COMMUNICATION METHOD, NETWORK DEVICE, AND TERMINAL DEVICE

Abstract

The present application provides a communication method, including: a first terminal device receives first downlink data from a network device through a first link; and after decoding the first downlink data to obtain a first decoding result, the first terminal device sends first information to a second terminal device through a second link, the first information including first hybrid automatic repeat request (HARQ-ACK) information, where the first HARQ-ACK information indicates the first decoding result. The first link is a link between the first terminal device and the network device, and the second link is a link between the first terminal device and the second terminal device. The first terminal device feeds back the HARQ-ACK information of the downlink data to the second terminal device. In this way, the first terminal device is prevented from directly feeding back the HARQ-ACK information of the downlink data to the network device, thereby reducing the uplink communication overhead of the first terminal device.

Description

[Technical Field]

[0001] The present application relates to the field of communications, and in particular to a communication method, a network device, and a terminal device. [Background technology]

[0002] This application claims priority to Chinese Patent Application No. 202310208329.6, entitled "XR TRANSMISSION METHOD, TERMINAL DEVICE, NETWORK DEVICE, AND COMMUNICATION SYSTEM," filed with the State Intellectual Property Office of China on January 20, 2023, and Chinese Patent Application No. 202310260750.1, entitled "COMMUNICATION METHOD, NETWORK DEVICE, AND TERMINAL DEVICE," filed with the State Intellectual Property Office of China on March 10, 2023, both of which are incorporated herein by reference in their entireties.

[0003] In a scenario where an extended reality (XR) device is connected to a network device, the XR device needs to communicate with a server through the network device, that is, the XR device sends uplink data (e.g., sends pose information of the XR device, audio data, and video data captured by the camera of the XR device) to the server through the network device. After receiving the data, the server generates corresponding downlink data (e.g., video to be displayed on the XR device) and sends the downlink data to the XR device through the network device.

[0004] The network device is usually far away from the XR device. To ensure the quality of uplink transmission, the XR device must perform power amplification on the data signal before sending the uplink data. As a result, the power consumption overhead of uplink transmission is high. In addition, the battery capacity of the XR device is small. If the XR device directly sends uplink data to the network device, the battery life of the XR device will be affected. Currently, the method for reducing the uplink communication power consumption of the XR device is as follows: The XR device sends uplink data to the network device through the terminal device.

[0005] Although the method in which the terminal device acts as a relay can avoid the XR device directly sending uplink data to the network device, when the XR device receives data scheduled by the network device, the XR device needs to feed back hybrid automatic repeat request acknowledgment (HARQ-ACK) information to the network device. How to reduce the power consumption overhead caused by the uplink HARQ-ACK information feedback implemented by the XR device has become an urgent problem to be solved. Summary of the Invention

[0006] To solve the above technical problems, the present application provides a communication method, in which a first terminal device indirectly feeds back HARQ-ACK information of downlink data to a network device through a second terminal device, to reduce uplink communication overhead of the first terminal device.

[0007] According to a first aspect, a communication method is provided. The method may be implemented by a first terminal device or a component (e.g., a chip or a circuit) of the first terminal device. This is not limited in the present application. For ease of explanation, the following description will be given using an example in which the first terminal device implements the method.

[0008] The communication method includes: a first terminal device receives first downlink data from a network device through a first link; the first terminal device decodes the first downlink data to obtain a first decoding result; the first terminal device sends first information to a second terminal device through a second link, the first information includes first hybrid automatic repeat request-acknowledgement (HARQ-ACK) information, the first HARQ-ACK information indicates the first decoding result, the first link is a transmission link between the first terminal device and the network device, and the second link is a transmission link between the first terminal device and the second terminal device.

[0009] Based on the above technical solution, after receiving first downlink data and decoding the first downlink data to obtain a first decoding result, the first terminal device sends first information, including first HARQ-ACK information, to the second terminal device through a second link, where the first HARQ-ACK information indicates the first decoding result. In this technical solution, the first terminal device no longer directly feeds back the HARQ-ACK information of the downlink data to the network device, but first feeds back the HARQ-ACK information of the downlink data to the second terminal device through the second link, and the second terminal device forwards the HARQ-ACK information of the downlink data to the network device. This prevents the first terminal device from directly feeding back the HARQ-ACK information of the downlink data to the network device, thereby reducing the uplink communication overhead of the first terminal device.

