CN115733592A

CN115733592A - Communication method and device

Info

Publication number: CN115733592A
Application number: CN202111007047.7A
Authority: CN
Inventors: 焦春旭; 苏宏家; 郭文婷; 卢磊
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-08-30
Filing date: 2021-08-30
Publication date: 2023-03-03
Also published as: WO2023029976A1

Abstract

The application provides a communication method and device, which can be applied to sidelink communication or car networking, such as V2X, or can be applied to the fields of intelligent driving and the like. The method comprises the following steps: the method includes receiving at least one transport block from a first apparatus and transmitting second level Sidelink Control Information (SCI) to the first apparatus in a sidelink data channel, the second level SCI carrying a first hybrid automatic repeat request (HARQ) codebook, wherein the first HARQ codebook is used for determining at least one HARQ feedback information corresponding to the at least one transport block.

Description

Communication method and device

Technical Field

The present application relates to the field of communications technologies, and in particular, to a communication method and apparatus.

Background

In the evolution of wireless communication systems, the reliability of transmissions has been one of the important technical directions in wireless communication. In a Uu interface between a User Equipment (UE) and a base station, a hybrid automatic repeat request (HARQ) is an effective method for improving transmission reliability. Based on HARQ, after a sender sends a Transport Block (TB) to a receiver for the first time, the receiver feeds back HARQ feedback information such as an Acknowledgement (ACK) or a Negative Acknowledgement (NACK) to the sender, and the sender determines whether to retransmit the TB to the receiver according to the HARQ feedback information, and improves the transmission reliability of data information based on Forward Error Correction (FEC) codes.

Similarly, HARQ is also used in Sidelink (SL) communication between UEs as one of the important methods for improving transmission reliability. In SL communication, a transmitting end may transmit a TB through a physical side link shared channel (PSSCH), and a receiving end may feed back ACK or NACK through a physical side link feedback channel (PSFCH) after receiving the TB. The slots containing the PSFCH resources may be periodic in time domain, e.g., there may be 1 slot containing the PSFCH resources in every L slots (slots), where L may have a value in the range of {0,1,2,4}. When the value of L is 0, it may indicate that there is no PSFCH in the current SL communication, that is, the receiving end does not need to send HARQ feedback information to the transmitting end.

With the continuous development of SL communication, the current SL feedback mechanism may not meet the requirements of increasing reliability and communication efficiency.

Disclosure of Invention

The application provides a communication method and a communication device, which can improve communication reliability.

In a first aspect, the present application provides a communication method, where an execution subject of the method may be a terminal device, or may be a combined device or a component having a function of the terminal device, or may be a chip or a circuit system (e.g., a processor, a baseband chip, a module, a Telematics BOX (TBOX), or a chip system, etc.) applied to the terminal device. The method comprises the following steps: the method includes receiving at least one transport block from a first apparatus, and transmitting second-level Sidelink Control Information (SCI) to the first apparatus in a sidelink data channel, the second-level SCI carrying a first HARQ codebook, wherein the first HARQ codebook includes at least one HARQ feedback information corresponding to the at least one transport block.

In the embodiment of the application, HARQ feedback can be carried out through the HARQ codebook in the sidelink communication system, the SL HARQ feedback efficiency is improved, and the communication reliability is further improved. In addition, compared with the method that the HARQ codebook is carried in the first-level SCI, the HARQ codebook is sent in the second-level SCI, so that the decoding complexity of the first-level SCI can be reduced, and the transmission efficiency of the control channel can be guaranteed. Meanwhile, compared with the method that the HARQ codebook is loaded in the sidelink data, the method that the HARQ codebook is loaded in the second-level SCI can improve the decoding reliability. Generally, the second-stage SCI is modulated by Quadrature Phase Shift Keying (QPSK), the sidelink data is modulated by a higher-order modulation method, and the HARQ codebook carried in the second-stage SCI is modulated by a lower-order method than the sidelink data, so that the reliability of decoding the HARQ codebook at the receiving end is higher.

In one possible design, the format of the second-level SCI includes at least a first format and a second format, where the first format includes a field for carrying the HARQ codebook and the second field does not include a field for carrying the HARQ codebook. The above design may implement transmitting the HARQ codebook in the second-level SCI by adding the first format.

In one possible design, the method further includes: first indication information may be received from a first apparatus, the first indication information indicating that a first HARQ codebook is transmitted. By means of sending the first indication information, the receiving end (i.e. the apparatus for performing the method) and the sending end (i.e. the first apparatus) are enabled to align understanding of the first HARQ codebook, so that communication performance can be further improved.

In one possible design, the method further includes: second indication information may be received from the first apparatus, the second indication information indicating an identity of one or more SL HARQ processes corresponding to the one or more transport blocks. By the method, HARQ feedback can be performed in a targeted manner, HARQ feedback information of all SL HARQ processes does not need to be continuously sent to the sending end (namely the first device), so that transmission resource overhead can be reduced, and the resource utilization rate is improved.

In one possible design, the method further includes: third indication information may be received from the first apparatus, the third indication information indicating a number of one or more SL HARQ processes corresponding to the one or more transport blocks. Through the above manner, the transmitting end (i.e., the first device) is beneficial to the receiving end to correctly generate the HARQ codebook by indicating the number of the specific SL HARQ processes to the receiving end (i.e., the device for executing the method), and is beneficial to the receiving end and the transmitting end to keep common identification for a plurality of bits included in the HARQ codebook, so that the communication performance can be further improved.

In one possible design, the method further includes: and sending fourth indication information in the sidelink control channel, wherein the fourth indication information is used for indicating that the second-level SCI is in the first format, and the sidelink control channel and the sidelink data channel are positioned in the same time slot.

In one possible design, the number Q of coded modulation symbols of the second level SCI _SCI2 Satisfies the following conditions:

wherein, L is ₁ An index of a first Orthogonal Frequency Division Multiplexing (OFDM) symbol occupied for the second level SCI, the L ₂ An index of the last OFDM symbol occupied by the second-level SCI; m ^SCI2 (l) Represents the number of coded modulation symbols of the second level SCI on the OFDM symbol with index l.

In one possible design, the method further comprises: transmitting a second HARQ codebook to the second apparatus in a sidelink data channel, the second HARQ codebook including HARQ feedback information for one or more transport blocks from the second apparatus; wherein the first HARQ codebook and the second HARQ codebook are time division multiplexed or frequency division multiplexed in the sidelink data channel. With the above design, the data receiving side apparatus (i.e. the apparatus performing the method) can transmit the plurality of HARQ codebooks corresponding to the plurality of data transmitting side apparatuses (e.g. the first apparatus, the second apparatus) to the plurality of data transmitting side apparatuses at one time, thereby further improving the efficiency of SL HARQ feedback.

In one possible design, a first HARQ codebook is carried in a first resource in a sidelink data channel, a second HARQ codebook is carried in a second resource in the sidelink data channel, the first resource includes at least one resource block group, the second resource includes at least one resource block group, and the first resource and the second resource are not overlapped, where the resource block group is composed of a plurality of resource blocks at equal intervals. By the design, the interference between the first HARQ codebook and the second HARQ codebook can be reduced.

In one possible design, the first HARQ codebook and the second HARQ codebook are carried in different second-level SCIs.

In one possible design, the second-level SCI occupies a first time-frequency resource in the sidelink data channel, where the first time-frequency resource is a remaining time-frequency resource in the sidelink data channel except for a second time-frequency resource used for transmitting a reference signal.

In the above manner, even though the receiving end (i.e., the apparatus performing the method) has no data to transmit to the transmitting end (i.e., the first apparatus), the first HARQ codebook may be transmitted to the transmitting end in a reasonable frame structure through the psch.

In a second aspect, the present application provides a communication method, where an execution subject of the method may be a terminal device, or may be a combined device or component having a function of the terminal device, or may be a chip or a circuit system (for example, a processor, a baseband chip, or a chip system) applied to the terminal device. The method comprises the following steps: transmitting at least one transport block to a communication device; and receiving a second-level SCI from the communication device in a sidelink data channel, the second-level SCI carrying a first HARQ codebook, wherein the first HARQ codebook is used for determining at least one HARQ feedback information corresponding to the at least one transport block.

In the embodiment of the application, HARQ feedback can be carried out through the HARQ codebook in the sidelink communication system, the SL HARQ feedback efficiency is improved, and the communication reliability is further improved. And compared with the method that the HARQ codebook is carried in the first-level SCI, the HARQ codebook is sent in the second-level SCI, so that the decoding complexity of the first-level SCI can be reduced, and the transmission efficiency of the control channel is guaranteed. Meanwhile, compared with the method that the HARQ codebook is loaded in the sidelink data, the method that the HARQ codebook is loaded in the second-level SCI can improve the decoding reliability. Generally, the second-level SCI is modulated by QPSK, the sidelink data is modulated by a higher-level modulation method, and the HARQ codebook carried in the second-level SCI is modulated by a lower-level method than the sidelink data, so that the reliability of decoding the HARQ codebook at the receiving end is higher.

In one possible design, the format of the second-level SCI includes at least a first format and a second format, where the first format includes a field for carrying a HARQ codebook and the second field does not include a field for carrying a HARQ codebook. The above design can realize transmitting the HARQ codebook in the second-level SCI by adding the first format.

In one possible design, the method further includes: first indication information may be transmitted to a communication apparatus, the first indication information indicating transmission of a first HARQ codebook. By means of sending the first indication information, the receiving end (i.e. the communication device) and the sending end (i.e. the device executing the method) are enabled to align understanding of the first HARQ codebook, so that communication performance can be further improved.

In one possible design, the method further includes: second indication information may be sent to the communication device, the second indication information indicating an identity of one or more SL HARQ processes corresponding to the one or more transport blocks. By the method, HARQ feedback can be performed in a targeted manner, HARQ feedback information of all SL HARQ processes does not need to be continuously sent to a sending end (namely, a device for executing the method), and therefore transmission resource overhead can be reduced, and resource utilization rate is improved.

In one possible design, the method further includes: third indication information may be sent to the communication apparatus, the third indication information indicating a number of one or more SL HARQ processes corresponding to the one or more transport blocks. Through the above manner, the transmitting end (i.e. the apparatus for executing the method) indicates the number of the specific SL HARQ processes to the receiving end (i.e. the communication apparatus), which is beneficial for the receiving end to correctly generate the HARQ codebook, and is beneficial for the receiving end and the transmitting end to keep common identification for a plurality of bits included in the HARQ codebook, thereby further improving the communication performance.

In one possible design, the method further includes: and receiving fourth indication information in the sidelink control channel, wherein the fourth indication information is used for indicating that the second-level SCI is in the first format, and the sidelink control channel and the sidelink data channel are positioned in the same time slot.

wherein L is ₁ Index of the first OFDM symbol occupied by the second level SCI, L ₂ An index of the last OFDM symbol occupied for the second level SCI; m ^SCI2 (l) Indicating the number of coded modulation symbols of the second level SCI on the OFDM symbol with index l.

In the above manner, even though the receiving end (i.e., a communication apparatus) has no data to transmit to the transmitting end (i.e., an apparatus performing the method), the first HARQ codebook may be transmitted to the transmitting end through the psch in a reasonable frame structure.

In a third aspect, the present application provides a communication method, where an execution subject of the method may be a terminal device, or may be a combined device or component having a terminal device function, or may be a chip or a circuit system (for example, a processor, a baseband chip, a module, a TBOX, or a system-on-a-chip, etc.) applied to the terminal device. The method comprises the following steps: receiving at least one transport block from a first apparatus; and transmitting a first HARQ codebook to the first device in a sidelink control channel, wherein a time slot in which the sidelink control channel is located does not include a sidelink data channel, and the first HARQ codebook includes at least one HARQ feedback information for the at least one transport block.

In the embodiment of the application, HARQ feedback can be carried out through the HARQ codebook in the sidelink communication system, the SL HARQ feedback efficiency is improved, and the communication reliability is further improved. In addition, in the embodiment of the present application, a Physical Sidelink Control Channel (PSCCH) of an independent (standby) physical sidelink that is not associated with the PSCCH is transmitted to the first apparatus, that is, the PSCCH may not be included in a time slot for transmitting the PSCCH, so that a speed at which the first apparatus receives HARQ feedback information may be increased.

In one possible design, the frequency domain bandwidth of the sidelink control channel is equal to the frequency domain bandwidth of the Channel Occupancy Time (COT). Through the design, other terminal devices working in the unlicensed spectrum can be prevented from accessing the channel and generating interference due to the fact that the terminal devices sense the idle channel.

In one possible design, prior to transmitting the first HARQ codebook, first indication information may be received from the first apparatus, the first indication information indicating that the first HARQ codebook is transmitted. By means of the first indication information sent by the first device to the second device, the first device and the second device are enabled to align understanding of the first HARQ codebook, and therefore communication performance can be further improved.

In one possible design, second indication information may be received from the first apparatus before transmitting the first HARQ codebook, the second indication information indicating identities of one or more SL HARQ processes corresponding to the one or more transport blocks. Through the above manner, the first device can make the second device perform HARQ feedback in a targeted manner, and HARQ feedback information of all SL HARQ processes does not need to be continuously sent to the first device, so that transmission resource overhead can be reduced, and resource utilization rate is improved.

In one possible design, third indication information may be received from the first apparatus before transmitting the first HARQ codebook, the third indication information indicating a number of one or more SL HARQ processes corresponding to the one or more transport blocks. Through the above manner, the first device indicates the number of the specific SL HARQ processes to the second device, which is beneficial for the second device to correctly generate the HARQ codebook, and is beneficial for the first device and the second device to keep common knowledge of a plurality of bits included in the HARQ codebook, so that the communication performance can be further improved.

