CN114402555A

CN114402555A - HARQ information indication method, communication device and communication system

Info

Publication number: CN114402555A
Application number: CN201980100481.4A
Authority: CN
Inventors: 董蕾; 张锦芳; 卢磊
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-09-30
Filing date: 2019-09-30
Publication date: 2022-04-26
Also published as: WO2021062819A1

Abstract

The embodiment of the application provides a HARQ information indication method, a communication device and a communication system, relates to the field of communication, and guarantees the scheduling accuracy of a base station through a HARQ process number, so that transmission confusion of a terminal is avoided as far as possible, the transmission performance is improved, and the method can be applied to the Internet of vehicles, such as V2X, LTE-V, V2V and the like, or can be applied to the fields of D2D, intelligent driving, intelligent Internet of vehicles and the like. The method comprises the following steps: the method comprises the steps that a first terminal receives first indication information from network equipment, wherein the first indication information is used for indicating a first HARQ process number, and the first HARQ process number is used for data transmission between the first terminal and a second terminal; and the first terminal sends side row control information to the second terminal, wherein the side row control information comprises second indication information, and the second indication information is used for indicating the first HARQ process number.

Description

HARQ information indication method, communication device and communication system

Technical Field

The present invention relates to the field of communications, and in particular, to a method, a communication apparatus, and a communication system for indicating hybrid automatic repeat request (HARQ) information.

Background

Long Term Evolution (LTE) communication system, fifth generation (5)^thgeneration, 5G) communication system also supports Sidelink (SL) communication between devices, such as: device to device (D2D) communication, vehicle to all (V2X) communication, etc., which may be referred to as new radio, NR) -vehicle to all (V2X) communication. In NR-V2X communication, a HARQ based retransmission scheme is supported. Specifically, the sender terminal may use an HARQ process to send a block (TB), receive HARQ feedback, and retransmit the TB; the receiving terminal may receive the TB and send HARQ feedback using the HARQ process.

When a User Equipment (UE) at a sending end is located in a network coverage of a base station, the base station may schedule a data transmission between the UE at the sending end and the UE at a receiving end through Downlink Control Information (DCI), for example, to indicate a sidelink resource used for the data transmission. The sending end UE can select the HARQ process number for the data transmission, and send data to the receiving end UE through the side link resource indicated by the base station. The base station and the sending end UE may not understand the HARQ process number of the same data transmission consistently, which affects the transmission reliability between terminals.

Disclosure of Invention

The embodiment of the application provides an HARQ information indication method, a communication device and a communication system, which solve the problem that a base station and a sending terminal UE have inconsistent understanding on the HARQ process number of the same data transmission, thereby improving the transmission reliability between terminals.

In a first aspect, a method for indicating HARQ information is provided, including: the method comprises the steps that a first terminal receives first indication information from network equipment, wherein the first indication information is used for indicating a first HARQ process number, and the first HARQ process number is used for data transmission between the first terminal and a second terminal; and the first terminal sends side row control information to the second terminal, wherein the side row control information comprises second indication information, and the second indication information is used for indicating the first HARQ process number.

In a first aspect, a first terminal receives first information from a network device, where the first information indicates that the network device allocates an HARQ process number (e.g., the first HARQ process number described above) for one data transmission between terminals. One HARQ process number is associated with one data transmission (including initial transmission and retransmission). The first terminal can determine the HARQ process number selected by the network equipment for one-time transmission according to the first information, so that the problem that the base station and the sending terminal UE have inconsistent understanding on the HARQ process number of the same-time data transmission is solved, and the transmission reliability between the terminals can be improved.

In one possible design, the sideline control information is further used for indicating the first data, and the method further includes: the first terminal sends first data to the second terminal, and the first data is related to the first HARQ process number.

In the first aspect, a specific implementation is provided for the first terminal to transmit data by using the HARQ process number: the first terminal sends first data to the second terminal, and the first data is related to the first HARQ process number, that is, the first terminal can directly transmit data by using the first HARQ process number indicated by the network device.

In one possible design, the first terminal maintains a first set of HARQ process numbers, the first HARQ process numbers belonging to the first set of HARQ process numbers, the first set of HARQ process numbers including at least one HARQ process number for data transmission of the first mode; the first mode is a mode for scheduling side link resources by the network equipment; and the first HARQ process number belongs to a second set of HARQ process numbers, which is maintained by the network device.

In the first aspect, the HARQ process number maintained by the base station may be used for mode-1 (i.e., the first mode), and when the terminal supports mode-1, the HARQ process number maintained by the terminal may be used for mode-1. The HARQ process numbers maintained by the base station and the terminal may be the same, and the terminal may directly use the process number indicated by the base station to perform data transmission.

In one possible design, the first HARQ process number set further includes at least one HARQ process number used for data transmission in a second mode, and the second mode is a mode in which the terminal determines the sidelink resource by itself; the at least one HARQ process number for data transmission of the second mode is different from the at least one HARQ process number for data transmission of the first mode.

In the first aspect, the HARQ process number maintained by the base station may be used for mode-1, the HARQ process number maintained by the terminal may be used for mode-1 and mode-2 (the second mode), and the HARQ process numbers in the two modes are different from each other, but the HARQ process numbers used by the base station and the terminal for mode-1 are the same, so that the terminal may directly use the process number indicated by the base station for data transmission.

In one possible design, the first indication information is carried in downlink control information, DCI.

In the embodiments of the present application, a possibility of sending the first information is provided.

In a second aspect, a method for indicating HARQ information is provided, the method including: the method comprises the steps that a first terminal receives first indication information from network equipment, wherein the first indication information is used for indicating a first HARQ process number, and the first HARQ process number is used for data transmission between the first terminal and a second terminal; under the condition that the first HARQ process number is not occupied by the first terminal, the first terminal sends side row control information to the second terminal, wherein the side row control information comprises second indication information, and the second indication information is used for indicating the first HARQ process number; and under the condition that the first HARQ process number is occupied by the first terminal, the first terminal sends side row control information to the second terminal, wherein the side row control information comprises third indication information, the third indication information is used for indicating a second HARQ process number, the second HARQ process number is an unoccupied HARQ process number in the first HARQ process number set, and the first HARQ process number set is an HARQ process number set maintained by the first terminal.

In the second aspect, the HARQ process number maintained by the base station may be used for mode-1, the HARQ process number maintained by the terminal may be used for mode-1 and mode-2 (the second mode described above), and the HARQ process numbers maintained by the terminal in the two modes are not distinguished, that is, the HARQ process number maintained by the terminal is mixed by data in the two modes, that is, the HARQ process number (mode-1) selected by the network device for one data transmission of the terminal may be occupied under this condition, and if the HARQ process number indicated by the first information is occupied by the data transmission of mode-2 being performed by the first terminal, the first terminal may select another HARQ process number for this data transmission. Therefore, the terminal side avoids the HARQ process number conflict of the sideline data transmission in the mode-1 and the mode-2. The first terminal may further send third indication information to the second terminal, where the third indication information indicates the HARQ process number determined by the first terminal, that is, the second HARQ process number, and the second HARQ process number is actually used for one-time data transmission between the first terminal and the second terminal. And the HARQ process number of the data mixing under the two modes of mode-1 and mode-2 can more flexibly support the data transmission under the two modes, and the condition that the number of the HARQ process number is not supported under the condition that the data transmission under one mode is too frequent is avoided.

In addition, if the HARQ process number (mode-1) selected by the network device for one data transmission of the terminal is not occupied, the first terminal does not reselect the HARQ process number for this transmission, and directly uses the HARQ process number indicated by the network device. The network equipment, the base station and the sending end UE have consistent understanding on the HARQ process number of the same data transmission, and the transmission reliability between the terminals can be improved.

In one possible design, the first HARQ process number is not occupied by the first terminal, including: the HARQ entity of the first terminal does not comprise the HARQ process corresponding to the first HARQ process number; the first HARQ process number is occupied by the first terminal, including: the HARQ entity of the first terminal comprises a HARQ process corresponding to the first HARQ process number.

In the second aspect, a specific scheme for determining whether the HARQ process is occupied is also provided.

In one possible design, the sideline control information is further used for indicating the first data, and the method further includes: the first terminal sends first data to the second terminal, and the first data is related to the first HARQ process number or the second HARQ process number.

In the second aspect, a specific scheme is further provided for the first terminal to transmit data by using the HARQ process number: the first terminal sends first data to the second terminal, and the first data is related to the first HARQ process number or the second HARQ process number. That is, the first HARQ process number is not occupied by the ongoing data transmission of the first terminal, and the first terminal directly transmits the first data using the first HARQ process number. And if the first HARQ process number is occupied by the ongoing data transmission of the first terminal, the first terminal reselects the second HARQ process number to transmit the first data.

In a third aspect, a communication apparatus is provided, including: a transceiving unit, configured to receive first indication information from a network device, where the first indication information is used to indicate a first HARQ process number, and the first HARQ process number is used for data transmission between a first terminal and a second terminal; the transceiving unit is further configured to send sideline control information to the second terminal, where the sideline control information includes second indication information, and the second indication information is used to indicate the first HARQ process number.

In one possible design, the sidelink control information is further configured to indicate first data, and the transceiver unit is further configured to send the first data to the second terminal, where the first data is associated with the first HARQ process number.