[0010] It should be noted that in this technical solution, the second terminal device is of downlink data and is configured to forward HARQ-ACK information received from the first terminal device to the network device. The second terminal device is a terminal device that establishes a communication connection to each of the first terminal device and the network device. In the present application, how the second terminal device knows to forward the HARQ-ACK information of downlink data for the first terminal device is not limited, and includes, but is not limited to, indicating to the second terminal device that it will forward the HARQ-ACK information of downlink data for the first terminal device in a pre-configured manner or in another manner.

[0011] Regarding the first aspect, in some implementations of the first aspect, before the first terminal device sends the first information to the second terminal device through the second link, the method further includes: the first terminal device determines a first time unit in which the first terminal device sends the first information.

[0012] Based on the above technical solution, before sending the first information to the second terminal device, the first terminal device needs to determine a first time unit for sending the first information, so as to avoid the second terminal device failing to receive when the first terminal device feeds back the first information in an inappropriate time unit.

[0013] Regarding the first aspect, in some implementations of the first aspect, the first terminal device determining a first time unit in which the first information is sent includes: the first terminal device determining a first time unit, where the first time gap is less than or equal to a time gap between the first time unit and a second time unit, the first terminal device determining the first time unit based on the first time unit and the second time unit, where the second time unit is a time unit in which the first terminal device receives first downlink data or a time unit in which the first terminal device receives first control information, where the first control information is used to schedule the first downlink data.

[0014] Based on the above technical solution, the first terminal device may determine a first time unit for sending first information by using a first time gap, where the first time gap is less than or equal to the time gap between the first time unit and the second time unit, and the second time unit is a time unit known to the first terminal device (for example, a time unit in which the first terminal device receives first downlink data or a time unit in which the first terminal device receives first control information). Therefore, when the second time unit is known, the first terminal device can quickly and accurately determine the first time unit based on the first time gap.

[0015] Regarding the first aspect, in some implementations of the first aspect, the first terminal device determining the first time gap includes: the first terminal device receiving first control information from the network device, where the first control information indicates the first time gap; or, before receiving the first downlink data, the first terminal device receiving first setting information from the network device and determining the first time gap based on the first setting information.

[0016] Based on the above technical solution, the network device may indicate the first time gap to the first terminal device in a dynamic indication (e.g., by delivering first control information) or a semi-static setting manner (e.g., by delivering first setting information), so that the first terminal device can learn the first time gap in different manners, thereby improving the flexibility of the solution.

[0017] Regarding the first aspect, in some implementations of the first aspect, before the first terminal device receives the first control information from the network device, the method further includes: the first terminal device receives second setting information from the network device, the second setting information is used to configure a time gap set, and the first time gap is one time gap in the time gap set.

[0018] Based on the above technical solution, before indicating the first time gap, the network device may configure a time gap set including multiple time gaps for the first terminal device by using second configuration information. When a specific time gap needs to be indicated, the time gap can be indicated by indicating a time gap index. When the network device needs to indicate a different time gap, a different time gap index may be indicated for implementation, thereby reducing signaling overhead.

[0019] Regarding the first aspect, in some implementations of the first aspect, when the first time gap is measured in a slot, the first terminal device determining the first time gap further includes: the first terminal device determining that a subcarrier spacing (SCS) referenced by the first time gap is a first SCS or a second SCS, the first SCS being an SCS corresponding to the first link, the second SCS being an SCS corresponding to the second link, and the first link being different from the second link.

[0020] Based on the above technical solution, when the first time gap is measured in a slot, in order to prevent the first terminal device from misunderstanding the specific gap duration of the first time gap, the first terminal device may determine an SCS referenced by the first time gap.

[0021] Regarding the first aspect, in some implementations of the first aspect, the first terminal device determining that the SCS referenced by the first time gap is the first SCS or the second SCS includes: the first terminal device determining that the SCS referenced by the first time gap is the first SCS or the second SCS based on a first parameter, the first parameter indicating the first SCS or the second SCS, the first parameter being configured by the network device, the first parameter being determined through negotiation by the first terminal device and the network device, or the first parameter being pre-programmed into the first terminal device.

[0022] Based on the above technical solution, the first terminal device can determine the SCS referenced by the first time gap based on the first parameter, and the first parameter can be obtained in different manners, thereby improving the flexibility of the solution.

[0023] Regarding the first aspect, in some implementations of the first aspect, the method further includes: the first terminal device determines a first transmission resource, the first transmission resource is used to transmit the first information, the first transmission resource includes a first time domain resource and a first frequency domain resource, and the first time domain resource is during a first time unit.

[0024] Based on the above technical solution, the first terminal device may determine a first transmission resource for transmitting first information, and thereby send the first information to the second terminal device through a second link, which prevents the first terminal device from directly feeding back HARQ-ACK information of downlink data to the network device, thereby reducing the uplink communication overhead of the first terminal device.

