WO2020144813A1 - Communication device and wireless communication system - Google Patents

Communication device and wireless communication system Download PDF

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Publication number
WO2020144813A1
WO2020144813A1 PCT/JP2019/000527 JP2019000527W WO2020144813A1 WO 2020144813 A1 WO2020144813 A1 WO 2020144813A1 JP 2019000527 W JP2019000527 W JP 2019000527W WO 2020144813 A1 WO2020144813 A1 WO 2020144813A1
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WIPO (PCT)
Prior art keywords
resource
data signal
signal
released
scheduler
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PCT/JP2019/000527
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French (fr)
Japanese (ja)
Inventor
紅陽 陳
ジヤンミン ウー
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富士通株式会社
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Priority to PCT/JP2019/000527 priority Critical patent/WO2020144813A1/en
Publication of WO2020144813A1 publication Critical patent/WO2020144813A1/en

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W28/00—Network traffic management; Network resource management
    • H04W28/02—Traffic management, e.g. flow control or congestion control
    • H04W28/04—Error control
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
    • H04W4/30—Services specially adapted for particular environments, situations or purposes
    • H04W4/40—Services specially adapted for particular environments, situations or purposes for vehicles, e.g. vehicle-to-pedestrians [V2P]
    • H04W4/46—Services specially adapted for particular environments, situations or purposes for vehicles, e.g. vehicle-to-pedestrians [V2P] for vehicle-to-vehicle communication [V2V]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W72/00—Local resource management
    • H04W72/02—Selection of wireless resources by user or terminal
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W92/00—Interfaces specially adapted for wireless communication networks
    • H04W92/16—Interfaces between hierarchically similar devices
    • H04W92/18—Interfaces between hierarchically similar devices between terminal devices

Definitions

  • the present invention relates to a communication device and a wireless communication system.
  • the traffic of mobile terminals (smartphones and feature phones) accounts for most of the network resources. Also, the traffic used by mobile terminals tends to continue to grow.
  • eMBB Enhanced Mobile BroadBand
  • Massive MTC Machine Type Communications
  • URLLC Ultra-Reliable and Low Latency Communication
  • V2X Vehicle to Everything
  • V2X refers to V2V (Vehicle to Vehicle) that indicates inter-vehicle communication
  • V2P Vehicle to Pedestrian
  • road infrastructure such as a car and a sign that use side link channels.
  • V2I Vehicle to Infrastructure
  • V2N Vehicle to Network
  • V2X in order to improve the reliability of communication, it is considered to transmit the transmission data multiple times. For example, a mode in which the allocation pattern of the resources used by each terminal device for the initial transmission and the retransmission of the data is notified in advance from the base station device, and each terminal device performs the initial transmission and the retransmission of the data according to the allocation pattern. Have been discussed.
  • 3GPP TS 22.186 V16.0.0 (2018-09) 3GPP TS 36.211 V15.2.0 (2018-06) 3GPP TS 36.212 V15.2.1 (2018-07) 3GPP TS 36.213 V15.2.0 (2018-06) 3GPP TS 36.300 V15.2.0 (2018-06) 3GPP TS 36.321 V15.2.0 (2018-07) 3GPP TS 36.322 V15.1.0 (2018-07) 3GPP TS 36.323 V15.0.0 (2018-07) 3GPP TS 36.331 V15.2.2 (2018-06) 3GPP TS 36.413 V15.2.0 (2018-06) 3GPP TS 36.423 V15.2.0 (2018-06) 3GPP TS 36.425 V15.0.0 (2018-06) 3GPP TS 37.340 V15.2.0 (2018-06) 3GPP TS 38.201 V15.0.0 (2017-12) 3GPP TS 38.202 V15.2.0 (2018-06)
  • the disclosed technology has been made in view of the above points, and an object thereof is to provide a communication device and a wireless communication system capable of improving resource utilization efficiency.
  • a communication device disclosed by the present application, a scheduler that determines a resource for transmitting and retransmitting a data signal, a transmitting unit that transmits a data signal using the resource determined by the scheduler, A receiver for receiving a feedback signal indicating whether or not the data signal transmitted by the transmitter can be decoded, and the scheduler indicates that the feedback signal received by the receiver indicates that the data signal has been decoded.
  • the resource for retransmitting the data signal is released.
  • the communication device and the wireless communication system disclosed in the present application it is possible to improve the resource utilization efficiency.
  • FIG. 1 is a block diagram showing the configuration of the terminal device according to the first embodiment.
  • FIG. 2 is a flowchart showing the first operation of the terminal device according to the first embodiment.
  • FIG. 3 is a flowchart showing the second operation of the terminal device according to the first embodiment.
  • FIG. 4 is a diagram showing a specific example of resource use according to the first embodiment.
  • FIG. 5 is a block diagram showing the configuration of the terminal device according to the second embodiment.
  • FIG. 6 is a flowchart showing the operation of the second terminal device according to the second embodiment.
  • FIG. 7 is a diagram showing a specific example of resource use according to the second embodiment.
  • FIG. 8 is a diagram showing a specific example of resource use according to the third embodiment.
  • the wireless communication system has a plurality of terminal devices provided in, for example, automobiles, pedestrians, road infrastructures, and the like. These terminal devices can wirelessly communicate with each other, and can wirelessly communicate with the base station device within the radio wave reachable range from the base station device of the cellular system constructed by the communication carrier, for example.
  • FIG. 1 is a block diagram showing the configuration of the terminal device 100 according to the first embodiment.
  • the terminal device 100 illustrated in FIG. 1 includes a processor 110, a memory 120, a wireless transmission unit 130, and a wireless reception unit 140.
  • a processing unit related to wireless communication between terminal devices is illustrated, and a processing unit related to wireless communication with a base station device is omitted.
  • the processor 110 includes, for example, a CPU (Central Processing Unit), an FPGA (Field Programmable Gate Array), a DSP (Digital Signal Processor), and the like, and integrally controls the entire terminal device 100.
  • the processor 110 includes a V2X scheduler 111, a data signal generation unit 112, an SCI (Sidelink Control Information) generation unit 113, a resource release signal generation unit 114, a control signal generation unit 115, a control signal decoding unit 116, and a data signal.
  • a decoding unit 117, a feedback (FB: Feed Back) signal detection unit 118, and a resource release signal detection unit 119 are included.
  • the V2X scheduler 111 executes V2X communication scheduling. Specifically, the V2X scheduler 111 determines the resource used for data transmission, and notifies the data signal generation unit 112 and the SCI generation unit 113 of the determined resource. At this time, the V2X scheduler 111 not only determines the resource for the initial transmission but also the resource for the retransmission for the transmission of one data. When deciding the resource, the V2X scheduler 111 selects the resource estimated not to be used by another terminal device, for example, from the result of sensing all the frequency bands available for data transmission in a predetermined sensing period. Alternatively, a resource designated in advance may be selected during wireless communication with the base station device.
  • the V2X scheduler 111 cancels this data retransmission and releases the resources reserved for the data retransmission. Then, the V2X scheduler 111 notifies the resource release signal generation unit 114 that the resource has been released.
  • the V2X scheduler 111 releases the data to be transmitted. Decide to use the specified resource. Then, the V2X scheduler 111 notifies the data signal generation unit 112 and the SCI generation unit 113 that the released resource will be used.
  • the data signal generation unit 112 generates a data signal including transmission data, and uses the resource determined by the V2X scheduler 111 to transmit the data signal via the wireless transmission unit 130. Specifically, the data signal generation unit 112 retransmits the same data signal using the resource for retransmission even after the initial transmission of the data signal. However, the data signal generation unit 112 does not retransmit the data signal when the retransmission is canceled.
  • the SCI generation unit 113 generates an SCI including control information regarding the resource determined by the V2X scheduler 111. Specifically, the SCI generation unit 113 is used for the maximum number of retransmissions of the data signal, the current number of transmissions of the data signal, the resources to be used for returning the FB signal such as ACK or NACK, and the data signal. SCI including information such as resources to be generated is generated.
  • the information indicating the current number of transmissions of the data signal is, for example, RV (Redundancy Version). If RV is 0, it indicates that the data signal is to be transmitted for the first time, and if RV is 1, it indicates that the data signal is to be retransmitted for the first time.
  • RV Redundancy Version
  • the resource release signal generation unit 114 generates a resource release signal indicating that the resource reserved for the retransmission of the data signal is released when the V2X scheduler 111 cancels the retransmission of the data signal. ..
  • the resource release signal generation unit 114 indicates, for example, that a resource reserved for retransmission of a data signal is used as “0” and that this resource is released as “1”, which is a 1-bit resource. Generate an open signal. That is, the resource release signal generation unit 114 generates a resource release signal indicating whether or not the resource for retransmission is used. However, the resource release signal generation unit 114 may generate the resource release signal only when the resource for retransmission is released.
  • the control signal generation unit 115 generates a control signal including the SCI and the resource release signal, and transmits the control signal via the wireless transmission unit 130 using the resource determined by the V2X scheduler 111.
  • the data signal generation unit 112 and the control signal generation unit 115 transmit the control signal at the beginning of the slot, for example, and transmit the corresponding data signal subsequent to the control signal.
  • the control signal decoding unit 116 receives the control signal via the wireless reception unit 140, and demodulates and decodes the control signal. That is, the control signal decoding unit 116 demodulates and decodes the control signal arranged at the beginning of the slot, for example.
  • the control signal decoded by the control signal decoding unit 116 includes the SCI and the resource release signal. Further, the control signal decoding unit 116 demodulates and decodes the FB signal such as ACK or NACK arranged at the end of the slot.
  • the FB signal is a signal indicating whether the data transmitted by the terminal device 100 has been correctly decoded on the receiving side, and the resource used for returning the FB signal is designated by the control signal transmitted by the control signal generation unit 115. Has been done.
  • the control signal decoding unit 116 When the control signal decoding unit 116 detects that the resource is released as a result of decoding the resource release signal, the control signal decoding unit 116 indicates the current number of times of transmission of the data signal such as RV, which is information included in the SCI. Decrypt the information. After that, the control signal decoding unit 116 can omit SCI decoding from the current number of transmissions to the maximum number of data signal retransmissions. This is because when the resource is released, the retransmission of the data signal is canceled and the SCI corresponding to the data signal is not transmitted.
  • the information about the maximum number of retransmissions of the data signal may be included in the SCI at the time of the first transmission of the data signal, and the SCI at the time of retransmission includes information indicating the current number of transmissions of the data signal. If so, the omission of the above SCI decoding can be realized. That is, it is possible to reduce the size of the SCI. Further, when the control signal decoding unit 116 detects that the resource is used, the control signal decoding unit 116 decodes the SCI as usual and specifies the resource used for transmitting the data signal.
  • the data signal decoding unit 117 receives the data signal via the wireless reception unit 140, and demodulates and decodes the data signal according to the SCI decoded by the control signal decoding unit 116. That is, the data signal decoding unit 117 specifies the resource of the data signal based on the SCI, and demodulates and decodes the data signal received in this resource. Although omitted in FIG. 1, when the decoding of the data signal is successful, the data signal decoding unit 117 transmits an ACK indicating that the data signal is correctly decoded as an FB signal from the wireless transmission unit 130. Further, when the decoding of the data signal fails, the data signal decoding unit 117 may transmit NACK indicating that the data signal was not correctly decoded from the wireless transmission unit 130 as an FB signal.
  • the FB signal detection unit 118 detects an FB signal such as ACK or NACK from the control signal decoded by the control signal decoding unit 116. Then, when the FB signal detection unit 118 detects an ACK indicating that the data signal is correctly decoded on the receiving side, it notifies the V2X scheduler 111 of that fact. Upon receiving this notification, the V2X scheduler 111 cancels the subsequent retransmission of the data signal.
  • an FB signal such as ACK or NACK from the control signal decoded by the control signal decoding unit 116.
  • the resource release signal detection unit 119 detects the resource release signal from the control signal decoded by the control signal decoding unit 116. That is, the resource release signal detection unit 119 detects the resource release signal transmitted from this terminal device when another terminal device cancels the retransmission of the data signal. When the resource release signal detection unit 119 detects the resource release signal, the resource release signal detection unit 119 notifies the V2X scheduler 111 that resources reserved by other terminal devices have been released.
  • the memory 120 includes, for example, a RAM (Random Access Memory) or a ROM (Read Only Memory), and stores information used by the processor 110 to execute processing.
  • a RAM Random Access Memory
  • ROM Read Only Memory
  • the wireless transmission unit 130 performs wireless transmission processing such as D/A (Digital/Analog) conversion and up-conversion on the data signal and the control signal generated by the processor 110, and wirelessly transmits the signals through the antenna.
  • wireless transmission processing such as D/A (Digital/Analog) conversion and up-conversion on the data signal and the control signal generated by the processor 110, and wirelessly transmits the signals through the antenna.
  • the wireless reception unit 140 performs wireless reception processing such as down conversion and A/D (Analog/Digital) conversion on the reception signal wirelessly received via the antenna, and outputs it to the processor 110.
  • the received signal includes a data signal and a control signal.
  • FIG. 2 is a flowchart showing a first operation of terminal device 100 transmitting a data signal.
  • the terminal device 100 releases the resource reserved for the retransmission when the retransmission of the data signal becomes unnecessary.
  • the V2X scheduler 111 determines the resource used for transmitting the data.
  • the resource may be determined, for example, by selecting a resource estimated not to be used by another terminal device from the sensing result in a predetermined sensing period, or may be designated in advance during wireless communication with the base station device. The selected resource may be selected. Further, in determining resources, not only resources for initial transmission of data but also resources for retransmission are determined and secured.
  • the SCI including the information on this resource is generated by the SCI generation unit 113.
  • the control signal generation unit 115 generates a control signal including the SCI, and transmits the control signal in a predetermined resource such as the beginning of the slot (step S101).
