 is configured to respond to a plurality of wireless terminals 3 including the own station 3 with a plurality of wireless resources used when transmitting a known signal such as SRS, at least partially overlapping with each other. Processing for determining transmission power of own station 3 so that known signals transmitted by own station 3 are received by some radio base stations 2 (or 1) of a plurality of radio base stations when assigned It functions as an example of a unit.
- the transmission unit 46 transmits a data signal, a control signal, and a reference signal via the antenna 31 using the radio resource allocated by the allocation unit 43 and the transmission power determined by the transmission power determination unit 45. That is, the transmission unit 46 functions as an example of a transmission unit that transmits a known signal using the transmission power determined by the transmission power determination unit 45.
- step S50 when the UE 3 starts the SRS transmission process (step S50), the UE 3 extracts the instruction signal described above from the control information received from the eNB 1 and the RRH 2 (step S51).
- UE3 switches the transmission power control method in the own station 3 according to the content of the extracted instruction
- the UE 3 transmits at least a known radio signal transmitted by the own station 3 to the serving radio base.
- the transmission power of the local station 3 can be determined so as to be received by the station 2 (or 1) and the other radio base station 1 (or 2).
- UE3 determines the transmission power of SRS according to the transmission power control method (control formula) after switching in step S52 (step S53).
- UE3 transmits SRS with the transmission power determined by step S53 (step S54), and complete
- step S53 step S54
- step S55 step S55
- the radio resources for SRS transmission are insufficient, the influence of SRS collision due to the overlap of radio resources for SRS transmission can be reduced. It becomes possible to obtain a high-quality UL-CQI (UpLink-Channel Quality Indicator).
- the eNB 1 can appropriately perform CoMP control, so that it is possible to maintain the data communication efficiency by CoMP.
- eNB1 and RRH2 have determined whether TPC switching is necessary. However, as in this example, UE3 is notified of the presence or absence of radio resource duplication from eNB1 and RRH2. Based on the notification contents, it may be determined whether or not TPC switching is necessary. For example, as shown in FIG. 12, first, eNB1 or RRH2 assigns radio resources for SRS transmission to each UE3, and whether or not the same radio resources are assigned to different UE3 in duplicate. Is detected.
- step S60 When it detects that the same radio resource is assigned to different UE3 in duplicate (duplication of SRS radio resource) (step S60), eNB1 or RRH2 detects at least one of UE3 to which the same radio resource is assigned. Then, it is notified that the radio resources for SRS transmission are allocated redundantly (step S61).
- the UE 3 that is notified that the radio resources for SRS transmission are allocated redundantly performs, for example, transmission power control according to the following control equation (1) so that the SRS reaches only the serving cell ( Step S62), SRS is transmitted with the determined transmission power (step S63).
- step S64 when eNB1 or RRH2 detects that the overlapping of the radio resources for SRS has been eliminated (step S64), among UE3 assigned with the same radio resource, UE3 that has instructed step S61 described above Then, it is notified that the SRS radio resource duplication has been resolved (step S65).
- UE3 that has been notified that the duplication of SRS radio resources has been resolved for example, performs transmission power control according to the following control equation (2) so that the SRS reaches all reception points in the CoMP set. (Step S66), SRS is transmitted with the determined transmission power (Step S67).
- the scheduler 18 performs radio resource allocation control. For example, as shown in FIG. 6, when the scheduler 18 starts radio resource allocation control (step S20), the scheduler 18 calculates the number of uplink radio resources that the UE 3 can use for transmission of SRS (step S21). Note that the number of uplink radio resources includes, for example, the number of resource blocks (RB) defined by the channel and transmission timing.
- RB resource blocks
- the scheduler 18 calculates the number of UEs 3 to which uplink radio resources for SRS transmission are allocated (step S22). Then, it is determined whether or not the number of UE3 is larger than the number of uplink radio resources (step S23). When it is determined that the number of UE3 is equal to or less than the number of uplink radio resources (No route of step S23), the scheduler 18 allocates different radio resources to each UE 3 (step S25), and ends the radio resource allocation control (step S26).
- the scheduler 18 will allocate the same radio resource to any of the plurality of UE3.
- the scheduler 18 in this example assigns the same radio resource to the UEs 3 having different radio areas in the same area (step S24), and ends the radio resource allocation control (step S26). Thereby, it is possible to prevent the SRS from the UE 3 to which the same radio resource is assigned in duplicate from colliding and interfering in the eNB 1 and the RRH 2 by the transmission power switching control of this example described later.
- the scheduler 18 performs notification processing regarding the presence or absence of radio resource duplication. For example, as illustrated in FIG. 13, when the scheduler 18 starts notification processing about the presence or absence of radio resource duplication (step S ⁇ b> 70), the scheduler 18 determines whether or not the same radio resource is assigned to different UEs 3 in duplicate. If there is no radio resource duplication (No route in step S71), the notification process is terminated (step S74).
- the scheduler 18 determines whether or not each UE 3 to which the same radio resource is assigned is a CoMP application target (step S72). .
- the scheduler 18 ends the notification process (Step S74).
- step S72 when it is determined that any of the UEs 3 to which the same radio resource is allocated is a CoMP application target (Yes route in step S72), the scheduler 18 Radio resources for SRS transmission are allocated to UE3 located in a radio area provided by another station different from the radio area provided by own stations 1 and 2 Then, it is notified that there is a possibility of interference of SRS (step S73), and the notification process is terminated (step S74).
- the scheduler 18 performs the following re-notification process after performing the process of step S73. For example, as shown in FIG. 14, when the scheduler 18 starts the re-notification process (step S80), the scheduler 18 determines whether or not the situation in which the same radio resource is allocated to different UEs 3 has been resolved. (Step S81).
- the scheduler 18 is the radio provided by the own stations 1 and 2 among the UEs 3 to which the same radio resource is allocated. Radio resources for SRS transmission are not allocated redundantly to UE3 located in a radio area provided by another station different from the area, and there is no possibility of SRS interference occurring This is notified (step S83), and the re-notification process is terminated (step S84).
- the scheduler 18 determines whether or not at least one of the UEs 3 to which the same radio resource is assigned is not subject to CoMP application. Is determined (step S82).
- the scheduler 18 has been allocated the same radio resource.
- SRS interference may occur for UEs 3 located in radio areas provided by other stations different from the radio areas provided by the own stations 1 and 2. Notify (step S83), and the re-notification process ends (step S84).
- Step S84 when it is determined that each of the UEs 3 to which the same radio resource is allocated is a CoMP application target (No route in Step S82), the scheduler 18 ends the re-notification process (Step S84).
- the notification process and the re-notification process will be described in detail.
- the scheduler 18 When performing the notification process shown in step S73 and the re-notification process shown in step S83, the scheduler 18 notifies the control signal generation unit 20 that radio resources are allocated in duplicate. Request to generate a signal.
- the notification signal is configured as a flag that can take two values, for example, “1” and “0”. For example, in the above step S73, the scheduler 18 sets the notification signal to “1” to notify the UE 3 that the radio resource is allocated redundantly. In step S83, the scheduler 18 sets the instruction signal to “0” to notify the UE 3 that the radio resources are not allocated redundantly.
- the notification signal may be transmitted by being stored in downlink control information such as DCI: A-CQI as shown in FIG. 15 (A), for example.
- DCI downlink control information
- A-CQI as shown in FIG. 15 (A)
- the notification signal is added as a new field (srs-ConfigTPC) to a control signal in an upper layer such as SoundingRS-UL-Config of RadioConfigresource control information elements, for example, as shown in FIG. May be sent.
- step S90 when the UE 3 starts the SRS transmission process (step S90), the UE 3 extracts the notification signal described above from the control information received from the eNB 1 and the RRH 2 (step S91).
- UE3 switches the transmission power control method in the own station 3 according to the content of the extracted notification signal (step S92). Specifically, for example, when a notification signal set to “1” is extracted, the UE 3 switches from transmission power control according to the following control equation (2) to transmission power control according to the following control equation (1). When the notification signal set to “0” is extracted, the UE 3 switches from transmission power control according to the following control equation (1) to transmission power control according to the following control equation (2).
- UE3 determines the transmission power of SRS according to the transmission power control method (control equation) after switching in step S92 (step S93). And UE3 transmits SRS with the transmission power determined by step S93 (step S94), and complete
- control equation control equation
- FIG. 17 shows an example of the hardware configuration of eNB1 and RRH2.
- the eNB 1 and the RRH 2 include an antenna 11, a wireless IF (wireless interface) 51, a processor 52, a memory 53, a logic circuit 54, and a wired IF (wired interface) 55. .
- the wireless IF 51 is an interface device for performing wireless communication with the UE 3.
- the processor 52 is a device that processes data, and includes, for example, a Central Processing Unit (CPU), a Digital Signal Processor (DSP), and the like.
- the memory 53 is a device that stores data, and includes, for example, Read Only Memory (ROM), Random Access Memory (RAM), and the like.
- the logic circuit 54 is an electronic circuit that performs a logical operation, and includes, for example, Large Scale Integration (LSI), Field Programmable Gate Array (FPGA), and the like.
- the wired IF 55 is an interface device for performing wired communication with another eNB 1 and another RRH 2.
- the wireless IF 51 corresponds to, for example, the duplexer 12, the reception unit 13, and the transmission unit 25.
- the processor 52, the memory 53, and the logic circuit 54 include, for example, a channel estimation unit 14, a control signal demodulation / decoding unit 15, a data signal demodulation / decoding unit 16, a reception quality calculation unit 17, a scheduler 18, a data signal generation unit 19, and a control signal generation. This corresponds to the unit 20, the reference signal generation unit 21, the data signal encoding / modulation unit 22, the control signal encoding / modulation unit 23, and the allocation unit 24.
- FIG. 18 shows an example of the hardware configuration of UE3.
- the UE 3 includes an antenna 31, a wireless IF 61, a processor 62, a memory 63, a logic circuit 64, an input IF (input interface) 65, and an output IF (output interface) 66.
- the wireless IF 61 is an interface device for performing wireless communication with the eNB 1 and the RRH 2.
- the processor 62 is a device that processes data, and includes, for example, a CPU and a DSP.
- the memory 63 is a device that stores data, and includes, for example, a ROM, a RAM, and the like.
- the logic circuit 64 is an electronic circuit that performs a logical operation, and includes, for example, an LSI, an FPGA, or the like.
- the input IF 65 is a device that performs input, and includes, for example, an operation button, a microphone, and the like.
- the output IF 66 is a device that performs output, and includes, for example, a speaker and a display.
- the correspondence relationship between each configuration of UE 3 illustrated in FIG. 10 and each configuration of UE 3 illustrated in FIG. 18 is, for example, as follows.
- the wireless IF 61 corresponds to, for example, the duplexer 32, the reception unit 33, and the transmission unit 46.
- the processor 62, the memory 63, and the logic circuit 64 include, for example, a channel estimation unit 34, a control signal demodulation / decoding unit 35, a data signal demodulation / decoding unit 36, a reception quality calculation unit 37, a data signal generation unit 38, a control signal generation unit 39, This corresponds to the reference signal generation unit 40, the data signal encoding / modulating unit 41, the control signal encoding / modulating unit 42, the allocating unit 43, the switching control unit 44 and the transmission power determining unit 45.
- each structure and each function of eNB1, RRH2, and UE3 in embodiment and the modification which were mentioned above may be selected as needed, and may be used in combination suitably.
- the above-described configurations and functions may be selected or used in appropriate combination so that the functions of the present invention can be exhibited.
- the SRS transmitted by the UE 3 is received only by the serving radio base station 2 (or 1).
- the transmission power is controlled, for example, the transmission power of UE3 is set so that the SRS transmitted by UE3 is received by a plurality of radio base stations other than radio base station 1 (or 2) where interference of SRS may occur. You may control. Specifically, for example, the transmission power can be determined based on the distance between the UE 3 and each of the radio base stations 1 and 2, the radio communication environment, and the like.
- the plurality of radio base stations excluding the radio base station 1 (or 2) in which SRS interference may occur include the serving radio base station 2 (or 1).
- the transmission power control method of UE3 when radio resources for SRS transmission are allocated in duplicate, the transmission power control method of UE3 is switched as a plurality of SRSs can interfere.
- the transmission power control method of UE 3 may be switched. Specifically, for example, in eNB1 and RRH2, SRS interference is detected by comparing the received power of each SRS, and based on the detection result, an instruction signal is transmitted to UE3 or a notification signal is transmitted. Then, the transmission power control method of UE3 may be switched.
- the radio communication system 6 includes the eNB 1 as an example of the macro base station that covers a radio area of the order of several hundred meters to several km, and the extension station (RRH) 2.
- the wireless communication system 6 is, for example, a micro base station (Micro eNB) that covers a wireless area on the order of several hundred meters, or a pico base that covers a wireless area on the order of several tens of meters to about 200 meters.
- a station (Pico eNB), a home base station dedicated to a specific user (also referred to as a Home eNB or a femtocell base station), a relay station that relays a radio signal, and the like may be provided.
- the micro base station, the pico base station, and the home base station may have the same configuration and function as the eNB 1 or the RRH 2 described above.
- the transmission power control method of UE 3 is switched. May be switched to the UE 3 transmission power control method.
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Abstract
In a wireless base station (1), in instances in which a plurality of wireless resources employed for transmission of known signals, and which wireless resources are at least partially redundant, are allocated to a plurality of wireless terminals (3-1, 3-7), interference of the known signals is minimized by controlling the transmission power of the wireless terminal (3-7) in such a way that the known signal transmitted by the wireless terminal (3-7), which of the plurality of wireless terminals (3-1, 3-7) is one located within the wireless area (5-2) of another wireless base station (2-2) different from its home station (1), is received by the wireless base station (2-2), while excluding the home station.
Description
本発明は、無線基地局、無線端末、無線通信システム及び通信制御方法に関する。
The present invention relates to a radio base station, a radio terminal, a radio communication system, and a communication control method.
近年、無線通信規格の標準化団体である3rd Generation Partnership Project(3GPP)のLong Term Evolution-Advanced(LTE-A)では、Coordinated Multi Point(CoMP、多地点協調)技術についての議論が盛んに行なわれている。
なお、下記特許文献1には、複数の基地局装置とUser Equipment(UE、ユーザ装置)との間の各伝搬ロスの差分に基づいて、UEに対するUpLink Coordinated Multiple Point(ULCoMP)の適用可否を判断し、送信電力制御を行なう技術が記載されている。 In recent years, the Long Term Evolution-Advanced (LTE-A) of the 3rd Generation Partnership Project (3GPP), a standardization organization for wireless communication standards, has been actively discussed about Coordinated Multi Point (CoMP) technology. Yes.
InPatent Document 1 below, whether or not UpLink Coordinated Multiple Point (ULCoMP) is applicable to a UE is determined based on the difference of each propagation loss between a plurality of base station apparatuses and User Equipment (UE, user apparatus). However, a technique for performing transmission power control is described.
なお、下記特許文献1には、複数の基地局装置とUser Equipment(UE、ユーザ装置)との間の各伝搬ロスの差分に基づいて、UEに対するUpLink Coordinated Multiple Point(ULCoMP)の適用可否を判断し、送信電力制御を行なう技術が記載されている。 In recent years, the Long Term Evolution-Advanced (LTE-A) of the 3rd Generation Partnership Project (3GPP), a standardization organization for wireless communication standards, has been actively discussed about Coordinated Multi Point (CoMP) technology. Yes.
In
LTE-Aのリリース11では、CoMPのシナリオ4の導入についての議論が行なわれている。
CoMPのシナリオ4は、図1に例示するように、eNodeB(eNB、無線基地局)100の無線エリア400内にRemote Radio Head(RRH、張り出し局)200-1,200-2を配置するとともに、eNB100と各RRH200-1,200-2とを光ファイバなどの高速インタフェースで接続したシステム構成を想定している。 InRelease 11 of LTE-A, discussions have been made on the introduction of CoMP scenario 4.
InCoMP scenario 4, remote radio heads (RRH, overhanging stations) 200-1 and 200-2 are arranged in a radio area 400 of eNodeB (eNB, radio base station) 100, as illustrated in FIG. A system configuration is assumed in which the eNB 100 and each of the RRHs 200-1 and 200-2 are connected by a high-speed interface such as an optical fiber.
CoMPのシナリオ4は、図1に例示するように、eNodeB(eNB、無線基地局)100の無線エリア400内にRemote Radio Head(RRH、張り出し局)200-1,200-2を配置するとともに、eNB100と各RRH200-1,200-2とを光ファイバなどの高速インタフェースで接続したシステム構成を想定している。 In
In
なお、図1に示す例では、eNB100の無線エリア400内にUE300-1~300-7が位置し、RRH200-1の無線エリア500-1内にUE300-3,300-4が位置している。さらに、RRH200-2の無線エリア500-2内にUE300-5~300-7が位置している。
また、CoMPのシナリオ4では、eNB100と各RRH200-1,200-2とでセルIDを共通化することにより、モビリティ制御の負荷軽減やセル固有リソースの共有などが図られている。 In the example shown in FIG. 1, UEs 300-1 to 300-7 are located in theradio area 400 of the eNB 100, and UEs 300-3 and 300-4 are located in the radio area 500-1 of the RRH 200-1. . Furthermore, UEs 300-5 to 300-7 are located in the radio area 500-2 of the RRH 200-2.
Also, inCoMP scenario 4, by sharing the cell ID between the eNB 100 and each of the RRHs 200-1 and 200-2, load reduction of mobility control, sharing of cell-specific resources, and the like are achieved.
また、CoMPのシナリオ4では、eNB100と各RRH200-1,200-2とでセルIDを共通化することにより、モビリティ制御の負荷軽減やセル固有リソースの共有などが図られている。 In the example shown in FIG. 1, UEs 300-1 to 300-7 are located in the
Also, in
CoMPでは、各UE300-1~300-7が、上り無線チャネルの品質を推定するための既知信号の一例としてSounding Reference Symbol(SRS)をeNB100やRRH200-1,200-2へ送信する。
LTE-Aのリリース10では、各UE300-1~300-7がSRSを送信する際の上り送信電力制御を、Physical Uplink Shared Channel(PUSCH、上り共有チャネル)のTransmission Power Control(TPC)にオフセットを加えた形を有する以下の制御式(1)に従って行なうことが規定されている。 In CoMP, each of the UEs 300-1 to 300-7 transmits a Sounding Reference Symbol (SRS) as an example of a known signal for estimating the quality of an uplink radio channel to the eNB 100 and the RRHs 200-1 and 200-2.
In Release 10 of LTE-A, the uplink transmission power control when each UE 300-1 to 300-7 transmits the SRS is offset to the Transmission Power Control (TPC) of the Physical Uplink Shared Channel (PUSCH). It is specified to be performed according to the following control equation (1) having the added shape.