In a fourth aspect, the present application provides a communication method, where an execution subject of the method may be a terminal device, or may be a combined device or component having a function of the terminal device, or may be a chip or a circuit system (for example, a processor, a baseband chip, a module, a TBOX, or a system-on-a-chip, etc.) applied to the terminal device. The method comprises the following steps: transmitting at least one transport block to a second apparatus; and receiving a first HARQ codebook from the second apparatus in a sidelink control channel, wherein the timeslot in which the sidelink control channel is located does not include a sidelink data channel, and the first HARQ codebook includes at least one HARQ feedback information for the at least one transport block.

In the embodiment of the application, HARQ feedback can be carried out through the HARQ codebook in the sidelink communication system, the SL HARQ feedback efficiency is improved, and the communication reliability is further improved. In addition, in the embodiment of the present application, the independent PSCCH not associated with the PSCCH is transmitted to the first apparatus, that is, the time slot for transmitting the PSCCH may not include the PSCCH, so that the speed of receiving the HARQ feedback information by the first apparatus may be increased.

In one possible design, the frequency domain bandwidth of the sidelink control channel is equal to the frequency domain bandwidth of the COT. Through the design, other terminal devices working in the unlicensed spectrum can be prevented from accessing the channel and generating interference due to the fact that the terminal devices sense the idle channel.

In one possible design, prior to receiving the first HARQ codebook, first indication information may be sent to the second apparatus, where the first indication information is used to indicate that the first HARQ codebook is sent. By means of sending the first indication information to the second device, the first device and the second device are enabled to align understanding of the first HARQ codebook, and therefore communication performance can be further improved.

In one possible design, second indication information indicating an identity of one or more SL HARQ processes corresponding to the one or more transport blocks may be sent to the second apparatus before receiving the first HARQ codebook. By the mode, the second device can perform HARQ feedback in a targeted manner, and HARQ feedback information of all SL HARQ processes does not need to be continuously sent to the first device, so that the transmission resource overhead can be reduced, and the resource utilization rate is improved.

In one possible design, third indication information may be sent to the second apparatus before receiving the first HARQ codebook, the third indication information indicating a number of one or more SL HARQ processes corresponding to the one or more transport blocks. Through the above manner, the number of the specific SL HARQ processes is indicated to the second device, which is beneficial for the second device to correctly generate the HARQ codebook, and is beneficial for the first device and the second device to keep common identification for a plurality of bits included in the HARQ codebook, so that the communication performance can be further improved.

In a fifth aspect, the present application provides a communication method, where an execution subject of the method may be a terminal device, or may be a combined device or component having a function of the terminal device, or may be a chip or a circuit system (for example, a processor, a baseband chip, a module, a TBOX, or a system-on-a-chip, etc.) applied to the terminal device. The method comprises the following steps: receiving at least one transport block from a first apparatus; and transmitting a first HARQ codebook to the first apparatus in a sidelink feedback channel, wherein the first HARQ codebook comprises at least one HARQ feedback information for the at least one transport block; and sending a source identifier and a destination identifier corresponding to a sidelink feedback channel in the sidelink control channel, wherein the sidelink feedback channel and the sidelink control channel are positioned in the same time slot.

In the embodiment of the application, HARQ feedback can be carried out through the HARQ codebook in the sidelink communication system, the SL HARQ feedback efficiency is improved, and the communication reliability is further improved. In addition, in the embodiment of the present application, by sending the PSFCH and the PSCCH in the same time slot, the sending end (i.e., the first device) may determine, according to the PSCCH, whether the HARQ codebook is from the receiving end (i.e., the device that executes the method) or not and whether the HARQ codebook is the HARQ codebook sent to itself, by indicating the source identifier, the destination identifier, and other indication information related to the first HARQ codebook through the PSCCH, and if the HARQ codebook is sent to itself, obtain the first HARQ codebook from the receiving end from the PSFCH, and then determine whether the TB that has been sent is correctly received by the receiving end based on the first HARQ codebook.

In one possible design, the time slot in which the sidelink feedback channel is located does not include a sidelink data channel. By the above manner, even if the receiving end (i.e. the apparatus for performing the method) does not have data to transmit to the transmitting end (i.e. the first apparatus), the source identifier and the destination identifier corresponding to the sidelink feedback channel can still be transmitted through the PSCCH.

In one possible design, the sidelink feedback channel is time division multiplexed with the sidelink control channel.

In one possible design, the frequency domain bandwidth of the sidelink feedback channel is equal to the frequency domain bandwidth corresponding to the COT. Through the design, other terminal devices working in the unlicensed spectrum can be prevented from accessing the channel and generating interference due to the fact that the terminal devices sense the idle channel.

In one possible design, the sidelink feedback channel is frequency division multiplexed with the sidelink control channel.

In one possible design, the frequency domain resources corresponding to the sidelink feedback channel and the frequency domain resources corresponding to the sidelink control channel are not overlapped and adjacent.

In one possible design, the frequency domain resource corresponding to the sidelink feedback channel includes at least one resource block group, the frequency domain resource corresponding to the sidelink control channel includes at least one resource block group, and the frequency domain resource corresponding to the sidelink feedback channel is not overlapped with the frequency domain resource corresponding to the sidelink control channel, where one resource block group includes a plurality of equally spaced resource blocks, or one resource block group is composed of a plurality of equally spaced resource blocks. Through the design, the interference between the side link feedback channel and the side link control channel can be reduced.

In one possible design, prior to transmitting the first HARQ codebook, first indication information may be received from the first apparatus, the first indication information indicating that the first HARQ codebook is transmitted. By means of sending the first indication information to the receiving end (i.e., the apparatus executing the method) by the sending end (i.e., the first apparatus), the sending end and the receiving end are aligned to understand the first HARQ codebook, so that the communication performance can be further improved.

In one possible design, second indication information may be received from the first apparatus before transmitting the first HARQ codebook, the second indication information indicating identities of one or more SL HARQ processes corresponding to the one or more transport blocks. By the above manner, the sending end (i.e. the first device) can make the receiving end (i.e. the device executing the method) perform HARQ feedback in a targeted manner, and the HARQ feedback information of all SL HARQ processes does not need to be continuously sent to the sending end, so that the transmission resource overhead can be reduced, and the resource utilization rate can be improved.

In one possible design, third indication information may be received from the first apparatus before transmitting the first HARQ codebook, the third indication information indicating a number of one or more SL HARQ processes corresponding to the one or more transport blocks. Through the above manner, the transmitting end (i.e., the first device) is beneficial to the receiving end to correctly generate the HARQ codebook by indicating the number of the specific SL HARQ processes to the receiving end (i.e., the device for executing the method), and the transmitting end and the receiving end are beneficial to keeping common identification for a plurality of bits included in the HARQ codebook, so that the communication performance can be further improved.

In one possible design, the method further comprises: transmitting a second HARQ codebook in a sidelink feedback channel, the second HARQ codebook including HARQ feedback information for one or more transport blocks from a second apparatus; wherein the first HARQ codebook and the second HARQ codebook are time division multiplexed or frequency division multiplexed in the sidelink feedback channel. Through the above design, the receiving end (i.e. the apparatus for performing the method) can transmit the plurality of HARQ codebooks corresponding to the plurality of transmitting ends at one time, thereby further improving the efficiency of SL HARQ feedback.

In one possible design, a first HARQ codebook is carried in a first resource of a sidelink feedback channel, a second HARQ codebook is carried in a second resource of the sidelink feedback channel, the first resource includes at least one resource block group, the second resource includes at least one resource block group, and the first resource and the second resource are not overlapped, where the resource block group includes or consists of a plurality of equally spaced resource blocks. Through the design, the interference between the first HARQ codebook and the second HARQ codebook can be reduced.

In a sixth aspect, the present application provides a communication method, where an execution subject of the method may be a terminal device, or may be a combined device or component having a function of the terminal device, or may be a chip or a circuit system (for example, a processor, a baseband chip, or a chip system) applied to the terminal device. The method comprises the following steps: transmitting at least one transport block to a communication device; and receiving a first HARQ codebook in a sidelink feedback channel, wherein the first HARQ codebook comprises at least one HARQ feedback information for the at least one transport block; and receiving a source identifier and a destination identifier corresponding to a side link feedback channel in the side link control channel, wherein the side link feedback channel and the side link control channel are positioned in the same time slot.

In the embodiment of the application, HARQ feedback can be carried out through the HARQ codebook in the sidelink communication system, the SL HARQ feedback efficiency is improved, and the communication reliability is further improved. In addition, in the embodiment of the present application, by sending the PSFCH and the PSCCH in the same time slot, the sending end (i.e., a device executing the method) may determine, according to the PSCCH, whether the HARQ codebook is from the receiving end (i.e., the communication device) or not and whether the HARQ codebook is the HARQ codebook sent to itself, by indicating, by the PSCCH, the indication information related to the first HARQ codebook, such as the source identifier, the destination identifier, and the like, so that if the HARQ codebook is sent to itself, the first HARQ codebook from the receiving end is obtained from the PSFCH, and then it is determined whether the TB that has been sent is correctly received by the receiving end based on the first HARQ codebook.

In one possible design, the time slot in which the sidelink feedback channel is located does not include a sidelink data channel. By the above method, even if the receiving end (i.e. the communication apparatus) has no data to transmit to the transmitting end (i.e. the apparatus performing the method), the source identifier and the destination identifier corresponding to the sidelink feedback channel can still be transmitted through the PSCCH.

In one possible design, the sidelink feedback channel is frequency division multiplexed with a sidelink control channel.

In one possible design, the frequency domain resource corresponding to the sidelink feedback channel includes at least one resource block group, the frequency domain resource corresponding to the sidelink control channel includes at least one resource block group, and the frequency domain resource corresponding to the sidelink feedback channel is not overlapped with the frequency domain resource corresponding to the sidelink control channel, where the resource block group includes a plurality of resource blocks at equal intervals, or is composed of a plurality of resource blocks at equal intervals. Through the design, the interference between the side link feedback channel and the side link control channel can be reduced.

In one possible design, prior to receiving the first HARQ codebook, first indication information may be transmitted to the communication apparatus, the first indication information indicating that the first HARQ codebook is transmitted. By means of sending the first indication information to the receiving end (i.e. the communication apparatus), the transmitting end (i.e. the apparatus performing the method) and the receiving end are enabled to align understanding of the first HARQ codebook, so that communication performance can be further improved.

In one possible design, second indication information indicating an identity of one or more SL HARQ processes corresponding to the one or more transport blocks may be sent to the communication apparatus prior to receiving the first HARQ codebook. By the above method, the receiving end (i.e. the communication device) can perform HARQ feedback with pertinence, and HARQ feedback information of all SL HARQ processes does not need to be continuously sent to the sending end (i.e. the device executing the method), so that transmission resource overhead can be reduced, and resource utilization rate can be improved.

In one possible design, third indication information may be sent to the communication apparatus before receiving the first HARQ codebook, the third indication information indicating a number of one or more SL HARQ processes corresponding to the one or more transport blocks. Through the above manner, by indicating the number of the specific SL HARQ processes to the receiving end (i.e., the communication apparatus), the receiving end is facilitated to correctly generate the HARQ codebook, and the transmitting end (i.e., the apparatus for performing the method) and the receiving end are facilitated to keep common knowledge for a plurality of bits included in the HARQ codebook, so that the communication performance can be further improved.

In a seventh aspect, an embodiment of the present application provides a communication apparatus, which may implement the method described in any one of the first to sixth aspects or any possible design thereof. The apparatus comprises corresponding units or means for performing the above-described method. The means comprising may be implemented by software and/or hardware means. The apparatus may be, for example, a terminal device, or a component or a baseband chip, a chip system, or a processor that can support the terminal device to implement the method.

Illustratively, the communication device may include a processing unit (or processing module), and may further include a transceiver unit (or communication module, transceiver module), etc. which may perform the method described in any one of the first to sixth aspects or any possible design thereof. When the communication apparatus is a terminal device, the transceiving unit may be a transmitter and a receiver, or a transceiver obtained by integrating the transmitter and the receiver. The transceiver unit may include an antenna, a radio frequency circuit, and the like, and the processing unit may be a processor, such as a baseband chip and the like. When the communication device is a component having the functions of the terminal equipment, the transceiver unit may be a radio frequency unit, and the processing unit may be a processor. When the communication device is a chip system, the transceiving unit may be an input/output interface of the chip system, and the processing unit may be a processor of the chip system, for example: a Central Processing Unit (CPU).

The transceiving unit may be adapted to perform the actions of receiving and/or transmitting in any of the first to sixth aspects or any possible design thereof. The processing unit may be configured to perform actions other than receiving and transmitting in any of the first to sixth aspects or any possible design thereof, such as determining a HARQ codebook and the like.

In an eighth aspect, there is provided a communications apparatus comprising one or more processors coupled with a memory and operable to execute a program or instructions in the memory to cause the apparatus to perform the method of any one of the first to sixth aspects or any possible design of the aspect. Optionally, the apparatus further comprises one or more memories. Optionally, the apparatus further comprises a communication interface, the processor being coupled to the communication interface.

In a ninth aspect, there is provided a computer readable storage medium for storing computer instructions which, when run on a computer, cause the computer to perform the method of any one of the first to sixth aspects above or any one of its possible designs.

A tenth aspect provides a computer program product comprising instructions for storing computer instructions that, when run on a computer, cause the computer to perform the method of any one of the first to sixth aspects above, or any one of its possible designs.