In a fourth aspect, an apparatus is provided, comprising: a transceiving unit, configured to receive first indication information from a network device, where the first indication information is used to indicate a first HARQ process number, and the first HARQ process number is used for data transmission between a first terminal and a second terminal; the processing unit is used for determining whether the first HARQ process number is occupied by the first terminal; the transceiving unit is further configured to, when the processing unit determines that the first HARQ process number is not occupied by the first terminal, send, by the first terminal, sidestream control information to the second terminal, where the sidestream control information includes second indication information, and the second indication information is used to indicate the first HARQ process number; the transceiving unit is further configured to, when the processing unit determines that the first HARQ process number is occupied by the first terminal, send, by the first terminal, side-row control information to the second terminal when the first HARQ process number is occupied by the first terminal, where the side-row control information includes third indication information, the third indication information is used to indicate a second HARQ process number, the second HARQ process number is an unoccupied HARQ process number in the first HARQ process number set, and the first HARQ process number set is an HARQ process number set maintained by the first terminal.

In one possible design, the processing unit is specifically configured to determine that the HARQ process corresponding to the first HARQ process number is unoccupied if the HARQ entity of the first terminal does not include the HARQ process corresponding to the first HARQ process number; and if the HARQ entity of the first terminal comprises the HARQ process corresponding to the first HARQ process number, determining that the first HARQ process number is occupied by the first terminal.

In one possible design, the sidelink control information is further configured to indicate first data, and the transceiver unit is further configured to send the first data to the second terminal, where the first data is associated with the first HARQ process number or the second HARQ process number.

In a fifth aspect, a communications apparatus is provided that includes a processor coupled with a memory; a memory for storing a computer program; a processor configured to execute the computer program stored in the memory to enable the communication apparatus to implement the method according to any one of the implementation manners of the first aspect and the first aspect, the second aspect, and the second aspect, where the communication apparatus may be a baseband chip, and the baseband chip reads the computer program to enable an apparatus in which the baseband chip is installed to implement the method according to any one of the implementation manners of the first aspect.

In a sixth aspect, a computer-readable storage medium is provided, comprising: the computer readable storage medium has instructions stored therein; when the computer readable storage medium is run on the communication apparatus according to any one of the third aspect and any one of the implementation manners of the third aspect, the fourth aspect and any one of the implementation manners of the fourth aspect, the communication apparatus is caused to implement the method according to any one of the implementation manners of the first aspect and any one of the implementation manners of the first aspect, the second aspect and the second aspect.

In a seventh aspect, a wireless communications apparatus is provided, including: instructions are stored in the wireless communication device; when the wireless communication device is operated on the communication device according to any one of the implementation manners of the third aspect and any one of the implementation manners of the fourth aspect and the fourth aspect, the wireless communication device is caused to implement the method according to any one of the implementation manners of the first aspect and the first aspect, the second aspect and the second aspect. The wireless communication device is a chip.

In an eighth aspect, there is provided a communication system comprising: the system comprises network equipment, a first terminal and a second terminal;

the network equipment is used for sending first indication information to the first terminal, wherein the first indication information is used for indicating a first HARQ process number, and the first HARQ process number is used for data transmission between the first terminal and the second terminal;

the first terminal is used for receiving first indication information from the network equipment and sending side row control information to the second terminal, wherein the side row control information comprises second indication information, and the second indication information is used for indicating a first HARQ process number;

the second terminal is used for receiving second indication information from the first terminal;

alternatively, the first and second electrodes may be,

the first terminal receives first indication information from the network equipment, and sends side-line control information to the second terminal under the condition that the first HARQ process number is not occupied by the first terminal, wherein the side-line control information comprises second indication information, and the second indication information is used for indicating the first HARQ process number; under the condition that the first HARQ process number is occupied by the first terminal, the first terminal sends side row control information to the second terminal, the side row control information comprises third indication information, the third indication information is used for indicating a second HARQ process number, the second HARQ process number is an unoccupied HARQ process number in the first HARQ process number set, and the first HARQ process number set is an HARQ process number set maintained by the first terminal;

the second terminal is used for receiving the side row control information from the first terminal.

Drawings

FIG. 1 is a schematic diagram of mode-1 scheduling provided in an embodiment of the present application;

fig. 2 is an architecture diagram of a communication system provided in an embodiment of the present application;

fig. 3a is a block diagram of a communication device according to an embodiment of the present disclosure;

fig. 3b is another block diagram of a communication device according to an embodiment of the present disclosure;

fig. 4 is a flowchart illustrating a HARQ information indication method according to an embodiment of the present application;

fig. 5 is a schematic diagram of a HARQ process number set according to an embodiment of the present application;

fig. 6 is another schematic diagram of a HARQ process number set according to an embodiment of the present application;

fig. 7 is another flowchart illustrating a HARQ information indication method according to an embodiment of the present application;

fig. 8 is another schematic diagram of a HARQ process number set according to an embodiment of the present application;

fig. 9 is another schematic diagram of a HARQ information indication method according to an embodiment of the present application;

fig. 10 is a schematic diagram of a HARQ information indication method according to an embodiment of the present application;

fig. 11 is another schematic diagram of a HARQ information indication method according to an embodiment of the present application;

fig. 12 is another block diagram of a communication device according to an embodiment of the present disclosure;

fig. 13 is another block diagram of a communication device according to an embodiment of the present disclosure;

fig. 14 is another block diagram of a communication device according to an embodiment of the present disclosure;

fig. 15 is another block diagram of a communication device according to an embodiment of the present application.

Detailed Description

The technical solution in the present application will be described below with reference to the accompanying drawings.

First, terms related to embodiments of the present invention are explained.

(1) HARQ process

At present, a HARQ process (process) may be used for data transmission, and a HARQ process number may also be allocated for one data transmission, where the HARQ process number may be used for the data transmission, and may be considered to correspond to the data transmission.

Further, one data transmission may include: the sending end uses the HARQ process to send the TB, and the receiving end uses the HARQ process to receive the TB.

The HARQ process also corresponds to one HARQ feedback. Wherein, the HARQ feedback may be Acknowledgement (ACK) or Negative Acknowledgement (NACK).

(2) HARQ process number

The HARQ process number may be considered as an Identification (ID) of HARQ, and the HARQ process may be identified by the HARQ ID. For example, the HARQ process number may be an arabic number: 0. 1, 2, 3, 4 …, and so on.

Specifically, the HARQ process uses a stop-and-wait protocol (stop-and-wait protocol) to transmit data, that is, after the transmitting end sends a TB, the data transmission on the HARQ process is suspended, and the transmitting end waits for acknowledgement information (i.e., the HARQ feedback). The receiving end may acknowledge the TB with 1-bit information, for example, if the TB is successfully received, it replies "1" (ACK) to the transmitting end; if the TB is not successfully received, "0" (NACK) is replied to the transmitting end.

The HARQ process stops at the sender after each transmission for acknowledgement information, which results in a low system throughput. It is therefore necessary to use multiple parallel HARQ processes for data transmission. While one HARQ process waits for acknowledgement information, the transmitting end may continue to transmit data using another HARQ process.

(3) HARQ buffer (buffer)

Both the transmitting side and the receiving side maintain HARQ buffers, for the transmitting side or the receiving side, each HARQ process corresponds to one HARQ buffer, and the HARQ buffers store data. The receiving end can perform soft combining on the data in the same HARQ buffer, so that the decoding performance is improved.

For example, a sending end and a receiving end use the HARQ process 1 to perform data transmission, the sending end may take out data from the HARQ buffer corresponding to the locally maintained HARQ process 1 and then send the data, and the receiving end stores the data in the HARQ buffer corresponding to the locally maintained HARQ process 1 after receiving the data.

Assuming that the receiving end does not successfully decode the data, "NACK" may be replied to the transmitting end. After receiving the "NACK", the sending end uses HARQ process 1 to retransmit data, and after receiving the retransmitted data, the receiving end stores the retransmitted data in the locally maintained HARQ buffer corresponding to HARQ process 1, so as to perform soft combining on the initial transmission data and the retransmitted data in the HARQ buffer corresponding to HARQ process 1.

(4) HARQ entity

Each terminal maintains one HARQ entity (HARQ entity) which is comprised by a plurality of HARQ processes being used for data transmission.

It can be understood that when a certain HARQ process is included in the HARQ entity, it indicates that the HARQ process is being used for data transmission, i.e. the HARQ process is being occupied by the terminal.

In a specific implementation, when an HARQ buffer corresponding to a certain HARQ process is occupied, it indicates that the HARQ process is being used for data transmission, that is, the HARQ process is occupied, and the HARQ entity includes the HARQ process. After the data transmission of the HARQ process is finished, the terminal may release the HARQ process. For example, after receiving ACK from the receiving end, the transmitting end clears the HARQ buffer and releases the HARQ process; or, the sending end receives NACK from the receiving end, and clears the HARQ buffer and releases the HARQ process when the current retransmission times exceeds the maximum transmission times.

When a HARQ entity does not include a HARQ process, it indicates that the HARQ process is not being used for data transmission, i.e. the HARQ process is not currently occupied by the terminal.