LTE-Aのリリース10では、各UE300-1~300-7がSRSを送信する際の上り送信電力制御を、Physical Uplink Shared Channel(PUSCH、上り共有チャネル)のTransmission Power Control(TPC)にオフセットを加えた形を有する以下の制御式(1)に従って行なうことが規定されている。 In CoMP, each of the UEs 300-1 to 300-7 transmits a Sounding Reference Symbol (SRS) as an example of a known signal for estimating the quality of an uplink radio channel to the eNB 100 and the RRHs 200-1 and 200-2.
In Release 10 of LTE-A, the uplink transmission power control when each UE 300-1 to 300-7 transmits the SRS is offset to the Transmission Power Control (TPC) of the Physical Uplink Shared Channel (PUSCH). It is specified to be performed according to the following control equation (1) having the added shape.
ここで、
はサブフレーム、
はSRSの送信電力、
は最大送信電力、
はPUSCHの送信電力からのオフセット値、
はPUSCHの割り当てリソース数、
はPUSCHの受信電力目標値、
はパスロス係数、
はUE300-1~300-7とサービング基地局との間の伝搬ロス(パスロス)、
はPUSCHの電力調整係数をそれぞれ表す。
上記の制御式(1)は、サービングセルのパスロスを補償することを目的としている。
これに対し、3GPP寄書「R1-113328」などでは、次のような制御式(2)が提案されている。 here,
Is a subframe,
Is the transmission power of SRS,
Is the maximum transmit power,
Is an offset value from the transmission power of PUSCH,
Is the number of PUSCH allocation resources,
Is the PUSCH received power target value,
Is the path loss coefficient,
Is a propagation loss (path loss) between the UE 300-1 to 300-7 and the serving base station,
Represents the power adjustment coefficient of PUSCH, respectively.
The above control equation (1) is intended to compensate for the path loss of the serving cell.
On the other hand, the following control expression (2) is proposed in 3GPP contribution “R1-113328” and the like.
はサブフレーム、
はSRSの送信電力、
は最大送信電力、
はPUSCHの送信電力からのオフセット値、
はPUSCHの割り当てリソース数、
はPUSCHの受信電力目標値、
はパスロス係数、
はUE300-1~300-7とサービング基地局との間の伝搬ロス(パスロス)、
はPUSCHの電力調整係数をそれぞれ表す。
上記の制御式(1)は、サービングセルのパスロスを補償することを目的としている。
これに対し、3GPP寄書「R1-113328」などでは、次のような制御式(2)が提案されている。 here,
Is a subframe,
Is the transmission power of SRS,
Is the maximum transmit power,
Is an offset value from the transmission power of PUSCH,
Is the number of PUSCH allocation resources,
Is the PUSCH received power target value,
Is the path loss coefficient,
Is a propagation loss (path loss) between the UE 300-1 to 300-7 and the serving base station,
Represents the power adjustment coefficient of PUSCH, respectively.
The above control equation (1) is intended to compensate for the path loss of the serving cell.
On the other hand, the following control expression (2) is proposed in 3GPP contribution “R1-113328” and the like.
ここで、
はCoMP受信の対象となるeNB100,RRH200-1,200-2(CoMPセットともいう)中で最大のパスロスを表す。
上記の制御式(2)は、CoMPセット全体でSRSを受信することを目的としており、より多くのeNB100,RRH200-1,200-2でUpLink(UL、アップリンク)の受信品質を得られる利点がある。 here,
Represents the maximum path loss in eNB 100, RRH 200-1, 200-2 (also referred to as a CoMP set) that is a target of CoMP reception.
The above control equation (2) is intended to receive the SRS in the entire CoMP set, and has the advantage that the reception quality of UpLink (UL, uplink) can be obtained by more eNBs 100, RRHs 200-1, 200-2. There is.
はCoMP受信の対象となるeNB100,RRH200-1,200-2(CoMPセットともいう)中で最大のパスロスを表す。
上記の制御式(2)は、CoMPセット全体でSRSを受信することを目的としており、より多くのeNB100,RRH200-1,200-2でUpLink(UL、アップリンク)の受信品質を得られる利点がある。 here,
Represents the maximum path loss in eNB 100, RRH 200-1, 200-2 (also referred to as a CoMP set) that is a target of CoMP reception.
The above control equation (2) is intended to receive the SRS in the entire CoMP set, and has the advantage that the reception quality of UpLink (UL, uplink) can be obtained by more eNBs 100, RRHs 200-1, 200-2. There is.
ところで、UE300-1~300-7は、SRSを送信するための無線リソースをeNB100から割り当てられ、割り当てられた無線リソースを用いてSRSを送信する。具体的には例えば、各UE300-1~300-7は、異なるベース系列,Cyclic Shift(CS),櫛の歯によって識別可能な無線リソースを割り当てられ、割り当てられた無線リソースに周波数ホッピングを適用してSRSを送信する。
By the way, the UEs 300-1 to 300-7 are allocated radio resources for transmitting SRS from the eNB 100, and transmit SRSs using the allocated radio resources. Specifically, for example, each UE 300-1 to 300-7 is assigned radio resources that can be identified by different base sequences, cyclic shifts (CS), and comb teeth, and applies frequency hopping to the assigned radio resources. SRS is transmitted.
ここで、上記無線リソースの割り当ての一例を図2に示す。この図2に示す例では、周波数と時間(タイミング)との組み合わせにより規定される無線リソースが各UEに割り当てられている。なお、図2中、無線リソース#1~#7は、UE300-1~300-7のそれぞれに割り当てられた無線リソースを表している。
しかしながら、CoMPのシナリオ4では、eNB100と各RRH200-1,200-2とで共通のセルIDを用いるのでベース系列は1通りである。また、CSが8通りであり、且つ、櫛の歯が2通りであることから、eNB100は、16台分のUEからのSRSを識別できるに留まる。 Here, an example of the radio resource allocation is shown in FIG. In the example shown in FIG. 2, radio resources defined by a combination of frequency and time (timing) are allocated to each UE. In FIG. 2,radio resources # 1 to # 7 represent radio resources allocated to the UEs 300-1 to 300-7, respectively.
However, inCoMP scenario 4, since a common cell ID is used by eNB 100 and each RRH 200-1 and 200-2, there is one base sequence. In addition, since there are 8 types of CS and 2 types of comb teeth, the eNB 100 can only identify SRSs from 16 UEs.
しかしながら、CoMPのシナリオ4では、eNB100と各RRH200-1,200-2とで共通のセルIDを用いるのでベース系列は1通りである。また、CSが8通りであり、且つ、櫛の歯が2通りであることから、eNB100は、16台分のUEからのSRSを識別できるに留まる。 Here, an example of the radio resource allocation is shown in FIG. In the example shown in FIG. 2, radio resources defined by a combination of frequency and time (timing) are allocated to each UE. In FIG. 2,
However, in
また、CoMPのシナリオ4に限らず、例えば、CoMPのシナリオ3などにおいても、UE数が増加した場合、SRSの送信タイミングの違いを考慮したとしても、同帯域及び同タイミングでSRSを送信するケースが十分起こり得る。
このような場合、SRSの干渉が発生する可能性がある。例えば、複数のUEが同一の無線リソースを用いてSRSを送信した場合や、複数のUEが互いに少なくとも一部が重複する無線リソースを用いてSRSを送信した場合、SRSの衝突が発生し、干渉が生じることがある。 Further, not only inCoMP scenario 4, but also in CoMP scenario 3, for example, when the number of UEs increases, even when considering the difference in SRS transmission timing, the case of transmitting SRS in the same band and the same timing Can happen enough.
In such a case, SRS interference may occur. For example, when a plurality of UEs transmit SRS using the same radio resource, or when a plurality of UEs transmit SRS using radio resources at least partially overlapping each other, an SRS collision occurs and interference occurs. May occur.
このような場合、SRSの干渉が発生する可能性がある。例えば、複数のUEが同一の無線リソースを用いてSRSを送信した場合や、複数のUEが互いに少なくとも一部が重複する無線リソースを用いてSRSを送信した場合、SRSの衝突が発生し、干渉が生じることがある。 Further, not only in
In such a case, SRS interference may occur. For example, when a plurality of UEs transmit SRS using the same radio resource, or when a plurality of UEs transmit SRS using radio resources at least partially overlapping each other, an SRS collision occurs and interference occurs. May occur.
特に、上記の制御式(2)を用いてSRSの送信電力制御を行なう場合、SRSがCoMPセット内の全受信ポイントに届くように送信電力制御(TPC)が行なわれるため、SRSの干渉が発生する可能性は一層高くなる。
そこで、本発明は、既知の信号の干渉を抑制することを目的の1つとする。
なお、上記の各目的に限らず、後述する発明を実施するための形態に示す各構成により導かれる作用効果であって、従来の技術によっては得られない作用効果を奏することも本発明の他の目的の1つとして位置付けることができる。 In particular, when performing SRS transmission power control using the above control equation (2), SRS interference occurs because transmission power control (TPC) is performed so that the SRS reaches all reception points in the CoMP set. The possibility of doing is even higher.
Accordingly, an object of the present invention is to suppress interference of known signals.
Note that the present invention is not limited to the above-described objects, and is an operation and effect derived from each configuration shown in the embodiment for carrying out the invention described below, and also exhibits an operation and effect that cannot be obtained by conventional techniques. It can be positioned as one of the purposes.
そこで、本発明は、既知の信号の干渉を抑制することを目的の1つとする。
なお、上記の各目的に限らず、後述する発明を実施するための形態に示す各構成により導かれる作用効果であって、従来の技術によっては得られない作用効果を奏することも本発明の他の目的の1つとして位置付けることができる。 In particular, when performing SRS transmission power control using the above control equation (2), SRS interference occurs because transmission power control (TPC) is performed so that the SRS reaches all reception points in the CoMP set. The possibility of doing is even higher.
Accordingly, an object of the present invention is to suppress interference of known signals.
Note that the present invention is not limited to the above-described objects, and is an operation and effect derived from each configuration shown in the embodiment for carrying out the invention described below, and also exhibits an operation and effect that cannot be obtained by conventional techniques. It can be positioned as one of the purposes.
(1)第1の案として、例えば、既知の信号を送信する際に用いられる複数の無線リソースのうち互いに少なくとも一部が重複する無線リソースが複数の無線端末に対して割り当てられている場合に、前記複数の無線端末のうち自局とは異なる他の無線基地局の無線エリア内に位置する無線端末が送信する既知の信号が前記自局を除く無線基地局で受信されるように前記他の無線基地局の無線エリア内に位置する無線端末の送信電力を制御する処理部と、前記複数の無線端末のうち自局の無線エリア内に位置する無線端末が送信する既知の信号を少なくとも受信する受信部とをそなえる、無線基地局を用いることができる。
(1) As a first proposal, for example, when a plurality of radio resources used when transmitting a known signal are allocated to a plurality of radio terminals at least partially overlapping with each other. The other signal so that a known signal transmitted by a wireless terminal located in a wireless area of another wireless base station different from the own station among the plurality of wireless terminals is received by a wireless base station other than the own station. A processing unit that controls transmission power of a wireless terminal located in the wireless area of the wireless base station, and at least a known signal transmitted by a wireless terminal located in the wireless area of the own station among the plurality of wireless terminals It is possible to use a radio base station that includes a receiving unit.
(2)また、第2の案として、例えば、既知の信号を送信する際に用いる複数の無線リソースのうち互いに少なくとも一部が重複する無線リソースが自局を含む複数の無線端末に対して割り当てられている場合に、自局が送信する既知の信号が複数の無線基地局の一部の無線基地局で受信されるように自局の送信電力を決定する処理部と、前記処理部で決定された送信電力を用いて前記既知の信号を送信する送信部とをそなえる、無線端末を用いることができる。
(2) As a second proposal, for example, among a plurality of radio resources used when transmitting a known signal, radio resources at least partially overlapping each other are allocated to a plurality of radio terminals including the own station. A processing unit that determines transmission power of the local station so that a known signal transmitted by the local station is received by some of the plurality of radio base stations, and the processing unit determines It is possible to use a wireless terminal including a transmission unit that transmits the known signal using the transmitted power.
(3)さらに、第3の案として、例えば、既知の信号を送信する際に用いられる複数の無線リソースのうち互いに少なくとも一部が重複する無線リソースが複数の無線端末に対して割り当てられている場合に、前記複数の無線端末のうち自局とは異なる他の無線基地局の無線エリア内に位置する無線端末が送信する既知の信号が前記自局を除く無線基地局で受信されるように前記他の無線基地局の無線エリア内に位置する無線端末の送信電力を制御する無線基地局と、前記他の無線基地局の無線エリア内に位置し、前記無線基地局で制御された送信電力を用いて前記既知の信号を送信する無線端末とをそなえる、無線通信システムを用いることができる。
(3) Furthermore, as a third proposal, for example, radio resources that are at least partially overlapping among a plurality of radio resources used when transmitting a known signal are allocated to a plurality of radio terminals. In this case, a known signal transmitted by a wireless terminal located in a wireless area of another wireless base station different from the own station among the plurality of wireless terminals is received by a wireless base station other than the own station. A radio base station that controls transmission power of a radio terminal located in the radio area of the other radio base station, and a transmission power that is located in the radio area of the other radio base station and controlled by the radio base station It is possible to use a wireless communication system that includes a wireless terminal that transmits the known signal using a wireless communication device.
(4)また、第4の案として、例えば、無線基地局において、既知の信号を送信する際に用いられる複数の無線リソースのうち互いに少なくとも一部が重複する無線リソースが複数の無線端末に対して割り当てられている場合に、前記複数の無線端末のうち自局とは異なる他の無線基地局の無線エリア内に位置する無線端末が送信する既知の信号が前記自局を除く無線基地局で受信されるように前記他の無線基地局の無線エリア内に位置する無線端末の送信電力を制御し、前記他の無線基地局の無線エリア内に位置する無線端末において、前記制御された送信電力を用いて前記既知の信号を送信する、通信制御方法を用いることができる。
(4) Further, as a fourth plan, for example, in a radio base station, radio resources at least partially overlapping each other among a plurality of radio resources used when transmitting a known signal to a plurality of radio terminals Among the plurality of wireless terminals, a known signal transmitted by a wireless terminal located in a wireless area of another wireless base station different from the own station is transmitted by a wireless base station other than the own station. The transmission power of a radio terminal located in the radio area of the other radio base station is controlled to be received, and the controlled transmission power is controlled in a radio terminal located in the radio area of the other radio base station. A communication control method can be used in which the known signal is transmitted using the.
既知の信号の干渉を抑制することが可能となる。
It becomes possible to suppress interference of known signals.
以下、図面を参照して本発明の実施の形態を説明する。ただし、以下に示す実施の形態は、あくまでも例示に過ぎず、以下に示す実施形態で明示しない種々の変形や技術の適用を排除する意図はない。即ち、以下に示す実施形態を、本発明の趣旨を逸脱しない範囲で組み合わせるなどして種々変形して実施できることはいうまでもない。
〔1〕一実施形態
(1.1)一実施形態に係る無線通信システムの構成の一例
図3は一実施形態に係る無線通信システムの構成の一例を示す図である。 Embodiments of the present invention will be described below with reference to the drawings. However, the embodiment described below is merely an example, and there is no intention to exclude various modifications and technical applications that are not explicitly described in the embodiment described below. That is, it goes without saying that the embodiments described below can be implemented in various modifications by combining them without departing from the scope of the present invention.
[1] One Embodiment (1.1) Example of Configuration of Radio Communication System According to One Embodiment FIG. 3 is a diagram illustrating an example of the configuration of a radio communication system according to one embodiment.
〔1〕一実施形態
(1.1)一実施形態に係る無線通信システムの構成の一例
図3は一実施形態に係る無線通信システムの構成の一例を示す図である。 Embodiments of the present invention will be described below with reference to the drawings. However, the embodiment described below is merely an example, and there is no intention to exclude various modifications and technical applications that are not explicitly described in the embodiment described below. That is, it goes without saying that the embodiments described below can be implemented in various modifications by combining them without departing from the scope of the present invention.
[1] One Embodiment (1.1) Example of Configuration of Radio Communication System According to One Embodiment FIG. 3 is a diagram illustrating an example of the configuration of a radio communication system according to one embodiment.
この図3に示す無線通信システム6は、例示的に、無線基地局の一例であるeNB1と、張り出し局(RRH)2-1,2-2と、複数のユーザ装置(UE)3-1~3-7とをそなえる。なお、以下では、RRH2-1,2-2を区別しない場合、単にRRH2と表記し、UE3-1~3-7を区別しない場合、単にUE3と表記する。また、RRH2及びUE3の数は、図3に例示する数にそれぞれ限定されない。
The radio communication system 6 shown in FIG. 3 illustratively includes an eNB 1 that is an example of a radio base station, extended stations (RRH) 2-1 and 2-2, and a plurality of user apparatuses (UE) 3-1 to 3-7. In the following description, when RRHs 2-1 and 2-2 are not distinguished, they are simply expressed as RRH2, and when UEs 3-1 to 3-7 are not distinguished, they are simply expressed as UE3. Further, the numbers of RRH2 and UE3 are not limited to the numbers illustrated in FIG.
eNB1は、セルやセクタなどの無線エリア4を提供しており、当該無線エリア4内に位置するUE3-1~3-7と無線通信することができる。
また、RRH2-1は、無線エリア5-1を提供しており、当該無線エリア5-1内に位置するUE3-3,3-4と無線通信することができる。同様に、RRH2-2は、無線エリア5-2を提供しており、当該無線エリア5-2内に位置するUE3-5~3-7と無線通信することができる。 TheeNB 1 provides a radio area 4 such as a cell or a sector, and can perform radio communication with the UEs 3-1 to 3-7 located in the radio area 4.
Further, the RRH 2-1 provides a radio area 5-1, and can perform radio communication with the UEs 3-3 and 3-4 located in the radio area 5-1. Similarly, the RRH 2-2 provides a radio area 5-2 and can perform radio communication with UEs 3-5 to 3-7 located in the radio area 5-2.
また、RRH2-1は、無線エリア5-1を提供しており、当該無線エリア5-1内に位置するUE3-3,3-4と無線通信することができる。同様に、RRH2-2は、無線エリア5-2を提供しており、当該無線エリア5-2内に位置するUE3-5~3-7と無線通信することができる。 The
Further, the RRH 2-1 provides a radio area 5-1, and can perform radio communication with the UEs 3-3 and 3-4 located in the radio area 5-1. Similarly, the RRH 2-2 provides a radio area 5-2 and can perform radio communication with UEs 3-5 to 3-7 located in the radio area 5-2.
eNB1とRRH2-1,2-2とは光ファイバなどの高速インタフェースで接続されており、互いに通信することができる。なお、eNB1とRRH2-1,2-2との間のインタフェースは、光ファイバに限定されず、例えば、X2インタフェースや、無線バックホールなどを用いてもよい。
図3に例示する無線通信システム6においては、CoMP技術を利用可能である。 TheeNB 1 and the RRHs 2-1 and 2-2 are connected by a high-speed interface such as an optical fiber and can communicate with each other. Note that the interface between the eNB 1 and the RRHs 2-1 and 2-2 is not limited to an optical fiber, and for example, an X2 interface or a wireless backhaul may be used.