[0025] Regarding the first aspect, in some implementations of the first aspect, the first transmission resource is a physical sidelink shared channel (PSSCH), and the first terminal device determining the first transmission resource includes: the first terminal device receives first control information from a network device, the first control information including second information, the second information indicating a first time domain resource and a first frequency domain resource; and the first terminal device determines the first transmission resource based on the second information.

[0026] Alternatively, the first terminal device determines the first time domain resource and the first frequency domain resource based on third configuration information, and the third configuration information is information received by the first terminal device from the network device before the first terminal device receives the first downlink data.

[0027] Based on the above technical solution, when the first transmission resource is a PSSCH, the network device may indicate the first transmission resource to the first terminal device in a dynamic indication (for example, by delivering the first control information) or a semi-static configuration manner (for example, by delivering the third configuration information), so that the first terminal device can know the first transmission resource in different manners, thereby improving the flexibility of the solution.

[0028] Regarding the first aspect, in some implementations of the first aspect, the second information includes a first field and a second field, where the first field indicates a time resource allocation and the second field indicates a frequency resource allocation.

[0029] Based on the above technical solution, when a network device indicates a first transmission resource in a dynamic indication manner, an existing field is reused to indicate the first transmission resource, thereby improving the backward compatibility of the solution.

[0030] Regarding the first aspect, in some implementations of the first aspect, the third configuration information includes information indicating the number of subchannels, information indicating the subchannel size, information indicating the starting resource block of the subchannel, information indicating the starting symbol of the first time domain resource in the first time unit, and information indicating the number of symbols occupied by the first time domain resource.

[0031] Based on the above technical solution, when a network device configures a first transmission resource in a semi-static manner, an existing resource pre-configuration scheme can be reused, thereby improving the backward compatibility of the solution.

[0032] Regarding the first aspect, in some implementations of the first aspect, the first information is a media access control-control element (MAC CE).

[0033] Regarding the first aspect, in some implementations of the first aspect, the first frequency domain resource is a resource block occupied by a physical sidelink feedback channel (PSFCH), and the first terminal device determining the first transmission resource includes: the first terminal device receives first control information from the network device, the first control information including third information, the third information indicating the first frequency domain resource, and the first terminal device determines the first frequency domain resource based on the third information.

[0034] Alternatively, The first terminal device determines a first quantity M of downlink data in a first downlink data set, the first downlink data being one of M pieces of downlink data, and all M pieces of HARQ-ACK information corresponding to the M pieces of downlink data being transmitted on a PSFCH, where M is a positive integer; the first terminal device determines a second quantity of resource blocks based on the first quantity and the first quantity of resource blocks, the first quantity of resource blocks being the number of resource blocks included in the PSFCH and the second quantity of resource blocks being the number of resource blocks included in the first frequency domain resource; and the first terminal device determines a position of the second quantity of resource blocks in the first quantity of resource blocks based on a position of the first downlink data in the downlink data set.

[0035] Based on the above technical solutions, when the first transmission resource is a PSFCH, the first terminal device may determine the resource blocks required for transmitting the HARQ-ACK information of the first downlink data based on an indication of the network device (for example, receiving the first control information), or may determine the resource blocks required for transmitting the HARQ-ACK information of the first downlink data based on the HARQ-ACK information transmission opportunity set of the downlink data (for example, the first quantity M of downlink data in the first downlink data set). Thus, the first terminal device can determine the transmission resource in different manners based on actual situations, thereby improving the flexibility of the solution.

[0036] Regarding the first aspect, in some implementations of the first aspect, the first transmission resource is used to transmit HARQ-ACK information of the downlink data.

[0037] Based on the above technical solution, the first transmission resource may be a separate resource for transmitting HARQ-ACK information of downlink data, that is, the transmission resource may be separately configured for transmitting HARQ-ACK information of downlink data, so as to avoid confusion with resources of other functions.