  • the control signal includes information such as the maximum number of retransmissions of the data signal, the current number of transmissions of the data signal, resources to be used for returning the FB signal and resources used for transmitting the data signal.
  • the data signal generation unit 112 generates a data signal including transmission data, and the data signal is first transmitted in the resource following the resource of the control signal (step S102).
  • the SCI included in the control signal is decoded, and the data signal is decoded based on the SCI.
  • the FB signal indicating whether the decoding of the data signal has succeeded is transmitted from the terminal device on the receiving side. At this time, the FB signal is transmitted using the resource designated by the SCI.
  • the FB signal transmitted from the terminal device on the receiving side is received by the control signal decoding unit 116 via the wireless reception unit 140. Then, the FB signal is demodulated and decoded by the control signal decoding unit 116, and then detected by the FB signal detection unit 118 (step S103). Further, the FB signal detection unit 118 determines whether or not the detected FB signal is an ACK indicating that the decoding of the data signal has succeeded (step S104).
  • the V2X scheduler 111 cancels the retransmission of the data signal because it is not necessary to retransmit the data signal (step S105). Then, the resource release signal indicating that the resource reserved for the retransmission of the data signal is released is generated by the resource release signal generation unit 114, and the control signal including the resource release signal is transmitted by the control signal generation unit 115. (Step S106).
  • the control signal including the resource release signal is transmitted in a predetermined resource such as the head of the slot, like the control signal including the SCI.
  • another terminal device that receives the resource release signal can transmit the data signal using the released resource. In other words, since the data signal is not retransmitted unnecessarily, useless consumption of resources can be avoided and the utilization efficiency of resources can be improved.
  • step S104 if the result of determination in step S104 is that the FB signal is NACK (No in step S104), since it is necessary to retransmit the data signal, the V2X scheduler 111 decides to continue the retransmission of the data signal. To be done. Then, the control signal including the SCI is transmitted from the control signal generation unit 115 using the resources reserved for the retransmission of the data signal (step S107), and the already transmitted data signal is transmitted from the data signal generation unit 112. It is retransmitted (step S108). Thus, when the ACK for the data signal is not received, the data signal is retransmitted using the resources reserved for retransmission until the number of retransmissions reaches a predetermined maximum number of retransmissions. To be done.
  • FIG. 3 is a flowchart showing a second operation of the terminal device 100 transmitting a data signal.
  • the terminal device 100 detects the resource release signal, the terminal device 100 transmits the data signal using the released resource.
  • the terminal device 100 receives a control signal arranged in a predetermined resource such as the head of a slot, and monitors whether or not a data signal addressed to itself is transmitted. That is, the control signal decoding unit 116 receives the control signal via the wireless reception unit 140 (step S201), and the control signal is demodulated and decoded. If the decoded control signal includes the SCI related to the data signal addressed to the own device, the data signal decoding unit 117 demodulates and decodes the data signal addressed to the own device according to the SCI.
  • the resource release signal detection unit 119 monitors whether or not the resource release signal is detected from the control signal (step S202). As a result, when the resource release signal is not detected (No in step S202), it is understood that there is no resource to be released and another terminal device continues to retransmit the data signal.
  • the V2X scheduler 111 is notified that the resource secured by the other terminal device is released. Then, when there is data to be transmitted, the V2X scheduler 111 decides to use the released resource. Specifically, it is well known that the released resource is used, and the SCI including the information about the resource used for transmitting the data signal is generated by the SCI generating unit 113, and the control signal including the SCI is generated by the control signal. It is transmitted by the unit 115 (step S203).
  • This SCI may be transmitted, for example, using the resource in the middle of the slot in which the resource at the beginning was used for transmitting the resource release signal. That is, the SCI may be transmitted by using the resource at the head of the minislot other than the head minislot among the plurality of minislots forming the slot.
  • the resource used for transmitting such SCI may be designated by the resource release signal.
  • a unique backoff time is set in advance for each terminal, and each terminal starts backoff from the beginning of the minislot.
  • the SCI may be transmitted after waiting for a time.
  • each terminal device senses whether another terminal device has started transmission. Then, the terminal device starts the transmission of the SCI when the transmission by the other terminal device is not started even after the backoff time set in the own device has elapsed.
  • the data signal generation unit 112 generates a data signal including transmission data, and the data signal is transmitted in the resource following the SCI resource (step S204). Accordingly, when another terminal device releases the resource reserved for the retransmission of the data signal, the terminal device 100 can use the released resource to transmit the data signal. In other words, the resource released by canceling the retransmission of the data signal can be effectively used, and the resource utilization efficiency can be improved.
  • each terminal device uses the resources of subchannels #1 and #2 to transmit control signals and data signals.
  • the control signal includes information related to the resource of the data signal, and information indicating that the data signal in slot #0 has been transmitted for the first time and that the maximum number of retransmissions of this data signal is three times. Is included.
  • the control signal for slot #0 includes SCI.
  • the control signal includes information designating a resource to be used for returning the FB signal to the data signal. That is, for example, the control signal of the sub-channel #1 includes information indicating at which frequency and time of the resource allocated to the SFCI the FB signal for the data signal of the sub-channel #1 should be returned.
  • the data signal corresponding to the SCI included in the control signal is transmitted on each of subchannels #1 and #2.
  • the FB signal for this data signal is transmitted using the resources allocated to the SFCI. That is, ACK is transmitted when the decoding of the data signal is successful in the receiving side terminal device, and NACK is transmitted when the decoding of the data signal fails.
  • each terminal device transmits a control signal according to the FB signal in slot #0.
  • the description will be continued assuming that both terminal devices using the sub-channels #1 and #2 received NACK in slot #0 or did not receive the FB signal.
  • each terminal device uses the control signal including SCI as the control signal for slot #1 as in slot #0. To send.
  • This SCI includes information indicating that the data signal in slot #1 is a retransmission of the data signal in slot #0.
  • the data signal initially transmitted in slot #0 is retransmitted in subchannels #1 and #2.
  • the FB signal for the data signal is transmitted using the resource assigned to the SFCI, as in slot #0.
  • each terminal device transmits a control signal according to the FB signal in slot #1.
  • the terminal device that uses subchannel #1 receives ACK in slot #1
  • the terminal device that uses subchannel #2 receives NACK in slot #1 or does not receive an FB signal.
  • the terminal device using subchannel #2 retransmits the data signal transmitted in slot #0, as in slot #1.
  • the terminal device using the sub-channel #1 cancels the retransmission of this data signal because the data signal transmitted in the slots #0 and #1 was correctly decoded by the terminal device on the receiving side.
  • the terminal device transmits a control signal 151 including a resource release signal as a control signal for slot #2.
  • the control signal 151 includes information indicating that the resources of the subchannel #1 after the slot #2 are released, and the control signal 152 is placed at the head of the minislots forming the slot #2. Is included.
  • the terminal device in the wireless communication system monitors the control signal of each slot in order to detect the data signal addressed to itself. Therefore, it is well known that the control signal 151 including the resource release signal is received by all the terminal devices in the vicinity, and the resources of the subchannel #1 and the slots after the slot #2 are released. Then, the terminal device that uses the released resource is known to transmit the control signal 152 including the SCI at the head of the minislot to use the released resource. Then, the data signal 153 is transmitted following the control signal 152. As described above, in slot #2 of subchannel #1, the retransmission of the data signal is canceled and the resource is released, and another terminal device transmits the data signal using the released resource.
  • slot #3 the resource of subchannel #1 is released similarly to slot #2, so that the terminal device that has transmitted control signal 152 and data signal 153 continues to transmit control signal 154 and data signal 155.
  • subchannel #1 resources after slot #2 are released, so that another terminal device can transmit a data signal and effective use of resources can be achieved.
  • the transmitting side terminal device cancels the retransmission of the data signal and transmits the resource release signal. To do. Then, the other terminal device grasps the resource released by the resource release signal and uses the released resource for transmitting the data signal. Therefore, the resource released by canceling the retransmission of the data signal can be effectively used, and the resource utilization efficiency can be improved.
  • the SCI and the resource release signal are generated separately in the first embodiment, they may be generated as one control signal such as generating the SCI including the resource release signal. Needless to say.
  • FIG. 5 is a block diagram showing the configuration of the terminal device 100 according to the second embodiment. 5, parts that are the same as those in FIG. 1 are given the same reference numerals, and descriptions thereof will be omitted.
  • the resource release signal generation unit 114 and the resource release signal detection unit 119 of the terminal device 100 shown in FIG. 1 are deleted, and the V2X scheduler 111, the control signal decoding unit 116, and the FB signal detection unit 118 are added. Instead, it has a V2X scheduler 203, a control signal decoding unit 201, and an FB signal relating unit 202.
  • the control signal decoding unit 201 receives the control signal via the wireless reception unit 140, and demodulates and decodes the control signal. That is, the control signal decoding unit 201 demodulates and decodes the control signal arranged at the beginning of the slot, for example.
  • the control signal decoded by the control signal decoding unit 201 includes SCI. Further, the control signal decoding unit 201 demodulates and decodes the FB signal such as ACK or NACK arranged at the end of the slot.
  • the control signal decoding unit 201 demodulates and decodes not only the FB signal for the data signal transmitted from the terminal device 100 but also the FB signal for the data signal transmitted from another terminal device.
  • the FB signal monitoring unit 202 monitors an FB signal such as ACK or NACK decoded by the control signal decoding unit 201. Then, when the FB signal monitoring unit 202 detects an ACK related to the data signal transmitted from the terminal device 100, the FB signal monitoring unit 202 notifies the V2X scheduler 203 of that fact. Also, when the FB signal monitoring unit 202 detects an ACK related to a data signal transmitted from another terminal device, the FB signal monitoring unit 202 also notifies the V2X scheduler 203 of that fact.
  • the V2X scheduler 203 executes V2X communication scheduling. Specifically, the V2X scheduler 203 determines the resource used for transmitting the data signal, and notifies the determined resource to the data signal generation unit 112 and the SCI generation unit 113. At this time, the V2X scheduler 203 determines not only the resource for initial transmission but also the resource for retransmission for transmission of one data signal. In determining the resource, the V2X scheduler 203 selects a resource that is estimated not to be used by another terminal device, for example, from the result of sensing all frequency bands available for data signal transmission in a predetermined sensing period. Alternatively, a resource designated in advance may be selected during wireless communication with the base station device.
  • the V2X scheduler 203 cancels this data retransmission and reserves the resource reserved for the data retransmission. Open up.
  • the V2X scheduler 203 determines that the resource reserved for the retransmission of this data signal is released. To do. Then, if there is data to be transmitted, the V2X scheduler 203 determines to use the released resource for transmitting the data signal, and to use the released resource, the data signal generation unit 112 and the SCI generation. Notify the unit 113.
  • FIG. 6 is a flowchart showing a second operation of transmitting a data signal using the released resource.
  • the same parts as those in FIG. 6 are identical parts as those in FIG.
  • the terminal device 100 receives a control signal arranged in a predetermined resource such as the head of a slot, and monitors whether or not a data signal addressed to itself is transmitted. That is, the control signal decoding unit 201 receives the control signal via the wireless reception unit 140 (step S301), and the control signal is demodulated and decoded. If the decoded control signal includes the SCI related to the data signal addressed to the own device, the data signal decoding unit 117 demodulates and decodes the data signal addressed to the own device according to the SCI.
  • the FB signal monitoring unit 202 monitors whether or not an ACK for a data signal transmitted from another terminal device is detected (step S302). That is, not only the FB signal for the data signal transmitted from the terminal device 100 but also the FB signal for the data signal transmitted from the other terminal device is monitored, and the data signal transmitted from the other terminal device is correctly received at the receiving side. It is determined whether or not it has been decrypted. As a result, when ACK is not detected (No in step S302), it is understood that there is no resource to be released and another terminal device continues to retransmit the data signal.
  • step S302 when the ACK for the data signal transmitted from the other terminal device is detected (Yes in step S302), it is determined that the resource reserved for the retransmission of the data signal by the other terminal device is released. It Then, the V2X scheduler 203 is notified that the resource is released, and if there is data to be transmitted, the V2X scheduler 203 decides to use the released resource. As a result, the control signal generating unit 115 transmits the control signal including the SCI using the released resource (step S203), and the data signal generating unit 112 transmits the data signal (step S204). Thereby, when another terminal device releases the resource reserved for the retransmission of the data signal, the terminal device 100 can transmit the data signal using the released resource. In other words, the resources released by canceling the retransmission of the data signal can be effectively used, and the resource utilization efficiency can be improved.
  • the first transmission and the retransmission of the data signal are executed in both subchannels #1 and #2 as in the first embodiment.
  • the ACK is transmitted using the resource of the SFCI 211 of slot #1.
  • the ACK is received by all the terminal devices in the vicinity, and it is understood that the resources of slot #2 and later of subchannel #1 are released. That is, the terminal device in the vicinity not only decodes the FB signal addressed to the own device but also decodes the FB signal addressed to another device and recognizes that the resource is released.
  • the terminal device that uses the released resource transmits the control signal 152 including the SCI at the head of the minislot to use the released resource. Then, the data signal 153 is transmitted following the control signal 152. As described above, in slot #2 of subchannel #1, the retransmission of the data signal is canceled and the resource is released, and another terminal device transmits the data signal using the released resource. In this way, the resource of the released slot #2 can be used for another terminal device. Further, the other terminal device can also communicate using the resources of slot #3 and later.
  • each terminal device when the data signal is correctly decoded at the receiving side terminal device, each terminal device detects the ACK transmitted from the receiving side terminal device, and the data signal It is determined that the resources reserved for the retransmission of are released. Then, each terminal device uses it for transmitting the resource data signal determined to be released. Therefore, the resource released by canceling the retransmission of the data signal can be effectively used, and the resource utilization efficiency can be improved. Further, the terminal device on the transmission side does not need to transmit the resource release signal, and an additional signal such as the resource release signal can be unnecessary.