In an eleventh aspect, there is provided a processing device, coupled to a memory, that invokes a program in the memory to perform the method of any one of the first to sixth aspects or any one of its possible designs. The processing means may comprise, for example, a system of chips.

The system-on-chip in the above aspect may be a system-on-chip (SOC), a baseband chip, and the like, where the baseband chip may include a processor, a channel encoder, a digital signal processor, a modem, an interface module, and the like.

Drawings

Fig. 1 is a schematic view of a V2X communication according to an embodiment of the present application;

fig. 2 is a schematic diagram of a mapping relationship between PSSCH and PSFCH according to an embodiment of the present application;

fig. 3 is a schematic architecture diagram of a network system according to an embodiment of the present application;

fig. 4 is a schematic architecture diagram of another network system according to an embodiment of the present application;

FIG. 5 is a block diagram of another network system according to an embodiment of the present application;

fig. 6 is a schematic structural diagram of a communication device according to an embodiment of the present application;

fig. 7 is a schematic structural diagram of another communication device according to an embodiment of the present application;

fig. 8 is a schematic structural diagram of a communication method according to an embodiment of the present application;

fig. 9 is a schematic diagram of a PSCCH and pschs according to an embodiment of the present disclosure;

fig. 10 is a schematic diagram of resource mapping of PSCCH and PSCCH in a frequency domain according to an embodiment of the present application;

fig. 11 is a schematic diagram of time division multiplexing of K HARQ codebooks according to an embodiment of the present application;

fig. 12 is a schematic diagram of frequency division multiplexing of K HARQ codebooks in an embodiment of the present application;

fig. 13 is a schematic diagram of another frequency division multiplexing of K HARQ codebooks in the embodiment of the present application;

fig. 14 is a diagram illustrating a PSCCH according to an embodiment of the present disclosure;

fig. 15 is a schematic resource mapping diagram of a PSCCH in a frequency domain according to an embodiment of the present application;

fig. 16 is a schematic diagram of time division multiplexing of a PSFCH and a PSCCH according to an embodiment of the present application;

fig. 17 is a schematic resource mapping diagram of a PSFCH in a frequency domain according to an embodiment of the present application;

fig. 18 is a schematic diagram of frequency division multiplexing of a PSFCH and a PSCCH according to an embodiment of the present disclosure;

fig. 19 is a schematic diagram of another PSFCH and PSCCH frequency division multiplexing according to an embodiment of the present application;

fig. 20 is a schematic resource mapping diagram of a PSFCH in a frequency domain according to an embodiment of the present application;

fig. 21 is a schematic diagram of time division multiplexing of K HARQ codebooks in the embodiment of the present application;

fig. 22 is a schematic diagram of another K HARQ codebook frequency division multiplexing according to an embodiment of the present application;

fig. 23 is a schematic diagram of another K HARQ codebook frequency division multiplexing according to an embodiment of the present application;

fig. 24 is a schematic diagram of another frequency division multiplexing of K HARQ codebooks in the embodiment of the present application;

fig. 25 is a schematic diagram of another K HARQ codebook frequency division multiplexing according to an embodiment of the present application;

fig. 26 is a schematic diagram of another frequency division multiplexing of K HARQ codebooks in the embodiment of the present application.

Detailed Description

Hereinafter, some terms in the embodiments of the present application are explained so as to be easily understood by those skilled in the art.

1) Terminal equipment, including equipment providing voice and/or data connectivity to a user, in particular, including equipment providing voice to a user, or including equipment providing data connectivity to a user, or including equipment providing voice and data connectivity to a user. For example, may include a handheld device having wireless connection capability, or a processing device connected to a wireless modem. The terminal device may communicate with a core network via a Radio Access Network (RAN), exchange voice or data with the RAN, or interact with the RAN. The terminal device may include a user device, a wireless terminal device, a mobile terminal device, a device-to-device communication (D2D) terminal device, a vehicle-to-all (V2X) terminal device, a machine-to-machine/machine-type communication (M2M/MTC) terminal device, an internet of things (IoT) terminal device, a subscriber unit (subscriber unit), a subscriber station (subscriber station), a mobile station (mobile station), a remote station (remote station), an access point (access point, AP), a remote terminal (remote terminal), an access terminal (access terminal), a user terminal (user terminal), a user agent (user agent), or a user equipment (user device), etc. For example, mobile telephones (otherwise known as "cellular" telephones), computers with mobile terminal equipment, portable, pocket, hand-held, computer-included mobile devices, and the like may be included. For example, personal Communication Service (PCS) phones, cordless phones, session Initiation Protocol (SIP) phones, wireless Local Loop (WLL) stations, personal Digital Assistants (PDAs), and the like. Also included are constrained devices such as devices that consume less power, or devices that have limited storage capabilities, or devices that have limited computing capabilities, etc. Examples of information sensing devices include bar codes, radio Frequency Identification (RFID), sensors, global Positioning Systems (GPS), laser scanners, and so forth.

A terminal device in V2X technology may be a Road Side Unit (RSU), and the RSU may be a fixed infrastructure entity supporting V2X applications, and may exchange messages with other entities supporting V2X applications, for example, the RSU may exchange messages with other entities supporting V2X applications through a PC5 port.

The terminal device in the V2X technology may also be a complete vehicle, a communication module (e.g., a communication chip, a chip system, etc.) in the complete vehicle, a TBOX, and so on.

By way of example and not limitation, in the embodiments of the present application, the terminal device may also be a wearable device. Wearable equipment can also be called wearable intelligent equipment or intelligent wearable equipment and the like, and is a general term for applying wearable technology to carry out intelligent design and develop wearable equipment for daily wearing, such as glasses, gloves, watches, clothes, shoes and the like. Illustratively, the wearable device may be a Virtual Reality (VR) device, an Augmented Reality (AR) device. A wearable device is a portable device that is worn directly on the body or integrated into the clothing or accessories of the user. The wearable device is not only a hardware device, but also realizes powerful functions through software support, data interaction and cloud interaction. The generalized wearable smart device has full functions and large size, and can realize complete or partial functions without depending on a smart phone, for example: smart watches or smart glasses and the like, and only focus on a certain type of application functions, and need to be used in cooperation with other devices such as smart phones, such as various smart bracelets, smart helmets, smart jewelry and the like for monitoring physical signs.

While the various terminal devices described above, if located on (e.g. placed in or installed in) a vehicle, may be considered to be vehicle-mounted terminal devices, also referred to as on-board units (OBUs), for example.

In this embodiment, the terminal device may further include a relay (relay). Or it is to be understood that all that can communicate data with the base station can be considered terminal equipment.

In the embodiment of the present application, the apparatus for implementing the function of the terminal device may be the terminal device, and may also be an apparatus that is applied to the terminal device and is capable of supporting the terminal device to implement the function, for example, a component or an assembly having a communication function, or a chip system, and the apparatus may be installed in the terminal device. In the embodiment of the present application, the chip system may be composed of a chip, and may also include a chip and other discrete devices. In the technical solution provided in the embodiment of the present application, a device for implementing a function of a terminal is taken as an example of a terminal device, and the technical solution provided in the embodiment of the present application is described.

2) A network device, for example, including AN Access Network (AN) device, such as a base station (e.g., AN access point), may refer to a device in the access network that communicates with a wireless terminal device through one or more cells over AN air interface, or, for example, a network device in V2X technology is a base station type RSU. The base station may be configured to interconvert the received air frame and an Internet Protocol (IP) packet, and serve as a router between the terminal device and the rest of the access network, where the rest of the access network may include an IP network. The RSU may be a fixed infrastructure entity supporting V2X applications, and may exchange messages with other entities supporting V2X applications, for example, the RSU may exchange messages with other entities supporting V2X applications through the Uu port. The network device may also coordinate attribute management for the air interface. For example, the network device may include an evolved Node B (NodeB or eNB or e-NodeB) in an LTE system or an advanced long term evolution-advanced (LTE-a), or may also include a next generation Node B (gNB) in a fifth generation mobile communication technology (5g) NR system (also referred to as an NR system) or may also include a Centralized Unit (CU) and a Distributed Unit (DU) in a Cloud access network (Cloud RAN) system, which is not limited in the embodiment of the present application. For example, the network device may be a CU in the Cloud RAN system, or a DU, or the whole of CU and DU.

The network device may also include a core network device including, for example, an access and mobility management function (AMF), etc. Since the embodiments of the present application mainly relate to an access network, unless otherwise specified, all the network devices refer to access network devices.

In this embodiment, the apparatus for implementing the function of the network device may be a network device, or may be an apparatus capable of supporting the network device to implement the function, for example, a system on chip, and the apparatus may be installed in the network device. In the technical solution provided in the embodiment of the present application, a device for implementing a function of a network device is taken as an example of a network device, and the technical solution provided in the embodiment of the present application is described.

3) V2X is the interconnection and intercommunication between the vehicle and the outside, which is the basic and key technology of future intelligent vehicles, automatic driving and intelligent transportation systems. The V2X optimizes the specific application requirements of the V2X based on the existing D2D technology, and needs to further reduce the access delay of the V2X device and solve the problem of resource conflict.

The V2X specifically includes several application requirements, such as vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-pedestrian (V2P) direct communication, and vehicle-to-network (V2N) communication interaction. As shown in fig. 1. V2V refers to inter-vehicle communication; V2P refers to vehicle-to-person communication (including pedestrians, cyclists, drivers, or passengers); V2I refers to vehicle communication with a network device, such as an RSU, and another V2N may be included in V2I, V2N refers to vehicle communication with a base station/network.

4) The resource block group according to the embodiment of the present application may include a plurality of equally spaced Resource Blocks (RBs), or may be composed of a plurality of equally spaced resource blocks. For example, the resource block groups may be interleaved resource blocks (resource blocks) defined in the NR. In NR, interleaving of multiple resource blocks is defined, and for example, with an interleaving value of M, one resource block group (or referred to as a group of interleaved resource blocks) may include resource blocks with indexes { M, M + M, 2m + M, 3m + M,. }, where M ∈ {0,1,.. And M-1}. M is an integer greater than 0. For example, M may be the value given in table 1.

TABLE 1

μ	M
		0	10
1	5

Where μmay be configured by sub-carrier spacing (SCS) corresponding to SL partial Bandwidth (BWP), for example, μmay be defined by table 2.

TABLE 2

μ	Subcarrier spacing (kHz)
		0	15
1	30
		2	60
3	120
		……	……

Existing protocols define two types of interleaved resource blocks: (1) for subcarrier spacing of 15kHz, a resource block group includes RBs with indices { m, m +10, m +20, \ 8230 }, where m has a value in the range {0,1, \8230;, 9}. Therefore, there are 10 resource block groups within the frequency domain bandwidth of N × 20 MHz; (2) for subcarrier spacing of 30kHz, a resource block group includes RBs with indices { m, m +5, m +10, \ 8230, where m has a value in the range {0,1, \8230;, 4}. Therefore, there are 5 resource block groups within the frequency domain bandwidth of N × 20MHz. It should be understood that M and M corresponding to the resource block group described in the present application may have different values, and are not limited to the above examples.

5) Listen Before Talk (LBT): a channel access rule in an unlicensed spectrum refers to that before data is sent, a network device or a terminal device immediately monitors whether a channel is idle or not in the next available initial Clear Channel Assessment (CCA) time, if the channel is idle, the data is sent in the subsequent channel occupation time, otherwise, the data is not sent; if the monitored channel is busy in the initial CCA time or the data is not transmitted in the channel occupation time, expanding the CCA time, detecting whether the channel is idle in each expanded CCA time interval, wherein the expanded CCA time interval is the same as the initial CCA time length, if the channel is detected to be idle, recording that the channel is idle once, and transmitting the data in the subsequent channel occupation time when G times of channel idle is recorded, or else, not transmitting the data. Wherein G is an integer from 1 to q, where q is a contention window length of the extended CCA time, and is greater than or equal to 4 and less than or equal to 32. When there is a regulatory requirement for unlicensed spectrum in a locality, LBT-based channel access is a mandatory feature on the unlicensed spectrum. LBT is also divided into various types, including: a class of LBTs (Category 1 LBTs) that transmit immediately after a short switching gap; class II LBT (Category 2 LBT), LBT without random back-off; a class three LBT (Category 3 LBT), which is a random backoff LBT with a fixed size contention window (contention window); four classes of LBT (Category 4 LBT), are random back-off LBT with variable size contention windows.

Generally, when a network device or a terminal device needs to send data, four types of LBT are used; when network equipment or terminal equipment needs to send important control information or synchronization information, the class II LBT is used, so that the control information or the synchronization information can be quickly sent out.

6) Second-stage SCI: SCI in sidelink communication is transmitted in two stages, the first stage SCI is carried in PSCCH, and the second stage SCI is carried in PSSCH. Wherein the first-level SCI may include one or more of the following control information: priority information, resource allocation (resource assignment) information, resource reservation period (resource reservation period) information, second-level SCI format information, modulation coding scheme information, and the like. The first stage SCI may be decoded using a demodulation reference signal (DMRS) in the PSCCH. The second-level SCI may include one or more of HARQ process number (HARQ process number) information, new Data Indicator (NDI) information, redundancy version (redundancy version) information, source identification information, destination identification information, and the like, among the following control information. The second level SCI may be decoded using the DMRS in the PSSCH.

In the embodiments of the present application, "at least one" means one or more, "a plurality" means two or more. "and/or" describes the association relationship of the associated object, indicating that there may be three relationships, for example, a and/or B, which may indicate: a alone, A and B together, and B alone, wherein A and B may be singular or plural. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. "at least one of the following" or similar expressions refer to any combination of these items, including any combination of the singular or plural items. For example, at least one (one) of a, b, or c, may represent: a, b, c, a and b, a and c, b and c, or a and b and c, wherein a, b and c can be single or multiple.

