CN111867080A

CN111867080A - Downlink channel indication method and device

Info

Publication number: CN111867080A
Application number: CN201910364600.9A
Authority: CN
Inventors: 刘晓峰
Original assignee: China Academy of Information and Communications Technology CAICT
Current assignee: China Academy of Information and Communications Technology CAICT
Priority date: 2019-04-30
Filing date: 2019-04-30
Publication date: 2020-10-30
Anticipated expiration: 2039-04-30
Also published as: CN111867080B; WO2020220561A1

Abstract

The application discloses a downlink channel indication method and equipment, wherein the method comprises the following steps: monitoring a frequency band on a carrier wave of an unauthorized frequency band; selecting a target carrier and a target frequency band according to the monitoring result, and sending the PDCCH or the PDSCH; and sending indication information for identifying the target carrier and the target frequency band. The application also comprises a network device and a system applying the method. The scheme of the application solves the problems of system resource waste and low working efficiency.

Description

Downlink channel indication method and device

Technical Field

The present application relates to the field of mobile communications technologies, and in particular, to a downlink channel indication method and device.

Background

5G has become the latest generation technology of mobile communication, and various extended applications based on 5G will be developed rapidly. An important application of 5G is the use of unlicensed frequency bands. The unlicensed band needs to consider coexistence usage of various wireless systems with respect to the licensed band. Typical applications in unlicensed frequency bands are Wifi, LTE-based LAA technology, etc. In order to make the various technologies coexist harmoniously, a forced Listen Before Transmit (LBT) technology is used for the unlicensed band, that is, data transmission can be performed only when the current channel is sensed to be unoccupied.

The problem caused by the mechanism is that some data cannot be sent at a determined position, especially when the design based on the 5G NR is independently deployed in an unauthorized frequency band, because the feedback information cannot be sent in a fixed time, when the service of the unauthorized frequency band is busy, the performance of the system based on the NR is greatly reduced.

According to the use of 5G NR in an unlicensed frequency band, the design of the system needs to support various scenes. When the usable bandwidth of the unlicensed frequency band is relatively large, for example, exceeding 100MHz, in order to use such an excessively large bandwidth, both the network-side device and the terminal-side device need to perform listening.

For a network side device, when the device operates on a plurality of listening bandwidths, the channel busy degree at the data transmission time cannot be predicted. For the terminal device, because the sending bandwidth to be used by the network device is uncertain, all available bandwidths need to be monitored, which causes workload, low efficiency and resource waste.

Disclosure of Invention

The application provides a downlink channel indication method and equipment, which solve the problems of system resource waste and low working efficiency.

The embodiment of the application provides a downlink channel indication method, which is used for network equipment and comprises the following steps:

Monitoring a frequency band on a carrier wave of an unauthorized frequency band;

selecting a target carrier and a target frequency band according to the monitoring result, and sending the PDCCH or the PDSCH;

and sending indication information for identifying the target carrier and the target frequency band.

Preferably, the target frequency bands are one or more, and the minimum bandwidth is 20 MHz; the number of the target carriers is one or more; at least one target frequency band is included on each target carrier.

Preferably, the length of the indication information is preset or configured by signaling.

Preferably, the indication information is transmitted in a common search space or in a dedicated search space.

Preferably, at least a part of the indication information is carried by a PDCCH or a demodulation reference signal.

Preferably, a value of every 1 bit in the indication information is used to indicate whether 1 frequency band is a target frequency band. Further preferably, the number of bits in the indication information is smaller than the total number of the frequency bands, or the number of bits in the indication information is equal to the total number of the frequency bands.

Preferably, the number of bits in the indication information is greater than the total number of the frequency bands.

Preferably, the validity period of the indication information is preset or configured by signaling. Further preferably, the network device updates the indication information during the validity period.

Preferably, the indication information includes C bits indicating the number of target carriers and D bits indicating the number of target frequency bands on each target carrier.

Preferably, the indication information represents the target carrier or the target frequency band in the following manner: only the target frequency band is indicated, the target carrier being the default; alternatively, only the target carrier is indicated, and the target band is the default.

Preferably, at least 1 bit in the indication information is used to represent a plurality (e.g., at least 2) of target carriers and/or a plurality of target frequency bands.

In addition, the present application also provides a network device for use in the method according to any one of the embodiments of the present application; the application also provides a terminal device for the method in any one of the embodiments of the application.