(5) Sidelink (sidelink) resource allocation pattern

In the New Radio (NR) -V2X, the sidelink resource can be configured in two ways, one is a base station allocation mode (referred to as mode-1) and the other is a user selection mode (referred to as mode-2).

mode-1 is mainly applicable to sidestream communication under a base station network coverage scene, that is, when a terminal is located in a base station network coverage area, a base station can allocate sidestream link resources to the terminal according to a BSR reported by the terminal to perform sidestream communication. Specifically, dynamic scheduling (dynamic scheduling) and preconfigured scheduling (configured scheduling) are included.

Referring to fig. 1, in the dynamic scheduling mode, when a new data packet arrives at a terminal, a Scheduling Request (SR) is first sent to a base station, and the base station informs the terminal of resources for reporting a BSR through DCI 1. And the terminal reports the BSR to the base station in the corresponding resource, the base station informs the terminal of sending the sidelink resource through the DCI2, and the terminal carries out sidelink communication through the sidelink resource indicated by the terminal after receiving the DCI 2.

In the SPS mode, the base station configures related sidelink resources through higher layer signaling, and the terminal directly transmits data (type-1) on the configured sidelink resources, or the base station transmits a DCI message to activate the terminal to transmit data (type-2) using the configured sidelink resources.

mode-2 is mainly applied to sidestream communication under the scene without base station network coverage, because there is no unified resource management of the base stations, the terminal can only select sidestream link resources for sidestream communication.

Fig. 2 is a schematic diagram of a communication system to which the technical solution provided by the present application is applicable, where the communication system may include a plurality of network devices (only network device 100 is shown) and a plurality of terminals (only terminal 201 and terminal 202 are shown). Fig. 2 is a schematic diagram, and does not limit the application scenarios of the technical solutions provided in the present application. The communication system supports sidelink communication, such as: device to device (D2D) communication, vehicle to all (V2X) communication, etc.

The network device and the terminal may perform uplink and downlink transmission through a cellular link (Uu link), and the terminal may perform communication through a sidelink link (sidelink link), for example, D2D communication, V2X communication, Machine Type Communication (MTC), and the like.

The network device may be a transmission reception node (TRP), a base station, a relay station, or an access point. The network device may be a network device in a 5G communication system or a network device in a future evolution network; but also wearable devices or vehicle-mounted devices, etc. In addition, the method can also comprise the following steps: a Base Transceiver Station (BTS) in a global system for mobile communication (GSM) or Code Division Multiple Access (CDMA) network, or an nb (nodeb) in Wideband Code Division Multiple Access (WCDMA), or an eNB or enodeb (evolved nodeb) in Long Term Evolution (LTE). The network device may also be a wireless controller in a Cloud Radio Access Network (CRAN) scenario. The embodiments of the present application will be described with reference to a base station as an example.

A terminal may be a User Equipment (UE), an access terminal, a UE unit, a UE station, a mobile station, a remote terminal, a mobile device, a UE terminal device, a wireless communication device, a UE agent, or a UE device, etc. The access terminal device may be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device with wireless communication capability, a computing device or other processing device connected to a wireless modem, a vehicle-mounted device, a wearable device, a terminal device in a 5G network or a terminal device in a future evolved Public Land Mobile Network (PLMN) network, etc. The terminal device of the present application may also be an on-board module, an on-board component, an on-board chip, or an on-board unit built into the vehicle as one or more components or units, and the vehicle may implement the method of the present application through the built-in on-board module, on-board component, on-board chip, or on-board unit. The first terminal, the second terminal and the network device of the present application may be one or more chips, and may also be a System On Chip (SOC), etc.

In the communication system shown in fig. 2, sidelink communication may be performed between the terminal 201 and the terminal 202, and data transmitted between the terminal 201 and the terminal 202 may be referred to as sidelink data, that is, data transmitted on a sidelink. Taking terminal 201 as a sender and terminal 202 as a receiver as an example, when terminal 201 needs to send data to terminal 202, terminal 201 may report BSR to network device 101, network device 101 may allocate sidelink resources for one transmission to terminal 201, terminal 201 selects an HARQ process number for this data transmission, and indicates the selected HARQ process number to terminal 202 through Sidelink Control Information (SCI). However, the network device 101 does not know the behavior of the terminal 201, and does not distinguish different HARQ process numbers when indicating resources to the terminal 201, and a resource allocated by the network device 101 for a certain data transmission may be used by the sending-end UE for data transmission corresponding to other HARQ process numbers. The terminal 201 does not determine which HARQ process number the sidelink resource indicated by the DCI is used for data transmission corresponding to, that is, the base station and the sending end UE do not understand the HARQ process number of the same data transmission consistently, which affects the transmission reliability between terminals.

For example, when decoding of the initial transmission data corresponding to HARQ process number "2" fails, network device 101 may indicate retransmission resources through DCI. After receiving the DCI, the terminal 201 does not determine which HARQ process number the retransmission resource is used for, and may use the retransmission resource for retransmitting another HARQ process number, for example, data corresponding to the HARQ process number "5" is retransmitted to the terminal 202 by using the retransmission resource, so that the terminal 202 cannot receive the retransmitted data corresponding to the HARQ process number "2" temporarily, which affects transmission reliability.

Illustratively, the network device sends DCI1 to terminal 201 indicating sidelink resource 1, sidelink resource 1 being used for transmission of TB 1. Terminal 201 receives DCI1 and allocates HARQ process number 3 for this data transmission. Terminal 201 may also send SCI1 to terminal 202 indicating HARQ process number 3. Terminal 202 may store the initial transmission data (TB1) in the HARQ buffer corresponding to HARQ process number 3.

When terminal 202 fails to decode the initial transmission data in the HARQ buffer, "NACK" is sent to terminal 201. Terminal 201 may also send a "NACK" to network device 101. After receiving the request, the network device sends DCI2 to the terminal 201, where DCI2 indicates retransmission resources.

The terminal 201 cannot determine which data retransmission the resource indicated by DCI2 is specifically used for after receiving DCI2, and may send a redundancy version of TB2 (i.e., retransmission data of TB 2) on the resource indicated by DCI 2. Assuming that the service priority corresponding to the TB1 is higher, for example, for a delay-sensitive service, retransmitting the redundancy version of the TB2 on the resource indicated by the DCI2 will cause the terminal 202 to fail to receive the redundancy version of the TB1 for a long time (i.e., retransmission data of the TB1), and the terminal 202 cannot soft-combine the redundancy version of the TB1 and the initial transmission version of the TB1 for a long time, which cannot meet the delay requirement of the delay-sensitive service, and seriously affects the transmission performance.

It can be seen that the prior art only provides a framework for HARQ retransmission in NR-V2X, and does not provide a specific design related thereto. The mapping relationship between the HARQ process number maintained by the base station and the HARQ process number maintained by the terminal is not clear, and the behaviors of the base station and the terminal are inconsistent.

The embodiment of the application provides a method for indicating HARQ information, wherein a first terminal receives first indication information from network equipment, the first indication information is used for indicating a first HARQ process number, and the first HARQ process number is used for data transmission between the first terminal and a second terminal. The first terminal may further send side-line control information to the second terminal, where the side-line control information includes second indication information, and the second indication information is used to indicate the first HARQ process number. In this embodiment, a sender terminal (e.g., a first terminal described in this embodiment) receives first indication information from a network device, and after determining a first HARQ process number related to this data transmission according to the first indication information, may also send second indication information to a receiver terminal (e.g., a second terminal described in this embodiment) to indicate the first HARQ process number related to this data transmission.

Therefore, the first terminal can determine the HARQ process number selected by the network device for one-time transmission according to the first information, the problem that the base station and the sending terminal UE have inconsistent understanding of the HARQ process number of the same data transmission is solved, and the transmission reliability between terminals can be improved.

The terminal according to the embodiment of the present application can be implemented by the communication device 310 in fig. 3 a. Fig. 3a is a schematic diagram illustrating a hardware structure of a communication device 310 according to an embodiment of the present disclosure. The communication device 310 includes a processor 3101, a memory 3102, and at least one communication interface (fig. 3a is merely exemplary and includes the communication interface 3103 for illustration). Among them, the processor 3101, the memory 3102, and the communication interface 3103 are connected to each other.

The processor 3101 may be a general-purpose Central Processing Unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to control the execution of programs in accordance with the teachings of the present disclosure.

Communication interface 3103 may be implemented using any transceiver or the like for communicating with other devices or communication networks, such as an ethernet, a Radio Access Network (RAN), a Wireless Local Area Network (WLAN), etc.

The memory 3102 may be, but is not limited to, a read-only memory (ROM) or other type of static storage device that may store static information and instructions, a Random Access Memory (RAM) or other type of dynamic storage device that may store information and instructions, an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disk storage, optical disk storage (including compact disc, laser disc, optical disc, digital versatile disc, blu-ray disc, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. The memory may be separate and coupled to the processor via communication line 3102. The memory may also be integral to the processor.

The memory 3102 is used for storing computer executable instructions for implementing the present scheme, and is controlled by the processor 3101. The processor 3101 is configured to execute computer-executable instructions stored in the memory 3102 to implement the intended processing methods provided by the embodiments described below in the present application.

Optionally, the computer-executable instructions in the embodiments of the present application may also be referred to as application program codes, which are not specifically limited in the embodiments of the present application.

In particular implementations, processor 3101 may include one or more CPUs, such as CPU0 and CPU1 in fig. 3a, as one embodiment.