And, unless stated to the contrary, the embodiments of the present application refer to the ordinal numbers "first", "second", etc., for distinguishing a plurality of objects, and do not limit the size, content, sequence, timing, priority, degree of importance, etc., of the plurality of objects. For example, the first HARQ codebook and the second HARQ codebook are only for differentiating different sets, and do not indicate a difference in priority, importance, or the like between the two HARQ codebooks.

The foregoing describes some of the noun concepts related to embodiments of the present application, and the following describes some features related to embodiments of the present application.

Currently, in sidelink communication, a transmitting end will transmit 1 TB through psch on 1 time-frequency resource, where the TB corresponds to 1 HARQ process of sidelink communication. And the transmitting end indicates the HARQ process number, NDI and other information corresponding to the HARQ process of the receiving end through the SCI. After receiving the SCI and the associated TB, the receiving end feeds back ACK or NACK through the PSFCH, or feeds back NACK only when receiving an error, and informs the transmitting end whether the TB corresponding to the HARQ process is correctly received.

A single PSFCH occupies 1 OFDM symbol in the time domain and 1 RB in the frequency domain, and only carries 1 bit of HARQ feedback information. When the terminal device needs to feed back HARQ feedback information of multiple HARQ processes, multiple PSFCHs need to be sent, and thus more communication resources need to be occupied, which reduces the resources of the PSSCH and reduces transmission efficiency.

Currently, the slots containing the PSFCH resource may be periodic in the time domain, for example, there may be 1 slot containing the PSFCH resource in every L slots (slots), where L may have a value range of {0,1,2,4}. When the value of L is 0, it may indicate that there is no PSFCH in the current SL communication, that is, the receiving end does not need to send HARQ feedback information to the sending end. For example, in fig. 2, L has a value of 4, and the total 12 slots are shown, where PSFCH may exist in the 4th, 8 th and 12 th slots. For example, the receiving end may transmit the PSFCHs corresponding to the PSSCHs in the 1st and 2nd slots in the 4th slot, may transmit the PSFCHs corresponding to the PSSCHs in the 3 rd, 4th, 5th and 6 th slots in the 8 th slot, and may transmit the PSFCHs corresponding to the PSSCHs in the 7 th, 8 th, 9 th and 10 th slots in the 12 th slot. As shown in fig. 2, the transmitting end transmits pschs corresponding to different HARQ process numbers to the receiving end at 2nd, 4th, 6 th, 7 th, and 8 th slots, respectively. Based on the mapping relation, the receiving end feeds back PSFCH corresponding to PSSCH of HARQ process number 0 on the 2nd time slot to the sending end on the 4th time slot; the receiving end feeds back PSFCH corresponding to PSSCH of HARQ process number 1 at 4th time slot and PSFCH corresponding to PSSCH of HARQ process number 2 at 6 th time slot to the transmitting end at 8 th time slot; the receiving end feeds back the PSFCH corresponding to the PSSCH corresponding to HARQ process number 3 at the 7 th time slot and the PSFCH corresponding to the PSSCH corresponding to HARQ process number 4 at the 8 th time slot to the transmitting end at the 12 th time slot.

With the development of communication, sidelink communication can be applied to unlicensed spectrum, but the HARQ feedback method cannot be directly applied to unlicensed spectrum. This is because the communication resources in the unlicensed spectrum are limited in the time domain by the COT, and after the sender initiates (initiate) the COT, the sender and the receiver can only communicate using the communication resources within the COT. This may cause PSSCHs transmitted in several slots at the tail of the COT to have no corresponding PSFCH within the COT, so that the transmitting end cannot acquire HARQ feedback information corresponding to these PSSCHs. One possible solution to this problem is that the receiving end initiatively initiates a COT to transmit the PSFCH, and then the mapping relationship between the PSSCH and the PSFCH in the sidelink communication (or the periodicity of the PSFCH) in the time domain will be destroyed due to the temporal randomness generated by the random backoff mechanism in the LBT. Therefore, the transmitting end cannot know whether the PSFCH is transmitted to itself, and therefore cannot know whether the receiving end successfully receives the TB in the corresponding PSSCH.

In addition, the current PSFCH only provides feedback at the TB level, and if the terminal device feeds back HARQ feedback information with finer granularity for one TB, because the current PSFCH can only carry HARQ feedback information with 1 bit, the current HARQ feedback method cannot support the terminal device to feed back HARQ feedback information with finer granularity for one TB.

Based on this, embodiments of the present application provide a communication method and apparatus, which can improve communication reliability. The method and the device are based on the same inventive concept, and because the principles of solving the problems of the method and the device are similar, the implementation of the device and the method can be mutually referred, and repeated parts are not described again.

The technical scheme provided by the embodiment of the application can be applied to a scene of D2D communication in an unauthorized frequency spectrum, for example, the technical scheme can be applied to communication between a mobile phone and wearable devices such as AR devices, XR devices and watches, and can also be applied to V2X communication between a vehicle and terminal devices such as RSUs, other vehicles and handheld devices carried by people, for example, the technical scheme can be applied to the fields such as LTE-V, NR V2X, intelligent driving and intelligent internet connection. The D2D communication may be NR D2D communication or LTE D2D communication. The embodiments of the present application may also be applied to a licensed spectrum, and are not limited herein.

The technical scheme provided by the embodiment of the application can be suitable for a mode of selecting resources autonomously by a user in a communication scene with or without network coverage. The following describes a network architecture to which the embodiments of the present application are applied. Please refer to fig. 3-5, which illustrate a network architecture applied in the present embodiment.

Fig. 3-5 include a network device and two terminal devices, terminal device 1 and terminal device 2 respectively. Both of the terminal devices may be within the coverage area of the network device, as shown in fig. 3; or the two terminal devices may only have terminal device 1 in the coverage of the network device and terminal device 2 not in the coverage of the network device, as shown in fig. 4; or neither of the two terminal devices is within the coverage area of the network device, as shown in fig. 5. The two terminal devices can communicate with each other through a sidelink. Of course, the number of terminal devices in fig. 3 to 5 is only an example, and in practical applications, the network device may provide services for a plurality of terminal devices.

The network devices in fig. 3-5 are, for example, access network devices, such as base stations. The access network device may correspond to different devices in different systems, for example, the access network device may correspond to an eNB in a fourth generation mobile communication technology (4G) system, an access network device in 5G in a 5G system, for example, a gNB, or an access network device in a communication system of subsequent evolution. It should be noted that the network devices in fig. 3 to fig. 5 may be optional network elements.

The terminal device in the network devices in fig. 3 to fig. 5 is a mobile phone as an example, but the terminal device in the embodiment of the present application is not limited thereto.

The following describes a possible structure of the terminal device with reference to the drawings.

By way of example, fig. 6 shows a schematic diagram of one possible configuration of the device. The apparatus shown in fig. 6 may be a terminal device, or may be a chip, a communication module, a TBOX, or other combined device, component (or assembly) having the functions of the terminal device shown in this application. The apparatus may include a processing module 610 and may also include a transceiver module 620. The transceiver module 620 may be a functional module, which can perform both a transmitting operation and a receiving operation, for example, the transceiver module 620 may be configured to perform the transmitting operation and the receiving operation performed by the terminal device, for example, when the transmitting operation is performed, the transceiver module 620 may be considered as a transmitting module, and when the receiving operation is performed, the transceiver module 620 may be considered as a receiving module; alternatively, the transceiver module 620 may also be two functional modules, and the transceiver module 620 may be regarded as a general term for the two functional modules, where the two functional modules are a transmitting module and a receiving module respectively, the transmitting module is used to complete a transmitting operation, for example, the transmitting module may be used to execute a transmitting operation executed by the terminal device, the receiving module is used to complete a receiving operation, and the receiving module may be used to execute a receiving operation executed by the terminal device.

Illustratively, when the apparatus is a terminal device, the transceiving module 620 may include a transceiver and/or a communication interface. The transceiver may include an antenna, radio frequency circuitry, and the like. A communications interface such as a fiber optic interface. The processing module 610 may be a processor, such as a baseband processor, which may include one or more central processing units, CPUs.

When the apparatus is a component having the functions of the terminal device shown in this application, the transceiver module 620 may be a radio frequency unit, and the processing module 610 may be a processor, such as a baseband processor.

When the apparatus is a chip system, the transceiver module 620 may be an input/output interface of a chip (e.g., a baseband chip), and the processing module 610 may be a processor of the chip system and may include one or more central processing units.

It should be understood that the processing module 610 in the embodiments of the present application may be implemented by a processor or a processor-related circuit component, and the transceiver module 620 may be implemented by a transceiver or a transceiver-related circuit component.

In one implementation, the processing module 610 may be configured to perform operations performed by the terminal device in the embodiments of the present application, such as processing operations and/or other processes for supporting the techniques described herein, processing messages, information and/or signaling received by the transceiving module 620, and so on. Transceiver module 620 may be used to perform receive and/or transmit operations performed by a terminal device in embodiments of the present application, and/or other processes for supporting the techniques described herein. Optionally, the processing module 610 may control the transceiver module 620 to perform receiving and/or transmitting operations.

Fig. 7 shows another possible structural diagram of a terminal device. As shown in fig. 7, the terminal device includes a processor, and may further include a memory, a radio frequency unit (or a radio frequency circuit), an antenna, an input/output device, or other structures. The processor is mainly used for processing a communication protocol and communication data, controlling the device, executing a software program, processing data of the software program, and the like. The memory is used primarily for storing software programs and data. The radio frequency unit is mainly used for converting baseband signals and radio frequency signals and processing the radio frequency signals. The antenna is mainly used for receiving and transmitting radio frequency signals in the form of electromagnetic waves. Input and output devices, such as touch screens, display screens, keyboards, etc., are used primarily for receiving data input by a user and for outputting data to the user. It should be noted that some kinds of terminal devices may not have input/output means.

When data needs to be sent, the processor performs baseband processing on the data to be sent and outputs baseband signals to the radio frequency circuit, and the radio frequency circuit performs radio frequency processing on the baseband signals and sends the radio frequency signals to the outside in the form of electromagnetic waves through the antenna. When data is sent to the terminal equipment, the radio frequency circuit receives radio frequency signals through the antenna, converts the radio frequency signals into baseband signals and outputs the baseband signals to the processor, and the processor converts the baseband signals into the data and processes the data. For ease of illustration, only one memory and processor are shown in FIG. 7. In an actual end device product, there may be one or more processors and one or more memories. The memory may also be referred to as a storage medium or a storage device, etc. The memory may be provided independently of the processor, or may be integrated with the processor, which is not limited in this embodiment.

In the embodiment of the present application, an antenna and a radio frequency circuit having a transceiving function may be regarded as a transceiving unit of a terminal device (the transceiving unit may be a functional unit, and the functional unit is capable of implementing a transmitting function and a receiving function, or the transceiving unit may also include two functional units, which are respectively a receiving unit capable of implementing a receiving function and a transmitting unit capable of implementing a transmitting function), and a processor having a processing function may be regarded as a processing unit of the terminal device. As shown in fig. 7, the terminal device includes a processing unit 720 and may further include a transceiver unit 710. A transceiver unit may also be referred to as a transceiver, a transceiving device, etc. A processing unit may also be referred to as a processor, a processing board, a processing module, a processing device, or the like. Optionally, a device for implementing the receiving function in the transceiver 710 may be regarded as a receiving unit, and a device for implementing the transmitting function in the transceiver 710 may be regarded as a transmitting unit, that is, the transceiver 710 includes a receiving unit and a transmitting unit. A transceiver unit may also sometimes be referred to as a transceiver, transceiver circuit, or the like. A receiving unit may also be referred to as a receiver, a receiving circuit, or the like. A transmitting unit may also sometimes be referred to as a transmitter, or a transmitting circuit, etc.

It should be understood that the transceiving unit 710 may correspond to the transceiving module 620, or the transceiving module 620 may be implemented by the transceiving unit 710. The transceiving unit 710 is configured to perform the transmitting operation and the receiving operation of the terminal device in the embodiments illustrated in this application, and/or other processes for supporting the techniques described herein. The processing unit 720 may correspond to the processing module 610, or the processing module 610 may be implemented by the processing unit 720. Processing unit 720 is configured to perform operations on the terminal device other than transceiving operations in the embodiments illustrated herein, such as to perform receiving and/or transmitting operations performed by the terminal device in the embodiments illustrated herein, and/or to support other processes for the techniques described herein.

The network architecture and the service scenario described in the embodiment of the present application are for more clearly illustrating the technical solution of the embodiment of the present application, and do not form a limitation on the technical solution provided in the embodiment of the present application, and it can be known by a person of ordinary skill in the art that the technical solution provided in the embodiment of the present application is also applicable to similar technical problems with the evolution of the network architecture and the occurrence of a new service scenario.

In the present embodiment, only the time slot is taken as an example as a time unit, and in a specific embodiment, the time unit may be replaced by another time unit, such as a frame, a subframe, a half frame, a mini slot, a symbol, and the like, and the time unit is not limited herein.

For one terminal device, it is possible to receive data (such as TB and psch) transmitted by other terminal devices, and hereinafter, the terminal device that transmits data is referred to as a transmitting terminal device, and the terminal device that receives data is referred to as a receiving terminal device. It should be understood that the terminal device on the transmitting side and the terminal device on the receiving side are relative, and the terminal device on the transmitting side may also have a receiving function, and the terminal device on the receiving side may also have a transmitting function.