In thewireless communication system 6 illustrated in FIG. 3, CoMP technology can be used.
図3に例示する無線通信システム6においては、CoMP技術を利用可能である。 The
In the
例えば、アップリンク(UL)に着目すれば、eNB1は、UE3から自局1へ送信された信号を直接受信するとともに、UE3から他局2へ送信された信号を光ファイバなどの高速インタフェース経由で受信し、受信した各信号を合成することにより、データのアップロードを高速化することができる。同様に、RRH2は、UE3から自局2へ送信された信号を直接受信するとともに、UE3から他局1へ送信された信号を光ファイバなどの高速インタフェース経由で受信し、受信した各信号を合成することにより、データのアップロードを高速化することができる。
For example, if attention is paid to the uplink (UL), the eNB 1 directly receives a signal transmitted from the UE 3 to the local station 1 and transmits a signal transmitted from the UE 3 to the other station 2 via a high-speed interface such as an optical fiber. By uploading and synthesizing the received signals, data upload can be accelerated. Similarly, the RRH 2 directly receives a signal transmitted from the UE 3 to the own station 2 and receives a signal transmitted from the UE 3 to the other station 1 via a high-speed interface such as an optical fiber, and combines the received signals. By doing so, uploading of data can be speeded up.
また、DownLink(DL、ダウンリンク)に着目すれば、UE3は、eNB1から自局3へ送信された信号を受信するとともに、RRH2から自局3へ送信された信号を受信し、受信した各信号を合成することにより、データのダウンロードを高速化することができる。
CoMPでは、各UE3は、上り無線チャネルの品質を推定するための既知の参照信号(SRS)を送信するための無線リソースをeNB1あるいはRRH2から予め割り当てられ、割り当てられた無線リソースを用いてSRSを送信する。なお、このSRSは、CoMPにおける合成処理の対象とはなっていない。 If attention is paid to DownLink (DL, downlink), theUE 3 receives a signal transmitted from the eNB 1 to the local station 3 and receives a signal transmitted from the RRH 2 to the local station 3. By combining, data download can be accelerated.
In CoMP, eachUE 3 is pre-assigned from eNB 1 or RRH 2 radio resources for transmitting a known reference signal (SRS) for estimating the quality of an uplink radio channel, and uses the assigned radio resources for SRS. Send. Note that this SRS is not a target of the synthesis process in CoMP.
CoMPでは、各UE3は、上り無線チャネルの品質を推定するための既知の参照信号(SRS)を送信するための無線リソースをeNB1あるいはRRH2から予め割り当てられ、割り当てられた無線リソースを用いてSRSを送信する。なお、このSRSは、CoMPにおける合成処理の対象とはなっていない。 If attention is paid to DownLink (DL, downlink), the
In CoMP, each
ここで、UE3数がSRS送信用の無線リソース数よりも多いと、同一の無線リソースが、異なるUE3に重複して割り当てられることがある。
例えば、UE3-1とUE3-7とに同一の無線リソースが割り当てられ、且つ、UE3-7が以下の制御式(2)に従った送信電力制御を行なっている場合、UE3-1は当該無線リソースを用いてeNB1にSRSを送信する一方、UE3-7は同一の無線リソースを用いてeNB1及びRRH2-2にSRSを送信する。 Here, if the number ofUEs 3 is larger than the number of radio resources for SRS transmission, the same radio resource may be allocated to different UEs 3 in duplicate.
For example, when the same radio resource is allocated to UE 3-1 and UE 3-7, and UE 3-7 performs transmission power control according to the following control equation (2), UE 3-1 The UE 3-7 transmits the SRS to theeNB 1 and the RRH 2-2 using the same radio resource while transmitting the SRS to the eNB 1 using the resource.
例えば、UE3-1とUE3-7とに同一の無線リソースが割り当てられ、且つ、UE3-7が以下の制御式(2)に従った送信電力制御を行なっている場合、UE3-1は当該無線リソースを用いてeNB1にSRSを送信する一方、UE3-7は同一の無線リソースを用いてeNB1及びRRH2-2にSRSを送信する。 Here, if the number of
For example, when the same radio resource is allocated to UE 3-1 and UE 3-7, and UE 3-7 performs transmission power control according to the following control equation (2), UE 3-1 The UE 3-7 transmits the SRS to the
このような場合、eNB1において、UE3-1から送信されたSRSとUE3-7から送信されたSRSとが衝突することがあり、SRSの干渉が発生する可能性がある。SRSの干渉が発生すると、eNB1は、上りチャネル品質を適切に推定することができず、効率的なCoMPを実施できないことがある。
そこで、本例では、図4に例示するように、まず、eNB1またはRRH2が、各UE3に対して、SRS送信用の無線リソースの割り当てを実施し、異なるUE3に同一の無線リソースが重複して割り当てられたか否かを検出する。 In such a case, theeNB 1 may collide with the SRS transmitted from the UE 3-1 and the SRS transmitted from the UE 3-7, and there is a possibility that SRS interference occurs. When SRS interference occurs, the eNB 1 cannot appropriately estimate the uplink channel quality and may not be able to perform efficient CoMP.
Therefore, in this example, as illustrated in FIG. 4, first, theeNB 1 or the RRH 2 assigns radio resources for SRS transmission to each UE 3, and the same radio resource is duplicated in different UE 3. Detect whether it was assigned or not.
そこで、本例では、図4に例示するように、まず、eNB1またはRRH2が、各UE3に対して、SRS送信用の無線リソースの割り当てを実施し、異なるUE3に同一の無線リソースが重複して割り当てられたか否かを検出する。 In such a case, the
Therefore, in this example, as illustrated in FIG. 4, first, the
異なるUE3に同一の無線リソースが重複して割り当てられた(SRS用無線リソースの重複)を検出すると(ステップS10)、eNB1またはRRH2は、同一の無線リソースを割り当てられたUE3の少なくともいずれかに対して、送信電力制御の切り替えを指示する(ステップS11)。
送信電力制御の切り替えを指示されたUE3は、SRSがサービングセルのみに届くように、例えば、以下の制御式(1)に従った送信電力制御を行なって(ステップS12)、決定した送信電力によりSRSを送信する(ステップS13)。 When it detects that the same radio resource is assigned to different UEs 3 (duplication of SRS radio resources) (step S10), eNB1 or RRH2 detects at least one ofUEs 3 to which the same radio resource is assigned. Then, switching of transmission power control is instructed (step S11).
TheUE 3 instructed to switch the transmission power control performs, for example, transmission power control according to the following control equation (1) so that the SRS reaches only the serving cell (step S12), and the SRS is determined based on the determined transmission power. Is transmitted (step S13).
送信電力制御の切り替えを指示されたUE3は、SRSがサービングセルのみに届くように、例えば、以下の制御式(1)に従った送信電力制御を行なって(ステップS12)、決定した送信電力によりSRSを送信する(ステップS13)。 When it detects that the same radio resource is assigned to different UEs 3 (duplication of SRS radio resources) (step S10), eNB1 or RRH2 detects at least one of
The
一方、eNB1またはRRH2は、SRS用無線リソースの重複が解消したことを検出すると(ステップS14)、同一の無線リソースを割り当てられていたUE3のうち、上記ステップS11の指示を行なったUE3に対して、送信電力制御の切り替えを指示する(ステップS15)。
送信電力制御の切り替えを指示されたUE3は、SRSがCoMPセット内の全ての受信ポイントに届くように、例えば、以下の制御式(2)に従った送信電力制御を行なって(ステップS16)、決定した送信電力によりSRSを送信する(ステップS17)。 On the other hand, when eNB1 or RRH2 detects that the duplication of SRS radio resources has been resolved (step S14), among UE3s that have been assigned the same radio resource, to UE3 that has instructed step S11. Then, switching of transmission power control is instructed (step S15).
UE3 instructed to switch transmission power control performs transmission power control according to the following control equation (2), for example, so that the SRS reaches all reception points in the CoMP set (step S16). The SRS is transmitted with the determined transmission power (step S17).
送信電力制御の切り替えを指示されたUE3は、SRSがCoMPセット内の全ての受信ポイントに届くように、例えば、以下の制御式(2)に従った送信電力制御を行なって(ステップS16)、決定した送信電力によりSRSを送信する(ステップS17)。 On the other hand, when eNB1 or RRH2 detects that the duplication of SRS radio resources has been resolved (step S14), among UE3s that have been assigned the same radio resource, to UE3 that has instructed step S11. Then, switching of transmission power control is instructed (step S15).
UE3 instructed to switch transmission power control performs transmission power control according to the following control equation (2), for example, so that the SRS reaches all reception points in the CoMP set (step S16). The SRS is transmitted with the determined transmission power (step S17).
本例によれば、同一の無線リソースを割り当てられた異なるUE3が、それぞれ送信したSRSの衝突を防止することができるので、SRSの干渉を抑制することが可能となる。
(1.2)eNB1,RRH2の構成の一例
図5はeNB1の構成の一例を示す図である。なお、RRH2もeNB1と同様の構成を有するため、RRH2の構成例については説明を省略する。 According to this example, sincedifferent UEs 3 to which the same radio resource is allocated can prevent collision of SRS transmitted respectively, it is possible to suppress SRS interference.
(1.2) Example of Configuration of eNB1 and RRH2 FIG. 5 is a diagram illustrating an example of the configuration of eNB1. Since RRH2 has the same configuration as eNB1, description of the configuration example of RRH2 is omitted.
(1.2)eNB1,RRH2の構成の一例
図5はeNB1の構成の一例を示す図である。なお、RRH2もeNB1と同様の構成を有するため、RRH2の構成例については説明を省略する。 According to this example, since
(1.2) Example of Configuration of eNB1 and RRH2 FIG. 5 is a diagram illustrating an example of the configuration of eNB1. Since RRH2 has the same configuration as eNB1, description of the configuration example of RRH2 is omitted.
この図5に示すeNB1は、例示的に、アンテナ11と、デュプレクサ12と、受信部13と、チャネル推定部14と、制御信号復調復号部15と、データ信号復調復号部16と、受信品質算出部17と、スケジューラ18とをそなえる。また、図5に示すeNB1は、例示的に、データ信号生成部19と、制御信号生成部20と、参照信号生成部21と、データ信号符号化変調部22と、制御信号符号化変調部23と、割当部24と、送信部25とをそなえる。
The eNB 1 illustrated in FIG. 5 exemplarily includes an antenna 11, a duplexer 12, a reception unit 13, a channel estimation unit 14, a control signal demodulation / decoding unit 15, a data signal demodulation / decoding unit 16, and a reception quality calculation. A unit 17 and a scheduler 18 are provided. In addition, eNB1 illustrated in FIG. 5 exemplarily includes a data signal generation unit 19, a control signal generation unit 20, a reference signal generation unit 21, a data signal encoding modulation unit 22, and a control signal encoding modulation unit 23. And an assigning unit 24 and a transmitting unit 25.
アンテナ11は、UE3からの無線信号を受信する受信アンテナとして機能するとともに、UE3へ無線信号を送信する送信アンテナとして機能する。つまり、本例のアンテナ11は、デュプレクサ12によって、受信アンテナと送信アンテナとが共用化された構成となっている。なお、図5はあくまでeNB1の構成の一例を示しているに過ぎず、例えば、デュプレクサ12を用いない場合、eNB1は、送信アンテナと受信アンテナとを個別に有していてもよい。
The antenna 11 functions as a reception antenna that receives a radio signal from the UE 3 and also functions as a transmission antenna that transmits a radio signal to the UE 3. That is, the antenna 11 of this example has a configuration in which the reception antenna and the transmission antenna are shared by the duplexer 12. Note that FIG. 5 merely shows an example of the configuration of the eNB 1. For example, when the duplexer 12 is not used, the eNB 1 may have a transmission antenna and a reception antenna individually.
受信部13は、アンテナ11で受信した、UE3から送信されたPUSCH、Physical Uplink Control Channel(PUCCH)などの上り無線信号から参照信号(SRS)、制御信号、データ信号を抽出する。受信部13によって抽出された参照信号、制御信号、データ信号は、チャネル推定部14、制御信号復調復号部15、データ信号復調復号部16へそれぞれ出力される。
The receiving unit 13 extracts a reference signal (SRS), a control signal, and a data signal from uplink radio signals such as PUSCH and Physical-Uplink-Control-Channel (PUCCH) transmitted from the UE 3 received by the antenna 11. The reference signal, control signal, and data signal extracted by the reception unit 13 are output to the channel estimation unit 14, the control signal demodulation / decoding unit 15, and the data signal demodulation / decoding unit 16, respectively.
即ち、受信部13は、複数の無線端末3のうち自局1の無線エリア内に位置する無線端末3が送信するSRSなどの既知の信号を少なくとも受信する受信部の一例として機能する。
チャネル推定部14は、受信部13で抽出された参照信号を用いて、チャネル推定値を算出する。チャネル推定部14によって算出されたチャネル推定値は、制御信号復調復号部15、データ信号復調復号部16、受信品質算出部17へそれぞれ出力される。 That is, the receivingunit 13 functions as an example of a receiving unit that receives at least a known signal such as SRS transmitted by the wireless terminal 3 located in the wireless area of the local station 1 among the plurality of wireless terminals 3.
Thechannel estimation unit 14 calculates a channel estimation value using the reference signal extracted by the reception unit 13. The channel estimation value calculated by the channel estimation unit 14 is output to the control signal demodulation / decoding unit 15, the data signal demodulation / decoding unit 16, and the reception quality calculation unit 17, respectively.
チャネル推定部14は、受信部13で抽出された参照信号を用いて、チャネル推定値を算出する。チャネル推定部14によって算出されたチャネル推定値は、制御信号復調復号部15、データ信号復調復号部16、受信品質算出部17へそれぞれ出力される。 That is, the receiving
The
制御信号復調復号部15は、チャネル推定部14によって算出されたチャネル推定値を用いて、受信部13で抽出された制御信号について、復調処理及び復号処理を施す。制御信号復調復号部15によって得られた制御情報は、データ信号復調復号部16、スケジューラ18へそれぞれ出力される。また、当該復号結果が正常であることを示すACKnowledgement(ACK)や、当該復号結果が異常であることを示すNegative ACKnowledgement(NACK)がスケジューラ18へ出力されてもよい。
The control signal demodulation / decoding unit 15 performs demodulation processing and decoding processing on the control signal extracted by the reception unit 13 using the channel estimation value calculated by the channel estimation unit 14. The control information obtained by the control signal demodulation / decoding unit 15 is output to the data signal demodulation / decoding unit 16 and the scheduler 18, respectively. Further, ACKnowledgement (ACK) indicating that the decoding result is normal or Negative ACKnowledgement (NACK) indicating that the decoding result is abnormal may be output to the scheduler 18.
データ信号復調復号部16は、チャネル推定部14によって算出されたチャネル推定値を用いて、受信部13で抽出されたデータ信号について、復調処理及び復号処理を施す。データ信号復調復号部16によって得られたデータは、スケジューラ18へ出力される。また、当該復号結果が正常であることを示すACKや、当該復号結果が異常であることを示すNACKがスケジューラ18へ出力されてもよい。
The data signal demodulation / decoding unit 16 performs demodulation processing and decoding processing on the data signal extracted by the reception unit 13 using the channel estimation value calculated by the channel estimation unit 14. The data obtained by the data signal demodulation / decoding unit 16 is output to the scheduler 18. Further, ACK indicating that the decoding result is normal or NACK indicating that the decoding result is abnormal may be output to the scheduler 18.
受信品質算出部17は、チャネル推定部14によって算出されたチャネル推定値を用いて、Signal-to-Interference Ratio(SIR)などの受信品質を算出する。受信品質算出部17によって算出された受信品質に関する情報は、スケジューラ18へ出力される。
スケジューラ18は、入力された各情報に基づき、データ信号生成部19、制御信号生成部20、参照信号生成部21に信号生成要求を送る。また、スケジューラ18は、入力された各情報に基づき、各信号に対する無線リソース割り当てを示すスケジューリング情報を割当部24へ送る。 The receptionquality calculation unit 17 uses the channel estimation value calculated by the channel estimation unit 14 to calculate reception quality such as a signal-to-interference ratio (SIR). Information regarding the reception quality calculated by the reception quality calculation unit 17 is output to the scheduler 18.
Thescheduler 18 sends a signal generation request to the data signal generation unit 19, the control signal generation unit 20, and the reference signal generation unit 21 based on each input information. Further, the scheduler 18 sends scheduling information indicating radio resource allocation for each signal to the allocation unit 24 based on each input information.
スケジューラ18は、入力された各情報に基づき、データ信号生成部19、制御信号生成部20、参照信号生成部21に信号生成要求を送る。また、スケジューラ18は、入力された各情報に基づき、各信号に対する無線リソース割り当てを示すスケジューリング情報を割当部24へ送る。 The reception
The
データ信号生成部19は、スケジューラ18からの信号生成要求に基づいて、データ信号を生成する。
データ信号符号化変調部22は、データ信号生成部19によって生成されたデータ信号について、符号化処理及び変調処理を施す。データ信号符号化変調部22によって得られた符号化及び変調後のデータ信号は、割当部24へ出力される。 The data signalgenerator 19 generates a data signal based on the signal generation request from the scheduler 18.
The data signal encoding / modulatingunit 22 performs encoding processing and modulation processing on the data signal generated by the data signal generating unit 19. The encoded and modulated data signal obtained by the data signal encoding / modulating unit 22 is output to the assigning unit 24.
データ信号符号化変調部22は、データ信号生成部19によって生成されたデータ信号について、符号化処理及び変調処理を施す。データ信号符号化変調部22によって得られた符号化及び変調後のデータ信号は、割当部24へ出力される。 The data signal
The data signal encoding / modulating
制御信号生成部20は、スケジューラ18からの信号生成要求に基づいて、制御信号を生成する。
制御信号符号化変調部23は、制御信号生成部20によって生成された制御信号について、符号化処理及び変調処理を施す。制御信号符号化変調部23によって得られた符号化及び変調後の制御信号は、割当部24へ出力される。 The controlsignal generation unit 20 generates a control signal based on the signal generation request from the scheduler 18.
The control signal encoding / modulatingunit 23 performs encoding processing and modulation processing on the control signal generated by the control signal generating unit 20. The encoded and modulated control signal obtained by the control signal encoding / modulating unit 23 is output to the allocating unit 24.