In one implementation, for example, the communication device 310 may include multiple processors, such as the processor 3101 and the processor 3106 of fig. 3 a. Each of these processors may be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. A processor herein may refer to one or more devices, circuits, and/or processing cores for processing data (e.g., computer program instructions).

In one implementation, the communication apparatus 310 may further include an output device 3104 and an input device 3105, as an example. Output device 3104, in communication with processor 3101, may display information in a variety of ways. For example, the output device 3104 may be a Liquid Crystal Display (LCD), a Light Emitting Diode (LED) display device, a Cathode Ray Tube (CRT) display device, a projector (projector), or the like. The input device 3105, which is in communication with the processor 3101, may receive user input in a variety of ways. For example, input device 3105 may be a mouse, keyboard, touch screen device, or sensing device, among others.

The communication device 310 may be a general-purpose device or a special-purpose device. In a specific implementation, the communication device 310 may be a desktop computer, a laptop computer, a web server, a Personal Digital Assistant (PDA), a mobile phone, a tablet computer, a wireless terminal device, an embedded device, or a device with a similar structure as in fig. 3 a. The embodiment of the present application does not limit the type of the communication device 310.

The communication device 310 may be a terminal complete machine, a functional component or a component that implements a terminal, or a communication chip, such as a baseband chip. When the communication device 310 is a terminal, the communication interface may be a radio frequency module. When the communication device 310 is a communication chip, the communication interface 3103 may be an input-output interface circuit of the chip, which is used to read in and output a baseband signal.

Fig. 3b is a schematic diagram of a network device. The structure of the network device 320 may refer to the structure shown in fig. 3 b.

The network device includes at least one processor 3201, at least one memory 3202, at least one transceiver 3203, at least one network interface 3204, and one or more antennas 3205. The processor 3201, memory 3202, transceiver 3203, and network interface 3204 are coupled, e.g., via a bus. An antenna 3205 is connected to the transceiver 3203. The network interface 3204 is used to connect the network device to other communication devices through communication links, for example, the network device is connected to a core network element through the S1 interface. In the embodiment of the present application, the connection may include various interfaces, transmission lines, buses, and the like, which is not limited in this embodiment.

The processor in the embodiment of the present application, for example, the processor 3201, may include at least one of the following types: a general-purpose Central Processing Unit (CPU), a Digital Signal Processor (DSP), a microprocessor, an Application-Specific Integrated Circuit (ASIC), a Microcontroller (MCU), a Field Programmable Gate Array (FPGA), or an Integrated Circuit for implementing logic operations. For example, the processor 3201 may be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. The at least one processor 3201 may be integrated in one chip or located on multiple different chips.

The memory in the embodiment of the present application, for example, the memory 3202, may include at least one of the following types: read-only memory (ROM) or other types of static memory devices that may store static information and instructions, Random Access Memory (RAM) or other types of dynamic memory devices that may store information and instructions, and Electrically erasable programmable read-only memory (EEPROM). In some scenarios, the memory may also be, but is not limited to, a compact disk-read-only memory (CD-ROM) or other optical disk storage, optical disk storage (including compact disk, laser disk, optical disk, digital versatile disk, blu-ray disk, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer.

The memory 3202 may be separate and coupled to the processor 3201. Optionally, the memory 3202 may also be integrated with the processor 3201, e.g., within a chip. The memory 3202 can store program codes for executing the technical solutions of the embodiments of the present application, and the processor 3201 controls the execution of the program codes, and the executed computer program codes can also be regarded as drivers of the processor 3201. For example, the processor 3201 is configured to execute the computer program code stored in the memory 3202, thereby implementing the technical solution in the embodiment of the present application.

The transceiver 3203 may be used to support reception or transmission of radio frequency signals between the network device and the terminal, and the transceiver 3203 may be connected to the antenna 3205. Specifically, one or more antennas 3205 may receive a radio frequency signal, and the transceiver 3203 may be configured to receive the radio frequency signal from the antennas, convert the radio frequency signal into a digital baseband signal or a digital intermediate frequency signal, and provide the digital baseband signal or the digital intermediate frequency signal to the processor 3201, so that the processor 3201 performs further processing on the digital baseband signal or the digital intermediate frequency signal, such as demodulation processing and decoding processing. In addition, the transceiver 3203 may be used to receive a modulated digital baseband signal or a digital intermediate frequency signal from the processor 3201, convert the modulated digital baseband signal or the digital intermediate frequency signal to a radio frequency signal, and transmit the radio frequency signal through one or more antennas 3205. Specifically, the transceiver 3203 may selectively perform one or more stages of down-mixing processing and analog-to-digital conversion processing on the radio frequency signal to obtain a digital baseband signal or a digital intermediate frequency signal, wherein the order of the down-mixing processing and the analog-to-digital conversion processing is adjustable. The transceiver 3203 may selectively perform one or more stages of up-mixing and digital-to-analog conversion processes on the modulated digital baseband signal or the digital intermediate frequency signal to obtain the radio frequency signal, wherein the order of the up-mixing and the digital-to-analog conversion processes is adjustable. The digital baseband signal and the digital intermediate frequency signal may be collectively referred to as a digital signal. A transceiver may be referred to as a transceiving circuit, a transceiving unit, a transceiving device, a transmitting circuit, a transmitting unit, a transmitting device, or the like.

It should be noted that the communication device 320 may be a network device complete machine, a component or assembly for implementing the functions of the network device, or a communication chip. When the communication device 320 is a communication chip, the transceiver 3203 may be an interface circuit of the chip, which is used to read in and output a baseband signal.

An embodiment of the present application provides a method for indicating HARQ information, as shown in fig. 4, the method includes the following steps:

step 401, the network device receives a BSR from a first terminal device, and allocates a first HARQ process number to the first terminal according to the BSR.

Wherein the network device may be the network device 101 in the communication system shown in fig. 2. The first terminal is the recipient of the sidestream communication, which may be referred to as the second terminal.

Specifically, when the first terminal needs to send data (for example, the first data described in this embodiment) to the second terminal, the SR indicates its own transmission requirement and is reported to the network device first. And responding to the SR reported by the first terminal, and sending the time-frequency resource for reporting the BSR to the first terminal by the network equipment. The first terminal may report the BSR using the time-frequency resources allocated by the base station, where the BSR includes a buffer size. The buffer size is used to indicate the size of the first data, and the network device may allocate, according to the buffer size in the BSR, the sidelink resource used for sending the first data and the HARQ process number used for this data transmission to the first terminal.

In a possible implementation manner, the network device itself maintains a HARQ process number set, and the network device may select one HARQ process number from the HARQ process number set as an HARQ process number related to the data transmission of the first terminal, for example, the first HARQ process number described in this embodiment of the present application.

It can be understood that the first HARQ process number is used for data transmission between the first terminal and the second terminal, that is, the process number of the HARQ process in which the first terminal sends the first data is the first HARQ process number. In addition, the "data transmission of the first terminal this time" refers to a data transmission process related to the first data, for example, the first terminal sends the first data, the second terminal receives the first data, the second terminal sends HARQ feedback to the first terminal, the first terminal receives the HARQ feedback, and the first terminal retransmits the first data.

It should be noted that the HARQ process number set maintained by the network device may be referred to as a second HARQ process number set, and the first HARQ process number described in this embodiment belongs to the second HARQ process number set.

Illustratively, the second set of HARQ process numbers maintained by the network device is {1, 2, 3 … 15}, which includes 15 HARQ process numbers. The network device may select one HARQ process number as the HARQ process number related to the data transmission of the first terminal, for example, the network device selects "3" as the HARQ process number related to the data transmission of the first terminal.

It should be noted that step 401 is an optional step, and step 402 and subsequent steps may be directly performed without performing step 401, that is, the method provided in this embodiment of the present application includes steps 402 to 404.

Step 402, the network device sends DCI including the first indication information to the first terminal.

Specifically, the DCI transmitted by the network device to the first terminal in step 402 indicates that the first terminal transmits the sidelink resource and the first HARQ process number allocated by the first data.

For example, the DCI may include time-frequency resource information and first indication information. The time frequency resource information is used for indicating a side link resource of the first data sent by the first terminal; the first indication information is used for indicating a first HARQ process number.

In a possible implementation manner, the second HARQ process number set maintained by the network device includes n HARQ process numbers, and the available length is n

Represents the HARQ process numbers in the second set of HARQ process numbers.

For example, referring to table 1, the 15 HARQ process numbers maintained by the network device may be represented by a binary sequence of 4 bits. Wherein, the first HARQ process number "1" in the second HARQ process number set is represented by binary sequence "0000", the second HARQ process number "2" in the second HARQ process number set is represented by binary sequence "0001", the third HARQ process number "3" in the second HARQ process number set is represented by binary sequence "0010", and so on, the 15 th HARQ process number "15" in the second HARQ process number set is represented by binary sequence "1110".

TABLE 1

Referring to the above example, it is assumed that the network device selects the third HARQ process number "3" in the second HARQ process number set as the HARQ process number related to the data transmission of the first terminal this time, that is, the first indication information may be a binary sequence "0010".

In another possible implementation manner, the first indication information may be a binary sequence, and the binary sequence is converted into a decimal value to obtain the first HARQ process number. Illustratively, the first indication information is "111", that is, the indicated first HARQ process number is "7".

Step 403, the first terminal receives first indication information from the network device, where the first indication information indicates the first HARQ process number.