Referring to fig. 8, a flowchart of a communication method provided in the present application is shown. The method comprises the following steps:

s801, a first device transmits at least one TB to a second device. Accordingly, the second device receives at least one TB from the first device.

In the embodiment of the present application, the first apparatus may be a terminal device on a transmitting side, or a chip or a circuit system (e.g., a processor, a baseband chip, a module, a TBOX, or a system of chips, etc.) applied in the terminal device on the transmitting side. The second device may be a receiving-side terminal device, or a chip or a circuit system (e.g., a processor, a baseband chip, a module, a TBOX, or a system of chips, etc.) applied in the receiving-side terminal device.

Wherein, the TB can be transmitted through the PSSCH. The 1 TB may correspond to one or more Code Block Groups (CBGs). When 1 TB corresponds to one or more code block groups, the second apparatus can perform HARQ feedback in units of code block groups. For example, the first device sends 1 TB containing 4 code block groups to the second device, and the second device successfully receives the first, second, and fourth code block groups but fails to successfully receive the third code block group. At this time, the second device may sequentially send ACK, NACK, and ACK, thereby informing the first device that the third code block group needs to be retransmitted.

In step S801, the "transmitting at least one TB to the second device" may be performed by the transceiver module 620 of the first device, or may also be performed by the processing module 610 of the first device by controlling the transceiver module 620. The "receiving at least one TB from the first device" may be performed by the transceiver module 620 of the second device, or may also be performed by the processing module 610 of the second device by controlling the transceiver module 620.

S802, the second device transmits a first HARQ codebook in a first sidelink channel. Accordingly, the first apparatus receives the first HARQ codebook.

In step S802, the "receiving the first HARQ codebook" may be performed by the transceiver module 620 of the first apparatus, or may be performed by the processing module 610 of the first apparatus by controlling the transceiver module 620. The "transmitting the first HARQ codebook" may be performed by the transceiving module 620 of the second device, or may also be performed by the processing module 610 of the second device through the control transceiving module 620.

Optionally, in step S802, the transmission manner of the first HARQ codebook may be determined by the processing module 610 of the second apparatus. Accordingly, the receiving manner of the first HARQ codebook may be determined by the processing module 610 of the first device.

The first HARQ codebook is used for determining at least one HARQ feedback information for the at least one transport block, where one transport block corresponds to the at least one HARQ feedback information. For example, the first HARQ codebook may include at least one piece of HARQ feedback information for the at least one transport block, or may also include indication information indicating the at least one piece of HARQ feedback information for the at least one transport block, or the like.

The "at least one HARQ feedback information for the at least one transport block" may also be described as at least one HARQ feedback information corresponding to the at least one transport block or at least one HARQ feedback information associated with the at least one transport block.

Illustratively, the first sidelink channel is at least one of: a sidelink data channel, a sidelink control channel, and a sidelink feedback channel. The sidelink data channel may be a PSSCH. The sidelink control channel may be a PSCCH. The sidelink feedback channel may be a PSFCH.

The implementation of step S802 will be described in detail below with reference to a specific example of the first sidelink channel.

In one possible implementation, when the second apparatus transmits the first HARQ codebook to the first apparatus through the first sidelink channel, the second apparatus may preempt the COT through the class-two LBT, within which the first sidelink channel is located. By the method, when the second device only needs to send the HARQ feedback information to the first device without sending side-link data, the second device can access the channel more quickly through the second-class LBT without random backoff, so that the first device can acquire the HARQ feedback information as early as possible, thereby reducing communication time delay and improving communication performance.

The embodiment of the application provides a method for generating an HARQ codebook and performing HARQ feedback to a sending side device through a sidelink channel, which can perform HARQ feedback for a plurality of SL HARQ processes at one time in a sidelink communication system, thereby improving SL HARQ feedback efficiency.

In one possible embodiment, the second apparatus may transmit the first HARQ codebook in triggering of first indication information of the first apparatus, where the first indication information is used to indicate that the second apparatus feeds back HARQ information, i.e., to indicate that the second apparatus transmits the first HARQ codebook. For example, the second apparatus may receive the first indication information from the first apparatus before transmitting the first HARQ codebook. Optionally, the first indication information may be carried by 1 bit in an SCI, where the SCI is sent from the first device to the second device, where the SCI may be a first-level SCI (1 st stage SCI) or a second-level SCI (2 nd stage SCI).

By means of the first indication information sent by the first device to the second device, the first device and the second device are enabled to align understanding of the first HARQ codebook, and therefore communication performance can be further improved.

In a possible implementation manner, the second apparatus may send the first HARQ codebook triggered by second indication information of the first apparatus, where the second indication information is used to indicate identities of one or more SL HARQ processes corresponding to the one or more TBs. For example, the second apparatus may receive the second indication information from the first apparatus before transmitting the first HARQ codebook. Optionally, the second indication information is a Media Access Control (MAC) Control Element (CE) or a Radio Resource Control (RRC) signaling parameter.

In an implementation manner, the second indication information may be implemented in a bitmap (bitmap), where an ith bit of the bitmap is used to indicate whether the first device needs HARQ feedback information of an SL HARQ process with an SL HARQ process number i. For example, the first device may transmit SL data to the second device through a total of 8 SL HARQ processes having SL HARQ process numbers {0,1,2,3, \ 8230;, 7}, and when the first device only needs the second device to feed back HARQ feedback information of 5 SL HARQ processes having SL

HARQ process numbers

0,1, 5,6,7, the first device may transmit a 11000111 bitmap, that is, second indication information, to the second device through the MAC CE. And after receiving the second indication information, the second device generates an HARQ codebook according to 5 SL HARQ processes with SL HARQ process numbers of 0,1, 5,6 and 7 and feeds back the HARQ codebook to the first device.

Through the above manner, the first device can make the second device perform HARQ feedback in a targeted manner, and HARQ feedback information of all SL HARQ processes does not need to be continuously sent to the first device, so that transmission resource overhead can be reduced, and resource utilization rate is improved.

For example, if the second apparatus receives the second indication information, it may be considered that the first apparatus indicates the second apparatus to feed back the HARQ information, that is, it may be considered that the first apparatus transmits the first indication information to the second apparatus. If the second apparatus does not receive the second indication information, it may be considered that the first apparatus does not indicate the second apparatus to feed back the HARQ information, i.e., it may be considered that the first apparatus does not send the first indication information to the second terminal.

In one possible implementation, the second apparatus may transmit the first HARQ codebook in trigger of third indication information of the first apparatus, where the third indication information is used to indicate the number of one or more SL HARQ processes corresponding to one or more transport blocks. For example, the second apparatus may receive the third indication information from the first apparatus before transmitting the first HARQ codebook. Optionally, the third indication information is a MAC CE, or an RRC signaling parameter.

It should be appreciated that there is a maximum number of SL HARQ processes used by the first device in the sidelink transmission, which may be 8 or 16, for example. The second apparatus may determine, when generating the HARQ codebook, a size of the HARQ codebook according to the number of SL HARQ processes.

Through the above manner, the first device indicates the number of the specific SL HARQ processes to the second device, which is beneficial for the second device to correctly generate the HARQ codebook, and is beneficial for the first device and the second device to keep common knowledge of a plurality of bits included in the HARQ codebook, so that the communication performance can be further improved.

For example, if the second apparatus receives the third indication information, it may be considered that the first apparatus indicates to feed back the HARQ information, that is, it may be considered that the first apparatus has transmitted the first indication information to the second apparatus. If the second apparatus does not receive the third indication information, it may be considered that the first apparatus does not indicate the second apparatus to feed back the HARQ information, i.e., it may be considered that the first apparatus does not send the first indication information to the second terminal.

By the first indication information, the second indication information or the third indication information, it is beneficial for the first device and the second device to keep common knowledge of a plurality of bits included in the HARQ codebook.

Fig. 8 describes a method for a scenario in which the second apparatus feeds back the HARQ codebook to a single transmission-side apparatus (i.e., the first apparatus). In some scenarios, the second apparatus may actually need to feed back the HARQ codebook to multiple transmitting-side terminal devices. In this partial scenario, the second apparatus may transmit the HARQ codebook to a plurality of transmitting-side terminal devices through the first sidelink channel. To facilitate understanding of the scheme, when the embodiment of step S802 is described with reference to a specific example of the first sidelink channel, a manner in which the second apparatus feeds back the HARQ codebook to the plurality of terminal devices will be described together.

It should be understood that, when multiple sending-side terminal devices send TBs to the second apparatus, the process of sending the first indication information, the second indication information, and the third indication information by the multiple sending-side terminal devices may refer to the process of sending the first indication information, the second indication information, and the third indication information by the first apparatus, and repeated parts are not described again.

The following describes, with reference to three examples of the first sidelink channel, that is, the first sidelink channel is a PSCCH (i.e., example one), the first sidelink channel is a PSCCH (i.e., example two), and the first sidelink channel is a PSFCH (i.e., example three), a scheme provided in the embodiment of the present application is described with respect to a scenario in which the second apparatus feeds back a HARQ codebook to a single transmitting terminal device, and a scenario in which the second apparatus feeds back a HARQ codebook to multiple terminal devices.

Example one: the second apparatus transmits a first HARQ codebook to the first apparatus in the psch.

The following description is directed to a scenario in which the second apparatus feeds back the HARQ codebook to a single transmitting-side terminal device.

In a specific implementation, the second apparatus may transmit the first HARQ codebook in the second level SCI of the PSSCH. In addition, in a sidelink transmission including both PSCCH and PSCCH from the second apparatus to the first apparatus, there are three implementation manners for transmitting the HARQ codebook to the first apparatus: first, the second device sends a first HARQ codebook in the first-stage SCI of the PSCCH; second, the second device sends the first HARQ codebook in the second-level SCI of the psch; third, the second device transmits the first HARQ codebook in the sidelink data of the psch. The embodiment of the present application adopts the second implementation manner for the following two reasons. On the one hand, the second implementation manner can reduce the decoding complexity of the first-level SCI compared with the first implementation manner. On the other hand, in the prior art, in order to improve the decoding performance of the second-level SCI, the second-level SCI is modulated by QPSK, and the sidelink data is generally transmitted at a high rate by QPSK and higher modulation. Therefore, the second implementation may improve decoding reliability of the HARQ codebook at the first apparatus through low order modulation, compared to the third implementation.

Alternatively, the second-level SCI carrying the first HARQ codebook may use a new second-level SCI format (format), hereinafter referred to as the first format. The first format may include a first field for carrying a HARQ codebook. In this manner, the format of the second-level SCI at least includes the first format and the second format, where the second format does not include a field for carrying the HARQ codebook.

In one illustration, the first format may include the following three fields: a first field for carrying a HARQ codebook, a second field for carrying a source identity (source ID), and a third field for carrying a destination identity (destination ID). Thus, the first field of the second-level SCI may carry the first HARQ codebook, the second field may carry the identifier of the second apparatus, and the third field may carry the identifier of the first apparatus. By the method, when the first device receives the second-level SCI, whether the HARQ codebook is from the second device can be judged through the source identifier, whether the HARQ codebook is sent to the first device can also be judged through the destination identifier, and whether the TB that has been sent is correctly received by the second device is determined based on the HARQ codebook.

In this implementation, the second device may indicate the format of the second-level SCI as the first format through fourth indication information. Optionally, the fourth indication information may be carried in the first-level SCI. For example, the second apparatus may send the first-level SCI in a PSCCH, where the PSCCH and a PSCCH carrying the first HARQ codebook are located in the same slot, and the first-level SCI indicates that the second-level SCI is in the first format.

Alternatively, in an embodiment where the first HARQ codebook is transmitted through the second-level SCI in the PSSCH, the PSSCH may be used only for transmission of the second-level SCI and the reference signal. It should be noted that, in the existing sidelink communication system, the second-level SCI and the reference signal may only be used as part of the PSSCH, but not as all of the PSSCH, that is, the PSSCH necessarily includes sidelink data, such as application layer service type information, sent from the sending end to the receiving end. When the aforementioned sidelink data is not included in the PSCCH, the prior protocol techniques will not provide a reasonable frame structure for transmitting the PSCCH, the second-level SCI, and the reference signal. For example, existing protocols provide that the first OFDM symbol to which the second-level SCI is mapped in the time domain is the first DMRS-containing OFDM symbol in the PSSCH, and therefore, when the DMRS is not present in the first OFDM symbol in the PSSCH, the exclusion of sidelink data in the PSSCH will result in the transmitting-side terminal device not transmitting any signal on that OFDM symbol, which in unlicensed spectrum communications will potentially cause a problem that the channel of the transmitting-side terminal device is occupied by other terminal devices. To address this problem, in the embodiment of the present application, when the PSSCH is only used for transmitting the second-level SCI and the reference signal, it may be additionally specified that the first OFDM symbol to which the second-level SCI is mapped in the time domain is the first OFDM symbol in the PSSCH.

In addition, since no sidelink data exists in the PSSCH, the second-level SCI may be mapped to any RE of the PSSCH except for a Resource Element (RE) occupied by a reference signal. In one illustration, the second-level SCI may map on all REs in the psch except for the REs occupied by the reference signal. In this example, the first-level SCI may not indicate the number of REs occupied by the second-level SCI.

In this way, even if the second device has no sidelink data to transmit to the first device, the first HARQ codebook may still be transmitted to the first device through the PSSCH in a reasonable frame structure.

For ease of understanding, the second apparatus transmitting the first HARQ codebook through the second-level SCI is illustrated herein.