The embodiment of the application adopts at least one technical scheme which can achieve the following beneficial effects:

in order to support the use of the 5G system in the unlicensed spectrum more reasonably, the invention provides the method and the device for indicating the occupied bandwidth by the network device, which can realize the indication of the occupied bandwidth by the base station, thereby reducing the invalid monitoring behavior of the terminal device. The method is favorable for improving the performance when a 5G new air interface design (NR) is used for an unauthorized frequency band. When part of bandwidth resources are not used by the network equipment, the network equipment configures the terminal according to the monitoring result on the bandwidth to send data, and the terminal equipment does not need to spend monitoring resources on the related bandwidth, thereby avoiding waste.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

FIG. 1 is a schematic diagram of a network device and a terminal device;

FIG. 2 is a flow chart of the method of the present invention;

fig. 3 is a diagram illustrating a scenario in which the indication information is the same as the number of frequency bands available for LBT;

fig. 4 is a diagram illustrating a scenario in which the indication information is less than the number of frequency bands available for LBT;

fig. 5 is a diagram illustrating a scenario of selecting a subset of available LBT bands;

fig. 6 is a schematic diagram of a scenario in which bits in the indication information are used to identify multiple bands or bands.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the technical solutions of the present application will be described in detail and completely with reference to the following specific embodiments of the present application and the accompanying drawings. It should be apparent that the described embodiments are only some of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

According to current NR design and protocol specifications, carrier aggregation and bandwidth allocation (BWP) techniques are used for large bandwidth usage. One or more large bandwidths are divided into multiple carriers, and multiple BWPs may be configured within each carrier. Each BWP is a contiguous plurality of PRBs (physical resource blocks) as defined for BWP in 38.211. The network device configures corresponding BWPs on different carriers for the terminal device, and then configures a search space (searching space) of a downlink control channel (PDCCH) on the corresponding BWPs. The terminal device needs to perform periodic monitoring of the PDCCH on the configured search space. The search space configuration process for PDCCH can be seen 38.213.

When a plurality of search spaces for PDCCH are configured, the terminal device needs to perform PDCCH monitoring in the search spaces periodically according to a certain period. The search space of the PDCCH is semi-statically configured according to the current standard and cannot be dynamically adjusted quickly. For the unlicensed frequency band, due to uncertainty caused by LBT, the network device exhibits dynamic characteristics in data transmission of BWP configured with PDCCH search space. For example, 3 BWPs are configured in one carrier, and the network device listens to interference for each BWP. The interference components not only originate from the terminal equipment but also from other network equipment, etc. The terminal equipment needs to monitor the PDCCH in BWP 1-3. If the network snooping at BWP 2 fails, the network device will not transmit data at BWP 2.

However, according to the prior art standard, the terminal device also constantly monitors the PDCCH at BWP 2. Obviously, the constant monitoring at BWP2 would make the UE useless for wasting resources. In order to reduce unnecessary monitoring behaviors of UE and improve the efficiency of the whole 5G system in an unauthorized frequency band, the invention provides a method and equipment for dynamically indicating occupied bandwidth by network equipment. By the method and the equipment, the indication of the occupied bandwidth by the network equipment can be realized, and the terminal equipment only monitors the effective working frequency band indicated by the network equipment, so that the invalid monitoring behavior of the terminal equipment is reduced.

The technical solutions provided by the embodiments of the present application are described in detail below with reference to the accompanying drawings.

Fig. 1 is a schematic diagram of a network device and a terminal device.

Consider a communication system comprised of network devices and terminal devices. One network device can simultaneously transmit and receive data to a plurality of terminal devices. The network device includes a network data unit and a network control unit. The terminal device includes a terminal data unit and a terminal control unit. The network data unit and the terminal data unit transmit data through a downlink data shared channel (PDSCH) and an uplink data shared channel (PUSCH). And the network control unit and the terminal control unit exchange control information through a downlink control channel (PDCCH) and an uplink control channel (PUCCH). The PDCCH transmits Downlink Control Information (DCI) and performs specific transmission format-related contents of the PDSCH, the PUSCH, and the PUCCH. And after the data of the terminal data unit is received, the terminal control unit feeds back whether the data correctly receives the ACK/NACK information or sends the data of the terminal to the network equipment according to the control information sent by the network control unit and the data receiving condition of the terminal data unit. Specifically, information such as ACK/NACK is carried on a PUCCH (uplink control channel). The network device, the functions and the method are realized by a network control unit; the terminal device, the functions and the method are realized by a terminal control unit.

FIG. 2 is a flow chart of the method of the present invention.

and step 21, monitoring the frequency band on the carrier wave of the unauthorized frequency band.