In a specific implementation, the first indication information may be carried in DCI (DCI transmitted by the network device in step 402). The first terminal receives DCI from the network equipment, and the first indication information can be acquired from the DCI by analyzing the DCI.

Step 404, the first terminal sends side-line control information to the second terminal, where the side-line control information includes second indication information, and the second indication information is used to indicate the first HARQ process number.

Specifically, the first terminal itself also maintains a HARQ process number set, for example, the first HARQ process number set described in this embodiment. Furthermore, the first set of HARQ process numbers comprises at least all HARQ process numbers of the second set of HARQ process numbers, e.g. the first HARQ process number. The first terminal may further send second indication information to the second terminal, where the second indication information is used to indicate the first HARQ process number. That is, the first terminal may notify the second terminal that the HARQ process number related to the data transmission is the first HARQ process number through the second indication information.

In one possible implementation manner, the first HARQ process number set maintained by the first terminal includes m HARQ process numbers, and the usable length is m

Represents the HARQ process numbers in the first set of HARQ process numbers. m is an integer of n or more.

For example, it is assumed that the second HARQ process number set maintained by the network device includes HARQ process numbers "1" to "15", and the first HARQ process number set maintained by the first terminal includes at least HARQ process numbers "1" to "15". Referring to table 2, the first HARQ process number "1" in the first set of HARQ process numbers is represented by binary sequence "000", the second HARQ process number "2" in the first set of HARQ process numbers is represented by binary sequence "001", the third HARQ process number "3" in the first set of HARQ process numbers is represented by binary sequence "010", and so on.

TABLE 2

For example, the HARQ process number indicated by the first indication information is "3", where "3" is the third HARQ process number in the HARQ process numbers maintained by the first terminal, and the second indication information may be a binary sequence "010".

In another possible implementation manner, the first indication information may be a binary sequence, and the binary sequence is converted into a decimal value to obtain the first HARQ process number. Similarly, the second indication information is also a binary sequence, and the binary sequence is converted into a decimal value to obtain the first HARQ process number indicated by the second indication information.

Illustratively, the first indication information is "111", that is, the first HARQ process number indicated by the first information is "7". The second indication information indicates the first HARQ process number "7", and the second indication information is "111".

Different from the resource configuration mode supported by the first terminal, the HARQ process number set locally maintained by the first terminal has the following two possible implementations:

in the first method, the first terminal only supports mode-1, the first terminal does not select the sidelink resource by itself, and the HARQ process number locally maintained by the first terminal is only used for mode-1.

Illustratively, referring to fig. 5, the first set of HARQ process numbers maintained locally by the first terminal includes at least one HARQ process number for data transmission of the first mode. The first HARQ process number set may be the same as a second HARQ process number set maintained by the network device, and the first HARQ process number set includes a first HARQ process number indicated by the first indication information; the first mode is a mode in which the network device schedules sidelink resources, that is, mode-1 described in the embodiment of the present application.

It should be noted that, HARQ process numbers maintained by the first terminal are all used in mode-1, and the HARQ process number selected by the network device for this data transmission is not occupied by mode-2. The first terminal receives the first indication information from the network device, determines a first HARQ process number indicated by the first indication information, the first HARQ process number is not occupied by mode-2, and the first terminal can directly use the HARQ process number selected by the network device for the data transmission, namely, send the second indication information to the second terminal to indicate the first HARQ process number. The second terminal receives the second indication information from the first terminal, and may determine, according to the first indication information, that the HARQ process number associated with the data transmission between the first terminal and the second terminal is the first HARQ process number.

And in the second mode, the first terminal supports two sidelink resource configuration modes of mode-1 and mode-2, the HARQ process number in the first HARQ process number set can be used for mode-1 and also can be used for mode-2, but the HARQ process number used for mode-1 and the HARQ process number used for mode-2 are completely different.

For example, referring to fig. 6, the first terminal maintains a first set of HARQ process numbers, and the second set of HARQ process numbers maintained by the network device is a subset of the first set of HARQ process numbers. The first set of HARQ process numbers includes at least one HARQ process number for data transmission of the first mode. The first HARQ process number set comprises the first HARQ process number indicated by the first indication information. Furthermore, the first set of HARQ process numbers further comprises at least one HARQ process number for data transmission of the second mode, the at least one HARQ process number for data transmission of the second mode being different from the at least one HARQ process number for data transmission of the first mode.

It should be noted that the second mode is a mode in which the terminal determines the sidelink resource by itself, that is, mode-2 described in the embodiment of the present application. The HARQ process number for the first mode in the first set of HARQ process numbers and the HARQ process number for the second mode therein are completely different. Illustratively, referring to fig. 6, the first set of HARQ process numbers includes HARQ process numbers "0" through HARQ process number "N". The HARQ process number from '0' to'm' is used for data transmission in the first mode, and the HARQ process number from'm + 1' to 'n' is used for data transmission in the second mode.

It can be understood that the HARQ process number maintained by the first terminal is for mode-1 or mode-2, but the HARQ process number for mode-1 is completely different from the HARQ process number for mode-2, and the HARQ process number selected by the network device for this data transmission is not occupied by mode-2. The first terminal receives the first indication information from the network equipment, determines a first HARQ process number indicated by the first indication information, wherein the first HARQ process number cannot be occupied by the mode-2, and the first terminal can directly use the HARQ process number selected by the network equipment for the data transmission, namely, sends second indication information to the second terminal to indicate the first HARQ process number. The second terminal receives the second indication information from the first terminal, and may determine, according to the first indication information, that the HARQ process number associated with the data transmission between the first terminal and the second terminal is the first HARQ process number.

Optionally, the sideline control information is further configured to indicate first data, that is, data transmitted by using the first HARQ process number between the first terminal and the second terminal. The method shown in fig. 4 further comprises: and the first terminal sends the first data to the second terminal. Wherein the first data is associated with the first HARQ process number.

It should be noted that the first data is related to the first HARQ process number, that is, the HARQ process corresponding to the first HARQ process number is used to transmit the first data. For example, the first terminal uses the HARQ process corresponding to the first HARQ process number to transmit the first data, and the second terminal uses the HARQ process corresponding to the first HARQ process number to receive the first data. For example, the data in the HARQ buffer corresponding to the first HARQ process number is merged and decoded to obtain the first data.

In the method shown in fig. 4 in this embodiment of the present application, HARQ process numbers of mode-1 and mode-2 are completely distinguished, HARQ process numbers in different modes used do not conflict, HARQ process numbers maintained by a network device and a terminal for the same data transmission can be the same, and one HARQ process number is associated with one data transmission (including initial transmission and retransmission). The network equipment sends the first indication information to the first terminal to indicate the HARQ process number selected for one-time data transmission, and the first terminal can determine the HARQ process number selected for one-time data transmission by the network equipment according to the first information, so that the problem that the base station and the sending terminal UE have inconsistent understanding on the HARQ process number of the same-time data transmission is solved, and the transmission reliability between the terminals can be improved.

In addition, the network device can schedule the HARQ process number, the first terminal can distinguish the resources allocated to the network device according to the process number, and the resources allocated to a certain data transmission by the network device cannot be used by the first terminal for data transmission corresponding to other HARQ process numbers, so that the accuracy of network device scheduling is improved, the influence on the data transmission can be reduced, and the transmission performance is improved.

Illustratively, the first terminal receives DCI from the network device, the DCI indicates the HARQ process number and the sidelink resource, and the first terminal may determine which HARQ process number the resource indicated by the DCI is used for data transmission corresponding to, so as to avoid using the sidelink resource for data transmission corresponding to other HARQ process numbers, thereby improving transmission reliability between terminals.

An embodiment of the present application further provides a method for indicating HARQ information, as shown in fig. 7, the method includes the following steps:

step 701, a network device receives a BSR from a first terminal device, and allocates a first HARQ process number to the first terminal according to the BSR.

It can be understood that the first HARQ process number is used for data transmission between the first terminal and the second terminal, that is, the process number of the HARQ process in which the first terminal sends the first data is the first HARQ process number. In addition, in the data transmission process related to the first data indicated by the current data transmission of the first terminal, for example, the first terminal sends the first data, the second terminal receives the first data, the second terminal sends HARQ feedback to the first terminal, the first terminal receives the HARQ feedback, and the first terminal retransmits the first data.

It should be noted that step 701 is an optional step, and step 702 and subsequent steps may be directly performed without performing step 701, that is, the method provided in this embodiment of the present application includes steps 702 to 705.

Step 702, the network device sends DCI including the first indication information to the first terminal.

Specifically, the network device indicates, in step 702, the DCI transmitted to the first terminal, where the first terminal transmits the first data allocated sidelink resource and the first HARQ process number.

Represents the HARQ process numbers in the second set of HARQ process numbers.

It is assumed that the network device selects the third HARQ process number "3" in the second HARQ process number set as the HARQ process number associated with the data transmission of the first terminal, that is, the first indication information may be a binary sequence "0010".

Step 703, the first terminal receives first indication information from the network device, where the first indication information is used to indicate the first HARQ process number.

In a specific implementation, the first indication information is carried in DCI (DCI transmitted by the network device in step 702). The first terminal receives DCI from the network equipment, and the first indication information can be acquired from the DCI by analyzing the DCI.