  • the resource release and reuse described in the first and second embodiments can be applied even when the resource allocation pattern is designated by the base station device, for example.
  • a pattern of resources used for initial transmission and retransmission of a data signal for each terminal device is determined as shown in FIG. 8 and is notified from the base station device to each terminal device.
  • resources of times t0 to t4 and frequencies f0 to f3 are allocated to ten terminal devices of UEs #1 to #10, respectively.
  • the resources (t0,f0) and (t1,f2) are allocated to the terminal device UE#1, and the resources (t0,f1) and (t2,f3) are allocated to the terminal device UE#2. ing.
  • Such a resource allocation pattern is previously notified from the base station apparatus to each terminal apparatus. Then, each terminal device uses the resources allocated to itself for the initial transmission and retransmission of the data signal.
  • the terminal device UE#3 uses the resource (t0, f2) allocated for the initial transmission,
  • the resource release signal is transmitted as in the first embodiment.
  • the resource release signal is received by another terminal device, and it is understood that the (t3, f0) resource 301 allocated for retransmission by the terminal device UE#3 is released. Therefore, another terminal device can use this resource 301 to transmit a data signal.
  • each terminal device when each ACK is transmitted/received for the data signal transmitted for the first time, each terminal device is Similar to 2, it can be understood that the resource for retransmission is released. Then, the terminal device, which recognizes that the resource is released, can use the released resource to transmit the data signal.
  • the terminal device UE#10 to which the resource adjacent to the resource 301 is assigned may use the resource 301.
  • the terminal device UE#10 may use the resource 301 to transmit the same data signal as the data signal to be transmitted using the (t3, f1) resource previously assigned to the own device. By doing so, redundancy can be secured and highly reliable communication can be executed.
  • the resource to which the representative terminal device is released is There is a method of allocating to that terminal device.
  • the resource release signal may be transmitted only to the representative terminal device.
  • a terminal device to which a resource of the same time as the resource to be released is allocated uses the released resource according to the priority order.
  • the terminal devices UE#6, #8, and #10 to which resources of the same time as the resource 301 are allocated, may use the resource 301 according to a predetermined priority order.
  • the terminal devices UE#6, #8, and #10 perform sensing for a short time in the order according to their respective priorities, and after confirming that the higher-level terminal device does not use the resource 301, You may use 301.
  • the base station apparatus determines the resource allocation pattern as described above but also when the base station apparatus individually allocates resources to the terminal apparatus, the resource allocation described in the first and second embodiments is not performed. It is possible to apply open and reuse. That is, when the base station device determines the resources for the initial transmission and the retransmission by each terminal device in advance, the base station device performs the retransmission according to the FB signal from the terminal device after the initial transmission. Resources may be released. Then, the base station device may allocate the released resource to another terminal device.

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Abstract

A communication device (100) includes: a scheduler (111, 203) which determines a resource for transmitting and retransmitting a data signal; a transmission unit (112, 130) which transmits the data signal by using the resource determined by the scheduler (111, 203); and a reception unit (116, 140, 201) which receives a feedback signal indicating whether the data signal transmitted by the transmission unit (112, 130) can be decoded. When the feedback signal received by the reception unit (116, 140, 201) indicates that the data signal has been decoded, the scheduler (111, 203) releases the resource for retransmitting the data signal.

Description

通信装置及び無線通信システムCommunication device and wireless communication system
　本発明は、通信装置及び無線通信システムに関する。 The present invention relates to a communication device and a wireless communication system.
　現在のネットワークは、モバイル端末（スマートフォンやフィーチャーホン）のトラフィックがネットワークのリソースの大半を占めている。また、モバイル端末が使うトラフィックは、今後も拡大していく傾向にある。 In the current network, the traffic of mobile terminals (smartphones and feature phones) accounts for most of the network resources. Also, the traffic used by mobile terminals tends to continue to grow.
　一方で、ＩｏＴ（Internet　of　Things）サービス（例えば、交通システム、スマートメータ、装置等の監視システム）の展開に合わせて、多様な要求条件を持つサービスに対応することが求められている。そのため、第５世代移動体通信（５Ｇ又はＮＲ（Ｎｅｗ　Ｒａｄｉｏ））の通信規格では、４Ｇ（第４世代移動体通信）の標準技術（例えば、非特許文献２～１２）に加えて、さらなる高データレート化、大容量化、低遅延化を実現する技術が求められている。なお、第５世代通信規格については、３ＧＰＰの作業部会（例えば、ＴＳＧ－ＲＡＮ　ＷＧ１、ＴＳＧ－ＲＡＮ　ＷＧ２等）で技術検討が進められている（非特許文献１３～３９）。 On the other hand, according to the development of IoT (Internet of Things) services (for example, monitoring systems for transportation systems, smart meters, devices, etc.), it is required to support services with various requirements. Therefore, in addition to the standard technology of 4G (4th generation mobile communication) (for example, non-patent documents 2 to 12), the communication standard of the 5th generation mobile communication (5G or NR (New Radio)) is higher. There is a demand for a technology that realizes a higher data rate, larger capacity, and lower delay. Regarding the fifth-generation communication standard, technical studies are underway in a working group of 3GPP (for example, TSG-RAN WG1, TSG-RAN WG2, etc.) (Non-Patent Documents 13 to 39).
　上述したように、多種多様なサービスに対応するために、５Ｇでは、ｅＭＢＢ（Enhanced　Mobile　BroadBand）、Ｍａｓｓｉｖｅ　ＭＴＣ（Machine　Type　Communications)及びＵＲＬＬＣ（Ultra－Reliable　and　Low　Latency　Communication）に分類される多くのユースケースのサポートが想定されている。 As mentioned above, in order to support a wide variety of services, in 5G, many uses are classified into eMBB (Enhanced Mobile BroadBand), Massive MTC (Machine Type Communications) and URLLC (Ultra-Reliable and Low Latency Communication). Case support is envisioned.
　また、３ＧＰＰの作業部会では、Ｖ２Ｘ（Vehicle　to　Everything）通信についても議論されている。Ｖ２Ｘは、それぞれサイドリンクチャネルを用いる、自動車間通信を示すＶ２Ｖ（Vehicle　to　Vehicle）、自動車と歩行者（Pedestrian）との通信を示すＶ２Ｐ（Vehicle　to　Pedestrian）、自動車と標識等の道路インフラとの通信を示すＶ２Ｉ（Vehicle　to　Infrastructure）、及び自動車とネットワークの通信を示すＶ２Ｎ（Vehicle　to　Network）等の総称である。Ｖ２Ｘに関する規定は、例えば非特許文献１に記載されている。 Also, V2X (Vehicle to Everything) communication is being discussed in the working group of 3GPP. V2X refers to V2V (Vehicle to Vehicle) that indicates inter-vehicle communication, V2P (Vehicle to Pedestrian) that indicates communication between a car and a pedestrian (Pedestrian), and road infrastructure such as a car and a sign that use side link channels. It is a generic term for V2I (Vehicle to Infrastructure) that indicates communication, and V2N (Vehicle to Network) that indicates communication between a vehicle and a network. The regulations regarding V2X are described in Non-Patent Document 1, for example.
　Ｖ２Ｘにおいては、通信の信頼性を向上するために、送信データを複数回繰り返して送信することが検討されている。例えば、各端末装置がデータの初回送信と再送信とに使用するリソースの割当パターンがあらかじめ基地局装置から報知され、各端末装置は、割当パターンに従ってデータの初回送信と再送信とを実行するモードなどが議論されている。 ▽ In V2X, in order to improve the reliability of communication, it is considered to transmit the transmission data multiple times. For example, a mode in which the allocation pattern of the resources used by each terminal device for the initial transmission and the retransmission of the data is notified in advance from the base station device, and each terminal device performs the initial transmission and the retransmission of the data according to the allocation pattern. Have been discussed.
　ところで、５ＧのＶ２Ｘでは、高信頼性が要求されることがあるため、データの再送信の回数を多くすることが考えられる。このため、端末装置がデータを送信する場合には、このデータの再送信のために多くのリソースが確保される。 By the way, in 5G V2X, high reliability may be required, so it is possible to increase the number of data retransmissions. Therefore, when the terminal device transmits data, many resources are reserved for the retransmission of this data.
　しかしながら、受信側において早い段階でデータが正しく復号された場合には、無駄な再送信が発生し、リソースの利用効率が悪いという問題がある。具体的には、例えば１つのデータを４回繰り返し送信するためのリソースが確保されている場合、初回送信されたデータが受信側において正しく復号されると、３回の無駄な再送信が発生する。そして、この３回の再送信のために確保されたリソースが不当に消費されてしまう。 However, if the data is correctly decoded at the receiving side at an early stage, there is a problem that useless retransmission occurs and resource utilization efficiency is poor. Specifically, for example, when a resource for repeatedly transmitting one data four times is secured, if the data transmitted for the first time is correctly decoded at the receiving side, three unnecessary retransmissions occur. .. Then, the resources reserved for the three retransmissions are unreasonably consumed.
　開示の技術は、かかる点に鑑みてなされたものであって、リソースの利用効率を向上することができる通信装置及び無線通信システムを提供することを目的とする。 The disclosed technology has been made in view of the above points, and an object thereof is to provide a communication device and a wireless communication system capable of improving resource utilization efficiency.
　本願が開示する通信装置は、１つの態様において、データ信号を送信及び再送信するためのリソースを決定するスケジューラと、前記スケジューラによって決定されたリソースを使用してデータ信号を送信する送信部と、前記送信部によって送信されたデータ信号の復号の可否を示すフィードバック信号を受信する受信部とを有し、前記スケジューラは、前記受信部によって受信されたフィードバック信号がデータ信号が復号されたことを示す場合に、当該データ信号を再送信するためのリソースを開放する。 In one aspect, a communication device disclosed by the present application, a scheduler that determines a resource for transmitting and retransmitting a data signal, a transmitting unit that transmits a data signal using the resource determined by the scheduler, A receiver for receiving a feedback signal indicating whether or not the data signal transmitted by the transmitter can be decoded, and the scheduler indicates that the feedback signal received by the receiver indicates that the data signal has been decoded. In this case, the resource for retransmitting the data signal is released.
　本願が開示する通信装置及び無線通信システムの１つの態様によれば、リソースの利用効率を向上することができるという効果を奏する。 According to one aspect of the communication device and the wireless communication system disclosed in the present application, it is possible to improve the resource utilization efficiency.
図１は、実施の形態１に係る端末装置の構成を示すブロック図である。FIG. 1 is a block diagram showing the configuration of the terminal device according to the first embodiment. 図２は、実施の形態１に係る端末装置の第１の動作を示すフロー図である。FIG. 2 is a flowchart showing the first operation of the terminal device according to the first embodiment. 図３は、実施の形態１に係る端末装置の第２の動作を示すフロー図である。FIG. 3 is a flowchart showing the second operation of the terminal device according to the first embodiment. 図４は、実施の形態１に係るリソース利用の具体例を示す図である。FIG. 4 is a diagram showing a specific example of resource use according to the first embodiment. 図５は、実施の形態２に係る端末装置の構成を示すブロック図である。FIG. 5 is a block diagram showing the configuration of the terminal device according to the second embodiment. 図６は、実施の形態２に係る第２の端末装置の動作を示すフロー図である。FIG. 6 is a flowchart showing the operation of the second terminal device according to the second embodiment. 図７は、実施の形態２に係るリソース利用の具体例を示す図である。FIG. 7 is a diagram showing a specific example of resource use according to the second embodiment. 図８は、実施の形態３に係るリソース利用の具体例を示す図である。FIG. 8 is a diagram showing a specific example of resource use according to the third embodiment.
　以下、本願が開示する通信装置及び無線通信システムの実施の形態について、図面を参照して詳細に説明する。なお、この実施の形態により本発明が限定されるものではない。 Embodiments of a communication device and a wireless communication system disclosed in the present application will be described below in detail with reference to the drawings. The present invention is not limited to this embodiment.
（実施の形態１）
　実施の形態１に係る無線通信システムは、例えば自動車、歩行者及び道路インフラなどに備えられた複数の端末装置を有する。これらの端末装置は、互いに無線通信可能であるとともに、例えば通信事業者が構築するセルラーシステムの基地局装置からの電波到達範囲内では、基地局装置と無線通信可能である。 (Embodiment 1)
The wireless communication system according to the first embodiment has a plurality of terminal devices provided in, for example, automobiles, pedestrians, road infrastructures, and the like. These terminal devices can wirelessly communicate with each other, and can wirelessly communicate with the base station device within the radio wave reachable range from the base station device of the cellular system constructed by the communication carrier, for example.
　図１は、実施の形態１に係る端末装置１００の構成を示すブロック図である。図１に示す端末装置１００は、プロセッサ１１０、メモリ１２０、無線送信部１３０及び無線受信部１４０を有する。図１においては、端末装置間の無線通信に関する処理部を図示しており、基地局装置との無線通信に関する処理部の図示を省略している。 FIG. 1 is a block diagram showing the configuration of the terminal device 100 according to the first embodiment. The terminal device 100 illustrated in FIG. 1 includes a processor 110, a memory 120, a wireless transmission unit 130, and a wireless reception unit 140. In FIG. 1, a processing unit related to wireless communication between terminal devices is illustrated, and a processing unit related to wireless communication with a base station device is omitted.