[0038] When the first transmission resource is a dedicated resource for transmitting HARQ-ACK information of downlink data, M, the number of first resource blocks, and the number of second resource blocks satisfy the following relationship:

[0039]

number

[0040] N represents the number of second resource blocks, K represents the number of first resource blocks,

[0041]

number

[0042] represents a floor operation, and the N resource blocks corresponding to the m-th downlink data among the M downlink data are the resource blocks with indexes (m-1)*N to m*N-1 among the K resource blocks; or or M, the number of first resource blocks, and the number of second resource blocks satisfy the following relationship:

[0043]

number

[0044] M is divisible by K, and the N resource blocks corresponding to the m-th downlink data among the M downlink data are the resource blocks with indexes (m-1)*N to m*N-1 among the K resource blocks; or In the case where M1>0, when m is any integer from 1 to M1, the N resource blocks corresponding to the m-th downlink data among the M downlink data are the resource blocks with indexes (m-1)*K1 to m*K1-1 among the K resource blocks, or when m is any integer from M1 to M, the N resource blocks corresponding to the m-th downlink data among the M downlink data are the resource blocks with indexes [M1*K1+(m-M1-1)*K2] to [M1*K1+(m-M1-1)*K2+K2-1] among the K resource blocks, or When M1=0, the N resource blocks corresponding to the m-th downlink data among the M downlink data are the [M1*K1+(m-M1-1)*K2]-th resource block to the [M1*K1+(m-M1-1)*K2+K2-1]-th resource block among the K resource blocks; K1 is

[0045]

number

[0046] and K2 is

[0047]

number

[0048] and M1 is

[0049]

number

[0050] is the remainder of

[0051]

number

[0052] represents the ceiling operation.

[0053] Regarding the first aspect, in some implementations of the first aspect, the first transmission resource is used to transmit HARQ-ACK information for downlink data and HARQ-ACK information for sidelink data.

[0054] Based on the above technical solution, the first transmission resource may be used to transmit HARQ-ACK information of downlink data and HARQ-ACK information of sidelink data. In other words, the configured transmission resource may be shared for HARQ-ACK information of downlink data and HARQ-ACK information of sidelink data.

[0055] When the first transmission resource is used to transmit HARQ-ACK information for downlink data and HARQ-ACK information for sidelink data, M, the number of first resource blocks, the number of second resource blocks, and the second quantity satisfy the following relationship:

[0056]

number

[0057] N represents the second number of resource blocks, K represents the first number of resource blocks, A represents the second number, the second number being for sidelink data and the number of HARQ-ACK information transmitted on the PSFCH;

[0058]

number

[0059] represents a floor operation, and N resource blocks corresponding to m-th downlink data among M downlink data and A sidelink data are resource blocks with indices (m-1)*N to m*N-1 among K resource blocks; or or M, the number of first resource blocks, the number of second resource blocks, and the second quantity satisfy the following relationship:

[0060]

number

[0061] M+A is divisible by K, and the N resource blocks corresponding to the m-th downlink data among the M downlink data and A sidelink data are the resource blocks with indices (m-1)*N to m*N-1 among the K resource blocks; or In the case where M>0, when m is any integer from 1 to M, the N resource blocks corresponding to the m-th downlink data among the M downlink data and the A sidelink data are the resource blocks with indices (m-1)*K to m*K among the K resource blocks, or when m is any integer from M to M, the N resource blocks corresponding to the m-th downlink data among the M downlink data are the resource blocks with indices [M*K+(m-M-1)*K] to [M*K+(m-M-1)*K+K-1] among the K resource blocks, or When M1=0, the N resource blocks corresponding to the m-th downlink data among the M downlink data and the A sidelink data are the [M1*K1+(m-M1-1)*K2]-th resource block to the [M1*K1+(m-M1-1)*K2+K2-1]-th resource block among the K resource blocks; K1 is

[0062] [Number]

[0063] and K2 is

[0064]

number

[0065] and M1 is

[0066]

number

[0067] is the remainder of

[0068]

number

[0069] represents the ceiling operation.

[0070] Regarding the first aspect, in some implementations of the first aspect, the first terminal device determining the first quantity includes: the first terminal device receiving fourth information from the network device, where the fourth information indicates the first quantity, or the first terminal device determining the first quantity based on at least one of the following information: a time gap set, a time domain resource allocation (TDRA) of the first link, a subcarrier spacing of the first link, a subcarrier spacing of the second link, a duration of the first transmission resource, or a first time unit, where the first time unit is one time gap in the time gap set.

[0071] Based on the above technical solution, the first terminal device may determine the value of the first quantity in different manners, thereby improving the flexibility of the solution.

[0072] Regarding the first aspect, in some implementations of the first aspect, when the first terminal device does not receive second downlink data in the downlink data set, the method further includes: the first terminal device does not transmit HARQ-ACK information on a second transmission resource corresponding to the second downlink data, or feeds back a negative acknowledgment (NACK) on the second transmission resource.

[0073] Based on the above technical solutions, for the received downlink data, the first terminal device may not send HARQ-ACK information, or may send and feedback a negative acknowledgement (NACK).