The network device LBT all carriers available for data transmission and the bandwidth available for transmission on the carriers.

The network device listens to the 20MHz, i.e. the minimum frequency band, and can only transmit data when the 20MHz bandwidth is idle.

The network device listens for interference for each frequency band. The interference components not only originate from the terminal equipment but also from other network equipment, etc. If the network listening in one band fails, the network device will not transmit data in that band.

And step 22, selecting a target carrier and a target frequency band according to the monitoring result, and sending the PDCCH or the PDSCH.

And the network equipment prepares corresponding DCI indication information according to the LBT result and the configuration of the indication information by the high layer.

And step 23, sending indication information for identifying the target carrier and the target frequency band.

And the network equipment performs channel coding, modulation and other operations on the DCI information prepared in the steps 21-22 to form a PDCCH (physical downlink control channel) containing downlink control information and transmits the PDCCH.

Step 24, the validity period of the indication information is preset or configured by signaling. Further preferably, during the valid period, the network device re-executes steps 21-23 to update the indication information.

Correspondingly to the steps 21-23, the working process of the terminal equipment is as follows:

Step 25, the terminal device receives the PDCCH containing the downlink control information sent by the network device, wherein the PDCCH contains the indication information.

And step 26, receiving the corresponding PDCCH and PDSCH according to the indication information sent by the network equipment.

The solution of the invention has an impact on existing standards 38.212 etc. If the indication information (including the identification of LBT band) is added to the format of the existing DCI, the existing DCI0_0/0_1/1_0/1_1 in the standard 7.3.1 needs to add the following contents:

LBT band indicator:A bits,according to LBT-Subband-indicator inSubclause xx of[9,TS38.331]

if a new DCI format is introduced to add the indication information, similar content needs to be added.

The LBT-sub-indicator introduced in 38.212 needs to be further specified (corresponding to the high layer configuration) in 38.311, such as:

LBT-Subband-indicator::＝SEQUENCE{

Carrier-number SEQUENCE(SIZE(1..carrierNum)

LBTband-number SEQUENCE(SIZE(1..LBTbandNum)

}

or

LBT-Subband-indicator::＝SEQUENCE{

Carrier-number SEQUENCE(SIZE(1..carrierNum)

LBTband-map-number SEQUENCE(SIZE(LBTbandmap1,LBTbandmap2…LBTbandmapnumber)

LBTbandmap SEQUENCE(SIZE(LBTbandmap1,LBTbandmap2…LBTbandmapnumber)

}

LBTbandmap::＝SEQUENCE{

LBTband SEQUENCE(1..LBTbandNumber)

}

Fig. 3 is a diagram illustrating a scenario in which the indication information is the same as the number of frequency bands available for LBT.

Preferably, a value of every 1 bit in the indication information is used to indicate whether 1 frequency band is a target frequency band. Further preferably, the number of bits in the indication information is equal to the total number of the frequency bands.

The length of the indication information is equal to the number of the frequency bands which can be listened to before being sent out by the network equipment. Each bit represents a frequency band that can be listened to before transmitted. The network device may directly set a bit values representing whether the target frequency band performs PDCCH and PDSCH transmission. As shown in fig. 3, there are two available carriers, each of which is configured with 2 sensing bandwidths. The network side indicates 4 bandwidths with 4 bits. And at the second moment, if the monitoring of the LBT frequency band 1\3\4 is successful, the downlink data is sent, and if the monitoring of the LBT frequency band 2 is not successful, the network side determines that the data is not sent any more within a certain time. Accordingly, the indication of 4 LBT bands is 1011.

Fig. 4 is a diagram illustrating a scenario in which the indication information is smaller than the number of frequency bands available for LBT.

Preferably, a value of every 1 bit in the indication information is used to indicate whether 1 frequency band is a target frequency band. Further preferably, the number of bits in the indication information is smaller than the total number of the frequency bands.

The length of the indication information is less than the number of the frequency bands which can be listened to before being sent by the network equipment. The median a may represent a subset of all LBT bands. The subset may be represented in a combination of carrier plus LBT band, or may be represented in a carrier alone or LBT band alone. Fig. 4 shows the 4-bit occupancy of 4 carriers, but the LBT band is no longer indicated.

Fig. 5 is a diagram illustrating a scenario of selecting a subset of available LBT bands.

The network device selects a subset of the plurality of LBT bands as an indication, each bit representing 1 LBT band. The following figure takes

LBT bands

1, 2, 4, 6 as indications. And the

LBT bands

3 and 5 do not indicate, and the terminal equipment receiving the indication can not monitor the LBT bands which are not in the indicated range and indicated as not-transmitting.