制御信号符号化変調部23は、制御信号生成部20によって生成された制御信号について、符号化処理及び変調処理を施す。制御信号符号化変調部23によって得られた符号化及び変調後の制御信号は、割当部24へ出力される。 The control
The control signal encoding / modulating
参照信号生成部21は、スケジューラ18からの信号生成要求に基づいて、参照信号を生成する。
割当部24は、データ信号符号化変調部22からのデータ信号、制御信号符号化変調部23からの制御信号、参照信号生成部21からの参照信号について、スケジューラ18から指示されたスケジューリング情報に基づいて、無線リソースの割り当てを行なう。なお、無線リソースには、無線信号の送受信に用いられる通信資源の一例として、例えば、送受信電力、送受信周波数(チャネル)、送受信タイミングなどが含まれる。 The referencesignal generation unit 21 generates a reference signal based on the signal generation request from the scheduler 18.
The allocatingunit 24 uses the scheduling information instructed by the scheduler 18 for the data signal from the data signal encoding and modulating unit 22, the control signal from the control signal encoding and modulating unit 23, and the reference signal from the reference signal generating unit 21. Wireless resources are allocated. Note that the radio resources include, for example, transmission / reception power, transmission / reception frequency (channel), transmission / reception timing, and the like as examples of communication resources used for transmission / reception of radio signals.
割当部24は、データ信号符号化変調部22からのデータ信号、制御信号符号化変調部23からの制御信号、参照信号生成部21からの参照信号について、スケジューラ18から指示されたスケジューリング情報に基づいて、無線リソースの割り当てを行なう。なお、無線リソースには、無線信号の送受信に用いられる通信資源の一例として、例えば、送受信電力、送受信周波数(チャネル)、送受信タイミングなどが含まれる。 The reference
The allocating
送信部25は、割当部24によって割り当てられた無線リソースを用いて、データ信号、制御信号、参照信号を、アンテナ11を介して送信する。
(1.3)eNB1,RRH2の動作の一例
次に、以上のように構成されたeNB1,RRH2の動作の一例について、図6~図9を用いて説明する。 Thetransmission unit 25 transmits a data signal, a control signal, and a reference signal via the antenna 11 using the radio resource allocated by the allocation unit 24.
(1.3) Example of Operation of eNB1 and RRH2 Next, an example of the operation of eNB1 and RRH2 configured as described above will be described with reference to FIGS.
(1.3)eNB1,RRH2の動作の一例
次に、以上のように構成されたeNB1,RRH2の動作の一例について、図6~図9を用いて説明する。 The
(1.3) Example of Operation of eNB1 and RRH2 Next, an example of the operation of eNB1 and RRH2 configured as described above will be described with reference to FIGS.
まず、スケジューラ18は、無線リソースの割り当て制御を行なう。
例えば、図6に示すように、スケジューラ18は、無線リソースの割り当て制御を開始すると(ステップS20)、UE3がSRSの送信に用いることのできる上り無線リソース数を算出する(ステップS21)。なお、上り無線リソース数は、例えば、チャネルと送信タイミングとで規定されるResource Block(RB、リソースブロック)の数などを含む。 First, thescheduler 18 performs radio resource allocation control.
For example, as shown in FIG. 6, when thescheduler 18 starts radio resource allocation control (step S20), the scheduler 18 calculates the number of uplink radio resources that the UE 3 can use for transmission of SRS (step S21). Note that the number of uplink radio resources includes, for example, the number of resource blocks (RB, resource blocks) defined by the channel and transmission timing.
例えば、図6に示すように、スケジューラ18は、無線リソースの割り当て制御を開始すると(ステップS20)、UE3がSRSの送信に用いることのできる上り無線リソース数を算出する(ステップS21)。なお、上り無線リソース数は、例えば、チャネルと送信タイミングとで規定されるResource Block(RB、リソースブロック)の数などを含む。 First, the
For example, as shown in FIG. 6, when the
次に、スケジューラ18は、SRS送信用の上り無線リソースを割り当てるUE3の数を算出する(ステップS22)。
そして、UE3の数が上記上り無線リソース数よりも大きいか否かを判定し(ステップS23)、UE3の数が上記上り無線リソース数以下であると判定した場合(ステップS23のNoルート)、スケジューラ18は、各UE3に対してそれぞれ異なる無線リソースを割り当てて(ステップS25)、無線リソースの割り当て制御を終了する(ステップS26)。 Next, thescheduler 18 calculates the number of UEs 3 to which uplink radio resources for SRS transmission are allocated (step S22).
Then, it is determined whether or not the number of UE3 is larger than the number of uplink radio resources (step S23). When it is determined that the number of UE3 is equal to or less than the number of uplink radio resources (No route of step S23), thescheduler 18 allocates different radio resources to each UE 3 (step S25), and ends the radio resource allocation control (step S26).
そして、UE3の数が上記上り無線リソース数よりも大きいか否かを判定し(ステップS23)、UE3の数が上記上り無線リソース数以下であると判定した場合(ステップS23のNoルート)、スケジューラ18は、各UE3に対してそれぞれ異なる無線リソースを割り当てて(ステップS25)、無線リソースの割り当て制御を終了する(ステップS26)。 Next, the
Then, it is determined whether or not the number of UE3 is larger than the number of uplink radio resources (step S23). When it is determined that the number of UE3 is equal to or less than the number of uplink radio resources (No route of step S23), the
一方、UE3の数が上記上り無線リソース数よりも大きいと判定した場合(ステップS23のYesルート)、スケジューラ18は、同一の無線リソースをいずれか複数のUE3に割り当てることとなるが、このとき、本例のスケジューラ18は、在圏している無線エリアが異なるUE3に対して、同一の無線リソースを重複して割り当てて(ステップS24)、無線リソースの割り当て制御を終了する(ステップS26)。これにより、後述する本例の送信電力切り替え制御により、同一の無線リソースを重複して割り当てられたUE3からのSRSがeNB1,RRH2において衝突、干渉するのを防止することができる。
On the other hand, if it is determined that the number of UE3 is larger than the number of uplink radio resources (Yes route in step S23), the scheduler 18 will allocate the same radio resource to any of the plurality of UE3. The scheduler 18 in this example assigns the same radio resource to the UEs 3 having different radio areas in the same area (step S24), and ends the radio resource allocation control (step S26). Thereby, it is possible to prevent the SRS from the UE 3 to which the same radio resource is assigned in duplicate from colliding and interfering in the eNB 1 and the RRH 2 by the transmission power switching control of this example described later.
即ち、スケジューラ18は、複数の無線リソースのうち互いに少なくとも一部が重複する無線リソースを、自局1の無線エリア内に位置する無線端末3と他の無線基地局2の無線エリア内に位置する無線端末3とに割り当てることができる。
次に、スケジューラ18は、送信電力切り替え制御を実施する。
例えば、図7に示すように、スケジューラ18は、送信電力切り替え制御を開始すると(ステップS30)、異なるUE3に対して同一の無線リソースが重複して割り当てられたか否かを判定し(ステップS31)、無線リソースの重複が無ければ(ステップS31のNoルート)、送信電力切り替え制御を終了する(ステップS34)。 That is, thescheduler 18 locates radio resources at least partially overlapping among the plurality of radio resources in the radio areas of the radio terminal 3 and other radio base stations 2 located in the radio area of the own station 1. It can be assigned to the wireless terminal 3.
Next, thescheduler 18 performs transmission power switching control.
For example, as shown in FIG. 7, when thescheduler 18 starts transmission power switching control (step S30), the scheduler 18 determines whether or not the same radio resource is allocated to different UEs 3 (step S31). If there is no radio resource duplication (No route in step S31), the transmission power switching control is terminated (step S34).
次に、スケジューラ18は、送信電力切り替え制御を実施する。
例えば、図7に示すように、スケジューラ18は、送信電力切り替え制御を開始すると(ステップS30)、異なるUE3に対して同一の無線リソースが重複して割り当てられたか否かを判定し(ステップS31)、無線リソースの重複が無ければ(ステップS31のNoルート)、送信電力切り替え制御を終了する(ステップS34)。 That is, the
Next, the
For example, as shown in FIG. 7, when the
一方、無線リソースの重複がある場合(ステップS31のYesルート)、スケジューラ18は、同一の無線リソースが割り当てられた各UE3がいずれもCoMPの適用対象であるか否かを判定する(ステップS32)。
ここで、同一の無線リソースが割り当てられた各UE3の少なくともいずれかがCoMPの適用対象でないと判定した場合(ステップS32のNoルート)、スケジューラ18は、送信電力切り替え制御を終了する(ステップS34)。 On the other hand, when there is duplication of radio resources (Yes route in step S31), thescheduler 18 determines whether or not each UE 3 to which the same radio resource is assigned is an application target of CoMP (step S32). .
Here, when it is determined that at least one of theUEs 3 to which the same radio resource is allocated is not a CoMP application target (No route in Step S32), the scheduler 18 ends the transmission power switching control (Step S34). .
ここで、同一の無線リソースが割り当てられた各UE3の少なくともいずれかがCoMPの適用対象でないと判定した場合(ステップS32のNoルート)、スケジューラ18は、送信電力切り替え制御を終了する(ステップS34)。 On the other hand, when there is duplication of radio resources (Yes route in step S31), the
Here, when it is determined that at least one of the
一方、同一の無線リソースが割り当てられた各UE3のいずれもがCoMPの適用対象であると判定した場合(ステップS32のYesルート)、スケジューラ18は、同一の無線リソースが割り当てられた各UE3のうち、自局1,2が提供している無線エリアとは異なる他局が提供している無線エリアに在圏しているUE3に対して、送信電力制御(TPC)の切り替えを指示して(ステップS33)、送信電力切り替え制御を終了する(ステップS34)。
On the other hand, when it is determined that any of the UEs 3 to which the same radio resource is allocated is a CoMP application target (Yes route in step S32), the scheduler 18 Instructing UE 3 residing in a radio area provided by another station different from the radio area provided by own stations 1 and 2 to switch transmission power control (TPC) (step S33), the transmission power switching control is terminated (step S34).
また、スケジューラ18は、上記ステップS33の処理を実施後、以下の送信電力再切り替え制御を実施する。
例えば、図8に示すように、スケジューラ18は、送信電力再切り替え制御を開始すると(ステップS40)、異なるUE3に対して同一の無線リソースが重複して割り当てられた状況が解消したか否かを判定する(ステップS41)。 Further, thescheduler 18 performs the following transmission power re-switching control after performing the process of step S33.
For example, as shown in FIG. 8, when thescheduler 18 starts transmission power re-switching control (step S40), it is determined whether or not the situation where the same radio resource is allocated to different UEs 3 has been resolved. Determination is made (step S41).
例えば、図8に示すように、スケジューラ18は、送信電力再切り替え制御を開始すると(ステップS40)、異なるUE3に対して同一の無線リソースが重複して割り当てられた状況が解消したか否かを判定する(ステップS41)。 Further, the
For example, as shown in FIG. 8, when the
そして、無線リソースの重複状態が解消していれば(ステップS41のYesルート)、スケジューラ18は、同一の無線リソースが割り当てられていた各UE3のうち、自局1,2が提供している無線エリアとは異なる他局が提供している無線エリアに在圏しているUE3に対して、送信電力制御(TPC)の切り替えを指示して(ステップS43)、送信電力再切り替え制御を終了する(ステップS44)。
If the overlapping state of the radio resources has been eliminated (Yes route in step S41), the scheduler 18 uses the radio provided by the own stations 1 and 2 among the UEs 3 to which the same radio resource is allocated. A UE 3 located in a radio area provided by another station different from the area is instructed to switch transmission power control (TPC) (step S43), and the transmission power re-switching control is terminated (step S43). Step S44).
一方、無線リソースの重複状態が解消していなければ(ステップS41のNoルート)、スケジューラ18は、同一の無線リソースが割り当てられている各UE3の少なくともいずれかがCoMPの適用対象外となったか否かを判定する(ステップS42)。
ここで、同一の無線リソースが割り当てられている各UE3の少なくともいずれかがCoMPの適用対象外であると判定した場合(ステップS42のYesルート)、スケジューラ18は、同一の無線リソースが割り当てられていた各UE3のうち、自局1,2が提供している無線エリアとは異なる他局が提供している無線エリアに在圏しているUE3に対して、送信電力制御(TPC)の切り替えを指示して(ステップS43)、送信電力再切り替え制御を終了する(ステップS44)。 On the other hand, if the overlapping state of the radio resources has not been resolved (No route in step S41), thescheduler 18 determines whether or not at least one of the UEs 3 to which the same radio resource is allocated is not subject to CoMP application. Is determined (step S42).
Here, if it is determined that at least one of theUEs 3 to which the same radio resource is assigned is not subject to CoMP application (Yes route in step S42), the scheduler 18 has been assigned the same radio resource. In addition, among the UEs 3, the transmission power control (TPC) is switched for the UEs 3 located in the wireless areas provided by other stations different from the wireless areas provided by the own stations 1 and 2. An instruction is given (step S43), and transmission power re-switching control is terminated (step S44).
ここで、同一の無線リソースが割り当てられている各UE3の少なくともいずれかがCoMPの適用対象外であると判定した場合(ステップS42のYesルート)、スケジューラ18は、同一の無線リソースが割り当てられていた各UE3のうち、自局1,2が提供している無線エリアとは異なる他局が提供している無線エリアに在圏しているUE3に対して、送信電力制御(TPC)の切り替えを指示して(ステップS43)、送信電力再切り替え制御を終了する(ステップS44)。 On the other hand, if the overlapping state of the radio resources has not been resolved (No route in step S41), the
Here, if it is determined that at least one of the
一方、同一の無線リソースが割り当てられている各UE3のいずれもがCoMPの適用対象であると判定した場合(ステップS42のNoルート)、スケジューラ18は、送信電力再切り替え制御を終了する(ステップS44)。
ここで、送信電力制御(TPC)の切り替え指示及び送信電力制御(TPC)の再切り替え指示について、詳述する。 On the other hand, when it is determined that each of theUEs 3 to which the same radio resource is allocated is a CoMP application target (No route in Step S42), the scheduler 18 ends the transmission power re-switching control (Step S44). ).
Here, a transmission power control (TPC) switching instruction and a transmission power control (TPC) switching instruction will be described in detail.
ここで、送信電力制御(TPC)の切り替え指示及び送信電力制御(TPC)の再切り替え指示について、詳述する。 On the other hand, when it is determined that each of the
Here, a transmission power control (TPC) switching instruction and a transmission power control (TPC) switching instruction will be described in detail.
上記ステップS33に示すTPCの切り替え指示及び上記ステップS43に示すTPCの再切り替え指示を行なう場合、スケジューラ18は、制御信号生成部20に対して、TPCの切り替えを指示するための指示信号を生成するよう要求する。
指示信号は、例えば、「1」,「0」の2値をとり得るフラグとして構成される。例えば、上記ステップS33では、スケジューラ18は、指示信号を「1」にセットすることにより、UE3に対してTPCを以下の制御式(2)から以下の制御式(1)に従って行なわせる。 When the TPC switching instruction shown in step S33 and the TPC re-switching instruction shown in step S43 are performed, thescheduler 18 generates an instruction signal for instructing the control signal generation unit 20 to switch the TPC. Request that.
The instruction signal is configured as, for example, a flag that can take two values “1” and “0”. For example, in step S33, thescheduler 18 sets the instruction signal to “1” to cause the UE 3 to perform TPC according to the following control equation (1) from the following control equation (2).
指示信号は、例えば、「1」,「0」の2値をとり得るフラグとして構成される。例えば、上記ステップS33では、スケジューラ18は、指示信号を「1」にセットすることにより、UE3に対してTPCを以下の制御式(2)から以下の制御式(1)に従って行なわせる。 When the TPC switching instruction shown in step S33 and the TPC re-switching instruction shown in step S43 are performed, the
The instruction signal is configured as, for example, a flag that can take two values “1” and “0”. For example, in step S33, the
即ち、スケジューラ18は、SRSなどの既知の信号を送信する際に用いられる複数の無線リソースのうち互いに少なくとも一部が重複する無線リソースが複数の無線端末3に対して割り当てられている場合に、前記複数の無線端末3のうち自局1とは異なる他の無線基地局2の無線エリア内に位置する無線端末3が送信する既知の信号が自局1を除く無線基地局2で受信されるように前記他の無線基地局2の無線エリア内に位置する無線端末3の送信電力を制御する処理部の一例として機能する。
That is, when the scheduler 18 allocates radio resources at least partially overlapping each other among the plurality of radio resources used when transmitting a known signal such as SRS to the plurality of radio terminals 3, Among the plurality of wireless terminals 3, a known signal transmitted by a wireless terminal 3 located in a wireless area of another wireless base station 2 different from the local station 1 is received by the wireless base station 2 except the local station 1. Thus, it functions as an example of a processing unit that controls the transmission power of the wireless terminal 3 located in the wireless area of the other wireless base station 2.
また、上記ステップS43では、スケジューラ18は、指示信号を「0」にセットすることにより、UE3に対してTPCを以下の制御式(1)から以下の制御式(2)に従って行なわせる。
In step S43, the scheduler 18 sets the instruction signal to “0” to cause the UE 3 to perform TPC according to the following control equation (1) to the following control equation (2).
即ち、スケジューラ18は、複数の無線リソースのうち互いに異なる無線リソースが複数の無線端末に対して割り当てられている場合に、他の無線基地局2の無線エリア内に位置する無線端末3が送信する既知の信号が少なくとも自局1と他の無線基地局2とで受信されるように他の無線基地局2の無線エリア内に位置する無線端末3の送信電力を制御することができる。
That is, the scheduler 18 transmits a radio terminal 3 located in a radio area of another radio base station 2 when different radio resources among a plurality of radio resources are allocated to a plurality of radio terminals. The transmission power of the radio terminal 3 located in the radio area of the other radio base station 2 can be controlled so that the known signal is received at least by the own station 1 and the other radio base station 2.
なお、上記指示信号は、例えば、図9(A)に示すように、DCI(Downlink Control Information):A-CQI(Channel Quality Indicator)などの下り制御情報に格納されて送信されてもよい。あるいは、上記指示信号は、例えば、図9(B)に示すように、Radio resource control information elementsのSoundingRS-UL-Configなどの上位レイヤにおける制御信号に新たなフィールド(srs-ConfigTPC)として追加されて送信されてもよい。
Note that the instruction signal may be stored and transmitted in downlink control information such as DCI (Downlink Control Information): A-CQI (Channel Quality Indicator) as shown in FIG. 9A, for example. Alternatively, for example, as shown in FIG. 9B, the instruction signal is added as a new field (srs-ConfigTPC) to a control signal in an upper layer such as SoundingRS-UL-Config of Radio 例 え ば resource control information elements. May be sent.