　プロセッサ１１０は、例えばＣＰＵ（Central　Processing　Unit）、ＦＰＧＡ（Field　Programmable　Gate　Array）又はＤＳＰ（Digital　Signal　Processor）などを備え、端末装置１００の全体を統括制御する。具体的には、プロセッサ１１０は、Ｖ２Ｘスケジューラ１１１、データ信号生成部１１２、ＳＣＩ（Sidelink　Control　Information）生成部１１３、リソース開放信号生成部１１４、制御信号生成部１１５、制御信号復号部１１６、データ信号復号部１１７、フィードバック（ＦＢ：Feed　Back）信号検出部１１８及びリソース開放信号検出部１１９を有する。 The processor 110 includes, for example, a CPU (Central Processing Unit), an FPGA (Field Programmable Gate Array), a DSP (Digital Signal Processor), and the like, and integrally controls the entire terminal device 100. Specifically, the processor 110 includes a V2X scheduler 111, a data signal generation unit 112, an SCI (Sidelink Control Information) generation unit 113, a resource release signal generation unit 114, a control signal generation unit 115, a control signal decoding unit 116, and a data signal. A decoding unit 117, a feedback (FB: Feed Back) signal detection unit 118, and a resource release signal detection unit 119 are included.
　Ｖ２Ｘスケジューラ１１１は、Ｖ２Ｘ通信のスケジューリングを実行する。具体的には、Ｖ２Ｘスケジューラ１１１は、データの送信に使用するリソースを決定し、決定したリソースをデータ信号生成部１１２及びＳＣＩ生成部１１３へ通知する。このとき、Ｖ２Ｘスケジューラ１１１は、１つのデータの送信に対して、初回送信のためのリソースを決定するだけではなく、再送信のためのリソースを決定する。リソースの決定に際しては、Ｖ２Ｘスケジューラ１１１は、例えば所定のセンシング期間においてデータの送信に利用可能な全周波数帯域をセンシングした結果から、他の端末装置が使用しないと推定されるリソースを選択しても良いし、基地局装置との無線通信時にあらかじめ指定されたリソースを選択しても良い。 The V2X scheduler 111 executes V2X communication scheduling. Specifically, the V2X scheduler 111 determines the resource used for data transmission, and notifies the data signal generation unit 112 and the SCI generation unit 113 of the determined resource. At this time, the V2X scheduler 111 not only determines the resource for the initial transmission but also the resource for the retransmission for the transmission of one data. When deciding the resource, the V2X scheduler 111 selects the resource estimated not to be used by another terminal device, for example, from the result of sensing all the frequency bands available for data transmission in a predetermined sensing period. Alternatively, a resource designated in advance may be selected during wireless communication with the base station device.
　また、Ｖ２Ｘスケジューラ１１１は、送信されたデータに対するＡＣＫがＦＢ信号検出部１１８によって検出された場合、このデータの再送信をキャンセルし、データの再送信のために確保されたリソースを開放する。そして、Ｖ２Ｘスケジューラ１１１は、リソースを開放したことをリソース開放信号生成部１１４へ通知する。 Also, when the FB signal detection unit 118 detects an ACK for the transmitted data, the V2X scheduler 111 cancels this data retransmission and releases the resources reserved for the data retransmission. Then, the V2X scheduler 111 notifies the resource release signal generation unit 114 that the resource has been released.
　さらに、Ｖ２Ｘスケジューラ１１１は、他の端末装置が確保していたリソースが開放されたことがリソース開放信号検出部１１９から通知された場合に送信すべきデータが存在すれば、このデータの送信に開放されたリソースを使用することを決定する。そして、Ｖ２Ｘスケジューラ１１１は、開放されたリソースを使用することをデータ信号生成部１１２及びＳＣＩ生成部１１３へ通知する。 Further, if there is data to be transmitted when the resource release signal detection unit 119 notifies that the resource secured by another terminal device is released, the V2X scheduler 111 releases the data to be transmitted. Decide to use the specified resource. Then, the V2X scheduler 111 notifies the data signal generation unit 112 and the SCI generation unit 113 that the released resource will be used.
　データ信号生成部１１２は、送信データを含むデータ信号を生成し、Ｖ２Ｘスケジューラ１１１が決定したリソースを使用して、データ信号を無線送信部１３０経由で送信する。具体的には、データ信号生成部１１２は、データ信号を初回送信した後も、再送信のためのリソースを使用して同じデータ信号を再送信する。ただし、データ信号生成部１１２は、再送信がキャンセルされた場合には、データ信号を再送信しない。 The data signal generation unit 112 generates a data signal including transmission data, and uses the resource determined by the V2X scheduler 111 to transmit the data signal via the wireless transmission unit 130. Specifically, the data signal generation unit 112 retransmits the same data signal using the resource for retransmission even after the initial transmission of the data signal. However, the data signal generation unit 112 does not retransmit the data signal when the retransmission is canceled.
　ＳＣＩ生成部１１３は、Ｖ２Ｘスケジューラ１１１が決定したリソースに関する制御情報を含むＳＣＩを生成する。具体的には、ＳＣＩ生成部１１３は、データ信号の最大の再送信回数、データ信号の現在の送信回数、ＡＣＫ又はＮＡＣＫなどのＦＢ信号の返信に使用すべきリソース及びデータ信号の送信に使用されるリソースなどの情報を含むＳＣＩを生成する。なお、データ信号の現在の送信回数を示す情報としては、例えばＲＶ（Redundancy　Version）などがある。ＲＶが０であれば、データ信号が初回送信されるものであることを示し、ＲＶが１であれば、データ信号が１回目に再送信されるものであることを示す。 The SCI generation unit 113 generates an SCI including control information regarding the resource determined by the V2X scheduler 111. Specifically, the SCI generation unit 113 is used for the maximum number of retransmissions of the data signal, the current number of transmissions of the data signal, the resources to be used for returning the FB signal such as ACK or NACK, and the data signal. SCI including information such as resources to be generated is generated. The information indicating the current number of transmissions of the data signal is, for example, RV (Redundancy Version). If RV is 0, it indicates that the data signal is to be transmitted for the first time, and if RV is 1, it indicates that the data signal is to be retransmitted for the first time.
　リソース開放信号生成部１１４は、Ｖ２Ｘスケジューラ１１１によってデータ信号の再送信がキャンセルされた場合に、このデータ信号の再送信のために確保されたリソースが開放されることを示すリソース開放信号を生成する。リソース開放信号生成部１１４は、例えばデータ信号の再送信のために確保されたリソースが使用されることを「０」で示し、このリソースが開放されることを「１」で示す１ビットのリソース開放信号を生成する。つまり、リソース開放信号生成部１１４は、再送信のためのリソースの使用の有無を示すリソース開放信号を生成する。ただし、リソース開放信号生成部１１４は、再送信のためのリソースが開放される場合にのみリソース開放信号を生成しても良い。 The resource release signal generation unit 114 generates a resource release signal indicating that the resource reserved for the retransmission of the data signal is released when the V2X scheduler 111 cancels the retransmission of the data signal. .. The resource release signal generation unit 114 indicates, for example, that a resource reserved for retransmission of a data signal is used as “0” and that this resource is released as “1”, which is a 1-bit resource. Generate an open signal. That is, the resource release signal generation unit 114 generates a resource release signal indicating whether or not the resource for retransmission is used. However, the resource release signal generation unit 114 may generate the resource release signal only when the resource for retransmission is released.
　制御信号生成部１１５は、ＳＣＩ及びリソース開放信号を含む制御信号を生成し、Ｖ２Ｘスケジューラ１１１が決定したリソースを使用して、制御信号を無線送信部１３０経由で送信する。なお、データ信号生成部１１２及び制御信号生成部１１５は、例えばスロットの先頭で制御信号を送信し、制御信号に続けて対応するデータ信号を送信する。 The control signal generation unit 115 generates a control signal including the SCI and the resource release signal, and transmits the control signal via the wireless transmission unit 130 using the resource determined by the V2X scheduler 111. The data signal generation unit 112 and the control signal generation unit 115 transmit the control signal at the beginning of the slot, for example, and transmit the corresponding data signal subsequent to the control signal.
　制御信号復号部１１６は、無線受信部１４０を経由して制御信号を受信し、制御信号の復調及び復号を実行する。すなわち、制御信号復号部１１６は、例えばスロットの先頭に配置された制御信号を復調及び復号する。制御信号復号部１１６が復号する制御信号には、ＳＣＩ及びリソース開放信号が含まれる。また、制御信号復号部１１６は、例えばスロットの末尾に配置されたＡＣＫ又はＮＡＣＫなどのＦＢ信号を復調及び復号する。ＦＢ信号は、端末装置１００が送信したデータが受信側において正しく復号されたか否かを示す信号であり、ＦＢ信号の返信に使用されるリソースは、制御信号生成部１１５が送信する制御信号によって指定されている。 The control signal decoding unit 116 receives the control signal via the wireless reception unit 140, and demodulates and decodes the control signal. That is, the control signal decoding unit 116 demodulates and decodes the control signal arranged at the beginning of the slot, for example. The control signal decoded by the control signal decoding unit 116 includes the SCI and the resource release signal. Further, the control signal decoding unit 116 demodulates and decodes the FB signal such as ACK or NACK arranged at the end of the slot. The FB signal is a signal indicating whether the data transmitted by the terminal device 100 has been correctly decoded on the receiving side, and the resource used for returning the FB signal is designated by the control signal transmitted by the control signal generation unit 115. Has been done.
　なお、制御信号復号部１１６は、リソース開放信号を復号した結果、リソースが開放されることを検知した場合には、ＳＣＩに含まれる情報であってＲＶなどのデータ信号の現在の送信回数を示す情報を復号する。その後、制御信号復号部１１６は、現在の送信回数からデータ信号の最大の再送信回数までの間は、ＳＣＩの復号を省略することができる。これは、リソースが開放される場合には、データ信号の再送信がキャンセルされるため、データ信号に対応するＳＣＩが送信されないからである。ここで、データ信号の最大の再送信回数に関する情報は、データ信号の初回送信時にＳＣＩに含まれていれば良く、再送信時のＳＣＩには、データ信号の現在の送信回数を示す情報が含まれていれば、上記のＳＣＩの復号の省略を実現することができる。すなわち、ＳＣＩのサイズを小さくすることが可能である。また、制御信号復号部１１６は、リソースが使用されることを検知した場合には、通常通りＳＣＩを復号し、データ信号の送信に使用されるリソースを特定する。 When the control signal decoding unit 116 detects that the resource is released as a result of decoding the resource release signal, the control signal decoding unit 116 indicates the current number of times of transmission of the data signal such as RV, which is information included in the SCI. Decrypt the information. After that, the control signal decoding unit 116 can omit SCI decoding from the current number of transmissions to the maximum number of data signal retransmissions. This is because when the resource is released, the retransmission of the data signal is canceled and the SCI corresponding to the data signal is not transmitted. Here, the information about the maximum number of retransmissions of the data signal may be included in the SCI at the time of the first transmission of the data signal, and the SCI at the time of retransmission includes information indicating the current number of transmissions of the data signal. If so, the omission of the above SCI decoding can be realized. That is, it is possible to reduce the size of the SCI. Further, when the control signal decoding unit 116 detects that the resource is used, the control signal decoding unit 116 decodes the SCI as usual and specifies the resource used for transmitting the data signal.
　データ信号復号部１１７は、無線受信部１４０を経由してデータ信号を受信し、制御信号復号部１１６によって復号されたＳＣＩに従って、データ信号の復調及び復号を実行する。すなわち、データ信号復号部１１７は、ＳＣＩに基づいてデータ信号のリソースを特定し、このリソースにおいて受信されたデータ信号を復調及び復号する。なお、図１においては省略したが、データ信号復号部１１７は、データ信号の復号が成功した場合に、データ信号が正しく復号されたことを示すＡＣＫをＦＢ信号として無線送信部１３０から送信する。また、データ信号復号部１１７は、データ信号の復号が失敗した場合には、データ信号が正しく復号されなかったことを示すＮＡＣＫをＦＢ信号として無線送信部１３０から送信しても良い。 The data signal decoding unit 117 receives the data signal via the wireless reception unit 140, and demodulates and decodes the data signal according to the SCI decoded by the control signal decoding unit 116. That is, the data signal decoding unit 117 specifies the resource of the data signal based on the SCI, and demodulates and decodes the data signal received in this resource. Although omitted in FIG. 1, when the decoding of the data signal is successful, the data signal decoding unit 117 transmits an ACK indicating that the data signal is correctly decoded as an FB signal from the wireless transmission unit 130. Further, when the decoding of the data signal fails, the data signal decoding unit 117 may transmit NACK indicating that the data signal was not correctly decoded from the wireless transmission unit 130 as an FB signal.
　ＦＢ信号検出部１１８は、制御信号復号部１１６によって復号された制御信号からＡＣＫ又はＮＡＣＫなどのＦＢ信号を検出する。そして、ＦＢ信号検出部１１８は、受信側においてデータ信号が正しく復号されたことを示すＡＣＫを検出した場合に、その旨をＶ２Ｘスケジューラ１１１へ通知する。この通知を受け、Ｖ２Ｘスケジューラ１１１は、以降のデータ信号の再送信をキャンセルする。 The FB signal detection unit 118 detects an FB signal such as ACK or NACK from the control signal decoded by the control signal decoding unit 116. Then, when the FB signal detection unit 118 detects an ACK indicating that the data signal is correctly decoded on the receiving side, it notifies the V2X scheduler 111 of that fact. Upon receiving this notification, the V2X scheduler 111 cancels the subsequent retransmission of the data signal.
　リソース開放信号検出部１１９は、制御信号復号部１１６によって復号された制御信号からリソース開放信号を検出する。すなわち、リソース開放信号検出部１１９は、他の端末装置がデータ信号の再送信をキャンセルした場合に、この端末装置から送信されるリソース開放信号を検出する。そして、リソース開放信号検出部１１９は、リソース開放信号を検出すると、他の端末装置が確保していたリソースが開放されたことをＶ２Ｘスケジューラ１１１へ通知する。 The resource release signal detection unit 119 detects the resource release signal from the control signal decoded by the control signal decoding unit 116. That is, the resource release signal detection unit 119 detects the resource release signal transmitted from this terminal device when another terminal device cancels the retransmission of the data signal. When the resource release signal detection unit 119 detects the resource release signal, the resource release signal detection unit 119 notifies the V2X scheduler 111 that resources reserved by other terminal devices have been released.