As shown in fig. 9, the second device may transmit the PSCCH and PSCCH in the same time slot, where the PSCCH is used to transmit the first-level SCI; the PSSCH is used for transmitting a second-level SCI and a reference signal, and the second-level SCI carries a first HARQ codebook. The first-level SCI may indicate that the second-level SCI is in a first format, where the second-level SCI in the first format carries a first HARQ codebook through a first field, carries a source identifier through a second field, and carries a destination identifier through a third field. The second-level SCI may be mapped on all REs in the PSSCH except the REs occupied by the reference signal.

In addition, the time slot for transmitting PSCCH and PSCCH may include an Automatic Gain Control (AGC) symbol and/or a GAP (GAP) symbol, where the AGC symbol is used to adjust hardware parameters such as an amplifier of a receiving module to improve quality of a received signal; the GAP symbol does not transmit signals and is used for receiving and transmitting conversion of the receiving module.

It should be noted that, although the frequency domain resources occupied by the PSCCH and PSCCH in fig. 9 are shown as continuous frequency domain resources, it does not mean that the PSCCH and PSCCH of the second apparatus are mapped to the continuous frequency domain resources in resource mapping, and in a specific implementation, the PSCCH and PSCCH may be mapped to discrete frequency domain resources, for example, to a plurality of RBs, as shown in fig. 10, or to the continuous frequency domain resources, which is not limited specifically herein. It is understood that fig. 10 is only an example of mapping on the resource block group, but is not limited to the resource block group.

In the above embodiment, when the second device feeds back the first HARQ codebook to the first device, the second device may determine the number Q of coded modulation symbols (coded modulation symbols) of the second-level SCI according to the following formula _SCI2 Alternatively, it can also be understood that the number of coded modulation symbols of the second-level SCI satisfies the following formula:

wherein L is ₁ Is the index, L, of the first OFDM symbol occupied by the second-level SCI in the current slot ₂ An index of the last OFDM symbol occupied by the second-level SCI in the current time slot;

indicating the coding of the second level SCI on an OFDM symbol with index lThe number of modulation symbols. It is understood that L ₂ -L ₁ +1 is the number of OFDM symbols occupied by the psch in the current slot. For example, for a slot including 14 OFDM symbols, the index of each OFDM symbol is {0,1, \8230;, 13}, L } ₁ ＝1，L ₂ =12, when the number of OFDM symbols occupied by the psch in the current slot is L ₂ -L ₁ +1=12, that is to say the second-level SCI carried in the PSSCH occupies 12 OFDM symbols with an index {1,2, \8230; \8230, 12} in the current slot.

Note that the above process of determining the number of coded modulation symbols may also be referred to as rate matching (rate matching). It should be understood that for the resource mapping of SCIs, one coded modulation symbol will be mapped onto one RE, i.e., one coded modulation symbol is transmitted through one RE, so the number of coded modulation symbols of the second-level SCI may be the same as the number of REs occupied by the second-level SCI.

The foregoing describes a manner in which the second apparatus feeds back the HARQ codebook to the single transmitting-side terminal device through the psch, and in a scenario in which the second apparatus feeds back the HARQ codebook to the multiple transmitting-side terminal devices, the manner in which the second apparatus feeds back the HARQ codebook to the multiple terminal devices through the psch is similar to the manner in which the second apparatus feeds back the HARQ codebook to the single transmitting-side terminal device through the psch, except that in a scenario in which the second apparatus feeds back the HARQ codebook to the single transmitting-side terminal device, the second apparatus transmits one HARQ codebook in the psch, and in a scenario in which the second apparatus feeds back the HARQ codebook to the multiple transmitting-side terminal devices, the second apparatus transmits multiple HARQ codebooks in the psch, where the multiple HARQ codebooks are HARQ codebooks corresponding to the multiple transmitting-side terminal devices, respectively. One HARQ codebook includes HARQ feedback information for one or more TBs from a corresponding transmitting-side terminal device. The repetition points can be referred to the description above, and are not described in detail here.

Taking K HARQ codebooks, where K is an integer greater than 1 as an example, when the second device transmits the K HARQ codebooks in the PSSCH, the K HARQ codebooks may be specifically transmitted in the PSSCH in a Time Division Multiplexing (TDM) or Frequency Division Multiplexing (FDM) manner. It should be understood that in the embodiment of the present application, TDM between multiple HARQ codebooks means that multiple channels carrying multiple HARQ codebooks are TDM, or multiple time-frequency resources carrying multiple HARQ codebooks are TDM; FDM among the HARQ codebooks means that a plurality of channels carrying the HARQ codebooks are FDM, or a plurality of time-frequency resources carrying the HARQ codebooks are FDM.

In a possible implementation manner, in the implementation manner of time division multiplexing, each HARQ codebook of the K HARQ codebooks may occupy at least one continuous time slot, and the time slots occupied by the K HARQ codebooks do not overlap each other. In this implementation, different HARQ codebooks may be carried in different second-level SCIs, and thus, K HARQ codebooks may be carried in K second-level SCIs on K consecutive slots, respectively.

In another possible implementation manner, in the time division multiplexing implementation manner, the K HARQ codebooks jointly occupy one slot. In this implementation, when the second device transmits K HARQ codebooks through K second-level SCIs in the psch, the second device may determine the number of coded modulation symbols of the K second-level SCI through the following formula, or may also understand that the number of coded modulation symbols of the K second-level SCI satisfies the following formula, K = {1,2, \ 8230; \8230;, K }:

wherein L is _k-1 Denotes the index, L, of the first OFDM symbol occupied by the kth second-level SCI in the current slot _k -1 represents the index of the last OFDM symbol occupied by the kth second level SCI in the current slot; m ^SCI2 (l) Indicating the number of coded modulation symbols of the second level SCI on the OFDM symbol with index l. It is understood that L _k -L _k-1 I.e. the number of OFDM symbols occupied by the kth second-level SCI. For the index of the first OFDM symbol occupied by the 1st second-level SCI in the current time slot, the second device can determine L by itself ₀ A value of, e.g., L ₀ =1 is the value given by the protocol.

Optionally, for L _k K = {2,3, \8230;, K } case, L corresponding to each second-level SCI _k Can be configured by RRC signaling. For example, the network device may configure the index of the last OFDM symbol occupied by each second-level SCI, i.e., each L, through RRC signaling _k -a value of 1. Also for example, the network device may directly configure each L through RRC signaling _k The value of (c). For another example, the network device may configure the number of OFDM symbols occupied by each second-level SCI, i.e. each L, through RRC signaling _k -L _k-1 The value of (c).

Alternatively to L _k K = {2,3, \8230;, K } case, the second device indicates the L corresponding to each second-level SCI through the first-level SCI carried in the PSCCH _k The value of (c). For example, the first-level SCIs indicate the index of the last OFDM symbol occupied by each second-level SCI, i.e., each L _k -a value of 1. As another example, the first level SCI directly indicates each L _k The value of (c). As another example, the first-level SCIs indicate the number of OFDM symbols occupied by each second-level SCI, i.e., each L _k -L _k-1 The value of (c).

For example, in fig. 11, assuming that the number of OFDM symbols occupied by pscch is 12 and the number of OFDM symbols occupied by pscch is 3, the protocol specifies L ₀ =1 (i.e. the index of the first OFDM symbol occupied by the 1st second level SCI in the current slot is 1), RRC signaling from the network device configures each L _k A value of-1 is L ₁ -1=4 (i.e. the index of the last OFDM symbol occupied by the 1st second level SCI in the current slot is 4, and the index of the first OFDM symbol occupied by the 2nd second level SCI in the current slot is 5), L ₂ -1=6 (i.e. the index of the last OFDM symbol occupied by the 2nd second level SCI in the current slot is 6, and the index of the first OFDM symbol occupied by the 3 rd second level SCI in the current slot is 7), L ₃ -1=8 (i.e. the index of the last OFDM symbol occupied by the 3 rd second level SCI in the current slot is 8, and the index of the first OFDM symbol occupied by the 4th second level SCI in the current slot is 9), L ₄ -1=10 (i.e. the last OFDM symbol occupied by the 4th second level SCI in the current slot)The index of the number is 10 and the index of the first OFDM symbol occupied by the 5th second level SCI in the current slot is 11). According to this configuration, the second device can feed back the HARQ codebook to at most K =5 transmission-side terminal apparatuses in one transmission of the psch, in which the second device has L = {1,2,3,4} of 14 OFDM symbols in the current slot ₁ -L ₀ Transmitting the 1st second-level SCI on 4 OFDM symbols, at L with number L = {5,6} ₂ -L ₁ =2 second level SCI transmitted on 2 OFDM symbols, in L with the number L = {7,8} ₃ -L ₂ Transmitting the 3 rd second level SCI on 2 OFDM symbols, L with number L = {9,10 = ₄ -L ₃ Transmitting the 4th second-level SCI on 2 OFDM symbols, at L with number L = {11,12} ₅ -L ₄ = transmit the 5th second-level SCI on 2 OFDM symbols.

In a possible implementation manner, in the implementation manner of frequency division multiplexing, each HARQ codebook of K HARQ codebooks may occupy one continuous frequency domain resource, and the frequency domain resources occupied by the K HARQ codebooks are not overlapped and adjacent to each other, as shown in fig. 12. Or, the K HARQ codebooks respectively occupy at least one resource block group, and resource blocks occupied by the K HARQ codebooks are not overlapped with each other, as shown in fig. 13. In this embodiment, the K HARQ codebooks are carried in one second-level SCI, or may be carried in the K second-level SCIs, respectively.

When the second apparatus transmits K HARQ codebooks to K transmission side terminal devices through the first sidelink channel, the second apparatus may further transmit SCIs including K destination identifiers to the K transmission side terminal devices, where there is a one-to-one correspondence between the K destination identifiers and the K HARQ codebooks. That is, the second-level SCI may carry K destination identifiers, for example, a third field of the second-level SCI may carry K destination identifiers.

It should be understood that the terminal device in the sidelink communication system has a destination identifier of 16 bits in the physical layer, and the terminal device can determine whether the control information and/or the data information and/or the feedback information is transmitted to itself according to the destination identifier. It should also be understood that in the prior art, the SCI used for a single sidelink transmission may only include 1 destination identification. By using the method of the invention, when the second device needs to feed back the HARQ codebook to K sending side terminal equipments, the first side uplink channel for transmitting the K HARQ codebooks comprises K SCIs with destination identifiers, thereby simultaneously feeding back the HARQ codebook to the K sending side terminal equipments through the first side uplink channel, and improving the HARQ feedback efficiency of the second device.

Example two: the second apparatus transmits the first HARQ codebook to the first apparatus in a PSCCH.

In this example, the second apparatus may transmit a stand-alone PSCCH to the first apparatus that does not have a PSCCH associated, i.e. the PSCCH may not be included in the time slot in which it is transmitted. By the method, the speed of receiving the HARQ feedback information by the first device can be increased.

In one possible implementation, the frequency domain bandwidth of the PSCCH may be equal to the frequency domain bandwidth of the COT. For example, the frequency domain bandwidth of the PSCCH is N × L MHz, where N is a positive integer and L is a positive integer. For example, L is 20, the frequency domain bandwidth of the PSCCH is N × 20MHz.

It should be understood that the frequency domain bandwidth of the terminal device operating in the unlicensed spectrum when accessing the channel needs to be a positive integer multiple of 20MHz, such as 20mhz,40mhz,60mhz, 80MHz, etc., and by making the frequency domain bandwidth of the PSCCH be nx20 MHz, it is possible to avoid other terminal devices operating in the unlicensed spectrum accessing the channel and generating interference due to channel idle sensing. It should also be understood that in this example, the frequency domain bandwidth of the PSCCH is N × 20MHz, which does not mean that the PSCCH occupies all of the frequency domain resources in N × 20MHz, and the PSCCH may occupy only a portion of the frequency domain resources in N × 20MHz, where the interval between the starting frequency and the ending frequency of the PSCCH may be up to 80% and above compared to N × 20MHz.

In one possible implementation, the time domain length of the PSCCH may be M OFDM symbols, where M is equal to P-P, where P is the number of OFDM symbols in one slot, and P is the number of symbols occupied by ACGs and GAPs in the slot, for example, a slot includes 14 OFDM symbols, where ACGs occupy 1 symbol and GAPs occupy 1 symbol, and then M =12. For another example, one slot includes 12 OFDM symbols, where ACG occupies 1 symbol, GAP occupies 1 symbol, and M =10.

For ease of understanding, the second apparatus transmitting the first HARQ codebook over the PSCCH is illustrated herein.

Taking an example where one slot includes 14 OFDM symbols, as shown in fig. 14, the second device transmits a PSCCH to the first device, the PSCCH having a time-domain length of 14-2=12 OFDM symbols, the PSCCH being used to transmit coded bits of an SCI and coded bits of a first HARQ codebook, the SCI may include a first-level SCI and a second-level SCI. There are AGC symbols before the PSCCH and GAP symbols after the PSCCH. It should be noted that although the frequency domain resources occupied by the PSCCH in fig. 14 are shown as continuous frequency domain resources, the PSCCH of the second apparatus is not meant to be mapped to the continuous frequency domain resources in resource mapping, and in a specific implementation, the PSCCH may be mapped to discrete frequency domain resources in the frequency domain, for example, to a plurality of RBs, as shown in fig. 15, or to continuous frequency domain resources, which is not limited herein. It is to be understood that fig. 15 is only an example of mapping on staggered resource blocks, but is not limited to staggered resource blocks.

Example three: the second apparatus transmits the first HARQ codebook to the first apparatus in the PSFCH.