(1.4)UE3の構成の一例
また、図10はUE3の構成の一例を示す図である。
この図10に示すUE3は、例示的に、アンテナ31と、デュプレクサ32と、受信部33と、チャネル推定部34と、制御信号復調復号部35と、データ信号復調復号部36と、受信品質算出部37とをそなえる。また、図10に示すUE3は、例示的に、データ信号生成部38と、制御信号生成部39と、参照信号生成部40と、データ信号符号化変調部41と、制御信号符号化変調部42と、割当部43と、切り替え制御部44と、送信電力決定部45と、送信部46とをそなえる。 (1.4) Exemplary Configuration of UE3 FIG. 10 is a diagram illustrating an exemplary configuration of UE3.
TheUE 3 shown in FIG. 10 exemplarily includes an antenna 31, a duplexer 32, a reception unit 33, a channel estimation unit 34, a control signal demodulation / decoding unit 35, a data signal demodulation / decoding unit 36, and a reception quality calculation. The unit 37 is provided. 10 exemplarily includes a data signal generation unit 38, a control signal generation unit 39, a reference signal generation unit 40, a data signal encoding modulation unit 41, and a control signal encoding modulation unit 42. And an allocating unit 43, a switching control unit 44, a transmission power determining unit 45, and a transmitting unit 46.
また、図10はUE3の構成の一例を示す図である。
この図10に示すUE3は、例示的に、アンテナ31と、デュプレクサ32と、受信部33と、チャネル推定部34と、制御信号復調復号部35と、データ信号復調復号部36と、受信品質算出部37とをそなえる。また、図10に示すUE3は、例示的に、データ信号生成部38と、制御信号生成部39と、参照信号生成部40と、データ信号符号化変調部41と、制御信号符号化変調部42と、割当部43と、切り替え制御部44と、送信電力決定部45と、送信部46とをそなえる。 (1.4) Exemplary Configuration of UE3 FIG. 10 is a diagram illustrating an exemplary configuration of UE3.
The
アンテナ31は、eNB1,RRH2からの無線信号を受信する受信アンテナとして機能するとともに、eNB1,RRH2へ無線信号を送信する送信アンテナとして機能する。つまり、本例のアンテナ31は、デュプレクサ32によって、受信アンテナと送信アンテナとが共用化された構成となっている。なお、図10はあくまでUE3の構成の一例を示しているに過ぎず、例えば、デュプレクサ32を用いない場合、UE3は、送信アンテナと受信アンテナとを個別に有していてもよい。
The antenna 31 functions as a reception antenna that receives radio signals from the eNB1 and RRH2, and also functions as a transmission antenna that transmits radio signals to the eNB1 and RRH2. That is, the antenna 31 of this example has a configuration in which the reception antenna and the transmission antenna are shared by the duplexer 32. Note that FIG. 10 merely shows an example of the configuration of the UE 3. For example, when the duplexer 32 is not used, the UE 3 may have a transmission antenna and a reception antenna individually.
受信部33は、アンテナ31で受信した、eNB1,RRH2から送信されたPhysical Downlink Shared Channel(PDSCH)、Physical Downlink Control Channel(PDCCH)などの下り無線信号から参照信号、制御信号、データ信号を抽出する。受信部33によって抽出された参照信号、制御信号、データ信号は、チャネル推定部34、制御信号復調復号部35、データ信号復調復号部36へそれぞれ出力される。
The receiving unit 33 extracts a reference signal, a control signal, and a data signal from downlink radio signals, such as Physical31Downlink Shared Channel (PDSCH) and Physical Downlink Control Channel (PDCCH) transmitted from eNB1 and RRH2 received by the antenna 31. . The reference signal, control signal, and data signal extracted by the reception unit 33 are output to the channel estimation unit 34, the control signal demodulation / decoding unit 35, and the data signal demodulation / decoding unit 36, respectively.
チャネル推定部34は、受信部33で抽出された参照信号を用いて、チャネル推定値を算出する。チャネル推定部34によって算出されたチャネル推定値は、制御信号復調復号部35、データ信号復調復号部36、受信品質算出部37へそれぞれ出力される。
制御信号復調復号部35は、チャネル推定部34によって算出されたチャネル推定値を用いて、受信部33で抽出された制御信号について、復調処理及び復号処理を施す。制御信号復調復号部35によって得られた制御情報は、データ信号復調復号部36、制御信号生成部39、割当部43、切り替え制御部44へそれぞれ出力される。また、当該復号結果が正常であることを示すACKや、当該復号結果が異常であることを示すNACKが制御信号生成部39へ出力されてもよい。 Thechannel estimation unit 34 calculates a channel estimation value using the reference signal extracted by the reception unit 33. The channel estimation value calculated by the channel estimation unit 34 is output to the control signal demodulation / decoding unit 35, the data signal demodulation / decoding unit 36, and the reception quality calculation unit 37, respectively.
The control signal demodulation /decoding unit 35 uses the channel estimation value calculated by the channel estimation unit 34 to perform demodulation processing and decoding processing on the control signal extracted by the reception unit 33. The control information obtained by the control signal demodulation / decoding unit 35 is output to the data signal demodulation / decoding unit 36, the control signal generation unit 39, the allocation unit 43, and the switching control unit 44, respectively. Further, ACK indicating that the decoding result is normal or NACK indicating that the decoding result is abnormal may be output to the control signal generation unit 39.
制御信号復調復号部35は、チャネル推定部34によって算出されたチャネル推定値を用いて、受信部33で抽出された制御信号について、復調処理及び復号処理を施す。制御信号復調復号部35によって得られた制御情報は、データ信号復調復号部36、制御信号生成部39、割当部43、切り替え制御部44へそれぞれ出力される。また、当該復号結果が正常であることを示すACKや、当該復号結果が異常であることを示すNACKが制御信号生成部39へ出力されてもよい。 The
The control signal demodulation /
データ信号復調復号部36は、チャネル推定部34によって算出されたチャネル推定値を用いて、受信部33で抽出されたデータ信号について、復調処理及び復号処理を施す。データ信号復調復号部36によって得られたデータは、制御信号生成部39へ出力される。また、当該復号結果が正常であることを示すACKや、当該復号結果が異常であることを示すNACKが制御信号生成部39へ出力されてもよい。
The data signal demodulation / decoding unit 36 performs demodulation processing and decoding processing on the data signal extracted by the receiving unit 33 using the channel estimation value calculated by the channel estimation unit 34. The data obtained by the data signal demodulation / decoding unit 36 is output to the control signal generation unit 39. Further, ACK indicating that the decoding result is normal or NACK indicating that the decoding result is abnormal may be output to the control signal generation unit 39.
受信品質算出部37は、チャネル推定部34によって算出されたチャネル推定値を用いて、SIRなどの受信品質を算出する。受信品質算出部37によって算出された受信品質に関する情報は、制御信号生成部39へ出力される。
データ信号生成部38は、データ信号を生成する。
データ信号符号化変調部41は、データ信号生成部38によって生成されたデータ信号について、符号化処理及び変調処理を施す。データ信号符号化変調部41によって得られた符号化及び変調後のデータ信号は、割当部43へ出力される。 The receptionquality calculation unit 37 calculates reception quality such as SIR using the channel estimation value calculated by the channel estimation unit 34. Information regarding the reception quality calculated by the reception quality calculation unit 37 is output to the control signal generation unit 39.
The data signalgeneration unit 38 generates a data signal.
The data signal encoding / modulatingunit 41 performs encoding processing and modulation processing on the data signal generated by the data signal generating unit 38. The encoded and modulated data signal obtained by the data signal encoding / modulating unit 41 is output to the assigning unit 43.
データ信号生成部38は、データ信号を生成する。
データ信号符号化変調部41は、データ信号生成部38によって生成されたデータ信号について、符号化処理及び変調処理を施す。データ信号符号化変調部41によって得られた符号化及び変調後のデータ信号は、割当部43へ出力される。 The reception
The data signal
The data signal encoding / modulating
制御信号生成部39は、制御信号復調復号部35、データ信号復調復号部36、受信品質算出部37からの各種情報に基づいて、制御信号を生成する。
制御信号符号化変調部42は、制御信号生成部39によって生成された制御信号について、符号化処理及び変調処理を施す。制御信号符号化変調部42によって得られた符号化及び変調後の制御信号は、割当部43へ出力される。 The controlsignal generation unit 39 generates a control signal based on various information from the control signal demodulation / decoding unit 35, the data signal demodulation / decoding unit 36, and the reception quality calculation unit 37.
The control signal encoding / modulatingunit 42 performs encoding processing and modulation processing on the control signal generated by the control signal generating unit 39. The encoded and modulated control signal obtained by the control signal encoding / modulating unit 42 is output to the allocating unit 43.
制御信号符号化変調部42は、制御信号生成部39によって生成された制御信号について、符号化処理及び変調処理を施す。制御信号符号化変調部42によって得られた符号化及び変調後の制御信号は、割当部43へ出力される。 The control
The control signal encoding / modulating
参照信号生成部40は、参照信号を生成する。
割当部43は、データ信号符号化変調部41からのデータ信号、制御信号符号化変調部42からの制御信号、参照信号生成部40からの参照信号について、制御信号復調復号部35から入力された制御情報に基づいて、無線リソースの割り当てを行なう。なお、無線リソースには、無線信号の送受信に用いられる通信資源の一例として、例えば、送受信周波数(チャネル)、送受信タイミングなどが含まれる。例えば、eNB1,RRH2において割り当て可能な無線リソース数よりもUE3の数の方が大きい場合、UE3は、SRSの送信に用いる無線リソースとして、他のUE3と同一の無線リソースを割り当てることとなる。 The referencesignal generation unit 40 generates a reference signal.
The allocatingunit 43 receives the data signal from the data signal encoding / modulating unit 41, the control signal from the control signal encoding / modulating unit 42, and the reference signal from the reference signal generating unit 40 from the control signal demodulation / decoding unit 35. Radio resources are allocated based on the control information. Note that the radio resources include, for example, transmission / reception frequencies (channels), transmission / reception timings, and the like as examples of communication resources used for transmission / reception of radio signals. For example, when the number of UE3 is larger than the number of radio resources that can be allocated in eNB1 and RRH2, UE3 allocates the same radio resource as other UE3 as the radio resource used for SRS transmission.
割当部43は、データ信号符号化変調部41からのデータ信号、制御信号符号化変調部42からの制御信号、参照信号生成部40からの参照信号について、制御信号復調復号部35から入力された制御情報に基づいて、無線リソースの割り当てを行なう。なお、無線リソースには、無線信号の送受信に用いられる通信資源の一例として、例えば、送受信周波数(チャネル)、送受信タイミングなどが含まれる。例えば、eNB1,RRH2において割り当て可能な無線リソース数よりもUE3の数の方が大きい場合、UE3は、SRSの送信に用いる無線リソースとして、他のUE3と同一の無線リソースを割り当てることとなる。 The reference
The allocating
切り替え制御部44は、制御信号復調復号部35から入力された制御情報に基づいて、UE3での送信電力制御(TPC)を切り替える。具体的には例えば、切り替え制御部44は、制御信号復調復号部35から入力された制御情報に前述した指示信号として「1」にセットされた指示信号が含まれる場合、以下の制御式(2)に従う送信電力制御から以下の制御式(1)に従う送信電力制御に切り替える。また、切り替え制御部44は、制御信号復調復号部35から入力された制御情報に前述した指示信号として「0」にセットされた指示信号が含まれる場合、以下の制御式(1)に従う送信電力制御から以下の制御式(2)に従う送信電力制御に切り替える。
The switching control unit 44 switches transmission power control (TPC) in the UE 3 based on the control information input from the control signal demodulation / decoding unit 35. Specifically, for example, when the control information input from the control signal demodulation / decoding unit 35 includes the instruction signal set to “1” as the above-described instruction signal, the switching control unit 44 uses the following control expression (2 ) To transmit power control according to the following control equation (1). When the control information input from the control signal demodulation / decoding unit 35 includes the instruction signal set to “0” as the above-described instruction signal, the switching control unit 44 transmits transmission power according to the following control expression (1). Control is switched to transmission power control according to the following control equation (2).
送信電力決定部45は、切り替え制御部44によって切り替え後の送信電力制御方法に従って、UE3の送信電力を決定する。より具体的には、送信電力決定部45は、切り替え制御部44によって切り替え後の送信電力制御式に従って、SRSについての送信電力を決定する。
即ち、送信電力決定部45は、SRSなどの既知の信号を送信する際に用いる複数の無線リソースのうち互いに少なくとも一部が重複する無線リソースが自局3を含む複数の無線端末3に対して割り当てられている場合に、自局3が送信する既知の信号が複数の無線基地局の一部の無線基地局2(または1)で受信されるように自局3の送信電力を決定する処理部の一例として機能する。 The transmissionpower determination unit 45 determines the transmission power of the UE 3 according to the transmission power control method after switching by the switching control unit 44. More specifically, the transmission power determination unit 45 determines the transmission power for the SRS according to the transmission power control equation after switching by the switching control unit 44.
That is, the transmissionpower determination unit 45 is configured to respond to a plurality of wireless terminals 3 including the own station 3 with a plurality of wireless resources used when transmitting a known signal such as SRS, at least partially overlapping with each other. Processing for determining transmission power of own station 3 so that known signals transmitted by own station 3 are received by some radio base stations 2 (or 1) of a plurality of radio base stations when assigned It functions as an example of a unit.
即ち、送信電力決定部45は、SRSなどの既知の信号を送信する際に用いる複数の無線リソースのうち互いに少なくとも一部が重複する無線リソースが自局3を含む複数の無線端末3に対して割り当てられている場合に、自局3が送信する既知の信号が複数の無線基地局の一部の無線基地局2(または1)で受信されるように自局3の送信電力を決定する処理部の一例として機能する。 The transmission
That is, the transmission
送信部46は、割当部43によって割り当てられた無線リソース及び送信電力決定部45によって決定された送信電力を用いて、データ信号、制御信号、参照信号を、アンテナ31を介して送信する。
即ち、送信部46は、送信電力決定部45で決定された送信電力を用いて既知の信号を送信する送信部の一例として機能する。 Thetransmission unit 46 transmits a data signal, a control signal, and a reference signal via the antenna 31 using the radio resource allocated by the allocation unit 43 and the transmission power determined by the transmission power determination unit 45.
That is, thetransmission unit 46 functions as an example of a transmission unit that transmits a known signal using the transmission power determined by the transmission power determination unit 45.
即ち、送信部46は、送信電力決定部45で決定された送信電力を用いて既知の信号を送信する送信部の一例として機能する。 The
That is, the
(1.5)UE3の動作の一例
次に、以上のように構成されたUE3の動作の一例について、図11を用いて説明する。
図11に例示するように、まず、UE3は、SRSの送信処理を開始すると(ステップS50)、eNB1,RRH2から受信した制御情報から前述の指示信号を抽出する(ステップS51)。 (1.5) Example of Operation of UE3 Next, an example of the operation of UE3 configured as described above will be described with reference to FIG.
As illustrated in FIG. 11, first, when theUE 3 starts the SRS transmission process (step S50), the UE 3 extracts the instruction signal described above from the control information received from the eNB 1 and the RRH 2 (step S51).
次に、以上のように構成されたUE3の動作の一例について、図11を用いて説明する。
図11に例示するように、まず、UE3は、SRSの送信処理を開始すると(ステップS50)、eNB1,RRH2から受信した制御情報から前述の指示信号を抽出する(ステップS51)。 (1.5) Example of Operation of UE3 Next, an example of the operation of UE3 configured as described above will be described with reference to FIG.
As illustrated in FIG. 11, first, when the
そして、UE3は、抽出した指示信号の内容に従って、自局3における送信電力制御方法を切り替える(ステップS52)。具体的には例えば、「1」にセットされた指示信号を抽出した場合、UE3は、以下の制御式(2)に従う送信電力制御から以下の制御式(1)に従う送信電力制御に切り替える。また、「0」にセットされた指示信号を抽出した場合、UE3は、以下の制御式(1)に従う送信電力制御から以下の制御式(2)に従う送信電力制御に切り替える。
And UE3 switches the transmission power control method in the own station 3 according to the content of the extracted instruction | indication signal (step S52). Specifically, for example, when an instruction signal set to “1” is extracted, the UE 3 switches from transmission power control according to the following control equation (2) to transmission power control according to the following control equation (1). When the instruction signal set to “0” is extracted, the UE 3 switches from transmission power control according to the following control equation (1) to transmission power control according to the following control equation (2).
即ち、UE3は、複数の無線リソースのうち互いに異なる無線リソースが自局3を含む複数の無線端末3に対して割り当てられている場合に、自局3が送信する既知の信号が少なくともサービング無線基地局2(または1)と他の無線基地局1(または2)とで受信されるように自局3の送信電力を決定することができる。
次に、UE3は、ステップS52で切り替え後の送信電力制御方法(制御式)に従って、SRSの送信電力を決定する(ステップS53)。 That is, when different radio resources among a plurality of radio resources are allocated to a plurality ofradio terminals 3 including the own station 3, the UE 3 transmits at least a known radio signal transmitted by the own station 3 to the serving radio base. The transmission power of the local station 3 can be determined so as to be received by the station 2 (or 1) and the other radio base station 1 (or 2).
Next, UE3 determines the transmission power of SRS according to the transmission power control method (control formula) after switching in step S52 (step S53).
次に、UE3は、ステップS52で切り替え後の送信電力制御方法(制御式)に従って、SRSの送信電力を決定する(ステップS53)。 That is, when different radio resources among a plurality of radio resources are allocated to a plurality of
Next, UE3 determines the transmission power of SRS according to the transmission power control method (control formula) after switching in step S52 (step S53).
そして、UE3は、ステップS53で決定した送信電力により、SRSを送信し(ステップS54)、SRSの送信処理を終了する(ステップS55)。
以上のように、本例によれば、SRS送信用の無線リソースが不足している場合であっても、SRS送信用の無線リソースの重複によるSRSの衝突の影響を低減することができるので、高品質なUL-CQI(UpLink - Channel Quality Indicator)を得ることが可能となる。その結果、eNB1は、CoMP制御を適切に行なうことができるので、CoMPによるデータ通信効率を維持することが可能となる。 And UE3 transmits SRS with the transmission power determined by step S53 (step S54), and complete | finishes the transmission process of SRS (step S55).
As described above, according to this example, even when the radio resources for SRS transmission are insufficient, the influence of SRS collision due to the overlap of radio resources for SRS transmission can be reduced. It becomes possible to obtain a high-quality UL-CQI (UpLink-Channel Quality Indicator). As a result, theeNB 1 can appropriately perform CoMP control, so that it is possible to maintain the data communication efficiency by CoMP.