　メモリ１２０は、例えばＲＡＭ（Random　Access　Memory）又はＲＯＭ（Read　Only　Memory）などを備え、プロセッサ１１０が処理を実行するために使用する情報を記憶する。 The memory 120 includes, for example, a RAM (Random Access Memory) or a ROM (Read Only Memory), and stores information used by the processor 110 to execute processing.
　無線送信部１３０は、プロセッサ１１０によって生成されるデータ信号及び制御信号に対して、例えばＤ／Ａ（Digital/Analog）変換及びアップコンバートなどの無線送信処理を施し、アンテナを介して無線送信する。 The wireless transmission unit 130 performs wireless transmission processing such as D/A (Digital/Analog) conversion and up-conversion on the data signal and the control signal generated by the processor 110, and wirelessly transmits the signals through the antenna.
　無線受信部１４０は、アンテナを介して無線受信した受信信号に対して、例えばダウンコンバート及びＡ／Ｄ（Analog/Digital）変換などの無線受信処理を施し、プロセッサ１１０へ出力する。受信信号には、データ信号及び制御信号が含まれる。 The wireless reception unit 140 performs wireless reception processing such as down conversion and A/D (Analog/Digital) conversion on the reception signal wirelessly received via the antenna, and outputs it to the processor 110. The received signal includes a data signal and a control signal.
　次いで、上記のように構成された端末装置１００の動作について説明する。図２は、データ信号を送信する端末装置１００の第１の動作を示すフロー図である。第１の動作においては、端末装置１００は、データ信号の再送信が不要となった場合に、再送信のために確保されたリソースを開放する。 Next, the operation of the terminal device 100 configured as above will be described. FIG. 2 is a flowchart showing a first operation of terminal device 100 transmitting a data signal. In the first operation, the terminal device 100 releases the resource reserved for the retransmission when the retransmission of the data signal becomes unnecessary.
　端末装置１００において送信すべきデータが発生した場合、Ｖ２Ｘスケジューラ１１１によって、データの送信に使用されるリソースが決定される。リソースの決定は、例えば所定のセンシング期間におけるセンシング結果から、他の端末装置が使用しないと推定されるリソースが選択されることにより行われても良いし、基地局装置との無線通信時にあらかじめ指定されたリソースが選択されることにより行われても良い。また、リソースの決定においては、データの初回送信のためのリソースのみではなく、再送信のためのリソースも決定されて確保される。 When data to be transmitted is generated in the terminal device 100, the V2X scheduler 111 determines the resource used for transmitting the data. The resource may be determined, for example, by selecting a resource estimated not to be used by another terminal device from the sensing result in a predetermined sensing period, or may be designated in advance during wireless communication with the base station device. The selected resource may be selected. Further, in determining resources, not only resources for initial transmission of data but also resources for retransmission are determined and secured.
　データ送信のためのリソースが決定されると、このリソースに関する情報を含むＳＣＩがＳＣＩ生成部１１３によって生成される。そして、制御信号生成部１１５によって、ＳＣＩを含む制御信号が生成され、例えばスロットの先頭などの所定のリソースにおいて制御信号が送信される（ステップＳ１０１）。この制御信号には、データ信号の最大の再送信回数、データ信号の現在の送信回数、ＦＢ信号の返信に使用すべきリソース及びデータ信号の送信に使用されるリソースなどの情報が含まれる。 When the resource for data transmission is determined, the SCI including the information on this resource is generated by the SCI generation unit 113. Then, the control signal generation unit 115 generates a control signal including the SCI, and transmits the control signal in a predetermined resource such as the beginning of the slot (step S101). The control signal includes information such as the maximum number of retransmissions of the data signal, the current number of transmissions of the data signal, resources to be used for returning the FB signal and resources used for transmitting the data signal.
　そして、データ信号生成部１１２によって、送信データを含むデータ信号が生成され、制御信号のリソースに続くリソースにおいてデータ信号が初回送信される（ステップＳ１０２）。受信側の端末装置においては、制御信号に含まれるＳＣＩが復号され、ＳＣＩに基づいてデータ信号が復号される。そして、データ信号の復号が成功したか否かを示すＦＢ信号が受信側の端末装置から送信される。このとき、ＦＢ信号は、ＳＣＩによって指定されるリソースを用いて送信される。 Then, the data signal generation unit 112 generates a data signal including transmission data, and the data signal is first transmitted in the resource following the resource of the control signal (step S102). In the terminal device on the receiving side, the SCI included in the control signal is decoded, and the data signal is decoded based on the SCI. Then, the FB signal indicating whether the decoding of the data signal has succeeded is transmitted from the terminal device on the receiving side. At this time, the FB signal is transmitted using the resource designated by the SCI.
　受信側の端末装置から送信されたＦＢ信号は、無線受信部１４０を介して制御信号復号部１１６によって受信される。そして、ＦＢ信号は、制御信号復号部１１６によって復調及び復号された後、ＦＢ信号検出部１１８によって検出される（ステップＳ１０３）。また、検出されたＦＢ信号がデータ信号の復号が成功したことを示すＡＣＫであるか否かがＦＢ信号検出部１１８によって判定される（ステップＳ１０４）。 The FB signal transmitted from the terminal device on the receiving side is received by the control signal decoding unit 116 via the wireless reception unit 140. Then, the FB signal is demodulated and decoded by the control signal decoding unit 116, and then detected by the FB signal detection unit 118 (step S103). Further, the FB signal detection unit 118 determines whether or not the detected FB signal is an ACK indicating that the decoding of the data signal has succeeded (step S104).
　この判定の結果、ＦＢ信号がＡＣＫである場合には（ステップＳ１０４Ｙｅｓ）、データ信号の再送信が不要であることから、Ｖ２Ｘスケジューラ１１１によってデータ信号の再送信がキャンセルされる（ステップＳ１０５）。そして、データ信号の再送信のために確保されたリソースが開放されることを示すリソース開放信号がリソース開放信号生成部１１４によって生成され、リソース開放信号を含む制御信号が制御信号生成部１１５によって送信される（ステップＳ１０６）。リソース開放信号を含む制御信号は、ＳＣＩを含む制御信号と同様に、例えばスロットの先頭などの所定のリソースにおいて送信される。これにより、リソース開放信号を受信する他の端末装置は、開放されたリソースを使用してデータ信号を送信することが可能となる。換言すれば、データ信号が不要に再送信されることがないため、リソースの無駄な消費を回避することができ、リソースの利用効率を向上することができる。 If the result of this determination is that the FB signal is an ACK (Yes in step S104), the V2X scheduler 111 cancels the retransmission of the data signal because it is not necessary to retransmit the data signal (step S105). Then, the resource release signal indicating that the resource reserved for the retransmission of the data signal is released is generated by the resource release signal generation unit 114, and the control signal including the resource release signal is transmitted by the control signal generation unit 115. (Step S106). The control signal including the resource release signal is transmitted in a predetermined resource such as the head of the slot, like the control signal including the SCI. As a result, another terminal device that receives the resource release signal can transmit the data signal using the released resource. In other words, since the data signal is not retransmitted unnecessarily, useless consumption of resources can be avoided and the utilization efficiency of resources can be improved.
　一方、ステップＳ１０４の判定の結果、ＦＢ信号がＮＡＣＫである場合には（ステップＳ１０４Ｎｏ）、データ信号の再送信が必要であることから、Ｖ２Ｘスケジューラ１１１によってデータ信号の再送信を継続することが決定される。そして、データ信号の再送信のために確保されたリソースを用いて、ＳＣＩを含む制御信号が制御信号生成部１１５から送信され（ステップＳ１０７）、既に送信されたデータ信号がデータ信号生成部１１２から再送信される（ステップＳ１０８）。このように、データ信号に対するＡＣＫが受信されない場合には、再送信の回数があらかじめ定められた最大の再送信回数に達するまで、再送信のために確保されたリソースを用いてデータ信号が再送信される。 On the other hand, if the result of determination in step S104 is that the FB signal is NACK (No in step S104), since it is necessary to retransmit the data signal, the V2X scheduler 111 decides to continue the retransmission of the data signal. To be done. Then, the control signal including the SCI is transmitted from the control signal generation unit 115 using the resources reserved for the retransmission of the data signal (step S107), and the already transmitted data signal is transmitted from the data signal generation unit 112. It is retransmitted (step S108). Thus, when the ACK for the data signal is not received, the data signal is retransmitted using the resources reserved for retransmission until the number of retransmissions reaches a predetermined maximum number of retransmissions. To be done.
　図３は、データ信号を送信する端末装置１００の第２の動作を示すフロー図である。第２の動作においては、端末装置１００は、リソース開放信号を検出した場合に、開放されたリソースを使用してデータ信号を送信する。 FIG. 3 is a flowchart showing a second operation of the terminal device 100 transmitting a data signal. In the second operation, when the terminal device 100 detects the resource release signal, the terminal device 100 transmits the data signal using the released resource.
　端末装置１００は、例えばスロットの先頭などの所定のリソースに配置される制御信号を受信し、自装置宛てのデータ信号が送信されたか否かを監視している。すなわち、無線受信部１４０を介して制御信号復号部１１６によって制御信号が受信され（ステップＳ２０１）、制御信号が復調及び復号される。復号された制御信号に、自装置宛てのデータ信号に関するＳＣＩが含まれていれば、データ信号復号部１１７によって、ＳＣＩに従って自装置宛てのデータ信号が復調及び復号される。 The terminal device 100 receives a control signal arranged in a predetermined resource such as the head of a slot, and monitors whether or not a data signal addressed to itself is transmitted. That is, the control signal decoding unit 116 receives the control signal via the wireless reception unit 140 (step S201), and the control signal is demodulated and decoded. If the decoded control signal includes the SCI related to the data signal addressed to the own device, the data signal decoding unit 117 demodulates and decodes the data signal addressed to the own device according to the SCI.
　また、リソース開放信号検出部１１９によって、制御信号からリソース開放信号が検出されるか否かが監視される（ステップＳ２０２）。この結果、リソース開放信号が検出されない場合には（ステップＳ２０２Ｎｏ）、開放されるリソースはなく、他の端末装置がデータ信号の再送信を継続することが把握される。 Further, the resource release signal detection unit 119 monitors whether or not the resource release signal is detected from the control signal (step S202). As a result, when the resource release signal is not detected (No in step S202), it is understood that there is no resource to be released and another terminal device continues to retransmit the data signal.
　一方、復号された制御信号からリソース開放信号が検出された場合は（ステップＳ２０２Ｙｅｓ）、他の端末装置が確保していたリソースが開放されたことがＶ２Ｘスケジューラ１１１へ通知される。そして、送信すべきデータがある場合には、Ｖ２Ｘスケジューラ１１１によって、開放されたリソースを使用することが決定される。具体的には、開放されたリソースを使用することを周知するとともに、データ信号の送信に使用されるリソースに関する情報を含むＳＣＩがＳＣＩ生成部１１３によって生成され、ＳＣＩを含む制御信号が制御信号生成部１１５によって送信される（ステップＳ２０３）。 On the other hand, when the resource release signal is detected from the decoded control signal (Yes in step S202), the V2X scheduler 111 is notified that the resource secured by the other terminal device is released. Then, when there is data to be transmitted, the V2X scheduler 111 decides to use the released resource. Specifically, it is well known that the released resource is used, and the SCI including the information about the resource used for transmitting the data signal is generated by the SCI generating unit 113, and the control signal including the SCI is generated by the control signal. It is transmitted by the unit 115 (step S203).
　このＳＣＩは、例えば先頭のリソースがリソース開放信号の送信に使用されたスロットの途中のリソースを使用して送信されても良い。すなわち、スロットを構成する複数のミニスロットのうち、先頭のミニスロットを除くミニスロットの先頭のリソースを使用してＳＣＩが送信されても良い。このようなＳＣＩの送信に使用されるリソースは、リソース開放信号によって指定されても良い。 This SCI may be transmitted, for example, using the resource in the middle of the slot in which the resource at the beginning was used for transmitting the resource release signal. That is, the SCI may be transmitted by using the resource at the head of the minislot other than the head minislot among the plurality of minislots forming the slot. The resource used for transmitting such SCI may be designated by the resource release signal.
　また、開放されたリソースを複数の端末装置が同時に使用する衝突を回避するために、あらかじめ端末装置ごとに固有のバックオフ時間が設定されており、各端末装置は、ミニスロットの先頭からバックオフ時間待機した後にＳＣＩを送信するようにしても良い。バックオフ時間においては、各端末装置は、他の端末装置が送信を開始したか否かをセンシングする。そして、端末装置は、自装置に設定されたバックオフ時間が経過しても他の端末装置による送信が開始されなかった場合に、ＳＣＩの送信を開始する。 Also, in order to avoid a collision where multiple terminals use the released resources at the same time, a unique backoff time is set in advance for each terminal, and each terminal starts backoff from the beginning of the minislot. The SCI may be transmitted after waiting for a time. During the backoff time, each terminal device senses whether another terminal device has started transmission. Then, the terminal device starts the transmission of the SCI when the transmission by the other terminal device is not started even after the backoff time set in the own device has elapsed.