The network device selects a subset of the plurality of LBT bands as an indication, each bit may represent 1 or more LBT bands, and when representing a plurality of LBT bands, the bits may be combined with or operated. The lower diagram indicates LBT band 1 and LBT band 2 with 1 bit, then two bands are or-ed, and as long as there is one LBT band to transmit, 1 is indicated. The terminal device performs a corresponding monitoring action.

It should be noted that, in fig. 3 to 6, the horizontal direction indicates slot unit distribution, and a dark square indicates successful monitoring and is used for sending a signal; the light square indicates that the listen was not successful and cannot be used to transmit a signal.

Other embodiments of the present application, for example, the number of bits in the indication information is greater than the total number of the frequency bands. The length of the indication information is larger than the number of the frequency bands which can be listened to before being sent by the network equipment. This case corresponds to the indication of the bandwidth occupancy in DCI that the number of reserved bits is greater than the number of available LBT bands. At this time, the same number of bits as the LBT band may be used for indication, and the remaining part is filled with all 0 s or 1 s.

The indication information may be carried on the smallest-numbered transmission LBT band indicated by the first signal by default, such as LBT band 1 in the above-described embodiment. The valid time of the indication information may default to several milliseconds (ms) or slots (slots), and this value is directly configured or directly agreed by the system (e.g., 10 slots, S + a-1 ═ 10). The valid time of the indication information can also be implicitly indicated by the second information sent at the same time of sending the indication information. For example, the second information indicates a continuous transmission duration and/or uplink and downlink configuration adopted by the network device and the terminal device within a duration of a future period, and the continuous transmission duration indicated by the second information may also be used as the duration of the indication information.

The embodiment of the present application further provides a network device, and with the method according to any one of the embodiments of the present application, the network device monitors a frequency band on a carrier of an unlicensed frequency band; selecting a target carrier and a target frequency band according to the monitoring result, and sending the PDCCH or the PDSCH; and sending indication information for identifying the target carrier and the target frequency band.

The embodiment of the present application further provides a terminal device, and in the method according to any embodiment of the present application, the terminal device receives indication information sent by the network device, and performs listen-on-Listen (LBT) and receives a corresponding PDCCH and a PDSCH according to a target carrier and a target frequency band identified by the indication information.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The above description is only an example of the present application and is not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A downlink channel indication method is used for network equipment and is characterized by comprising the following steps:

2. The method of claim 1,

the target frequency bands are one or more, and the minimum bandwidth is 20 MHz; the number of the target carriers is one or more; at least one target frequency band is included on each target carrier.

3. The method of claim 1, wherein a length of the indication information is preset or configured by signaling.

4. The method of claim 1, wherein the indication information is transmitted in a common search space or in a dedicated search space.

5. The method of claim 1, wherein at least a portion of the indication information is carried by a PDCCH or a demodulation reference signal.

6. The method of claim 1, wherein a value of 1 bit in the indication information is used to indicate whether 1 band is a target band.

7. The method of claim 6,

the number of bits in the indication information is smaller than the total number of the frequency bands, or

The number of bits in the indication information is equal to the total number of the frequency bands.

8. The method of claim 1, wherein a valid period of the indication information is preset or configured by signaling.

9. The method of claim 1, wherein the number of bits in the indication information is greater than the total number of the frequency bands.

10. The method of claim 8, comprising the step of updating the indication information by the network device during the validity period.

11. The method of claim 1, wherein the indication information comprises C bits indicating a target number of carriers and D bits indicating a target number of frequency bands on each target carrier.

12. The method of claim 1, wherein the indication information represents the target carrier or target frequency band by:

only the target frequency band is indicated, the target carrier being the default; or

Only the target carrier is indicated and the target band is the default.

13. The method of claim 1, wherein at least 1 bit of the indication information is used for indicating a plurality of target carriers and/or a plurality of target frequency bands.

14. A network device, which uses the method according to any one of claims 1 to 13, wherein the network device monitors a frequency band on a carrier of an unlicensed frequency band; selecting a target carrier and a target frequency band according to the monitoring result, and sending the PDCCH or the PDSCH; and sending indication information for identifying the target carrier and the target frequency band.

15. A terminal device, using the method of any one of claims 1 to 13, wherein the terminal device receives indication information sent by the network device, and performs sensing and receiving corresponding PDCCH and PDSCH according to a target carrier and a target frequency band identified by the indication information.