以上のように、本例によれば、SRS送信用の無線リソースが不足している場合であっても、SRS送信用の無線リソースの重複によるSRSの衝突の影響を低減することができるので、高品質なUL-CQI(UpLink - Channel Quality Indicator)を得ることが可能となる。その結果、eNB1は、CoMP制御を適切に行なうことができるので、CoMPによるデータ通信効率を維持することが可能となる。 And UE3 transmits SRS with the transmission power determined by step S53 (step S54), and complete | finishes the transmission process of SRS (step S55).
As described above, according to this example, even when the radio resources for SRS transmission are insufficient, the influence of SRS collision due to the overlap of radio resources for SRS transmission can be reduced. It becomes possible to obtain a high-quality UL-CQI (UpLink-Channel Quality Indicator). As a result, the
〔2〕第1変形例
また、上述した例では、eNB1,RRH2がTPCの切り替え要否を判断したが、本例のように、UE3が、eNB1,RRH2から無線リソースの重複の有無を通知され、当該通知内容に基づいて、TPCの切り替え要否を判断するようにしてもよい。
例えば、図12に示すように、まず、eNB1またはRRH2が、各UE3に対して、SRS送信用の無線リソースの割り当てを実施し、異なるUE3に同一の無線リソースが重複して割り当てられたか否かを検出する。 [2] First Modification In the above example, eNB1 and RRH2 have determined whether TPC switching is necessary. However, as in this example, UE3 is notified of the presence or absence of radio resource duplication from eNB1 and RRH2. Based on the notification contents, it may be determined whether or not TPC switching is necessary.
For example, as shown in FIG. 12, first, eNB1 or RRH2 assigns radio resources for SRS transmission to each UE3, and whether or not the same radio resources are assigned to different UE3 in duplicate. Is detected.
また、上述した例では、eNB1,RRH2がTPCの切り替え要否を判断したが、本例のように、UE3が、eNB1,RRH2から無線リソースの重複の有無を通知され、当該通知内容に基づいて、TPCの切り替え要否を判断するようにしてもよい。
例えば、図12に示すように、まず、eNB1またはRRH2が、各UE3に対して、SRS送信用の無線リソースの割り当てを実施し、異なるUE3に同一の無線リソースが重複して割り当てられたか否かを検出する。 [2] First Modification In the above example, eNB1 and RRH2 have determined whether TPC switching is necessary. However, as in this example, UE3 is notified of the presence or absence of radio resource duplication from eNB1 and RRH2. Based on the notification contents, it may be determined whether or not TPC switching is necessary.
For example, as shown in FIG. 12, first, eNB1 or RRH2 assigns radio resources for SRS transmission to each UE3, and whether or not the same radio resources are assigned to different UE3 in duplicate. Is detected.
異なるUE3に同一の無線リソースが重複して割り当てられた(SRS用無線リソースの重複)を検出すると(ステップS60)、eNB1またはRRH2は、同一の無線リソースを割り当てられたUE3の少なくともいずれかに対して、SRS送信用の無線リソースが重複して割当てられていることを通知する(ステップS61)。
SRS送信用の無線リソースが重複して割当てられていることを通知されたUE3は、SRSがサービングセルのみに届くように、例えば、以下の制御式(1)に従った送信電力制御を行なって(ステップS62)、決定した送信電力によりSRSを送信する(ステップS63)。 When it detects that the same radio resource is assigned to different UE3 in duplicate (duplication of SRS radio resource) (step S60), eNB1 or RRH2 detects at least one of UE3 to which the same radio resource is assigned. Then, it is notified that the radio resources for SRS transmission are allocated redundantly (step S61).
TheUE 3 that is notified that the radio resources for SRS transmission are allocated redundantly performs, for example, transmission power control according to the following control equation (1) so that the SRS reaches only the serving cell ( Step S62), SRS is transmitted with the determined transmission power (step S63).
SRS送信用の無線リソースが重複して割当てられていることを通知されたUE3は、SRSがサービングセルのみに届くように、例えば、以下の制御式(1)に従った送信電力制御を行なって(ステップS62)、決定した送信電力によりSRSを送信する(ステップS63)。 When it detects that the same radio resource is assigned to different UE3 in duplicate (duplication of SRS radio resource) (step S60), eNB1 or RRH2 detects at least one of UE3 to which the same radio resource is assigned. Then, it is notified that the radio resources for SRS transmission are allocated redundantly (step S61).
The
一方、eNB1またはRRH2は、SRS用無線リソースの重複が解消したことを検出すると(ステップS64)、同一の無線リソースを割り当てられていたUE3のうち、上記ステップS61の指示を行なったUE3に対して、SRS用無線リソースの重複が解消したことを通知する(ステップS65)。
SRS用無線リソースの重複が解消したことを通知されたUE3は、SRSがCoMPセット内の全ての受信ポイントに届くように、例えば、以下の制御式(2)に従った送信電力制御を行なって(ステップS66)、決定した送信電力によりSRSを送信する(ステップS67)。 On the other hand, when eNB1 or RRH2 detects that the overlapping of the radio resources for SRS has been eliminated (step S64), among UE3 assigned with the same radio resource, UE3 that has instructed step S61 described above Then, it is notified that the SRS radio resource duplication has been resolved (step S65).
UE3 that has been notified that the duplication of SRS radio resources has been resolved, for example, performs transmission power control according to the following control equation (2) so that the SRS reaches all reception points in the CoMP set. (Step S66), SRS is transmitted with the determined transmission power (Step S67).
SRS用無線リソースの重複が解消したことを通知されたUE3は、SRSがCoMPセット内の全ての受信ポイントに届くように、例えば、以下の制御式(2)に従った送信電力制御を行なって(ステップS66)、決定した送信電力によりSRSを送信する(ステップS67)。 On the other hand, when eNB1 or RRH2 detects that the overlapping of the radio resources for SRS has been eliminated (step S64), among UE3 assigned with the same radio resource, UE3 that has instructed step S61 described above Then, it is notified that the SRS radio resource duplication has been resolved (step S65).
UE3 that has been notified that the duplication of SRS radio resources has been resolved, for example, performs transmission power control according to the following control equation (2) so that the SRS reaches all reception points in the CoMP set. (Step S66), SRS is transmitted with the determined transmission power (Step S67).
(2.1)eNB1及びRRH2の動作の一例
次に、eNB1,RRH2の動作の一例について、図6及び図13~図15を用いて説明する。
まず、スケジューラ18は、無線リソースの割り当て制御を行なう。
例えば、図6に示すように、スケジューラ18は、無線リソースの割り当て制御を開始すると(ステップS20)、UE3がSRSの送信に用いることのできる上り無線リソース数を算出する(ステップS21)。なお、上り無線リソース数は、例えば、チャネルと送信タイミングとで規定されるリソースブロック(RB)の数などを含む。 (2.1) Example of Operation ofeNB 1 and RRH 2 Next, an example of the operation of eNB 1 and RRH 2 will be described using FIG. 6 and FIGS. 13 to 15.
First, thescheduler 18 performs radio resource allocation control.
For example, as shown in FIG. 6, when thescheduler 18 starts radio resource allocation control (step S20), the scheduler 18 calculates the number of uplink radio resources that the UE 3 can use for transmission of SRS (step S21). Note that the number of uplink radio resources includes, for example, the number of resource blocks (RB) defined by the channel and transmission timing.
次に、eNB1,RRH2の動作の一例について、図6及び図13~図15を用いて説明する。
まず、スケジューラ18は、無線リソースの割り当て制御を行なう。
例えば、図6に示すように、スケジューラ18は、無線リソースの割り当て制御を開始すると(ステップS20)、UE3がSRSの送信に用いることのできる上り無線リソース数を算出する(ステップS21)。なお、上り無線リソース数は、例えば、チャネルと送信タイミングとで規定されるリソースブロック(RB)の数などを含む。 (2.1) Example of Operation of
First, the
For example, as shown in FIG. 6, when the
次に、スケジューラ18は、SRS送信用の上り無線リソースを割り当てるUE3の数を算出する(ステップS22)。
そして、UE3の数が上記上り無線リソース数よりも大きいか否かを判定し(ステップS23)、UE3の数が上記上り無線リソース数以下であると判定した場合(ステップS23のNoルート)、スケジューラ18は、各UE3に対してそれぞれ異なる無線リソースを割り当てて(ステップS25)、無線リソースの割り当て制御を終了する(ステップS26)。 Next, thescheduler 18 calculates the number of UEs 3 to which uplink radio resources for SRS transmission are allocated (step S22).
Then, it is determined whether or not the number of UE3 is larger than the number of uplink radio resources (step S23). When it is determined that the number of UE3 is equal to or less than the number of uplink radio resources (No route of step S23), thescheduler 18 allocates different radio resources to each UE 3 (step S25), and ends the radio resource allocation control (step S26).
そして、UE3の数が上記上り無線リソース数よりも大きいか否かを判定し(ステップS23)、UE3の数が上記上り無線リソース数以下であると判定した場合(ステップS23のNoルート)、スケジューラ18は、各UE3に対してそれぞれ異なる無線リソースを割り当てて(ステップS25)、無線リソースの割り当て制御を終了する(ステップS26)。 Next, the
Then, it is determined whether or not the number of UE3 is larger than the number of uplink radio resources (step S23). When it is determined that the number of UE3 is equal to or less than the number of uplink radio resources (No route of step S23), the
一方、UE3の数が上記上り無線リソース数よりも大きいと判定した場合(ステップS23のYesルート)、スケジューラ18は、同一の無線リソースをいずれか複数のUE3に割り当てることとなるが、このとき、本例のスケジューラ18は、在圏している無線エリアが異なるUE3に対して、同一の無線リソースを重複して割り当てて(ステップS24)、無線リソースの割り当て制御を終了する(ステップS26)。これにより、後述する本例の送信電力切り替え制御により、同一の無線リソースを重複して割り当てられたUE3からのSRSがeNB1,RRH2において衝突、干渉するのを防止することができる。
On the other hand, if it is determined that the number of UE3 is larger than the number of uplink radio resources (Yes route in step S23), the scheduler 18 will allocate the same radio resource to any of the plurality of UE3. The scheduler 18 in this example assigns the same radio resource to the UEs 3 having different radio areas in the same area (step S24), and ends the radio resource allocation control (step S26). Thereby, it is possible to prevent the SRS from the UE 3 to which the same radio resource is assigned in duplicate from colliding and interfering in the eNB 1 and the RRH 2 by the transmission power switching control of this example described later.
次に、スケジューラ18は、無線リソースの重複有無についての通知処理を実施する。
例えば、図13に示すように、スケジューラ18は、無線リソースの重複有無についての通知処理を開始すると(ステップS70)、異なるUE3に対して同一の無線リソースが重複して割り当てられたか否かを判定し(ステップS71)、無線リソースの重複が無ければ(ステップS71のNoルート)、通知処理を終了する(ステップS74)。 Next, thescheduler 18 performs notification processing regarding the presence or absence of radio resource duplication.
For example, as illustrated in FIG. 13, when thescheduler 18 starts notification processing about the presence or absence of radio resource duplication (step S <b> 70), the scheduler 18 determines whether or not the same radio resource is assigned to different UEs 3 in duplicate. If there is no radio resource duplication (No route in step S71), the notification process is terminated (step S74).
例えば、図13に示すように、スケジューラ18は、無線リソースの重複有無についての通知処理を開始すると(ステップS70)、異なるUE3に対して同一の無線リソースが重複して割り当てられたか否かを判定し(ステップS71)、無線リソースの重複が無ければ(ステップS71のNoルート)、通知処理を終了する(ステップS74)。 Next, the
For example, as illustrated in FIG. 13, when the
一方、無線リソースの重複がある場合(ステップS71のYesルート)、スケジューラ18は、同一の無線リソースが割り当てられた各UE3がいずれもCoMPの適用対象であるか否かを判定する(ステップS72)。
ここで、同一の無線リソースが割り当てられた各UE3の少なくともいずれかがCoMPの適用対象でないと判定した場合(ステップS72のNoルート)、スケジューラ18は、通知処理を終了する(ステップS74)。 On the other hand, when there is duplication of radio resources (Yes route in step S71), thescheduler 18 determines whether or not each UE 3 to which the same radio resource is assigned is a CoMP application target (step S72). .
Here, when it is determined that at least one of theUEs 3 to which the same radio resource is allocated is not a CoMP application target (No route in Step S72), the scheduler 18 ends the notification process (Step S74).
ここで、同一の無線リソースが割り当てられた各UE3の少なくともいずれかがCoMPの適用対象でないと判定した場合(ステップS72のNoルート)、スケジューラ18は、通知処理を終了する(ステップS74)。 On the other hand, when there is duplication of radio resources (Yes route in step S71), the
Here, when it is determined that at least one of the
一方、同一の無線リソースが割り当てられた各UE3のいずれもがCoMPの適用対象であると判定した場合(ステップS72のYesルート)、スケジューラ18は、同一の無線リソースが割り当てられた各UE3のうち、自局1,2が提供している無線エリアとは異なる他局が提供している無線エリアに在圏しているUE3に対して、SRS送信用の無線リソースが重複して割り当てられており、SRSの干渉が発生する可能性があることを通知して(ステップS73)、通知処理を終了する(ステップS74)。
On the other hand, when it is determined that any of the UEs 3 to which the same radio resource is allocated is a CoMP application target (Yes route in step S72), the scheduler 18 Radio resources for SRS transmission are allocated to UE3 located in a radio area provided by another station different from the radio area provided by own stations 1 and 2 Then, it is notified that there is a possibility of interference of SRS (step S73), and the notification process is terminated (step S74).
また、スケジューラ18は、上記ステップS73の処理を実施後、以下の再通知処理を実施する。
例えば、図14に示すように、スケジューラ18は、再通知処理を開始すると(ステップS80)、異なるUE3に対して同一の無線リソースが重複して割り当てられた状況が解消したか否かを判定する(ステップS81)。 Further, thescheduler 18 performs the following re-notification process after performing the process of step S73.
For example, as shown in FIG. 14, when thescheduler 18 starts the re-notification process (step S80), the scheduler 18 determines whether or not the situation in which the same radio resource is allocated to different UEs 3 has been resolved. (Step S81).
例えば、図14に示すように、スケジューラ18は、再通知処理を開始すると(ステップS80)、異なるUE3に対して同一の無線リソースが重複して割り当てられた状況が解消したか否かを判定する(ステップS81)。 Further, the
For example, as shown in FIG. 14, when the
そして、無線リソースの重複状態が解消していれば(ステップS81のYesルート)、スケジューラ18は、同一の無線リソースが割り当てられていた各UE3のうち、自局1,2が提供している無線エリアとは異なる他局が提供している無線エリアに在圏しているUE3に対して、SRS送信用の無線リソースが重複して割り当てられておらず、SRSの干渉が発生する可能性がないことを通知して(ステップS83)、再通知処理を終了する(ステップS84)。
If the overlapping state of the radio resources has been eliminated (Yes route in step S81), the scheduler 18 is the radio provided by the own stations 1 and 2 among the UEs 3 to which the same radio resource is allocated. Radio resources for SRS transmission are not allocated redundantly to UE3 located in a radio area provided by another station different from the area, and there is no possibility of SRS interference occurring This is notified (step S83), and the re-notification process is terminated (step S84).
一方、無線リソースの重複状態が解消していなければ(ステップS81のNoルート)、スケジューラ18は、同一の無線リソースが割り当てられている各UE3の少なくともいずれかがCoMPの適用対象外となったか否かを判定する(ステップS82)。
ここで、同一の無線リソースが割り当てられている各UE3の少なくともいずれかがCoMPの適用対象外であると判定した場合(ステップS82のYesルート)、スケジューラ18は、同一の無線リソースが割り当てられていた各UE3のうち、自局1,2が提供している無線エリアとは異なる他局が提供している無線エリアに在圏しているUE3に対して、SRSの干渉が発生する可能性がないことを通知して(ステップS83)、再通知処理を終了する(ステップS84)。 On the other hand, if the overlapping state of the radio resources has not been resolved (No route in step S81), thescheduler 18 determines whether or not at least one of the UEs 3 to which the same radio resource is assigned is not subject to CoMP application. Is determined (step S82).
Here, when it is determined that at least one of theUEs 3 to which the same radio resource is allocated is not subject to CoMP application (Yes route in step S82), the scheduler 18 has been allocated the same radio resource. In addition, among the UEs 3, there is a possibility that SRS interference may occur for UEs 3 located in radio areas provided by other stations different from the radio areas provided by the own stations 1 and 2. Notify (step S83), and the re-notification process ends (step S84).
ここで、同一の無線リソースが割り当てられている各UE3の少なくともいずれかがCoMPの適用対象外であると判定した場合(ステップS82のYesルート)、スケジューラ18は、同一の無線リソースが割り当てられていた各UE3のうち、自局1,2が提供している無線エリアとは異なる他局が提供している無線エリアに在圏しているUE3に対して、SRSの干渉が発生する可能性がないことを通知して(ステップS83)、再通知処理を終了する(ステップS84)。 On the other hand, if the overlapping state of the radio resources has not been resolved (No route in step S81), the
Here, when it is determined that at least one of the
一方、同一の無線リソースが割り当てられている各UE3のいずれもがCoMPの適用対象であると判定した場合(ステップS82のNoルート)、スケジューラ18は、再通知処理を終了する(ステップS84)。
ここで、上記の通知処理及び再通知処理について、詳述する。
上記ステップS73に示す通知処理及び上記ステップS83に示す再通知処理を行なう場合、スケジューラ18は、制御信号生成部20に対して、無線リソースが重複して割り当てられていることを通知するための通知信号を生成するよう要求する。 On the other hand, when it is determined that each of theUEs 3 to which the same radio resource is allocated is a CoMP application target (No route in Step S82), the scheduler 18 ends the re-notification process (Step S84).
Here, the notification process and the re-notification process will be described in detail.
When performing the notification process shown in step S73 and the re-notification process shown in step S83, thescheduler 18 notifies the control signal generation unit 20 that radio resources are allocated in duplicate. Request to generate a signal.
ここで、上記の通知処理及び再通知処理について、詳述する。
上記ステップS73に示す通知処理及び上記ステップS83に示す再通知処理を行なう場合、スケジューラ18は、制御信号生成部20に対して、無線リソースが重複して割り当てられていることを通知するための通知信号を生成するよう要求する。 On the other hand, when it is determined that each of the
Here, the notification process and the re-notification process will be described in detail.
When performing the notification process shown in step S73 and the re-notification process shown in step S83, the
通知信号は、例えば、「1」,「0」の2値をとり得るフラグとして構成される。例えば、上記ステップS73では、スケジューラ18は、通知信号を「1」にセットすることにより、UE3に対して、無線リソースが重複して割り当てられていることを通知する。また、上記ステップS83では、スケジューラ18は、指示信号を「0」にセットすることにより、UE3に対して、無線リソースが重複して割り当てられていないことを通知する。
The notification signal is configured as a flag that can take two values, for example, “1” and “0”. For example, in the above step S73, the scheduler 18 sets the notification signal to “1” to notify the UE 3 that the radio resource is allocated redundantly. In step S83, the scheduler 18 sets the instruction signal to “0” to notify the UE 3 that the radio resources are not allocated redundantly.