Step 704, under the condition that the first HARQ process number is not occupied by the first terminal, the first terminal sends side-line control information to the second terminal, where the side-line control information includes second indication information, and the second indication information is used to indicate the first HARQ process number.

Specifically, the first terminal itself maintains a HARQ process number set, for example, the first HARQ process number set described in this embodiment. Meanwhile, the first terminal can support two sidelink resource configuration modes of mode-1 and mode-2, and does not limit which HARQ process numbers are used for mode-1 and which HARQ process numbers are used for mode-2. It is possible that a certain HARQ process number in the first set of HARQ process numbers is used for both mode-1 and mode-2. That is to say, when the network device allocates the HARQ process number to the data transmission of the first terminal this time, the network device does not know the behavior of the first terminal itself, and it is assumed that the network device allocates the HARQ process number "x" to the data transmission of the first terminal this time, and actually, the HARQ process number "x" may have been already allocated to other HARQ processes by the first terminal.

The first terminal maintains a first set of HARQ process numbers, and a certain HARQ process number in the set may be used for mode-1 or mode-2. That is, the HARQ process number "x" in the first HARQ process number set may be an HARQ process number selected by the network device under mode-1 for sidelink data transmission of the terminal, or an HARQ process number selected by the terminal under mode-2 for sidelink data transmission of the terminal itself.

For example, referring to fig. 8, the first set of HARQ process numbers and the second set of HARQ process numbers maintained by the network device may be the same. The first set of HARQ process numbers includes HARQ process numbers "0" to "N". Any HARQ process number can be used for sidelink data transmission under mode-1 and mode-2.

It can be understood that the HARQ process number maintained by the first terminal is used for mode-1 or mode-2, and the HARQ process number selected by the network device for this data transmission may be occupied by mode-2. The first terminal receives the first indication information from the network device, determines the first HARQ process number indicated by the first indication information, and if the first HARQ process number is not occupied, the first terminal may directly use the HARQ process number selected by the network device for the data transmission, that is, send the second indication information to the second terminal to indicate the first HARQ process number. The second terminal receives the second indication information from the first terminal, and may determine, according to the first indication information, that the HARQ process number associated with the data transmission between the first terminal and the second terminal is the first HARQ process number.

In a possible implementation manner, the HARQ entity of the first terminal does not include the HARQ process corresponding to the first HARQ process number, and the first HARQ process number is considered to be unoccupied by the first terminal.

Step 705, in a case that the first HARQ process number is occupied by the first terminal, the first terminal sends side row control information to the second terminal, where the side row control information includes third indication information, and the third indication information is used to indicate the second HARQ process number.

The second HARQ process number is an unoccupied HARQ process number in the first HARQ process number set maintained by the first terminal.

It can be understood that the HARQ process number maintained by the first terminal is used for mode-1 or mode-2, and the HARQ process number selected by the network device for this data transmission may be occupied by mode-2. The first terminal receives the first indication information from the network equipment and determines a first HARQ process number indicated by the first indication information. Assuming that the first HARQ process number is occupied, the first terminal selects an unoccupied HARQ process number (e.g., the second HARQ process number described in this embodiment) from the first HARQ process number set as the HARQ process number associated with the data transmission of the first terminal. The first terminal may also send third indication information to the second terminal, indicating the second HARQ process number. The second terminal receives the third indication information from the first terminal, and may determine, according to the third indication information, that the HARQ process number associated with the data transmission between the first terminal and the second terminal is the second HARQ process number.

In a possible implementation manner, the HARQ entity of the first terminal includes an HARQ process corresponding to the first HARQ process number, and the first HARQ process number is considered to be occupied by the first terminal.

Optionally, the sideline control information is further configured to indicate first data, that is, data transmitted by using the first HARQ process number between the first terminal and the second terminal. The method shown in fig. 7 further comprises: and the first terminal sends the first data to the second terminal. Wherein the first data is associated with the first HARQ process number.

It should be noted that the first data is related to the first HARQ process number, that is, the HARQ process corresponding to the first HARQ process number is used to transmit the first data. For example, the first terminal uses the HARQ process corresponding to the first HARQ process number to transmit the first data, and the second terminal uses the HARQ process corresponding to the first HARQ process number to receive the first data.

In addition, if the HARQ process number (mode-1) selected by the network device for one data transmission of the terminal is not occupied, the first terminal does not need to reselect the HARQ process number for the transmission, the network device selected by the network device is directly used, the base station and the sending terminal UE have consistent understanding on the HARQ process number of the same data transmission, and the transmission reliability between the terminals can be improved.

In addition, the network device can also schedule the HARQ process number, the first terminal can distinguish the resources allocated to the network device according to the process number, and the resources allocated to a certain data transmission by the network device cannot be used by the first terminal for data transmission corresponding to other HARQ process numbers, so that the accuracy of network device scheduling is improved, the influence on the data transmission can be reduced, and the transmission performance is improved.

The method provided by the embodiment of the application is described in detail below with reference to specific examples. The sender of the sidestream communication is called a sending UE, and the receiver of the sidestream communication is called a receiving UE.

In one possible implementation, the sending UE only supports mode-1, and the network device and the sending UE maintain the same HARQ process number. For example, as shown in fig. 9, it is assumed that HARQ process numbers for the sidelink maintained by the network device are 0 to M, and HARQ process numbers maintained by the sending UE are 0 to M.

The base station needs a HARQ process number field in DCI sent to the sending UE, where the HARQ process number field is used to indicate a HARQ process number selected by the network device for sending the data transmission of the UE this time. The SCI sent by the sending UE to the receiving UE also needs to include a HARQ process number field for indicating the UE-side HARQ process number. Note that the HARQ process number indicated by the DCI and the HARQ process number indicated by the SCI are consistent.

The sending UE only needs to decode the HARQ process number field of the DCI from the base station, and then directly loads the field in the SCI to send to the receiving UE without modifying the field. For example, referring to fig. 9, assume that the HARQ process number field in DCI transmitted by the network device is "110", indicating HARQ process number 6. And the sending UE receives the DCI, analyzes the DCI to obtain the HARQ process number field of 110, directly loads the HARQ process number field of 110 in the SCI and sends the HARQ process number field to the receiving UE.

In another possible implementation manner, the sending UE supports mode-1 and mode-2 simultaneously, HARQ process numbers maintained by the network device and the sending UE are not identical, and a HARQ process number set maintained by the network device is a subset of a HARQ process number set maintained by the sending UE. Specifically, as shown in fig. 10, HARQ process numbers maintained by the network device are 0 to N, HARQ process numbers maintained by the sending UE side are 0 to M, N, M is a configurable parameter, and M is greater than N. HARQ process numbers 0-N maintained by the sending UE side can be used for mode-1, and HARQ process numbers N + 1-M can be used for mode-2.

The base station needs a HARQ process number field in DCI sent to the sending UE, where the HARQ process number field is used to indicate a HARQ process number selected by the network device for sending the data transmission of the UE this time. The SCI sent by the sending UE to the receiving UE also needs to include a HARQ process number field for indicating the HARQ process number on the UE side. Note that the HARQ process number indicated by the DCI and the HARQ process number indicated by the SCI are consistent.

The sending UE only needs to decode the HARQ process number field of the DCI from the base station, and then directly loads the field in the SCI to send to the receiving UE without modifying the field. For example, referring to fig. 10, assume that the HARQ process number field in DCI transmitted by the network device is "110", indicating HARQ process number 6. And the sending UE receives the DCI, analyzes the DCI to obtain the HARQ process number field of 110, directly loads the HARQ process number field of 110 in the SCI and sends the HARQ process number field to the receiving UE.

In another possible implementation manner, the sending UE supports mode-1 and mode-2 at the same time, the HARQ process numbers maintained by the network device and the sending UE are the same, and the HARQ process number on the network device side and the HARQ process number on the UE side may conflict with each other, that is, the HARQ process number selected by the network device for data transmission of the sending UE in mode-1 may already be occupied by the sending UE.

The base station needs a HARQ process number field in DCI sent to the sending UE, where the HARQ process number field is used to indicate a HARQ process number selected by the network device for sending the data transmission of the UE this time. The SCI sent by the sending UE to the receiving UE also needs to include a HARQ process number field for indicating the HARQ process number on the UE side. The HARQ process number indicated by the DCI may be different from the HARQ process number indicated by the SCI, which is as follows:

after receiving DCI from the network equipment, the sending UE finds that the HARQ process number indicated by the HARQ process number field of the DCI is occupied, selects one of the unoccupied HARQ process numbers and sends SCI to the receiving UE, wherein the HARQ process number field of the SCI indicates the HARQ process number selected by the sending UE in the unoccupied HARQ process number.

It should be noted that the occupied HARQ process numbers include: the transmitting UE in mode-2 allocates the HARQ process number for data transmission. However, if the data corresponding to the HARQ process number is not yet transmitted, the transmitting UE may still preempt the HARQ process number and send the HARQ process number to the receiving UE by carrying it in DCI. And if the data corresponding to the HARQ process number is already sent, the sending UE abandons the HARQ process number, and selects other unoccupied HARQ process numbers to carry the HARQ process numbers in the DCI and sends the DCI to the receiving UE.

Of course, if the sending UE receives DCI from the network device, finds that the HARQ process number indicated by the HARQ process number field of the DCI is not occupied, sends an SCI to the receiving UE, and the HARQ process number field of the SCI indicates the same HARQ process number.