　そして、データ信号生成部１１２によって、送信データを含むデータ信号が生成され、ＳＣＩのリソースに続くリソースにおいてデータ信号が送信される（ステップＳ２０４）。これにより、他の端末装置がデータ信号の再送信のために確保されたリソースを開放した場合には、端末装置１００は、開放されたリソースを使用してデータ信号を送信することができる。換言すれば、データ信号の再送信のキャンセルにより開放されたリソースを有効に使用することができ、リソースの利用効率を向上することができる。 Then, the data signal generation unit 112 generates a data signal including transmission data, and the data signal is transmitted in the resource following the SCI resource (step S204). Accordingly, when another terminal device releases the resource reserved for the retransmission of the data signal, the terminal device 100 can use the released resource to transmit the data signal. In other words, the resource released by canceling the retransmission of the data signal can be effectively used, and the resource utilization efficiency can be improved.
　次に、実施の形態１に係るリソース利用の具体例について、図４を参照しながら説明する。ここでは、データ信号の最大の再送回数が３回に設定されているものとし、サブチャネル＃１、＃２において異なる端末装置がそれぞれデータ信号を送信するものとする。また、図４に示すように各スロットの先頭にはＳＣＩを含む制御信号が配置され、制御信号に続いてデータ信号が配置される。そして、スロットの末尾は、ＦＢ信号を含むＳＦＣＩ（Sidelink　Feedback　Control　Information）の送信に使用される。 Next, a specific example of resource use according to the first embodiment will be described with reference to FIG. Here, it is assumed that the maximum number of times the data signal is retransmitted is set to 3, and different terminal devices respectively transmit data signals in subchannels #1 and #2. Further, as shown in FIG. 4, a control signal including SCI is arranged at the head of each slot, and a data signal is arranged following the control signal. Then, the end of the slot is used for transmitting SFCI (Sidelink Feedback Control Information) including the FB signal.
　スロット＃０においては、各端末装置は、それぞれサブチャネル＃１、＃２のリソースを使用して制御信号及びデータ信号を送信する。制御信号には、データ信号のリソースに関する情報が含まれるとともに、スロット＃０のデータ信号が初回送信されたものであることや、このデータ信号の最大の再送回数が３回であることを示す情報が含まれる。要するに、スロット＃０の制御信号にはＳＣＩが含まれる。また、制御信号には、データ信号に対するＦＢ信号の返信に使用すべきリソースを指定する情報が含まれる。すなわち、例えばサブチャネル＃１のデータ信号に対するＦＢ信号を、ＳＦＣＩに割り当てられたリソースのどの周波数及び時間において返信すべきであるかを示す情報が、サブチャネル＃１の制御信号に含まれる。 In slot #0, each terminal device uses the resources of subchannels #1 and #2 to transmit control signals and data signals. The control signal includes information related to the resource of the data signal, and information indicating that the data signal in slot #0 has been transmitted for the first time and that the maximum number of retransmissions of this data signal is three times. Is included. In short, the control signal for slot #0 includes SCI. Further, the control signal includes information designating a resource to be used for returning the FB signal to the data signal. That is, for example, the control signal of the sub-channel #1 includes information indicating at which frequency and time of the resource allocated to the SFCI the FB signal for the data signal of the sub-channel #1 should be returned.
　スロット＃０の制御信号に続いて、制御信号に含まれるＳＣＩに対応するデータ信号がそれぞれのサブチャネル＃１、＃２において送信される。データ信号が受信側の端末装置によって受信されると、このデータ信号に対するＦＢ信号がＳＦＣＩに割り当てられたリソースを使用して送信される。すなわち、受信側の端末装置においてデータ信号の復号が成功した場合にはＡＣＫが送信され、データ信号の復号が失敗した場合にはＮＡＣＫが送信される。 Subsequent to the control signal of slot #0, the data signal corresponding to the SCI included in the control signal is transmitted on each of subchannels #1 and #2. When the data signal is received by the terminal device on the receiving side, the FB signal for this data signal is transmitted using the resources allocated to the SFCI. That is, ACK is transmitted when the decoding of the data signal is successful in the receiving side terminal device, and NACK is transmitted when the decoding of the data signal fails.
　スロット＃１においては、各端末装置は、スロット＃０におけるＦＢ信号に従って、制御信号を送信する。ここでは、サブチャネル＃１、＃２を使用する双方の端末装置が、スロット＃０においてＮＡＣＫを受信したか、ＦＢ信号を受信しなかったものとして説明を続ける。この場合、スロット＃０で送信されたデータ信号が受信側の端末装置において正しく復号されていないため、各端末装置は、スロット＃１の制御信号として、スロット＃０と同様にＳＣＩを含む制御信号を送信する。このＳＣＩは、スロット＃１のデータ信号がスロット＃０のデータ信号を再送信するものであることを示す情報を含む。 In slot #1, each terminal device transmits a control signal according to the FB signal in slot #0. Here, the description will be continued assuming that both terminal devices using the sub-channels #1 and #2 received NACK in slot #0 or did not receive the FB signal. In this case, since the data signal transmitted in slot #0 is not correctly decoded by the terminal device on the receiving side, each terminal device uses the control signal including SCI as the control signal for slot #1 as in slot #0. To send. This SCI includes information indicating that the data signal in slot #1 is a retransmission of the data signal in slot #0.
　スロット＃１の制御信号に続いて、スロット＃０で初回送信されたデータ信号がそれぞれのサブチャネル＃１、＃２において再送信される。データ信号が受信側の端末装置によって受信されると、スロット＃０と同様に、データ信号に対するＦＢ信号がＳＦＣＩに割り当てられたリソースを使用して送信される。 Following the control signal of slot #1, the data signal initially transmitted in slot #0 is retransmitted in subchannels #1 and #2. When the data signal is received by the terminal device on the receiving side, the FB signal for the data signal is transmitted using the resource assigned to the SFCI, as in slot #0.
　スロット＃２においては、各端末装置は、スロット＃１におけるＦＢ信号に従って、制御信号を送信する。ここでは、サブチャネル＃１を使用する端末装置が、スロット＃１においてＡＣＫを受信し、サブチャネル＃２を使用する端末装置が、スロット＃１においてＮＡＣＫを受信したか、ＦＢ信号を受信しなかったものとして説明を続ける。この場合、サブチャネル＃２を使用する端末装置は、スロット＃１と同様に、スロット＃０で送信されたデータ信号の再送信を実行する。一方、サブチャネル＃１を使用する端末装置は、スロット＃０、＃１で送信したデータ信号が受信側の端末装置において正しく復号されたため、このデータ信号の再送信をキャンセルする。そして、端末装置は、スロット＃２の制御信号として、リソース開放信号を含む制御信号１５１を送信する。この制御信号１５１には、サブチャネル＃１のスロット＃２以降のリソースが開放されることを示す情報が含まれるとともに、スロット＃２を構成するミニスロットの先頭に制御信号１５２が配置されることを示す情報が含まれる。 In slot #2, each terminal device transmits a control signal according to the FB signal in slot #1. Here, the terminal device that uses subchannel #1 receives ACK in slot #1, and the terminal device that uses subchannel #2 receives NACK in slot #1 or does not receive an FB signal. The explanation will continue. In this case, the terminal device using subchannel #2 retransmits the data signal transmitted in slot #0, as in slot #1. On the other hand, the terminal device using the sub-channel #1 cancels the retransmission of this data signal because the data signal transmitted in the slots #0 and #1 was correctly decoded by the terminal device on the receiving side. Then, the terminal device transmits a control signal 151 including a resource release signal as a control signal for slot #2. The control signal 151 includes information indicating that the resources of the subchannel #1 after the slot #2 are released, and the control signal 152 is placed at the head of the minislots forming the slot #2. Is included.
　無線通信システム内の端末装置は、自装置宛てのデータ信号を検出するために、各スロットの制御信号を監視する。このため、リソース開放信号を含む制御信号１５１が付近のすべての端末装置によって受信され、サブチャネル＃１のスロット＃２以降のリソースが開放されることが周知される。そして、開放されたリソースを使用する端末装置は、ミニスロットの先頭において、ＳＣＩを含む制御信号１５２を送信して開放されたリソースを使用することを周知する。そして、制御信号１５２に続いてデータ信号１５３が送信される。このように、サブチャネル＃１のスロット＃２においては、データ信号の再送信がキャンセルされてリソースが開放され、他の端末装置が開放されたリソースを使用してデータ信号を送信する。 The terminal device in the wireless communication system monitors the control signal of each slot in order to detect the data signal addressed to itself. Therefore, it is well known that the control signal 151 including the resource release signal is received by all the terminal devices in the vicinity, and the resources of the subchannel #1 and the slots after the slot #2 are released. Then, the terminal device that uses the released resource is known to transmit the control signal 152 including the SCI at the head of the minislot to use the released resource. Then, the data signal 153 is transmitted following the control signal 152. As described above, in slot #2 of subchannel #1, the retransmission of the data signal is canceled and the resource is released, and another terminal device transmits the data signal using the released resource.
　スロット＃３においては、スロット＃２と同様にサブチャネル＃１のリソースが開放されているため、制御信号１５２及びデータ信号１５３を送信した端末装置が引き続き制御信号１５４及びデータ信号１５５を送信する。このように、サブチャネル＃１においては、スロット＃２以降のリソースが開放されるため、他の端末装置がデータ信号を送信することができ、リソースの有効利用を図ることができる。 In slot #3, the resource of subchannel #1 is released similarly to slot #2, so that the terminal device that has transmitted control signal 152 and data signal 153 continues to transmit control signal 154 and data signal 155. In this way, in subchannel #1, resources after slot #2 are released, so that another terminal device can transmit a data signal and effective use of resources can be achieved.
　以上のように、本実施の形態によれば、受信側の端末装置においてデータ信号が正しく復号された場合には、送信側の端末装置がデータ信号の再送信をキャンセルしてリソース開放信号を送信する。そして、他の端末装置は、リソース開放信号によって開放されたリソースを把握し、開放されたリソースをデータ信号の送信に使用する。このため、データ信号の再送信のキャンセルにより開放されたリソースを有効に使用することができ、リソースの利用効率を向上することができる。 As described above, according to the present embodiment, when the data signal is correctly decoded at the receiving side terminal device, the transmitting side terminal device cancels the retransmission of the data signal and transmits the resource release signal. To do. Then, the other terminal device grasps the resource released by the resource release signal and uses the released resource for transmitting the data signal. Therefore, the resource released by canceling the retransmission of the data signal can be effectively used, and the resource utilization efficiency can be improved.
　なお、上記実施の形態１においては、ＳＣＩとリソース開放信号が別々に生成されるものとしたが、例えばリソース開放信号を含むＳＣＩを生成するなどのように１つの制御信号として生成されて良いことはいうまでもない。 Although the SCI and the resource release signal are generated separately in the first embodiment, they may be generated as one control signal such as generating the SCI including the resource release signal. Needless to say.
（実施の形態２）
　実施の形態２の特徴は、各端末装置がＦＢ信号を監視することによって、リソースの開放を把握する点である。 (Embodiment 2)
The feature of the second embodiment is that each terminal device recognizes the release of the resource by monitoring the FB signal.
　図５は、実施の形態２に係る端末装置１００の構成を示すブロック図である。図５において、図１と同じ部分には同じ符号を付し、その説明を省略する。図５に示す端末装置１００は、図１に示す端末装置１００のリソース開放信号生成部１１４及びリソース開放信号検出部１１９を削除し、Ｖ２Ｘスケジューラ１１１、制御信号復号部１１６及びＦＢ信号検出部１１８に代えて、Ｖ２Ｘスケジューラ２０３、制御信号復号部２０１及びＦＢ信号関し部２０２を有する。 FIG. 5 is a block diagram showing the configuration of the terminal device 100 according to the second embodiment. 5, parts that are the same as those in FIG. 1 are given the same reference numerals, and descriptions thereof will be omitted. In the terminal device 100 shown in FIG. 5, the resource release signal generation unit 114 and the resource release signal detection unit 119 of the terminal device 100 shown in FIG. 1 are deleted, and the V2X scheduler 111, the control signal decoding unit 116, and the FB signal detection unit 118 are added. Instead, it has a V2X scheduler 203, a control signal decoding unit 201, and an FB signal relating unit 202.
　制御信号復号部２０１は、無線受信部１４０を経由して制御信号を受信し、制御信号の復調及び復号を実行する。すなわち、制御信号復号部２０１は、例えばスロットの先頭に配置された制御信号を復調及び復号する。制御信号復号部２０１が復号する制御信号には、ＳＣＩ含まれる。また、制御信号復号部２０１は、例えばスロットの末尾に配置されたＡＣＫ又はＮＡＣＫなどのＦＢ信号を復調及び復号する。制御信号復号部２０１は、端末装置１００から送信されたデータ信号に対するＦＢ信号のみではなく、他の端末装置から送信されたデータ信号に対するＦＢ信号も復調及び復号する。 The control signal decoding unit 201 receives the control signal via the wireless reception unit 140, and demodulates and decodes the control signal. That is, the control signal decoding unit 201 demodulates and decodes the control signal arranged at the beginning of the slot, for example. The control signal decoded by the control signal decoding unit 201 includes SCI. Further, the control signal decoding unit 201 demodulates and decodes the FB signal such as ACK or NACK arranged at the end of the slot. The control signal decoding unit 201 demodulates and decodes not only the FB signal for the data signal transmitted from the terminal device 100 but also the FB signal for the data signal transmitted from another terminal device.
　ＦＢ信号監視部２０２は、制御信号復号部２０１によって復号されるＡＣＫ又はＮＡＣＫなどのＦＢ信号を監視する。そして、ＦＢ信号監視部２０２は、端末装置１００から送信されたデータ信号に関するＡＣＫを検出した場合に、その旨をＶ２Ｘスケジューラ２０３へ通知する。また、ＦＢ信号監視部２０２は、他の端末装置から送信されたデータ信号に関するＡＣＫを検出した場合にも、その旨をＶ２Ｘスケジューラ２０３へ通知する。 The FB signal monitoring unit 202 monitors an FB signal such as ACK or NACK decoded by the control signal decoding unit 201. Then, when the FB signal monitoring unit 202 detects an ACK related to the data signal transmitted from the terminal device 100, the FB signal monitoring unit 202 notifies the V2X scheduler 203 of that fact. Also, when the FB signal monitoring unit 202 detects an ACK related to a data signal transmitted from another terminal device, the FB signal monitoring unit 202 also notifies the V2X scheduler 203 of that fact.