なお、上記通知信号は、例えば、図15(A)に示すように、DCI:A-CQIなどの下り制御情報に格納されて送信されてもよい。あるいは、上記通知信号は、例えば、図15(B)に示すように、Radio resource control information elementsのSoundingRS-UL-Configなどの上位レイヤにおける制御信号に新たなフィールド(srs-ConfigTPC)として追加されて送信されてもよい。
Note that the notification signal may be transmitted by being stored in downlink control information such as DCI: A-CQI as shown in FIG. 15 (A), for example. Alternatively, the notification signal is added as a new field (srs-ConfigTPC) to a control signal in an upper layer such as SoundingRS-UL-Config of RadioConfigresource control information elements, for example, as shown in FIG. May be sent.
(2.2)UE3の動作の一例
次に、UE3の動作の一例について、図16を用いて説明する。
図16に例示するように、まず、UE3は、SRSの送信処理を開始すると(ステップS90)、eNB1,RRH2から受信した制御情報から前述の通知信号を抽出する(ステップS91)。 (2.2) Example of Operation of UE3 Next, an example of the operation of UE3 will be described with reference to FIG.
As illustrated in FIG. 16, first, when theUE 3 starts the SRS transmission process (step S90), the UE 3 extracts the notification signal described above from the control information received from the eNB 1 and the RRH 2 (step S91).
次に、UE3の動作の一例について、図16を用いて説明する。
図16に例示するように、まず、UE3は、SRSの送信処理を開始すると(ステップS90)、eNB1,RRH2から受信した制御情報から前述の通知信号を抽出する(ステップS91)。 (2.2) Example of Operation of UE3 Next, an example of the operation of UE3 will be described with reference to FIG.
As illustrated in FIG. 16, first, when the
そして、UE3は、抽出した通知信号の内容に従って、自局3における送信電力制御方法を切り替える(ステップS92)。具体的には例えば、「1」にセットされた通知信号を抽出した場合、UE3は、以下の制御式(2)に従う送信電力制御から以下の制御式(1)に従う送信電力制御に切り替える。また、「0」にセットされた通知信号を抽出した場合、UE3は、以下の制御式(1)に従う送信電力制御から以下の制御式(2)に従う送信電力制御に切り替える。
And UE3 switches the transmission power control method in the own station 3 according to the content of the extracted notification signal (step S92). Specifically, for example, when a notification signal set to “1” is extracted, the UE 3 switches from transmission power control according to the following control equation (2) to transmission power control according to the following control equation (1). When the notification signal set to “0” is extracted, the UE 3 switches from transmission power control according to the following control equation (1) to transmission power control according to the following control equation (2).
次に、UE3は、ステップS92で切り替え後の送信電力制御方法(制御式)に従って、SRSの送信電力を決定する(ステップS93)。
そして、UE3は、ステップS93で決定した送信電力により、SRSを送信し(ステップS94)、SRSの送信処理を終了する(ステップS95)。
以上のように、本例によれば、前述した一実施形態と同様の効果が得られる。 Next, UE3 determines the transmission power of SRS according to the transmission power control method (control equation) after switching in step S92 (step S93).
And UE3 transmits SRS with the transmission power determined by step S93 (step S94), and complete | finishes the transmission process of SRS (step S95).
As described above, according to this example, the same effect as that of the above-described embodiment can be obtained.
そして、UE3は、ステップS93で決定した送信電力により、SRSを送信し(ステップS94)、SRSの送信処理を終了する(ステップS95)。
以上のように、本例によれば、前述した一実施形態と同様の効果が得られる。 Next, UE3 determines the transmission power of SRS according to the transmission power control method (control equation) after switching in step S92 (step S93).
And UE3 transmits SRS with the transmission power determined by step S93 (step S94), and complete | finishes the transmission process of SRS (step S95).
As described above, according to this example, the same effect as that of the above-described embodiment can be obtained.
〔3〕ハードウェア構成例
図17にeNB1,RRH2のハードウェア構成の一例を示す。
この図17に例示するように、eNB1,RRH2は、アンテナ11と、無線IF(無線インタフェース)51と、プロセッサ52と、メモリ53と、論理回路54と、有線IF(有線インタフェース)55とをそなえる。 [3] Example of Hardware Configuration FIG. 17 shows an example of the hardware configuration of eNB1 and RRH2.
As illustrated in FIG. 17, theeNB 1 and the RRH 2 include an antenna 11, a wireless IF (wireless interface) 51, a processor 52, a memory 53, a logic circuit 54, and a wired IF (wired interface) 55. .
図17にeNB1,RRH2のハードウェア構成の一例を示す。
この図17に例示するように、eNB1,RRH2は、アンテナ11と、無線IF(無線インタフェース)51と、プロセッサ52と、メモリ53と、論理回路54と、有線IF(有線インタフェース)55とをそなえる。 [3] Example of Hardware Configuration FIG. 17 shows an example of the hardware configuration of eNB1 and RRH2.
As illustrated in FIG. 17, the
無線IF51は、UE3と無線通信を行なうためのインタフェース装置である。プロセッサ52は、データを処理する装置であり、例えばCentral Processing Unit(CPU)やDigital Signal Processor(DSP)等を含む。メモリ53は、データを記憶する装置であり、例えばRead Only Memory(ROM)やRandom Access Memory(RAM)等を含む。論理回路54は、論理演算を行なう電子回路であり、例えば、Large Scale Integration(LSI)やField Programmable Gate Array(FPGA)等を含む。有線IF55は、他のeNB1,他のRRH2と有線通信を行なうためのインタフェース装置である。
The wireless IF 51 is an interface device for performing wireless communication with the UE 3. The processor 52 is a device that processes data, and includes, for example, a Central Processing Unit (CPU), a Digital Signal Processor (DSP), and the like. The memory 53 is a device that stores data, and includes, for example, Read Only Memory (ROM), Random Access Memory (RAM), and the like. The logic circuit 54 is an electronic circuit that performs a logical operation, and includes, for example, Large Scale Integration (LSI), Field Programmable Gate Array (FPGA), and the like. The wired IF 55 is an interface device for performing wired communication with another eNB 1 and another RRH 2.
なお、図5に例示したeNB1,RRH2の各構成と図17に例示するeNB1,RRH2の各構成との対応関係は、例えば次の通りである。
無線IF51は、例えば、デュプレクサ12,受信部13及び送信部25に対応する。プロセッサ52,メモリ53及び論理回路54は、例えば、チャネル推定部14,制御信号復調復号部15,データ信号復調復号部16,受信品質算出部17,スケジューラ18,データ信号生成部19,制御信号生成部20,参照信号生成部21,データ信号符号化変調部22,制御信号符号化変調部23及び割当部24に対応する。 The correspondence relationship between the configurations of eNB1 and RRH2 illustrated in FIG. 5 and the configurations of eNB1 and RRH2 illustrated in FIG. 17 is as follows, for example.
The wireless IF 51 corresponds to, for example, theduplexer 12, the reception unit 13, and the transmission unit 25. The processor 52, the memory 53, and the logic circuit 54 include, for example, a channel estimation unit 14, a control signal demodulation / decoding unit 15, a data signal demodulation / decoding unit 16, a reception quality calculation unit 17, a scheduler 18, a data signal generation unit 19, and a control signal generation. This corresponds to the unit 20, the reference signal generation unit 21, the data signal encoding / modulation unit 22, the control signal encoding / modulation unit 23, and the allocation unit 24.
無線IF51は、例えば、デュプレクサ12,受信部13及び送信部25に対応する。プロセッサ52,メモリ53及び論理回路54は、例えば、チャネル推定部14,制御信号復調復号部15,データ信号復調復号部16,受信品質算出部17,スケジューラ18,データ信号生成部19,制御信号生成部20,参照信号生成部21,データ信号符号化変調部22,制御信号符号化変調部23及び割当部24に対応する。 The correspondence relationship between the configurations of eNB1 and RRH2 illustrated in FIG. 5 and the configurations of eNB1 and RRH2 illustrated in FIG. 17 is as follows, for example.
The wireless IF 51 corresponds to, for example, the
また、図18にUE3のハードウェア構成の一例を示す。
この図18に例示するように、UE3は、アンテナ31と、無線IF61と、プロセッサ62と、メモリ63と、論理回路64と、入力IF(入力インタフェース)65と、出力IF(出力インタフェース)66とをそなえる。
無線IF61は、eNB1,RRH2と無線通信を行なうためのインタフェース装置である。プロセッサ62は、データを処理する装置であり、例えばCPUやDSP等を含む。メモリ63は、データを記憶する装置であり、例えばROMやRAM等を含む。論理回路64は、論理演算を行なう電子回路であり、例えば、LSIやFPGA等を含む。入力IF65は、入力を行なう装置であり、例えば操作ボタンやマイク等を含む。出力IF66は、出力を行なう装置であり、例えばスピーカやディスプレイ等を含む。 FIG. 18 shows an example of the hardware configuration of UE3.
As illustrated in FIG. 18, theUE 3 includes an antenna 31, a wireless IF 61, a processor 62, a memory 63, a logic circuit 64, an input IF (input interface) 65, and an output IF (output interface) 66. Is provided.
The wireless IF 61 is an interface device for performing wireless communication with theeNB 1 and the RRH 2. The processor 62 is a device that processes data, and includes, for example, a CPU and a DSP. The memory 63 is a device that stores data, and includes, for example, a ROM, a RAM, and the like. The logic circuit 64 is an electronic circuit that performs a logical operation, and includes, for example, an LSI, an FPGA, or the like. The input IF 65 is a device that performs input, and includes, for example, an operation button, a microphone, and the like. The output IF 66 is a device that performs output, and includes, for example, a speaker and a display.
この図18に例示するように、UE3は、アンテナ31と、無線IF61と、プロセッサ62と、メモリ63と、論理回路64と、入力IF(入力インタフェース)65と、出力IF(出力インタフェース)66とをそなえる。
無線IF61は、eNB1,RRH2と無線通信を行なうためのインタフェース装置である。プロセッサ62は、データを処理する装置であり、例えばCPUやDSP等を含む。メモリ63は、データを記憶する装置であり、例えばROMやRAM等を含む。論理回路64は、論理演算を行なう電子回路であり、例えば、LSIやFPGA等を含む。入力IF65は、入力を行なう装置であり、例えば操作ボタンやマイク等を含む。出力IF66は、出力を行なう装置であり、例えばスピーカやディスプレイ等を含む。 FIG. 18 shows an example of the hardware configuration of UE3.
As illustrated in FIG. 18, the
The wireless IF 61 is an interface device for performing wireless communication with the
なお、図10に例示したUE3の各構成と図18に例示するUE3の各構成との対応関係は、例えば次の通りである。
無線IF61は、例えば、デュプレクサ32,受信部33及び送信部46に対応する。プロセッサ62,メモリ63及び論理回路64は、例えば、チャネル推定部34,制御信号復調復号部35,データ信号復調復号部36,受信品質算出部37,データ信号生成部38,制御信号生成部39,参照信号生成部40,データ信号符号化変調部41,制御信号符号化変調部42,割当部43,切り替え制御部44及び送信電力決定部45に対応する。 The correspondence relationship between each configuration ofUE 3 illustrated in FIG. 10 and each configuration of UE 3 illustrated in FIG. 18 is, for example, as follows.
The wireless IF 61 corresponds to, for example, theduplexer 32, the reception unit 33, and the transmission unit 46. The processor 62, the memory 63, and the logic circuit 64 include, for example, a channel estimation unit 34, a control signal demodulation / decoding unit 35, a data signal demodulation / decoding unit 36, a reception quality calculation unit 37, a data signal generation unit 38, a control signal generation unit 39, This corresponds to the reference signal generation unit 40, the data signal encoding / modulating unit 41, the control signal encoding / modulating unit 42, the allocating unit 43, the switching control unit 44 and the transmission power determining unit 45.
無線IF61は、例えば、デュプレクサ32,受信部33及び送信部46に対応する。プロセッサ62,メモリ63及び論理回路64は、例えば、チャネル推定部34,制御信号復調復号部35,データ信号復調復号部36,受信品質算出部37,データ信号生成部38,制御信号生成部39,参照信号生成部40,データ信号符号化変調部41,制御信号符号化変調部42,割当部43,切り替え制御部44及び送信電力決定部45に対応する。 The correspondence relationship between each configuration of
The wireless IF 61 corresponds to, for example, the
〔4〕その他
なお、上述した実施形態及び変形例におけるeNB1,RRH2及びUE3の各構成及び各機能は、必要に応じて取捨選択してもよいし、適宜組み合わせて用いてもよい。即ち、本発明の機能を発揮できるように、上記の各構成及び各機能を取捨選択したり、適宜組み合わせて用いたりしてもよい。 [4] Others In addition, each structure and each function of eNB1, RRH2, and UE3 in embodiment and the modification which were mentioned above may be selected as needed, and may be used in combination suitably. In other words, the above-described configurations and functions may be selected or used in appropriate combination so that the functions of the present invention can be exhibited.
なお、上述した実施形態及び変形例におけるeNB1,RRH2及びUE3の各構成及び各機能は、必要に応じて取捨選択してもよいし、適宜組み合わせて用いてもよい。即ち、本発明の機能を発揮できるように、上記の各構成及び各機能を取捨選択したり、適宜組み合わせて用いたりしてもよい。 [4] Others In addition, each structure and each function of eNB1, RRH2, and UE3 in embodiment and the modification which were mentioned above may be selected as needed, and may be used in combination suitably. In other words, the above-described configurations and functions may be selected or used in appropriate combination so that the functions of the present invention can be exhibited.
上述した実施形態及び変形例では、SRS送信用の無線リソースが重複して割り当てられた場合に、UE3が送信するSRSがサービング無線基地局2(または1)のみで受信されるように、UE3の送信電力を制御したが、例えば、UE3が送信するSRSが、SRSの干渉が発生し得る無線基地局1(または2)を除く複数の無線基地局で受信されるように、UE3の送信電力を制御してもよい。具体的には例えば、UE3と各無線基地局1,2との間の距離や無線通信環境などに基づいて、上記送信電力を決定することができる。なお、SRSの干渉が発生し得る無線基地局1(または2)を除く複数の無線基地局には、サービング無線基地局2(または1)が含まれる。
In the embodiment and the modification described above, when radio resources for SRS transmission are allocated in duplicate, the SRS transmitted by the UE 3 is received only by the serving radio base station 2 (or 1). Although the transmission power is controlled, for example, the transmission power of UE3 is set so that the SRS transmitted by UE3 is received by a plurality of radio base stations other than radio base station 1 (or 2) where interference of SRS may occur. You may control. Specifically, for example, the transmission power can be determined based on the distance between the UE 3 and each of the radio base stations 1 and 2, the radio communication environment, and the like. The plurality of radio base stations excluding the radio base station 1 (or 2) in which SRS interference may occur include the serving radio base station 2 (or 1).
さらに、上述した実施形態及び変形例では、SRS送信用の無線リソースが重複して割り当てられた場合に、複数のSRSが干渉し得るものとして、UE3の送信電力制御方法を切り替えたが、例えば、実際にSRSの干渉が発生した場合に、UE3の送信電力制御方法を切り替えるようにしてもよい。具体的には例えば、eNB1,RRH2において、各SRSの受信電力の比較などによりSRSの干渉を検出し、当該検出結果に基づいて、UE3へ指示信号を送信したり、通知信号を送信したりして、UE3の送信電力制御方法を切り替えるようにしてもよい。
Furthermore, in the above-described embodiment and the modification, when radio resources for SRS transmission are allocated in duplicate, the transmission power control method of UE3 is switched as a plurality of SRSs can interfere. When SRS interference actually occurs, the transmission power control method of UE 3 may be switched. Specifically, for example, in eNB1 and RRH2, SRS interference is detected by comparing the received power of each SRS, and based on the detection result, an instruction signal is transmitted to UE3 or a notification signal is transmitted. Then, the transmission power control method of UE3 may be switched.
また、上述した実施形態及び変形例では、無線通信システム6が数百m~数kmオーダーの無線エリアをカバーするマクロ基地局の一例としてeNB1を有するとともに、張り出し局(RRH)2を有する例を用いて本発明を説明したが、無線通信システム6は、例えば、数百mオーダーの無線エリアをカバーするマイクロ基地局(Micro eNB),数十m~約200mオーダーの無線エリアをカバーするピコ基地局(Pico eNB),特定のユーザ専用のホーム基地局(Home eNB、フェムトセル基地局ともいう),無線信号を中継する中継局などをそなえていてもよい。このとき、マイクロ基地局,ピコ基地局,ホーム基地局については、上述したeNB1またはRRH2と同様の構成及び機能を有するようにしてもよい。
In the embodiment and the modification described above, the radio communication system 6 includes the eNB 1 as an example of the macro base station that covers a radio area of the order of several hundred meters to several km, and the extension station (RRH) 2. The wireless communication system 6 is, for example, a micro base station (Micro eNB) that covers a wireless area on the order of several hundred meters, or a pico base that covers a wireless area on the order of several tens of meters to about 200 meters. A station (Pico eNB), a home base station dedicated to a specific user (also referred to as a Home eNB or a femtocell base station), a relay station that relays a radio signal, and the like may be provided. At this time, the micro base station, the pico base station, and the home base station may have the same configuration and function as the eNB 1 or the RRH 2 described above.
さらに、上述した実施形態及び変形例では、同一の無線リソースが異なるUE3に重複して割り当てられた場合に、UE3の送信電力制御方法を切り替えたが、例えば、互いに少なくとも一部が重複する無線リソースが異なるUE3に割り当てられた場合に、UE3の送信電力制御方法を切り替えるようにしてもよい。
Furthermore, in the above-described embodiment and modification, when the same radio resource is assigned to different UEs 3 in a duplicated manner, the transmission power control method of UE 3 is switched. May be switched to the UE 3 transmission power control method.