For example, referring to fig. 11, assuming that HARQ process numbers for the sidelink maintained by the transmitting UE are 0 to 15, the transmitting UE sequentially receives DCI1, DCI2, and DCI3 sent by the network device, where the HARQ process number indicated by the HARQ process number field of DCI1 is 0, the HARQ process number indicated by the HARQ process number field of DCI1 is 1, and the HARQ process number indicated by the HARQ process number field of DCI2 is 2. And at this time, the HARQ process number of the UE side is not occupied by the mode-2, so

HARQ process numbers

0, 1, and 2 from the base station in the mode of mode-1 are sequentially mapped to

HARQ process numbers

0, 1, and 2 of the UE side. That is, the transmitting UE transmits SCI1 after receiving DCI1, and the HARQ process number indicated by the HARQ process number field of SCI1 is 0; the transmitting UE transmits SCI2 after receiving the DCI2, and the HARQ process number indicated by the HARQ process number field of SCI2 is 1; and the transmitting UE transmits SCI3 after receiving the DCI3, wherein the HARQ process number indicated by the HARQ process number field of SCI3 is 2.

Subsequently, assuming that the

HARQ process numbers

3 and 4 maintained by the sending UE are occupied by mode-2, the sending UE receives DCI4 from the network device, and the HARQ process number indicated by the HARQ process number field of DCI4 is 3. Because the

HARQ process numbers

3 and 4 maintained by the sending UE side are occupied, the sending UE maps the HARQ process number indicated by the DCI4 to the HARQ process number 5. The transmitting UE transmits SCI4 to the receiving UE, and the HARQ process number indicated by the HARQ process number field of SCI4 is 5.

In the embodiment of the application, HARQ process numbers occupied by mode-1 and mode-2 are not distinguished. When allocating sidelink resources, the network device allocates HARQ process number for one transmission at the same time, but this HARQ process number may be occupied by mode-2. If the sending end UE still uses the occupied HARQ process number to transmit data, the sending end UE may obtain data in the wrong HARQ buffer, thereby causing transmission of wrong data. In order to avoid the problem, when the sending end UE identifies that the HARQ process number selected by the base station is occupied, the sending end UE reallocates an unoccupied HARQ process number for the data transmission, thereby ensuring the correctness of the transmission. That is to say, one HARQ process number or two HARQ process numbers may be associated with one transmission (including initial transmission and retransmission), the base station may indicate a corresponding HARQ process number when allocating retransmission resources, and the terminal may determine, according to a mapping relationship of the HARQ process numbers, which redundancy version of data is used for transmitting retransmission resources, so as to avoid transmission confusion.

For example, if the process number selected by the base station for one transmission is "2", and it is assumed that the process number "2" is occupied, that is, there is data in the HARQ buffer corresponding to the process number "2", if the first terminal still uses the process number "2" to perform the data transmission, the data in the HARQ buffer corresponding to the process number "2" is sent to the second terminal, and erroneous data is transmitted.

Conversely, if the first terminal recognizes that process number "2" is occupied, the unoccupied process number "5" is reallocated for the data transmission. The first terminal may put the data to be transmitted into the HARQ buffer corresponding to the process number "5", and may also obtain the data from the HARQ buffer corresponding to the process number "5", and send the obtained data to the second terminal, thereby ensuring the correctness of data transmission.

Optionally, the first terminal maintains a mapping relationship between the first HARQ process number and the second HARQ process number. The first terminal receives DCI from the network device, the DCI indicating retransmission resources, the DCI including a first HARQ process number. The first terminal puts the retransmission data into the HARQ buffer corresponding to the second HARQ process number, and may also indicate the second HARQ process number to the second terminal through the SCI. And then, the first terminal retransmits the data on the retransmission resource indicated by the DCI, stores the retransmission data in the HARQ buffer corresponding to the second HARQ process number, and performs combined decoding on the initial transmission data and the retransmission data in the HARQ buffer corresponding to the second HARQ process number.

Illustratively, the network device selects HARQ process number "3" for one transmission corresponding to TB1, when HARQ process number "3" is occupied, the first terminal reallocates HARQ process number "5" for this data transmission, and the first terminal maintains a mapping relationship between HARQ process number "3" and HARQ process number "5". The second terminal stores TB1 in the HARQ buffer corresponding to HARQ process number "5".

Assuming that the second terminal did not successfully decode TB1, the network device allocates retransmission resources while indicating process number "3". The first terminal stores TB2 (redundancy version of TB1) in HARQ buffer of HARQ process number "5" according to mapping relationship of HARQ process number "3" and HARQ process number "5", then acquires TB2 therein and sends TB2 to the second terminal. The second terminal stores TB2 in HARQ buffer of HARQ process number "5", and may also perform combined decoding on TB1 and TB2 in HARQ buffer of HARQ process number "5".

Fig. 12 shows a schematic diagram of a possible structure of the communication device according to the above embodiment, in the case of dividing each functional module according to each function. The communication apparatus shown in fig. 12 may be the first terminal described in the embodiment of the present application, or may be a component of the first terminal, which implements the method described above. As shown in fig. 12, the communication apparatus includes a processing unit 1201 and a transmitting/receiving unit 1202. The processing unit may be one or more processors and the transceiving unit may be a transceiver.

A processing unit 1201 for enabling the first terminal to generate the second indication information, and/or other processes for the techniques described herein.

A transceiver unit 1202, configured to perform step 402, step 403, step 404, step 702, step 703, step 704, and/or other processes for the techniques described herein for the terminal.

It should be noted that all relevant contents of each step related to the above method embodiment may be referred to the functional description of the corresponding functional module, and are not described herein again.

In a possible implementation manner, the communication device shown in fig. 12 may also be a chip applied in a terminal. The Chip may be a System-On-a-Chip (SOC) or a baseband Chip with a communication function.

The above transceiving unit 1202 for receiving/transmitting may be an interface circuit of the apparatus for receiving signals from other apparatuses. For example, when the apparatus is implemented in the form of a chip, the transceiver unit 1202 is an interface circuit of the chip, and the interface circuit is used for reading in or outputting a baseband signal.

For example, in the case of using an integrated unit, a schematic structural diagram of a communication device provided in an embodiment of the present application is shown in fig. 13. In fig. 13, the communication apparatus includes: a processing module 1301 and a communication module 1302. Processing module 1301 is used to control and manage the actions of the communication apparatus, e.g., to perform the steps performed by processing unit 1401 described above, and/or other processes for performing the techniques described herein. The communication module 1302 is configured to perform the steps performed by the transceiver 1402, and support interaction between the communication apparatus and other devices, such as interaction with other terminal apparatuses. As shown in fig. 13, the communication device may further include a storage module 1303, and the storage module 1303 is used for storing program codes and data of the communication device.

When the processing module 1301 is a processor, the communication module 1302 is a transceiver, and the storage module 1303 is a memory, the communication device is the communication device shown in fig. 3 a.

Fig. 14 shows a schematic diagram of a possible structure of the communication device according to the above-described embodiment, in a case where each functional module is divided according to each function. The communication apparatus shown in fig. 14 may be a network device according to the embodiment of the present application, or may be a component in the network device, which implements the foregoing method. As shown in fig. 14, the communication apparatus includes a processing unit 1401 and a transmitting/receiving unit 1402. The processing unit may be one or more processors and the transceiving unit may be a transceiver.

A processing unit 1401 for enabling the network device to perform steps 701, 401, generate the first indication information, and/or other processes for the techniques described herein.

A transceiving unit 1402 for supporting communication between the network device and other communication apparatuses, e.g., for supporting the network device to perform steps 402 and 702, and/or other processes for the techniques described herein.

In a possible implementation manner, the communication apparatus shown in fig. 14 may also be a chip applied in a network device. The Chip may be a System-On-a-Chip (SOC) or a baseband Chip with a communication function.

The above transceiving unit 1402 for receiving/transmitting may be an interface circuit of the apparatus for reading in a baseband signal. For example, when the apparatus is implemented in the form of a chip, the transceiving unit 1402 is an interface circuit for the chip to read in a baseband signal, or the transceiving unit 1402 is an interface circuit for the chip to output a baseband signal.

For example, in the case of using an integrated unit, a schematic structural diagram of a communication device provided in an embodiment of the present application is shown in fig. 15. In fig. 15, the communication apparatus includes: a processing module 1501 and a communication module 1502. The processing module 1501 is used for controlling and managing the actions of the communication device, e.g., performing the steps performed by the processing unit 1601 described above, and/or other processes for performing the techniques described herein. The communication module 1502 is configured to perform the steps performed by the transceiver unit 1602 described above, and support interaction between the communication apparatus and other devices, such as interaction with other terminal apparatuses. As shown in fig. 15, the communication device may further include a storage module 1503 for storing program codes and data of the communication device.

When the processing module 1501 is a processor, the communication module 1502 is a transceiver, and the storage module 1503 is a memory, the communication device is the communication device shown in fig. 3 b.

The embodiment of the application provides a computer-readable storage medium, wherein instructions are stored in the computer-readable storage medium; the instructions are for performing a method as shown in fig. 4 or fig. 7.

Embodiments of the present application provide a computer program product comprising instructions, which when run on a communication apparatus, cause the communication apparatus to implement a method as shown in fig. 4 or fig. 7.