In an example, the second apparatus may transmit the first HARQ codebook in a PSFCH, and transmit a source identifier and a destination identifier corresponding to the PSFCH in a PSCCH, where a sidelink feedback channel and a sidelink control channel are located in a same time slot. Optionally, the slot may not include the psch.

In the above manner, by transmitting the PSCCH and the PSCCH in the same time slot, the first device may determine, according to the PSCCH, whether the HARQ codebook is from the second device and whether the HARQ codebook is a HARQ codebook addressed to itself, by indicating, by the PSCCH, the indication information related to the first HARQ codebook, such as the source identifier, the destination identifier, and the like, so that the first device may determine, according to the PSCCH, whether the HARQ codebook is from the second device and, if the HARQ codebook is transmitted to itself by the second device, obtain, from the PSCCH, the first HARQ codebook from the second device, and then determine, based on the first HARQ codebook, whether the TB that has been transmitted is correctly received by the second device.

In this example, the PSFCH and the PSCCH may be time or frequency multiplexed.

In a possible implementation manner, in the time division multiplexing embodiment, the PSFCH may occupy Q1 symbols, the PSCCH may occupy Q2 symbols, and the symbols occupied by the PSFCH and the symbols occupied by the PSCCH are not overlapped. Q1+ Q2= P-P, where P is the number of OFDM symbols in a slot, and P is the number of symbols occupied by ACG and GAP in the slot. For example, one slot includes 14 OFDM symbols, where ACG occupies 1 symbol, GAP occupies 1 symbol, and Q1+ Q2=12. For another example, one slot includes 12 OFDM symbols, where ACG occupies 1 symbol and GAP occupies 1 symbol, then Q1+ Q2=10.

For example, assuming that the PSCCH may occupy 2 or 3 OFDM symbols, i.e. Q2 has a value range of {2,3}, the PSFCH may occupy 7 or 8 or 9 or 10 symbols, i.e. Q1 has a value range of {7,8,9,10}. Specifically, if 1 timeslot includes 14 symbols, ACG occupies 1 symbol, GAP occupies 1 symbol, and PSCCH occupies 2 OFDM symbols, then PSFCH occupies 10 symbols, and PSCCH occupies 3 OFDM symbols, then PSFCH occupies 9 symbols. If 1 slot includes 12 symbols, ACG occupies 1 symbol, GAP occupies 1 symbol, PSCCH occupies 2 OFDM symbols, then PSFCH occupies 8 symbols, PSCCH occupies 3 OFDM symbols, then PSFCH occupies 7 symbols.

In this embodiment, the frequency domain bandwidths of the PSFCH and the PSCCH may be the same, and both are N × L MHz, where N is a positive integer and L is a positive integer. For example, if L is 20, the frequency domain bandwidth of the PSFCH or the PSCCH is N × 20MHz. By setting the frequency domain bandwidth of the above-mentioned PSFCH or the above-mentioned PSCCH to N × 20MHz, the second apparatus can continue to transmit the PSFCH of the same frequency domain bandwidth after completing transmission of the PSCCH. It should be understood that, when the frequency domain bandwidth of the PSCCH is smaller than the frequency domain bandwidth of the PSFCH, for example, the frequency domain bandwidth of the PSCCH is N1 × 20MHz, the frequency domain bandwidth of the PSFCH is N2 × 20MHz, where N1< N2, the second apparatus cannot guarantee that the channel is occupied on the (N2-N1) × 20MHz bandwidth when the PSCCH is transmitted, potentially causing a terminal device operating in an unlicensed spectrum to access the channel due to the fact that the channel sensing the (N2-N1) × 20MHz bandwidth is in an idle state, and further causing interference to a subsequent PSFCH having the frequency domain bandwidth of N2 × 20MHz. Therefore, by setting the frequency domain bandwidth of the PSFCH or the PSCCH to be N × 20MHz, other terminal devices operating in an unlicensed spectrum can be prevented from accessing a channel and generating interference due to sensing that the channel is idle.

In this example, the frequency domain bandwidth of the PSCCH (or PSFCH) is N × L MHz, which does not mean that the PSCCH (or PSFCH) occupies all frequency domain resources in N × L MHz, and the PSCCH (or PSFCH) may occupy only a portion of the frequency domain resources in N × L MHz, wherein the interval between the start frequency and the end frequency of the PSCCH (or PSFCH) may be up to 80% or more compared to N × L MHz.

For ease of understanding, the PSFCH and PSCCH time division multiplexing are illustrated here. In this example, it is assumed that a slot includes 14 OFDM symbols, ACG occupies 1 symbol, GAP occupies 1 symbol, PSCCH occupies 3 symbols, and PSFCH occupies 9 symbols. As shown in fig. 16.

It should be noted that, although the frequency domain resources occupied by the PSFCH (or PSCCH) in fig. 16 are shown as continuous frequency domain resources, it does not mean that the PSFCH (or PSCCH) of the second apparatus is mapped to continuous frequency domain resources in resource mapping, and in a specific implementation, the PSFCH (or PSCCH) may be mapped to discrete frequency domain resources in frequency domain, for example, to multiple RBs, as shown in fig. 17, or to continuous frequency domain resources, which is not limited herein. It is to be understood that fig. 17 is only an example of mapping on staggered resource blocks, but is not limited to staggered resource blocks.

In one possible implementation manner, in the frequency division multiplexing embodiment, the PSFCH and the PSCCH may respectively occupy one continuous frequency domain resource, and the frequency domain resources occupied by the PSFCH and the PSCCH are not overlapped and adjacent to each other, as shown in fig. 18.

Or the PSFCH and the PSCCH occupy at least one resource block group respectively, and the resource blocks occupied by the PSFCH and the PSCCH are not overlapped with each other. For example, as shown in FIG. 19, taking the subcarrier spacing of 30kHz as an example, one resource block group includes RBs with indices { m, m +5, m +10, \8230 }, where m ranges from {0,1, \8230;, 4}. Therefore, there are 5 resource block groups within the frequency domain bandwidth of N × 20MHz. The second device may transmit the PSCCH using 1 resource block group including an RB with an index of {0,5,10, \8230; }, transmit the PSFCH using a resource block group including an RB with an index of {1,6,11, \8230; }, and transmit the PSFCH using 2 resource block groups including a resource block group with an index of {2,7,12, \8230; }.

In this embodiment, the time domain lengths of the PSFCH and the PSCCH may be M OFDM symbols, where M is equal to P-P, where P is the number of OFDM symbols in one slot, and P is the number of symbols occupied by ACGs and GAPs in the slot, for example, one slot includes 14 OFDM symbols, where ACGs occupy 1 symbol, and GAPs occupy 1 symbol, and then M =12. For another example, one slot includes 12 OFDM symbols, where ACG occupies 1 symbol, GAP occupies 1 symbol, and M =10.

It should be noted that although the frequency domain resources occupied by the PSFCH (or PSCCH) in fig. 18 are illustrated as continuous frequency domain resources, it does not mean that the PSFCH (or PSCCH) of the second apparatus is mapped to continuous frequency domain resources in resource mapping, and in a specific implementation, the PSFCH (or PSCCH) may be mapped to discrete frequency domain resources in frequency domain, for example, to a plurality of RBs, as illustrated in fig. 19 and 20, or to continuous frequency domain resources, which is not limited herein. It can be understood that in fig. 19, PSCCH occupies 1 resource block group, and PSFCH occupies 2 resource block groups. In fig. 20, the PSCCH and the PSFCH jointly occupy 2 resource block groups. Fig. 19 and 20 are only examples of mapping on the interleaved resource blocks, but are not limited to the interleaved resource blocks.

In this embodiment, if the sum of the frequency domain bandwidths of the PSFCH and the PSCCH is N × L MHz, for example, if L is 20, the sum of the frequency domain bandwidths of the PSFCH and the PSCCH is N × 20MHz. By making the sum of the frequency domain bandwidths of the PSFCH and the PSCCH be nxl MHz, other terminal devices operating in an unlicensed spectrum can be prevented from accessing a channel and generating interference due to sensing that the channel is idle.

In this example, the sum of the frequency domain bandwidths of the PSFCH and the PSCCH is N × L MHz, which does not mean that the PSFCH and the PSCCH occupy all frequency domain resources in N × L MHz, and the PSFCH and the PSCCH may occupy only a part of the frequency domain resources in N × L MHz, wherein an interval between a start frequency and an end frequency of the resources occupied by the PSFCH and the PSCCH may be 80% or more compared to N × L MHz.

Furthermore, the PSCCH and the PSFCH can ensure that the terminal equipment occupies more than 80% of the bandwidth of the allocated frequency band by using the frequency division multiplexing mode of the staggered resource blocks, and the regulatory requirement of the unlicensed spectrum is met.

By the above mode, the detection process of the first device can be simplified, so that the RB of the PSCCH and the PSFCH transmitted by the second device can be more easily detected, and the transmission reliability of the control information and the HARQ codebook can be improved.

In the scenario where the second apparatus feeds back the HARQ codebook to the single transmitting-side terminal device through the PSFCH, the manner in which the second apparatus feeds back the HARQ codebook to the multiple transmitting-side terminal devices through the PSFCH is similar to the manner in which the second apparatus feeds back the HARQ codebook to the single transmitting-side terminal device through the PSFCH. The repetition points can be referred to the description above, and are not repeated here.

Taking K HARQ codebooks, where K is an integer greater than 1 as an example, when the second apparatus transmits the K HARQ codebooks in the PSFCH, the K HARQ codebooks may be specifically transmitted in the PSFCH by using a time division multiplexing or frequency division multiplexing manner.

In a possible implementation manner, in the implementation manner of time division multiplexing, each HARQ codebook of the K HARQ codebooks may occupy at least one continuous time slot, and the time slots occupied by the K HARQ codebooks do not overlap each other. Exemplarily, as shown in fig. 21, the value of K is 3, that is, the second apparatus needs to feed back the HARQ codebook to 3 terminal devices on the transmitting side. In this example, the second device initial COT includes 3 slots. The second apparatus may use the 1st slot to feed back the HARQ codebook to the terminal equipment on the transmitting side numbered 1, use the 2nd slot to feed back the HARQ codebook to the terminal equipment on the transmitting side numbered 2, and use the 3 rd slot to feed back the HARQ codebook to the terminal equipment on the transmitting side numbered 3.

One possible implementation manner is that, in the frequency division multiplexing implementation manner, K HARQ codebooks may be carried by K time-frequency resources in the PSFCH, where the K time-frequency resources are the same in the time domain and do not overlap with each other in the frequency domain, and one frequency-domain resource carries one HARQ codebook.

Optionally, the K frequency-domain resources may be continuous in the frequency domain, as shown in fig. 22 or fig. 23. Alternatively, any one of the K frequency domain resources includes at least one resource block group in the frequency domain, as shown in fig. 24, 25, or 26. Exemplarily, in fig. 24, 25, and 26, it is assumed that the value of K is 3, that is, the second device needs to feed back the HARQ codebook to 3 transmitting-side terminal devices, and it is assumed that one resource block group includes RBs with indexes { m, m +5, m +10, \8230 }, where m has a value range of {0,1, \8230;, 4}.

In one illustration, in fig. 24, PSCCH and PSFCH are frequency division multiplexed and occupy 4 resource block groups. The second device may transmit the PSCCH using 1 resource block group including RBs with indexes of 0,5,10, \8230;). The second apparatus may transmit the HARQ codebook, i.e., the 1st HARQ codebook, to the transmission-side terminal device numbered 1 using 1 resource block group including an RB with an index {1,6,11, \8230; }. The second apparatus may transmit the HARQ codebook, i.e., the 2nd HARQ codebook, to the transmission-side terminal device numbered 2 using 1 resource block group including the RB with index {2,7,12, \8230; }. The second device may transmit the HARQ codebook, i.e., the 3 rd HARQ codebook, to the transmission-side terminal device numbered 3 using 1 resource block group including RBs indexed 3,8,13, \8230;).

By way of example, in fig. 25, PSCCH and PSFCH are frequency division multiplexed and occupy 3 resource block groups. The second device may transmit the PSCCH using a part of 3 resource block groups including RBs with

indexes

0,5,10, \8230;, {1,6,11, \8230;, {2,7,12, \8230; }, and 6 RBs with

indexes

0,1,2,5,6,7 are used in the drawing for example only and are not particularly limited thereto. The second apparatus may transmit the HARQ codebook, i.e., the 1st HARQ codebook, to the transmission-side terminal device numbered 1 using the remaining part of RBs except for the RBs occupied by the PSCCH among the 1 resource block group including the RB with an index {0,5,10, \8230; }. The second apparatus may transmit the HARQ codebook, i.e., the 2nd HARQ codebook, to the transmitting-side terminal device numbered 2 using the remaining part of RBs except for the RBs occupied by the PSCCH among the 1 resource block group including the RB with index {1,6,11, \8230; }. The second apparatus may transmit the HARQ codebook, i.e., the 3 rd HARQ codebook, to the transmission-side terminal device numbered 3 using the remaining part of RBs except for the RBs occupied by the PSCCH among the 1 resource block group including the RB with index {2,7,12, \8230;).