　Ｖ２Ｘスケジューラ２０３は、Ｖ２Ｘ通信のスケジューリングを実行する。具体的には、Ｖ２Ｘスケジューラ２０３は、データ信号の送信に使用するリソースを決定し、決定したリソースをデータ信号生成部１１２及びＳＣＩ生成部１１３へ通知する。このとき、Ｖ２Ｘスケジューラ２０３は、１つのデータ信号の送信に対して、初回送信のためのリソースを決定するだけではなく、再送信のためのリソースを決定する。リソースの決定に際しては、Ｖ２Ｘスケジューラ２０３は、例えば所定のセンシング期間においてデータ信号の送信に利用可能な全周波数帯域をセンシングした結果から、他の端末装置が使用しないと推定されるリソースを選択しても良いし、基地局装置との無線通信時にあらかじめ指定されたリソースを選択しても良い。 The V2X scheduler 203 executes V2X communication scheduling. Specifically, the V2X scheduler 203 determines the resource used for transmitting the data signal, and notifies the determined resource to the data signal generation unit 112 and the SCI generation unit 113. At this time, the V2X scheduler 203 determines not only the resource for initial transmission but also the resource for retransmission for transmission of one data signal. In determining the resource, the V2X scheduler 203 selects a resource that is estimated not to be used by another terminal device, for example, from the result of sensing all frequency bands available for data signal transmission in a predetermined sensing period. Alternatively, a resource designated in advance may be selected during wireless communication with the base station device.
　また、Ｖ２Ｘスケジューラ２０３は、端末装置１００から送信されたデータ信号に対するＡＣＫがＦＢ信号監視部２０２によって検出された場合、このデータの再送信をキャンセルし、データの再送信のために確保されたリソースを開放する。 Further, when the FB signal monitoring unit 202 detects an ACK for the data signal transmitted from the terminal device 100, the V2X scheduler 203 cancels this data retransmission and reserves the resource reserved for the data retransmission. Open up.
　さらに、Ｖ２Ｘスケジューラ２０３は、他の端末装置から送信されたデータ信号に対するＡＣＫがＦＢ信号監視部２０２によって検出された場合、このデータ信号の再送信のために確保されたリソースが開放されると判断する。そして、Ｖ２Ｘスケジューラ２０３は、送信すべきデータが存在すれば、開放されるリソースをデータ信号の送信に使用することを決定し、開放されるリソースを使用することをデータ信号生成部１１２及びＳＣＩ生成部１１３へ通知する。 Furthermore, when the FB signal monitoring unit 202 detects an ACK for a data signal transmitted from another terminal device, the V2X scheduler 203 determines that the resource reserved for the retransmission of this data signal is released. To do. Then, if there is data to be transmitted, the V2X scheduler 203 determines to use the released resource for transmitting the data signal, and to use the released resource, the data signal generation unit 112 and the SCI generation. Notify the unit 113.
　次いで、上記のように構成された端末装置１００の動作について説明する。実施の形態２においては、再送信のために確保されたリソースを開放する第１の動作は実施の形態１と同様である。ただし、実施の形態２においては、第１の動作において、リソース開放信号は送信されない。図６は、開放されたリソースを使用してデータ信号を送信する第２の動作を示すフロー図である。図６において図３と同じ部分には同じ符号を付し、その詳しい説明を省略する。 Next, the operation of the terminal device 100 configured as above will be described. In the second embodiment, the first operation of releasing the resource reserved for retransmission is the same as that of the first embodiment. However, in the second embodiment, the resource release signal is not transmitted in the first operation. FIG. 6 is a flowchart showing a second operation of transmitting a data signal using the released resource. In FIG. 6, the same parts as those in FIG.
　端末装置１００は、例えばスロットの先頭などの所定のリソースに配置される制御信号を受信し、自装置宛てのデータ信号が送信されたか否かを監視している。すなわち、無線受信部１４０を介して制御信号復号部２０１によって制御信号が受信され（ステップＳ３０１）、制御信号が復調及び復号される。復号された制御信号に、自装置宛てのデータ信号に関するＳＣＩが含まれていれば、データ信号復号部１１７によって、ＳＣＩに従って自装置宛てのデータ信号が復調及び復号される。 The terminal device 100 receives a control signal arranged in a predetermined resource such as the head of a slot, and monitors whether or not a data signal addressed to itself is transmitted. That is, the control signal decoding unit 201 receives the control signal via the wireless reception unit 140 (step S301), and the control signal is demodulated and decoded. If the decoded control signal includes the SCI related to the data signal addressed to the own device, the data signal decoding unit 117 demodulates and decodes the data signal addressed to the own device according to the SCI.
　また、ＦＢ信号監視部２０２によって、他の端末装置から送信されたデータ信号に対するＡＣＫが検出されるか否かが監視される（ステップＳ３０２）。すなわち、端末装置１００から送信されたデータ信号に対するＦＢ信号のみではなく、他の端末装置から送信されたデータ信号に対するＦＢ信号が監視され、他の端末装置から送信されたデータ信号が受信側において正しく復号されたか否かが判定される。この結果、ＡＣＫが検出されない場合には（ステップＳ３０２Ｎｏ）、開放されるリソースはなく、他の端末装置がデータ信号の再送信を継続することが把握される。 Also, the FB signal monitoring unit 202 monitors whether or not an ACK for a data signal transmitted from another terminal device is detected (step S302). That is, not only the FB signal for the data signal transmitted from the terminal device 100 but also the FB signal for the data signal transmitted from the other terminal device is monitored, and the data signal transmitted from the other terminal device is correctly received at the receiving side. It is determined whether or not it has been decrypted. As a result, when ACK is not detected (No in step S302), it is understood that there is no resource to be released and another terminal device continues to retransmit the data signal.
　一方、他の端末装置から送信されたデータ信号に対するＡＣＫが検出された場合は（ステップＳ３０２Ｙｅｓ）、他の端末装置がデータ信号の再送信のために確保していたリソースが開放されると判断される。そして、リソースが開放されることがＶ２Ｘスケジューラ２０３へ通知され、送信すべきデータがある場合には、Ｖ２Ｘスケジューラ２０３によって、開放されるリソースを使用することが決定される。この結果、開放されるリソースを使用して、制御信号生成部１１５によってＳＣＩを含む制御信号が送信され（ステップＳ２０３）、データ信号生成部１１２によってデータ信号が送信される（ステップＳ２０４）。これにより、他の端末装置がデータ信号の再送信のために確保されたリソースを開放する場合には、端末装置１００は、開放されるリソースを使用してデータ信号を送信することができる。換言すれば、データ信号の再送信のキャンセルにより開放されるリソースを有効に使用することができ、リソースの利用効率を向上することができる。 On the other hand, when the ACK for the data signal transmitted from the other terminal device is detected (Yes in step S302), it is determined that the resource reserved for the retransmission of the data signal by the other terminal device is released. It Then, the V2X scheduler 203 is notified that the resource is released, and if there is data to be transmitted, the V2X scheduler 203 decides to use the released resource. As a result, the control signal generating unit 115 transmits the control signal including the SCI using the released resource (step S203), and the data signal generating unit 112 transmits the data signal (step S204). Thereby, when another terminal device releases the resource reserved for the retransmission of the data signal, the terminal device 100 can transmit the data signal using the released resource. In other words, the resources released by canceling the retransmission of the data signal can be effectively used, and the resource utilization efficiency can be improved.
　次に、実施の形態２に係るリソース利用の具体例について、図７を参照しながら説明する。ここでは、データ信号の最大の再送回数が３回に設定されているものとし、サブチャネル＃１、＃２において異なる端末装置がそれぞれデータ信号を送信するものとする。また、図７に示すように各スロットの先頭にはＳＣＩを含む制御信号が配置され、制御信号に続いてデータ信号が配置される。そして、スロットの末尾は、ＦＢ信号を含むＳＦＣＩの送信に使用される。なお、図７において、図４と同じ部分には同じ符号を付す。 Next, a specific example of resource use according to the second embodiment will be described with reference to FIG. Here, it is assumed that the maximum number of times the data signal is retransmitted is set to 3, and different terminal devices respectively transmit data signals in subchannels #1 and #2. Further, as shown in FIG. 7, a control signal including SCI is arranged at the head of each slot, and a data signal is arranged following the control signal. Then, the end of the slot is used for transmitting the SFCI including the FB signal. 7, the same parts as those in FIG. 4 are designated by the same reference numerals.
　スロット＃０、＃１においては、実施の形態１と同様にサブチャネル＃１、＃２のいずれにおいても、データ信号の初回送信及び再送信が実行される。そして、サブチャネル＃１のリソースを使用して送信されたデータ信号が受信側の端末装置において正しく復号されると、スロット＃１のＳＦＣＩ２１１のリソースを使用して、ＡＣＫが送信される。ＡＣＫは、付近の端末装置すべてによって受信され、サブチャネル＃１のスロット＃２以降のリソースが開放されることが把握される。すなわち、付近の端末装置は、自装置宛てのＦＢ信号を復号するのみではなく、他装置宛てのＦＢ信号を復号し、リソースが開放されることを把握する。 In slots #0 and #1, the first transmission and the retransmission of the data signal are executed in both subchannels #1 and #2 as in the first embodiment. Then, when the data signal transmitted using the resource of subchannel #1 is correctly decoded by the terminal device on the receiving side, the ACK is transmitted using the resource of the SFCI 211 of slot #1. The ACK is received by all the terminal devices in the vicinity, and it is understood that the resources of slot #2 and later of subchannel #1 are released. That is, the terminal device in the vicinity not only decodes the FB signal addressed to the own device but also decodes the FB signal addressed to another device and recognizes that the resource is released.
　そこで、開放されるリソースを使用する端末装置は、ミニスロットの先頭において、ＳＣＩを含む制御信号１５２を送信して開放されたリソースを使用することを周知する。そして、制御信号１５２に続いてデータ信号１５３が送信される。このように、サブチャネル＃１のスロット＃２においては、データ信号の再送信がキャンセルされてリソースが開放され、他の端末装置が開放されたリソースを使用してデータ信号を送信する。このように、開放されるスロット＃２のリソースは、他の端末装置の使用に供することができる。また、他の端末装置は、スロット＃３以降のリソースを使用して通信することも可能である。 Therefore, it is well known that the terminal device that uses the released resource transmits the control signal 152 including the SCI at the head of the minislot to use the released resource. Then, the data signal 153 is transmitted following the control signal 152. As described above, in slot #2 of subchannel #1, the retransmission of the data signal is canceled and the resource is released, and another terminal device transmits the data signal using the released resource. In this way, the resource of the released slot #2 can be used for another terminal device. Further, the other terminal device can also communicate using the resources of slot #3 and later.
　スロット＃３においては、スロット＃２と同様にサブチャネル＃１のリソースが開放されているため、制御信号１５２及びデータ信号１５３を送信した端末装置が引き続き制御信号１５４及びデータ信号１５５を送信する。このように、サブチャネル＃１においては、スロット＃２以降のリソースが開放されるため、他の端末装置がデータ信号を送信することができ、リソースの有効利用を図ることができる。 In slot #3, since the resource of subchannel #1 is released similarly to slot #2, the terminal device that has transmitted control signal 152 and data signal 153 continues to transmit control signal 154 and data signal 155. In this way, in subchannel #1, resources after slot #2 are released, so that another terminal device can transmit a data signal and effective use of resources can be achieved.
　以上のように、本実施の形態によれば、受信側の端末装置においてデータ信号が正しく復号された場合には、受信側の端末装置から送信されるＡＣＫを各端末装置が検出し、データ信号の再送信のために確保されたリソースが開放されると判断する。そして、各端末装置は、開放されると判断したリソースデータ信号の送信に使用する。このため、データ信号の再送信のキャンセルにより開放されるリソースを有効に使用することができ、リソースの利用効率を向上することができる。また、送信側の端末装置がリソース開放信号を送信する必要がなく、リソース開放信号などの追加の信号を不要とすることができる。 As described above, according to the present embodiment, when the data signal is correctly decoded at the receiving side terminal device, each terminal device detects the ACK transmitted from the receiving side terminal device, and the data signal It is determined that the resources reserved for the retransmission of are released. Then, each terminal device uses it for transmitting the resource data signal determined to be released. Therefore, the resource released by canceling the retransmission of the data signal can be effectively used, and the resource utilization efficiency can be improved. Further, the terminal device on the transmission side does not need to transmit the resource release signal, and an additional signal such as the resource release signal can be unnecessary.
　なお、上記実施の形態１、２において説明したリソースの開放及び再利用は、例えば基地局装置によってリソース割り当てのパターンが指定されている場合にも適用することができる。具体的に、例えば端末装置ごとのデータ信号の初回送信と再送信に使用するリソースのパターンが図８のように決定され、基地局装置から各端末装置へ通知される場合を考える。図８においては、ＵＥ＃１～＃１０の１０個の端末装置に時間ｔ０～ｔ４及び周波数ｆ０～ｆ３のリソースがそれぞれ割り当てられている。 Note that the resource release and reuse described in the first and second embodiments can be applied even when the resource allocation pattern is designated by the base station device, for example. Specifically, consider a case where, for example, a pattern of resources used for initial transmission and retransmission of a data signal for each terminal device is determined as shown in FIG. 8 and is notified from the base station device to each terminal device. In FIG. 8, resources of times t0 to t4 and frequencies f0 to f3 are allocated to ten terminal devices of UEs #1 to #10, respectively.