An embodiment of the present application provides a wireless communication apparatus, including: instructions are stored in the wireless communication device; when the wireless communication device is operating on the communication device shown in fig. 3a, 3b, 12-15, the communication device is caused to implement the method as shown in fig. 4 or 7. The wireless communication device may be a chip or the like.

Through the description of the above embodiments, it is clear to those skilled in the art that, for convenience and simplicity of description, the foregoing division of the functional modules is merely used as an example, and in practical applications, the above functions may be distributed by different functional modules according to needs, that is, the internal structure of the database access apparatus may be divided into different functional modules to complete all or part of the above described functions.

In the several embodiments provided in the present application, it should be understood that the disclosed database access apparatus and method may be implemented in other ways. For example, the above-described database access device embodiments are merely illustrative, and for example, the division of the modules or units is only one logical division, and there may be other divisions when actually implemented, for example, multiple units or components may be combined or integrated into another device, or some features may be omitted, or not executed. In addition, the shown or discussed coupling or direct coupling or communication connection between each other may be an indirect coupling or communication connection through some interfaces, database access devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may be one physical unit or a plurality of physical units, that is, may be located in one place, or may be distributed in a plurality of different places. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a readable storage medium. Based on such understanding, the technical solutions of the embodiments of the present application may be essentially or partially contributed to by the prior art, or all or part of the technical solutions may be embodied in the form of a software product, where the software product is stored in a storage medium and includes several instructions to enable a device (which may be a single chip microcomputer, a chip, or the like) or a processor to execute all or part of the steps of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a U disk, a removable hard disk, a ROM, a RAM, a magnetic disk, or an optical disk.

The above description is only an embodiment of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions within the technical scope of the present disclosure should be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

A method for indicating hybrid automatic repeat request (HARQ) information,

a first terminal receives first indication information from network equipment, wherein the first indication information is used for indicating a first HARQ process number, and the first HARQ process number is used for data transmission between the first terminal and a second terminal;

and the first terminal sends side row control information to the second terminal, wherein the side row control information comprises second indication information, and the second indication information is used for indicating the first HARQ process number.
The method of claim 1, wherein the sideline control information is further used for indicating first data, and wherein the method further comprises:

and the first terminal sends the first data to the second terminal, wherein the first data is related to the first HARQ process number.
The method according to claim 1 or 2, characterized in that the first terminal maintains a first set of HARQ process numbers, the first HARQ process number belonging to the first set of HARQ process numbers, the first set of HARQ process numbers comprising at least one HARQ process number for data transmission of a first mode; the first mode is a mode for scheduling side link resources by the network equipment;

and the first HARQ process number belongs to a second set of HARQ process numbers maintained by the network device.
The method of claim 3, wherein the first set of HARQ process numbers further comprises at least one HARQ process number for data transmission in a second mode, the second mode being a mode in which the terminal determines sidelink resources on its own; the at least one HARQ process number for data transmission of the second mode is different from the at least one HARQ process number for data transmission of the first mode.
The method according to any of claims 1-4, wherein the first indication information is carried in downlink control information, DCI.
A method for indicating hybrid automatic repeat request (HARQ) information, the method comprising:

a first terminal receives first indication information from network equipment, wherein the first indication information is used for indicating a first HARQ process number, and the first HARQ process number is used for data transmission between the first terminal and a second terminal;

under the condition that the first HARQ process number is not occupied by the first terminal, the first terminal sends side row control information to the second terminal, wherein the side row control information comprises second indication information, and the second indication information is used for indicating the first HARQ process number;

and under the condition that the first HARQ process number is occupied by the first terminal, the first terminal sends side row control information to the second terminal, wherein the side row control information comprises third indication information, the third indication information is used for indicating a second HARQ process number, the second HARQ process number is an unoccupied HARQ process number in a first HARQ process number set, and the first HARQ process number set is an HARQ process number set maintained by the first terminal.
The method of claim 6, wherein the first HARQ process number is not occupied by the first terminal, comprising:

the HARQ entity of the first terminal does not comprise the HARQ process corresponding to the first HARQ process number;

the first HARQ process number being occupied by the first terminal, including:

and the HARQ entity of the first terminal comprises the HARQ process corresponding to the first HARQ process number.
The method of claim 6 or 7, wherein the sideline control information is further used for indicating first data, and wherein the method further comprises:

and the first terminal sends the first data to the second terminal, wherein the first data is related to the first HARQ process number or the second HARQ process number.
The method according to any of claims 6-7, wherein the first indication information is carried in downlink control information, DCI.
A communications apparatus, comprising:

a transceiving unit, configured to receive first indication information from a network device, where the first indication information is used to indicate a first HARQ process number, and the first HARQ process number is used for data transmission between the first terminal and a second terminal;

the transceiver unit is further configured to send sidestream control information to the second terminal, where the sidestream control information includes second indication information, and the second indication information is used to indicate the first HARQ process number.
The apparatus of claim 10, wherein the sidelink control information is further configured to indicate first data, and wherein the transceiver unit is further configured to transmit the first data to the second terminal, and wherein the first data is associated with the first HARQ process number.
The apparatus of claim 10 or 11, wherein the first terminal maintains a first set of HARQ process numbers, the first HARQ process number belonging to the first set of HARQ process numbers, the first set of HARQ process numbers comprising at least one HARQ process number for data transmission of a first mode; the first mode is a mode for scheduling side link resources by the network equipment;

and the first HARQ process number belongs to a second set of HARQ process numbers maintained by the network device.
The apparatus of claim 12, wherein the first set of HARQ process numbers further comprises at least one HARQ process number for data transmission in a second mode, the second mode being a mode in which the terminal determines sidelink resources on its own; the at least one HARQ process number for data transmission of the second mode is different from the at least one HARQ process number for data transmission of the first mode.
The apparatus according to any of claims 10-13, wherein the first indication information is carried in downlink control information, DCI.
An apparatus, comprising:

a transceiving unit, configured to receive first indication information from a network device, where the first indication information is used to indicate a first HARQ process number, and the first HARQ process number is used for data transmission between the first terminal and a second terminal;

the processing unit is used for determining whether the first HARQ process number is occupied by the first terminal;

the transceiving unit is further configured to, when the processing unit determines that the first HARQ process number is not occupied by the first terminal, send, by the first terminal, sidestream control information to the second terminal, where the sidestream control information includes second indication information, and the second indication information is used to indicate the first HARQ process number;

the transceiving unit is further configured to, when the processing unit determines that the first HARQ process number is occupied by the first terminal, send, by the first terminal, sidestream control information to the second terminal when the first HARQ process number is occupied by the first terminal, where the sidestream control information includes third indication information, the third indication information is used to indicate a second HARQ process number, the second HARQ process number is an unoccupied HARQ process number in a first HARQ process number set, and the first HARQ process number set is a HARQ process number set maintained by the first terminal.
The apparatus according to claim 15, wherein the processing unit is specifically configured to determine that the HARQ process corresponding to the first HARQ process number is unoccupied if the HARQ entity of the first terminal does not include the HARQ process corresponding to the first HARQ process number;

and if the HARQ entity of the first terminal comprises the HARQ process corresponding to the first HARQ process number, determining that the first HARQ process number is occupied by the first terminal.
The apparatus of claim 15 or 16, wherein the sidelink control information is further configured to indicate first data, and wherein the transceiving unit is further configured to transmit the first data to the second terminal, and wherein the first data is related to the first HARQ process number or the second HARQ process number.
The apparatus according to any of claims 15-17, wherein the first indication information is carried in downlink control information, DCI.
A communications apparatus comprising at least one processor and a memory, the at least one processor coupled with the memory;

the memory for storing a computer program;

the at least one processor configured to execute a computer program stored in the memory to cause the apparatus to perform the method of any of claims 1-9.
A computer-readable storage medium, characterized in that it stores a computer program or instructions which, when executed, implement the method of any one of claims 1 to 9.
A communication system, comprising: the system comprises network equipment, a first terminal and a second terminal;

the network device is configured to send first indication information to a first terminal, where the first indication information is used to indicate a first HARQ process number, and the first HARQ process number is used for data transmission between the first terminal and a second terminal;

the first terminal is configured to receive first indication information from the network device, and send sidestream control information to the second terminal, where the sidestream control information includes second indication information, and the second indication information is used to indicate the first HARQ process number;

the second terminal is used for receiving the second indication information from the first terminal;

alternatively, the first and second electrodes may be,

the network equipment is used for sending first indication information to a first terminal, wherein the first indication information is used for indicating a first HARQ process number, and the first HARQ process number is used for data transmission between the first terminal and a second terminal;

the first terminal receives first indication information from network equipment, and sends side-line control information to the second terminal under the condition that the first HARQ process number is not occupied by the first terminal, wherein the side-line control information comprises second indication information, and the second indication information is used for indicating the first HARQ process number; under the condition that the first HARQ process number is occupied by the first terminal, the first terminal sends side row control information to the second terminal, wherein the side row control information comprises third indication information, the third indication information is used for indicating a second HARQ process number, the second HARQ process number is an unoccupied HARQ process number in a first HARQ process number set, and the first HARQ process number set is an HARQ process number set maintained by the first terminal;

the second terminal is used for receiving the sideline control information from the first terminal.