In one example, in fig. 26, PSCCH and PSFCH are time division multiplexed and occupy 3 resource block groups. The second device may transmit the PSCCH using a partial time domain resource, e.g., 3 OFDM symbols, of 3 resource block groups including RBs with indices of 0,5,10, \8230; {1,6,11, \8230; {2,7,12, \8230;). The second apparatus may transmit the HARQ codebook, i.e., the 1st HARQ codebook, to the transmitting-side terminal device numbered 1 using the remaining part of the time domain resources except for the time domain resources occupied by the PSCCH among the 1 resource block group including the RB with index {0,5,10, \8230;). The second apparatus may transmit the HARQ codebook, i.e., the 2nd HARQ codebook, to the transmission-side terminal device numbered 2 using the remaining time domain resources except for the time domain resources occupied by the PSCCH from the 1 resource block group including the RB with an index {1,6,11, \8230 }. The second apparatus may transmit the HARQ codebook, i.e., the 3 rd HARQ codebook, to the transmitting-side terminal device numbered 3 using the remaining part of the time domain resources except for the time domain resources occupied by the PSCCH among the 1 resource block group including the RB with index {2,7,12, \8230;).

The manner of time division multiplexing and frequency division multiplexing of K time frequency resources carrying K HARQ codebooks may refer to the manner of time division multiplexing and frequency division multiplexing of K time frequency resources carrying K HARQ codebooks in the above example one, and will not be repeated herein.

In this embodiment, 1 shared PSCCH may be used to provide physical layer control information for K time-frequency resources, and the K time-frequency resources may be separately encoded and bear HARQ codebooks for different transmitting-side terminal devices, so that the second apparatus may simultaneously feed back the HARQ codebooks to multiple transmitting-side terminal devices on a single time-domain resource, which may reduce the time delay of HARQ feedback, may also reduce the overhead of HARQ feedback, and improve the resource utilization efficiency of the unlicensed spectrum.

In a possible implementation manner, when the second apparatus sends K HARQ codebooks to K transmission side terminal devices through the first sidelink channel, the second apparatus may also send SCIs including K destination identifiers to the K transmission side terminal devices, where there is a one-to-one correspondence between the K destination identifiers and the K HARQ codebooks. That is, the PSCCH may carry K destination identifiers.

It should be understood that the terminal device in the sidelink communication system has a destination identifier of 16 bits in the physical layer, and the terminal device can determine whether the control information and/or the data information and/or the feedback information is transmitted to itself according to the destination identifier. It should also be understood that in the prior art, the SCI used for a single sidelink transmission may only include 1 destination identifier. By using the method of the invention, when the second device needs to feed back the HARQ codebook to K sending side terminal equipments, the first side uplink channel for transmitting the K HARQ codebooks comprises K SCIs with destination identifiers, thereby simultaneously feeding back the HARQ codebook to the K sending side terminal equipments through the first side uplink channel, and improving the HARQ feedback efficiency of the second device.

Aiming at the scene that the second device feeds back the HARQ codebooks to a plurality of sending side terminal devices, the second device can only initiate 1 COT and respectively feed back the corresponding HARQ codebooks to the K sending side terminal devices at one time by using K time domain resources in the COT, thereby reducing the time delay of HARQ feedback and reducing the expense of HARQ feedback.

At present, through the mapping relationship between the pscch and the PSFCH in the time domain and the frequency domain, the terminal device may determine the location of the PSFCH corresponding to the mapping according to the location of the pscch, so as to obtain the HARQ information of the pscch. However, in the unlicensed spectrum, regulations require that the channel needs to be continuously occupied or otherwise needs to be re-accessed through an additional LBT process, which potentially destroys the mapping relationship between the psch and the PSFCH in the time domain and the frequency domain, resulting in that the terminal device on the transmitting side cannot correctly acquire the HARQ feedback information from the terminal device on the receiving side. In the embodiment of the application, when the receiving-side terminal device needs the initial COT and transmits the HARQ codebook by using the COT, the HARQ codebook is transmitted together with indication information such as a source identifier, a destination identifier, and the like, or the HARQ codebook is transmitted together with an SCI carrying the source identifier and the destination identifier, so that the transmitting-side terminal device effectively acquires the HARQ codebook from the receiving-side terminal device, and further determines whether the TB that has been transmitted is correctly received by the receiving-side terminal device based on the HARQ codebook. Meanwhile, the HARQ feedback information based on 1 bit is converted into the HARQ codebook indicating a plurality of TBs, so that the retransmission overhead can be effectively reduced, and the resource utilization efficiency of the unlicensed spectrum is improved.

By the scheme provided by the embodiment of the application, the terminal equipment at the receiving side can transmit the HARQ feedback information of a plurality of SL HARQ processes corresponding to the terminal equipment at the single sending side to the terminal equipment at the sending side at one time, so that the feedback efficiency of SL HARQ can be improved. In addition, in the embodiment of the present application, the receiving side terminal device is further enabled to transmit the plurality of HARQ codebooks corresponding to the plurality of transmitting side terminal devices at one time, so that the efficiency of SL HARQ feedback is further improved.

The embodiment of the application provides a communication device. The communication apparatus may be used to implement the functions of the terminal device according to the above embodiments, for example, the communication apparatus may be a terminal device itself, such as a vehicle-mounted terminal device or a roadside unit, or the communication apparatus may also be an apparatus capable of supporting the terminal device to implement the functions, such as a chip, a module, a TBOX applied in the terminal device, or other combined devices or components (or called assemblies) having the functions of the terminal device shown in this application, for example, the communication apparatus may be a chip, a module, or an assembly in a device such as a vehicle-mounted terminal device or a roadside unit. The communication device may include the structure shown in fig. 6 and/or fig. 7.

An embodiment of the present application further provides a computer-readable storage medium, where a computer program is stored, and when the computer program is executed by a computer, the computer may implement the process related to the terminal device in the foregoing embodiments.

The embodiment of the present application further provides a computer program product, where the computer program product is used to store a computer program, and when the computer program is executed by a computer, the computer may implement the process related to the terminal device in the foregoing embodiments.

The embodiments of the present application further provide a chip or a chip system, where the chip may include a processor, and the processor may be configured to call a program or an instruction in a memory, and execute the flow related to the terminal device in the foregoing embodiments. The chip system may include the chip, and may also include other components such as a memory or transceiver.

Embodiments of the present application further provide a circuit, which may be coupled to a memory and configured to execute the processes related to the terminal device in the foregoing embodiments. The chip system may include the chip, and may also include other components such as memory or a transceiver.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.

Claims

1. A method of communication, the method comprising:

receiving at least one transport block from a first apparatus;

and transmitting second-level Sidelink Control Information (SCI) to the first device in a sidelink data channel, wherein the second-level SCI carries a first hybrid automatic repeat request (HARQ) codebook, and the first HARQ codebook is used for determining at least one HARQ feedback information corresponding to the at least one transport block.

2. The method of claim 1, wherein the format of the second level SCI comprises at least a first format and a second format, wherein the first format comprises a field for carrying a HARQ codebook and the second field does not comprise a field for carrying a HARQ codebook.

3. The method of claim 1 or 2, wherein the method further comprises:

receiving first indication information from the first device, wherein the first indication information is used for indicating that the first HARQ codebook is transmitted; or alternatively

Receiving second indication information from the first apparatus, where the second indication information is used to indicate identities of one or more SL HARQ processes corresponding to the one or more transport blocks; or alternatively

Receiving third indication information from the first apparatus, where the third indication information is used to indicate the number of one or more SL HARQ processes corresponding to the one or more transport blocks.

4. The method according to any of claims 1-3, wherein the number Q of coded modulation symbols of the second level SCI _SCI2 Satisfies the following conditions:

wherein, L is ₁ Index of the first OFDM symbol occupied by the second-level SCI, L ₂ An index of the last OFDM symbol occupied by the second-level SCI; m ^SCI2 (l) Represents the number of coded modulation symbols of the second level SCI on an OFDM symbol with index i.

5. The method of any one of claims 1-4, further comprising:

transmitting a second HARQ codebook to the second apparatus in the sidelink data channel, the second HARQ codebook including HARQ feedback information for one or more transport blocks from the second apparatus;

wherein the first HARQ codebook and the second HARQ codebook are time division multiplexed in the sidelink data channel; or

The first HARQ codebook and the second HARQ codebook are frequency division multiplexed in the sidelink data channel.

6. The method of claim 5, wherein the first HARQ codebook is carried on a first resource in the sidelink data channel, wherein the second HARQ codebook is carried on a second resource in the sidelink data channel, wherein the first resource comprises at least one resource block group, wherein the second resource comprises at least one resource block group, wherein the first resource and the second resource do not overlap, and wherein the resource block group consists of a plurality of resource blocks with equal spacing.

7. The method of claim 5 or 6, wherein the first HARQ codebook and the second HARQ codebook are carried on different second level SCIs.

8. A method of communication, the method comprising:

transmitting at least one transport block to a communication device;

receiving a second level sidelink control information, SCI, from the communication device in a sidelink data channel, the second level SCI carrying a first hybrid automatic repeat request, HARQ, codebook, wherein the first HARQ codebook is used for determining at least one HARQ feedback information corresponding to the at least one transport block.

9. The method of claim 8, wherein the format of the second level SCI comprises at least a first format and a second format, wherein the first format comprises a field for carrying a HARQ codebook and the second field does not comprise a field for carrying a HARQ codebook.

10. The method of claim 8 or 9, wherein the method further comprises:

sending first indication information to the communication device, wherein the first indication information is used for indicating the sending of the first HARQ codebook; or alternatively

Sending second indication information to the communication device, wherein the second indication information is used for indicating the identification of one or more SL HARQ processes corresponding to the one or more transport blocks; or

Sending third indication information to the communication device, wherein the third indication information is used for indicating the number of one or more SL HARQ processes corresponding to the one or more transport blocks.

11. The method of any of claims 8-10, wherein the number Q of coded modulation symbols of the second-level SCI _SCI2 Satisfies the following conditions:

wherein, L is ₁ Index of the first OFDM symbol occupied by the second-level SCI, L ₂ An index of the last OFDM symbol occupied by the second-level SCI; m is a group of ^SCI2 (l) Represents the number of coded modulation symbols of the second level SCI on an OFDM symbol with index i.

12. A communications apparatus, comprising:

a processing module for receiving one or more transport blocks from the first apparatus via a transceiver module;

the processing module is further configured to control the transceiver module to send, to the first apparatus, second-level sidelink control information SCI in a sidelink data channel, where the second-level SCI carries a first hybrid automatic repeat request HARQ codebook, and the first HARQ codebook is used to determine at least one HARQ feedback information corresponding to the at least one transport block.

13. The apparatus of claim 12, wherein the formats of the second-level SCI comprise at least a first format and a second format, wherein the first format comprises a field for carrying a HARQ codebook and the second field does not comprise a field for carrying a HARQ codebook.

14. The apparatus of claim 12 or 13, wherein the processing module is further configured to:

receiving first indication information from the first apparatus through the transceiver module, wherein the first indication information is used for indicating that the first HARQ codebook is transmitted; or

Receiving, by the transceiver module, second indication information from the first apparatus, where the second indication information is used to indicate identities of one or more SL HARQ processes corresponding to the one or more transport blocks; or alternatively

Receiving, by the transceiver module, third indication information from the first apparatus, where the third indication information is used to indicate a number of one or more SL HARQ processes corresponding to the one or more transport blocks.

15. The apparatus according to any of claims 12-14, wherein the number Q of coded modulation symbols of the second level SCI _SCI2 Satisfies the following conditions:

16. The apparatus of any of claims 12-15, wherein the processing module is further configured to:

transmitting, by the transceiver module, a second HARQ codebook to a second apparatus in the sidelink data channel, the second HARQ codebook including HARQ feedback information for one or more transport blocks from the second apparatus;

17. The apparatus of claim 16, wherein the first HARQ codebook is carried on a first resource in the sidelink data channel, the second HARQ codebook is carried on a second resource in the sidelink data channel, the first resource comprises at least one resource block group, the second resource comprises at least one resource block group, and the first resource and the second resource do not overlap, wherein the resource block group consists of a plurality of resource blocks with equal spacing.

18. The apparatus of claim 16 or 17, wherein the first HARQ codebook and the second HARQ codebook are carried on different second level SCIs.

19. A communications apparatus, the apparatus comprising:

a processing module for transmitting at least one transport block to the communication device through the transceiving module;

the processing module is further configured to control the transceiver module to receive a second-level sidelink control information SCI from the communication apparatus in a sidelink data channel, where the second-level SCI carries a first HARQ codebook, and the first HARQ codebook is used to determine at least one HARQ feedback information corresponding to the at least one transport block.

20. The apparatus of claim 19, wherein the format of the second level SCI comprises at least a first format and a second format, wherein the first format comprises a field for carrying a HARQ codebook and the second field does not comprise a field for carrying a HARQ codebook.

21. The apparatus of claim 19 or 20, wherein the processing module is further configured to:

sending first indication information to the communication device through the transceiver module, wherein the first indication information is used for indicating to send the first HARQ codebook; or

Sending second indication information to the communication device through the transceiver module, wherein the second indication information is used for indicating the identification of one or more SL HARQ processes corresponding to the one or more transport blocks; or alternatively

Sending third indication information to the communication device through the transceiver module, where the third indication information is used to indicate the number of one or more SL HARQ processes corresponding to the one or more transport blocks.

22. The apparatus according to any of claims 19-21, wherein the number Q of coded modulation symbols of the second level SCI _SCI2 Satisfies the following conditions:

23. A computer-readable storage medium, for storing a computer program which, when run on a computer, causes the computer to perform the method of any one of claims 1 to 7 or causes the computer to perform the method of any one of claims 8 to 11.

24. A computer program product comprising a computer program or instructions which, when executed by a processor, carries out the method of any one of claims 1 to 7 or which, when executed by a processor, carries out the method of any one of claims 8 to 11.

25. A chip comprising a processor and a communication interface, the processor being configured to read instructions through the communication interface, the instructions when executed implementing the method of any one of claims 1 to 7 or the instructions when executed implementing the method of any one of claims 8 to 11.