1 eNB
2-1,2-2 RRH
3-1~3-7 UE
4 無線エリア
5-1,5-2 無線エリア
6 無線通信システム
11 アンテナ
12 デュプレクサ
13 受信部
14 チャネル推定部
15 制御信号復調復号部
16 データ信号復調復号部
17 受信品質算出部
18 スケジューラ
19 データ信号生成部
20 制御信号生成部
21 参照信号生成部
22 データ信号符号化変調部
23 制御信号符号化変調部
24 割当部
25 送信部
31 アンテナ
32 デュプレクサ
33 受信部
34 チャネル推定部
35 制御信号復調復号部
36 データ信号復調復号部
37 受信品質算出部
38 データ信号生成部
39 制御信号生成部
40 参照信号生成部
41 データ信号符号化変調部
42 制御信号符号化変調部
43 割当部
44 切り替え制御部
45 送信電力決定部
46 送信部
51 無線IF
52 プロセッサ
53 メモリ
54 論理回路
55 有線IF
61 無線IF
62 プロセッサ
63 メモリ
64 論理回路
65 入力IF
66 出力IF
100 eNB
200-1,200-2 RRH
300-1~300-7 UE
400 無線エリア
500-1,500-2 無線エリア 1 eNB
2-1, 2-2 RRH
3-1 to 3-7 UE
4 Radio Area 5-1 and 5-2Radio Area 6 Wireless Communication System 11 Antenna 12 Duplexer 13 Receiver 14 Channel Estimator 15 Control Signal Demodulator / Decoder 16 Data Signal Demodulator / Decoder 17 Reception Quality Calculator 18 Scheduler 19 Data Signal Generation Unit 20 control signal generation unit 21 reference signal generation unit 22 data signal encoding modulation unit 23 control signal encoding modulation unit 24 allocation unit 25 transmission unit 31 antenna 32 duplexer 33 reception unit 34 channel estimation unit 35 control signal demodulation decoding unit 36 data Signal demodulation decoding unit 37 Reception quality calculation unit 38 Data signal generation unit 39 Control signal generation unit 40 Reference signal generation unit 41 Data signal encoding modulation unit 42 Control signal encoding modulation unit 43 Allocation unit 44 Switching control unit 45 Transmission power determination unit 46 Transmitter 51 Wireless IF
52Processor 53 Memory 54 Logic Circuit 55 Wired IF
61 Wireless IF
62processor 63 memory 64 logic circuit 65 input IF
66 Output IF
100 eNB
200-1, 200-2 RRH
300-1 to 300-7 UE
400 Wireless area 500-1,500-2 Wireless area
2-1,2-2 RRH
3-1~3-7 UE
4 無線エリア
5-1,5-2 無線エリア
6 無線通信システム
11 アンテナ
12 デュプレクサ
13 受信部
14 チャネル推定部
15 制御信号復調復号部
16 データ信号復調復号部
17 受信品質算出部
18 スケジューラ
19 データ信号生成部
20 制御信号生成部
21 参照信号生成部
22 データ信号符号化変調部
23 制御信号符号化変調部
24 割当部
25 送信部
31 アンテナ
32 デュプレクサ
33 受信部
34 チャネル推定部
35 制御信号復調復号部
36 データ信号復調復号部
37 受信品質算出部
38 データ信号生成部
39 制御信号生成部
40 参照信号生成部
41 データ信号符号化変調部
42 制御信号符号化変調部
43 割当部
44 切り替え制御部
45 送信電力決定部
46 送信部
51 無線IF
52 プロセッサ
53 メモリ
54 論理回路
55 有線IF
61 無線IF
62 プロセッサ
63 メモリ
64 論理回路
65 入力IF
66 出力IF
100 eNB
200-1,200-2 RRH
300-1~300-7 UE
400 無線エリア
500-1,500-2 無線エリア 1 eNB
2-1, 2-2 RRH
3-1 to 3-7 UE
4 Radio Area 5-1 and 5-2
52
61 Wireless IF
62
66 Output IF
100 eNB
200-1, 200-2 RRH
300-1 to 300-7 UE
400 Wireless area 500-1,500-2 Wireless area
Claims (19)
- 既知の信号を送信する際に用いられる複数の無線リソースのうち互いに少なくとも一部が重複する無線リソースが複数の無線端末に対して割り当てられている場合に、前記複数の無線端末のうち自局とは異なる他の無線基地局の無線エリア内に位置する無線端末が送信する既知の信号が前記自局を除く無線基地局で受信されるように前記他の無線基地局の無線エリア内に位置する無線端末の送信電力を制御する処理部と、
前記複数の無線端末のうち自局の無線エリア内に位置する無線端末が送信する既知の信号を少なくとも受信する受信部と、をそなえる、
ことを特徴とする、無線基地局。 When a plurality of radio resources used when transmitting a known signal are assigned to a plurality of radio terminals at least partially overlapping with each other, Is located in the radio area of the other radio base station so that a known signal transmitted by a radio terminal located in the radio area of another different radio base station is received by the radio base station other than the local station. A processing unit for controlling the transmission power of the wireless terminal;
A receiving unit that receives at least a known signal transmitted by a wireless terminal located in the wireless area of the local station among the plurality of wireless terminals;
A radio base station characterized by that. - 前記処理部が、
前記複数の無線リソースのうち互いに少なくとも一部が重複する無線リソースが複数の無線端末に対して割り当てられている場合に、前記複数の無線端末のうち自局とは異なる他の無線基地局の無線エリア内に位置する無線端末が送信する既知の信号が前記他の無線基地局のみで受信されるように前記他の無線基地局の無線エリア内に位置する無線端末の送信電力を制御する、
ことを特徴とする、請求項1記載の無線基地局。 The processing unit is
When radio resources that at least partially overlap each other among the plurality of radio resources are allocated to a plurality of radio terminals, radios of other radio base stations different from the own station among the plurality of radio terminals Controlling the transmission power of a wireless terminal located in the wireless area of the other wireless base station so that a known signal transmitted by the wireless terminal located in the area is received only by the other wireless base station;
The radio base station according to claim 1, wherein: - 前記処理部が、
前記複数の無線リソースのうち互いに異なる無線リソースが複数の無線端末に対して割り当てられている場合に、前記他の無線基地局の無線エリア内に位置する無線端末が送信する既知の信号が少なくとも自局と前記他の無線基地局とで受信されるように前記他の無線基地局の無線エリア内に位置する無線端末の送信電力を制御する、
ことを特徴とする、請求項1または2に記載の無線基地局。 The processing unit is
When different radio resources among the plurality of radio resources are allocated to a plurality of radio terminals, at least a known signal transmitted by a radio terminal located in a radio area of the other radio base station is at least Controlling the transmission power of a radio terminal located in the radio area of the other radio base station so as to be received by the station and the other radio base station;
The radio base station according to claim 1 or 2, wherein - 前記処理部が、
前記複数の無線リソースのうち互いに少なくとも一部が重複する無線リソースを、自局の無線エリア内に位置する無線端末と前記他の無線基地局の無線エリア内に位置する無線端末とに割り当てる、
ことを特徴とする、請求項1~3のいずれか1項に記載の無線基地局。 The processing unit is
A radio resource at least partially overlapping among the plurality of radio resources is allocated to a radio terminal located in a radio area of the own station and a radio terminal located in a radio area of the other radio base station,
The radio base station according to any one of claims 1 to 3, characterized in that: - 前記処理部が、
前記送信電力の切り替えを指示する指示信号、または、前記複数の無線リソースのうち互いに少なくとも一部が重複する無線リソースが前記複数の無線端末に対して割り当てられていることを通知する通知信号を前記他の無線基地局の無線エリア内に位置する無線端末に送信することにより、当該無線端末の送信電力を制御する、
ことを特徴とする、請求項1~4のいずれか1項に記載の無線基地局。 The processing unit is
An instruction signal for instructing switching of the transmission power, or a notification signal for notifying that radio resources at least partially overlapping each other among the plurality of radio resources are allocated to the plurality of radio terminals By controlling transmission power of the wireless terminal by transmitting to the wireless terminal located in the wireless area of another wireless base station,
The radio base station according to any one of claims 1 to 4, characterized in that: - 前記指示信号または前記通知信号は、前記他の無線基地局の無線エリア内に位置する無線端末に送信される下り制御情報、または、前記既知の信号が処理される通信レイヤよりも上位の通信レイヤで前記他の無線基地局の無線エリア内に位置する無線端末に送信される制御信号に格納される、
ことを特徴とする、請求項5記載の無線基地局。 The instruction signal or the notification signal is downlink control information transmitted to a radio terminal located in a radio area of the other radio base station, or a communication layer higher than a communication layer in which the known signal is processed And stored in a control signal transmitted to a wireless terminal located in a wireless area of the other wireless base station.
The radio base station according to claim 5, wherein: - 既知の信号を送信する際に用いる複数の無線リソースのうち互いに少なくとも一部が重複する無線リソースが自局を含む複数の無線端末に対して割り当てられている場合に、自局が送信する既知の信号が複数の無線基地局の一部の無線基地局で受信されるように自局の送信電力を決定する処理部と、
前記処理部で決定された送信電力を用いて前記既知の信号を送信する送信部と、をそなえる、
ことを特徴とする、無線端末。 A known resource transmitted by the own station when a plurality of wireless resources used when transmitting a known signal are assigned to a plurality of wireless terminals including at least one part of the wireless resource. A processing unit that determines the transmission power of the local station so that the signal is received by some of the plurality of wireless base stations;
A transmission unit that transmits the known signal using the transmission power determined by the processing unit;
A wireless terminal characterized by that. - 前記処理部が、
前記複数の無線リソースのうち互いに少なくとも一部が重複する無線リソースが自局を含む複数の無線端末に対して割り当てられている場合に、自局が送信する既知の信号がサービング無線基地局のみで受信されるように自局の送信電力を決定する、
ことを特徴とする、請求項7記載の無線端末。 The processing unit is
When radio resources at least partially overlapping each other among the plurality of radio resources are allocated to a plurality of radio terminals including the own station, a known signal transmitted by the own station is transmitted only by the serving radio base station. Determine the transmission power of your station so that it can be received.
The wireless terminal according to claim 7, wherein: - 前記処理部が、
前記複数の無線リソースのうち互いに異なる無線リソースが自局を含む複数の無線端末に対して割り当てられている場合に、自局が送信する既知の信号が少なくとも前記サービング無線基地局と他の無線基地局とで受信されるように自局の送信電力を決定する、
ことを特徴とする、請求項7または8に記載の無線端末。 The processing unit is
When different radio resources among the plurality of radio resources are allocated to a plurality of radio terminals including the own station, at least the serving radio base station and another radio base Determine the transmission power of your station so that it is received by the station.
The wireless terminal according to claim 7, wherein the wireless terminal is a wireless terminal. - 既知の信号を送信する際に用いられる複数の無線リソースのうち互いに少なくとも一部が重複する無線リソースが複数の無線端末に対して割り当てられている場合に、前記複数の無線端末のうち自局とは異なる他の無線基地局の無線エリア内に位置する無線端末が送信する既知の信号が前記自局を除く無線基地局で受信されるように前記他の無線基地局の無線エリア内に位置する無線端末の送信電力を制御する無線基地局と、
前記他の無線基地局の無線エリア内に位置し、前記無線基地局で制御された送信電力を用いて前記既知の信号を送信する無線端末と、をそなえる、
ことを特徴とする、無線通信システム。 When a plurality of radio resources used when transmitting a known signal are assigned to a plurality of radio terminals at least partially overlapping with each other, Is located in the radio area of the other radio base station so that a known signal transmitted by a radio terminal located in the radio area of another different radio base station is received by the radio base station other than the local station. A radio base station that controls the transmission power of the radio terminal;
A wireless terminal located in a wireless area of the other wireless base station and transmitting the known signal using transmission power controlled by the wireless base station;
A wireless communication system. - 前記無線基地局が、
前記複数の無線リソースのうち互いに少なくとも一部が重複する無線リソースが複数の無線端末に対して割り当てられている場合に、前記複数の無線端末のうち自局とは異なる他の無線基地局の無線エリア内に位置する無線端末が送信する既知の信号が前記他の無線基地局のみで受信されるように前記他の無線基地局の無線エリア内に位置する無線端末の送信電力を制御する、
ことを特徴とする、請求項10記載の無線通信システム。 The radio base station is
When radio resources that at least partially overlap each other among the plurality of radio resources are allocated to a plurality of radio terminals, radios of other radio base stations different from the own station among the plurality of radio terminals Controlling the transmission power of a wireless terminal located in the wireless area of the other wireless base station so that a known signal transmitted by the wireless terminal located in the area is received only by the other wireless base station;
The wireless communication system according to claim 10, wherein: - 前記無線基地局が、
前記複数の無線リソースのうち互いに異なる無線リソースが複数の無線端末に対して割り当てられている場合に、前記他の無線基地局の無線エリア内に位置する無線端末が送信する既知の信号が少なくとも自局と前記他の無線基地局とで受信されるように前記他の無線基地局の無線エリア内に位置する無線端末の送信電力を制御する、
ことを特徴とする、請求項10または11に記載の無線通信システム。 The radio base station is
When different radio resources among the plurality of radio resources are allocated to a plurality of radio terminals, at least a known signal transmitted by a radio terminal located in a radio area of the other radio base station is at least Controlling the transmission power of a radio terminal located in the radio area of the other radio base station so as to be received by the station and the other radio base station;
The wireless communication system according to claim 10 or 11, characterized by the above. - 前記無線基地局が、
前記複数の無線リソースのうち互いに少なくとも一部が重複する無線リソースを、自局の無線エリア内に位置する無線端末と前記他の無線基地局の無線エリア内に位置する無線端末とに割り当てる、
ことを特徴とする、請求項10~12のいずれか1項に記載の無線通信システム。 The radio base station is
A radio resource at least partially overlapping among the plurality of radio resources is allocated to a radio terminal located in a radio area of the own station and a radio terminal located in a radio area of the other radio base station,
The wireless communication system according to any one of claims 10 to 12, characterized in that: - 前記無線基地局と前記無線端末との間で多地点協調(CoMP:Coordinated Multi Point)通信を行なう、
ことを特徴とする、請求項10~13のいずれか1項に記載の無線通信システム。 Multipoint coordinated (CoMP: Coordinated Multi Point) communication is performed between the wireless base station and the wireless terminal.
The wireless communication system according to any one of claims 10 to 13, wherein the wireless communication system is characterized in that: - 無線基地局において、
既知の信号を送信する際に用いられる複数の無線リソースのうち互いに少なくとも一部が重複する無線リソースが複数の無線端末に対して割り当てられている場合に、前記複数の無線端末のうち自局とは異なる他の無線基地局の無線エリア内に位置する無線端末が送信する既知の信号が前記自局を除く無線基地局で受信されるように前記他の無線基地局の無線エリア内に位置する無線端末の送信電力を制御し、
前記他の無線基地局の無線エリア内に位置する無線端末において、
前記制御された送信電力を用いて前記既知の信号を送信する、
ことを特徴とする、通信制御方法。 In the radio base station
When a plurality of radio resources used when transmitting a known signal are assigned to a plurality of radio terminals at least partially overlapping with each other, Is located in the radio area of the other radio base station so that a known signal transmitted by a radio terminal located in the radio area of another different radio base station is received by the radio base station other than the local station. Control the transmission power of the wireless terminal,
In a radio terminal located in a radio area of the other radio base station,
Transmitting the known signal using the controlled transmission power;
A communication control method. - 前記無線基地局において、
前記複数の無線リソースのうち互いに少なくとも一部が重複する無線リソースが複数の無線端末に対して割り当てられている場合に、前記複数の無線端末のうち自局とは異なる他の無線基地局の無線エリア内に位置する無線端末が送信する既知の信号が前記他の無線基地局のみで受信されるように前記他の無線基地局の無線エリア内に位置する無線端末の送信電力を制御する、
ことを特徴とする、請求項15記載の通信制御方法。 In the radio base station,
When radio resources that at least partially overlap each other among the plurality of radio resources are allocated to a plurality of radio terminals, radios of other radio base stations different from the own station among the plurality of radio terminals Controlling the transmission power of a wireless terminal located in the wireless area of the other wireless base station so that a known signal transmitted by the wireless terminal located in the area is received only by the other wireless base station;
The communication control method according to claim 15, wherein: - 前記無線基地局において、
前記複数の無線リソースのうち互いに異なる無線リソースが複数の無線端末に対して割り当てられている場合に、前記他の無線基地局の無線エリア内に位置する無線端末が送信する既知の信号が少なくとも自局と前記他の無線基地局とで受信されるように前記他の無線基地局の無線エリア内に位置する無線端末の送信電力を制御する、
ことを特徴とする、請求項15または16に記載の通信制御方法。 In the radio base station,
When different radio resources among the plurality of radio resources are allocated to a plurality of radio terminals, at least a known signal transmitted by a radio terminal located in a radio area of the other radio base station is at least Controlling the transmission power of a radio terminal located in the radio area of the other radio base station so as to be received by the station and the other radio base station;
The communication control method according to claim 15 or 16, characterized by the above. - 前記無線基地局において、
前記複数の無線リソースのうち互いに少なくとも一部が重複する無線リソースを、自局の無線エリア内に位置する無線端末と前記他の無線基地局の無線エリア内に位置する無線端末とに割り当てる、
ことを特徴とする、請求項15~17のいずれか1項に記載の通信制御方法。 In the radio base station,
A radio resource at least partially overlapping among the plurality of radio resources is allocated to a radio terminal located in a radio area of the own station and a radio terminal located in a radio area of the other radio base station,
The communication control method according to any one of claims 15 to 17, characterized in that: - 前記無線基地局と前記無線端末との間で多地点協調(CoMP:Coordinated Multi Point)通信を行なう、
ことを特徴とする、請求項15~18のいずれか1項に記載の通信制御方法。 Multipoint coordinated (CoMP: Coordinated Multi Point) communication is performed between the wireless base station and the wireless terminal.
The communication control method according to any one of claims 15 to 18, characterized in that:
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Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2021100260A (en) * | 2016-05-05 | 2021-07-01 | 株式会社Nttドコモ | Mechanism and procedure of base station selection based on uplink pilot and distributed user-proximity detection |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010199902A (en) * | 2009-02-24 | 2010-09-09 | Kyocera Corp | Radio base station, and transmission power control method |
JP2011009866A (en) * | 2009-06-23 | 2011-01-13 | Ntt Docomo Inc | Wireless base station apparatus, mobile terminal and transmission power control method |
WO2012008593A1 (en) * | 2010-07-16 | 2012-01-19 | 京セラ株式会社 | Wireless base station and communications control method |
-
2012
- 2012-04-27 WO PCT/JP2012/061362 patent/WO2013161054A1/en active Application Filing
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010199902A (en) * | 2009-02-24 | 2010-09-09 | Kyocera Corp | Radio base station, and transmission power control method |
JP2011009866A (en) * | 2009-06-23 | 2011-01-13 | Ntt Docomo Inc | Wireless base station apparatus, mobile terminal and transmission power control method |
WO2012008593A1 (en) * | 2010-07-16 | 2012-01-19 | 京セラ株式会社 | Wireless base station and communications control method |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2021100260A (en) * | 2016-05-05 | 2021-07-01 | 株式会社Nttドコモ | Mechanism and procedure of base station selection based on uplink pilot and distributed user-proximity detection |
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