　例えば端末装置ＵＥ＃１には、（ｔ０，ｆ０）及び（ｔ１，ｆ２）のリソースが割り当てられ、端末装置ＵＥ＃２には、（ｔ０，ｆ１）及び（ｔ２，ｆ３）のリソースが割り当てられている。このようなリソースの割り当てパターンは、あらかじめ基地局装置から各端末装置へ通知されている。そして、各端末装置は、自装置に割り当てられたリソースをデータ信号の初回送信と再送信に使用する。 For example, the resources (t0,f0) and (t1,f2) are allocated to the terminal device UE#1, and the resources (t0,f1) and (t2,f3) are allocated to the terminal device UE#2. ing. Such a resource allocation pattern is previously notified from the base station apparatus to each terminal apparatus. Then, each terminal device uses the resources allocated to itself for the initial transmission and retransmission of the data signal.
　ここで、例えば端末装置ＵＥ＃３が送信すべきデータを有していない場合には、端末装置ＵＥ＃３は、初回送信のために割り当てられた（ｔ０，ｆ２）のリソースを使用して、実施の形態１と同様にリソース開放信号を送信する。リソース開放信号は、他の端末装置によって受信され、端末装置ＵＥ＃３による再送信のために割り当てられた（ｔ３，ｆ０）のリソース３０１が開放されることが把握される。そこで、他の端末装置は、このリソース３０１を使用して、データ信号を送信することができる。 Here, for example, when the terminal device UE#3 does not have data to be transmitted, the terminal device UE#3 uses the resource (t0, f2) allocated for the initial transmission, The resource release signal is transmitted as in the first embodiment. The resource release signal is received by another terminal device, and it is understood that the (t3, f0) resource 301 allocated for retransmission by the terminal device UE#3 is released. Therefore, another terminal device can use this resource 301 to transmit a data signal.
　また、例えば各端末装置に割り当てられたリソースの末尾においてＦＢ信号が送受信されるようにすれば、初回送信されたデータ信号に対してＡＣＫが送受信された場合に、各端末装置は、実施の形態２と同様に、再送信のためのリソースが開放されることを把握することができる。そして、リソースが開放されることを把握した端末装置は、開放されるリソースを使用して、データ信号を送信することができる。 Further, for example, if the FB signal is transmitted/received at the end of the resources allocated to each terminal device, when each ACK is transmitted/received for the data signal transmitted for the first time, each terminal device is Similar to 2, it can be understood that the resource for retransmission is released. Then, the terminal device, which recognizes that the resource is released, can use the released resource to transmit the data signal.
　開放されるリソースを使用する端末装置の決定方法には、例えば以下のようなものがある。すなわち、まず第１に、リソースの割り当てパターンでリソースが割り当てられていない端末装置が優先的に開放されたリソースを使用する方法がある。つまり、図８のリソースがあらかじめ割り当てられていない例えば端末装置ＵＥ＃１１がリソース３０１を使用してデータ信号を送信することが可能である。この場合、端末装置ＵＥ＃１１は、例えばリソース３０１の先頭において短時間のセンシングを実行し、他の端末装置とのリソース使用の衝突を回避しても良い。 The following are examples of methods for determining the terminal device that uses the released resource. That is, first, there is a method in which a terminal device to which a resource is not allocated according to a resource allocation pattern preferentially uses the released resource. That is, for example, the terminal device UE#11 to which the resource of FIG. 8 is not assigned in advance can use the resource 301 to transmit the data signal. In this case, the terminal device UE#11 may perform sensing for a short time at the beginning of the resource 301, for example, to avoid collision of resource usage with other terminal devices.
　第２に、開放されるリソースに周波数方向で隣接するリソースを割り当てられた端末装置が優先的に開放されたリソースを使用する方法がある。図８に示した例では、リソース３０１に隣接するリソースを割り当てられた端末装置ＵＥ＃１０がリソース３０１を使用しても良い。このとき、端末装置ＵＥ＃１０は、自装置にあらかじめ割り当てられた（ｔ３，ｆ１）のリソースを使用して送信するデータ信号と同一のデータ信号をリソース３０１を使用して送信しても良い。こうすることにより、冗長性を確保して信頼性の高い通信を実行することができる。 Secondly, there is a method in which a terminal device to which resources to be released are allocated adjacent resources in the frequency direction uses the resources released preferentially. In the example illustrated in FIG. 8, the terminal device UE#10 to which the resource adjacent to the resource 301 is assigned may use the resource 301. At this time, the terminal device UE#10 may use the resource 301 to transmit the same data signal as the data signal to be transmitted using the (t3, f1) resource previously assigned to the own device. By doing so, redundancy can be secured and highly reliable communication can be executed.
　第３に、互いに通信可能な端末装置のうちいずれかの端末装置が例えばクラスタヘッダのような代表の端末装置に選択される無線通信システムにおいては、この代表の端末装置が開放されるリソースをいずれかの端末装置に割り当てる方法がある。この場合、リソース開放信号は、代表の端末装置のみへ送信されるようにしても良い。開放されるリソースを代表の端末装置が割り当てる場合には、リソース使用の衝突を回避することができる。 Thirdly, in a wireless communication system in which any one of the terminal devices capable of communicating with each other is selected as a representative terminal device such as a cluster header, the resource to which the representative terminal device is released is There is a method of allocating to that terminal device. In this case, the resource release signal may be transmitted only to the representative terminal device. When the representative terminal device allocates the resource to be released, it is possible to avoid resource use conflict.
　第４に、開放されるリソースと同じ時間のリソースを割り当てられた端末装置が優先順位に従って開放されたリソースを使用する方法がある。図８に示した例では、リソース３０１と同じ時間のリソースを割り当てられた端末装置ＵＥ＃６、＃８、＃１０が所定の優先順位に従ってリソース３０１を使用しても良い。このとき、端末装置ＵＥ＃６、＃８、＃１０は、それぞれ優先順位に従った順序で短時間のセンシングを実行し、上位の端末装置がリソース３０１を使用しないことを確認してから、リソース３０１を使用しても良い。 Fourth, there is a method in which a terminal device to which a resource of the same time as the resource to be released is allocated uses the released resource according to the priority order. In the example shown in FIG. 8, the terminal devices UE#6, #8, and #10, to which resources of the same time as the resource 301 are allocated, may use the resource 301 according to a predetermined priority order. At this time, the terminal devices UE#6, #8, and #10 perform sensing for a short time in the order according to their respective priorities, and after confirming that the higher-level terminal device does not use the resource 301, You may use 301.
　なお、上記のように基地局装置がリソース割り当てのパターンを決定する場合のみではなく、基地局装置が個別に端末装置にリソースを割り当てる場合にも、上記実施の形態１、２において説明したリソースの開放及び再利用を適用することが可能である。すなわち、基地局装置が各端末装置による初回送信及び再送信のためのリソースをあらかじめ決定している場合、基地局装置は、初回送信後の端末装置からのＦＢ信号に応じて、再送信のためのリソースを開放しても良い。そして、基地局装置は、開放したリソースを他の端末装置に割り当てても良い。 Note that not only when the base station apparatus determines the resource allocation pattern as described above but also when the base station apparatus individually allocates resources to the terminal apparatus, the resource allocation described in the first and second embodiments is not performed. It is possible to apply open and reuse. That is, when the base station device determines the resources for the initial transmission and the retransmission by each terminal device in advance, the base station device performs the retransmission according to the FB signal from the terminal device after the initial transmission. Resources may be released. Then, the base station device may allocate the released resource to another terminal device.
　１１０　プロセッサ
　１１１、２０３　Ｖ２Ｘスケジューラ
　１１２　データ信号生成部
　１１３　ＳＣＩ生成部
　１１４　リソース開放信号生成部
　１１５　制御信号生成部
　１１６、２０１　制御信号復号部
　１１７　データ信号復号部
　１１８　ＦＢ信号検出部
　１１９　リソース開放信号検出部
　１２０　メモリ
　１３０　無線送信部
　１４０　無線受信部
　２０２　ＦＢ信号監視部 110 processor 111, 203 V2X scheduler 112 data signal generation unit 113 SCI generation unit 114 resource release signal generation unit 115 control signal generation unit 116, 201 control signal decoding unit 117 data signal decoding unit 118 FB signal detection unit 119 resource release signal detection unit 120 memory 130 wireless transmission unit 140 wireless reception unit 202 FB signal monitoring unit

Claims (7)

  1. 　データ信号を送信及び再送信するためのリソースを決定するスケジューラと、
    　前記スケジューラによって決定されたリソースを使用してデータ信号を送信する送信部と、
    　前記送信部によって送信されたデータ信号の復号の可否を示すフィードバック信号を受信する受信部とを有し、
    　前記スケジューラは、
    　前記受信部によって受信されたフィードバック信号がデータ信号が復号されたことを示す場合に、当該データ信号を再送信するためのリソースを開放する
    　ことを特徴とする通信装置。     A scheduler for determining resources for transmitting and retransmitting data signals,
    A transmitter that transmits a data signal using the resources determined by the scheduler;
    A receiver for receiving a feedback signal indicating whether the data signal transmitted by the transmitter can be decoded,
    The scheduler is
    A communication device, which releases resources for retransmitting the data signal when the feedback signal received by the receiving unit indicates that the data signal is decoded.
  2. 　前記スケジューラによってリソースが開放された場合に、リソース開放信号を生成する生成部をさらに有し、
    　前記送信部は、
    　前記生成部によって生成されたリソース開放信号を送信する
    　ことを特徴とする請求項１記載の通信装置。     When a resource is released by the scheduler, the scheduler further includes a generation unit that generates a resource release signal,
    The transmitter is
    The communication device according to claim 1, wherein the resource release signal generated by the generation unit is transmitted.
  3. 　前記スケジューラは、
    　複数の通信装置に対してあらかじめ割り当てられたリソースの配置を示す割り当てパターンに従ってデータ信号を送信及び再送信するためのリソースを決定し、送信すべきデータ信号が存在しない場合に、データ信号を再送信するためのリソースを開放する
    　ことを特徴とする請求項１記載の通信装置。     The scheduler is
    A resource for transmitting and retransmitting a data signal is determined according to an allocation pattern indicating allocation of resources pre-allocated to a plurality of communication devices, and the data signal is retransmitted when there is no data signal to be transmitted. The communication device according to claim 1, wherein a resource for doing so is released.
  4. 　他の通信装置によるデータ信号の再送信に割り当てられたリソースが開放されることを検出する検出部と、
    　前記検出部によってリソースが開放されることが検出された場合に、開放されるリソースを自装置のデータ信号の送信に割り当てるスケジューラと、
    　前記スケジューラによって割り当てられたリソースを使用してデータ信号を送信する送信部と
    　を有することを特徴とする通信装置。     A detection unit that detects that the resource allocated to the retransmission of the data signal by another communication device is released,
    When it is detected that the resource is released by the detection unit, a scheduler that allocates the released resource to the transmission of the data signal of its own device,
    A transmission unit that transmits a data signal using the resource allocated by the scheduler.
  5. 　前記他の通信装置から送信されるリソース開放信号を受信する受信部をさらに有し、
    　前記検出部は、
    　前記受信部によってリソース開放信号が受信された場合に、リソースが開放されることを検出する
    　ことを特徴とする請求項４記載の通信装置。     Further comprising a receiving unit for receiving a resource release signal transmitted from the other communication device,
    The detection unit,
    The communication device according to claim 4, wherein when the resource release signal is received by the receiving unit, it is detected that the resource is released.
  6. 　前記他の通信装置から送信されたデータ信号の復号の可否を示すフィードバック信号を受信する受信部をさらに有し、
    　前記検出部は、
    　前記受信部によってデータ信号が復号されたことを示すフィードバック信号が受信された場合に、リソースが開放されることを検出する
    　ことを特徴とする請求項４記載の通信装置。     Further comprising a receiver for receiving a feedback signal indicating whether or not the data signal transmitted from the other communication device can be decoded,
    The detection unit,
    The communication device according to claim 4, wherein when the feedback signal indicating that the data signal has been decoded is received by the receiving unit, it is detected that the resource is released.
  7. 　第１の通信装置と第２の通信装置とを有する無線通信システムであって、
    　前記第１の通信装置は、
    　データ信号を送信及び再送信するためのリソースを決定する第１のスケジューラと、
    　前記第１のスケジューラによって決定されたリソースを使用してデータ信号を送信する第１の送信部と、
    　前記第１の送信部によって送信されたデータ信号の復号の可否を示すフィードバック信号を受信する受信部とを有し、
    　前記第１のスケジューラは、
    　前記受信部によって受信されたフィードバック信号がデータ信号が復号されたことを示す場合に、当該データ信号を再送信するためのリソースを開放し、
    　前記第２の通信装置は、
    　前記第１の通信装置によるデータ信号の再送信に割り当てられたリソースが開放されることを検出する検出部と、
    　前記検出部によってリソースが開放されることが検出された場合に、開放されるリソースを自装置のデータ信号の送信に割り当てる第２のスケジューラと、
    　前記第２のスケジューラによって割り当てられたリソースを使用してデータ信号を送信する第２の送信部とを有する
    　ことを特徴とする無線通信システム。     A wireless communication system having a first communication device and a second communication device,
    The first communication device is
    A first scheduler that determines resources for transmitting and retransmitting data signals;
    A first transmitter for transmitting a data signal using the resources determined by the first scheduler;
    A receiver for receiving a feedback signal indicating whether the data signal transmitted by the first transmitter can be decoded,
    The first scheduler is
    Releasing a resource for retransmitting the data signal when the feedback signal received by the receiver indicates that the data signal has been decoded,
    The second communication device is
    A detection unit that detects that the resource allocated to the retransmission of the data signal by the first communication device is released;
    A second scheduler that allocates the released resource to the transmission of the data signal of the own device when the detecting unit detects that the resource is released;
    A second transmission unit for transmitting a data signal using the resource allocated by the second scheduler.
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