[0074] Regarding the first aspect, in some implementations of the first aspect, when the first terminal device is one of a plurality of terminal devices that feed back HARQ-ACK information through the second terminal device, the method further includes: the first terminal device sends the first HARQ-ACK information to the second terminal device on a first transmission resource in a code division multiplexing manner.

[0075] Based on the above technical solutions, in a scenario where multiple first terminal devices transmit HARQ-ACK information by using transmission resources on the same frequency band, resource multiplexing can be implemented in a code division multiplexing manner to avoid interference between different terminal devices.

[0076] Regarding the first aspect, in some implementations of the first aspect, before receiving the first downlink data from the network device, the method further includes: the first terminal device receives fourth configuration information from the network device, the fourth configuration information is used to configure R resource pools, the first transmission resource is a resource in one of the R resource pools, and R is a positive integer.

[0077] Regarding the first aspect, in some implementations of the first aspect, the first downlink data includes a physical downlink shared channel (PDSCH), the first link is a link for communication based on a first communication interface, the second link is a link for communication based on a second communication interface, the first communication interface is a first Uu interface (or a cellular network interface), the second communication interface is a PC5 interface (or a sidelink interface), the first terminal device includes an extended reality XR device, and the second terminal device includes a mobile terminal.

[0078] According to a second aspect, a communication method is provided. The method may be implemented by a network device or a component (e.g., a chip or a circuit) of the network device. This is not limited in the present application. For ease of explanation, the following description will be given using an example in which the network device implements the method.

[0079] The communication method includes: a network device sends first downlink data to a first terminal device through a first link; the network device receives fifth information from a second terminal device through a third link, the fifth information including first hybrid automatic repeat request-acknowledgement (HARQ-ACK) information, the first HARQ-ACK information indicating a first decoding result corresponding to the first downlink data, the first link being a transmission link between the first terminal device and the network device, and the third link being a transmission link between the second terminal device and the network device.

[0080] Regarding the second aspect, in some implementations of the second aspect, the method further includes: the network device configures a first transmission resource for the first terminal device through a first link, the first transmission resource is used by the first terminal device to send first information to the second terminal device through a second link, the first information includes first HARQ-ACK information, and the second link is a transmission link between the first terminal device and the second terminal device.

[0081] Regarding the second aspect, in some implementations of the second aspect, the first transmission resource includes a first time domain resource and a first frequency domain resource, the first time domain resource is in a first time unit, and the method further includes: the network device sends first control information to the first terminal device, the first control information indicating a first time gap, or before sending the first downlink data to the first terminal device, the network device sends first configuration information to the first terminal device, the first configuration information indicating the first time gap, the first time gap being less than or equal to the time gap between the first time unit and a second time unit, the second time unit being a time unit in which the first terminal device receives the first downlink data or a time unit in which the first terminal device receives the first control information, and the first control information is further used to schedule the first downlink data.

[0082] Regarding the second aspect, in some implementations of the second aspect, before the network device sends the first control information to the first terminal device, the method further includes: the network device sends second configuration information to the first terminal device, the second configuration information is used to configure a time gap set, and the first time gap is one time gap in the time gap set.

[0083] Regarding the second aspect, in some implementations of the second aspect, when the first time gap is measured in a slot, the method further includes: the network device sends a first parameter to the first terminal device, the first parameter indicating that a subcarrier spacing (SCS) referenced by the first time gap is a first SCS or a second SCS, the first SCS being an SCS corresponding to the first link, and the second SCS being an SCS corresponding to the second link, and the first link being different from the second link.

[0084] Regarding the second aspect, in some implementations of the second aspect, the first transmission resource is a physical sidelink shared channel (PSSCH), and the method further includes: the network device sends first control information to the first terminal device, where the first control information includes second information, and the second information indicates the first time domain resource and the first frequency domain resource; or before sending the first downlink data to the first terminal device, the network device sends third configuration information to the first terminal device, where the third configuration information indicates the first time domain resource and the first frequency domain resource.

[0085] Regarding the second aspect, in some implementations of the second aspect, the second information includes a first field and a second field, where the first field indicates a time resource allocation and the second field indicates a frequency resource allocation.

[0086] Regarding the second aspect, in some implementations of the second aspect, the third configuration information includes information indicating the number of subchannels, information indicating the subchannel size, information indicating the starting resource block of the subchannel, information indicating the starting symbol of the first time domain resource in the first time unit, and information indicating the number of symbols occupied by the first time domain resource.

[0087] Regarding the second aspect, in some implementations of the second aspect, the first information is a medium access control control element (MAC CE).

[0088] Regarding the second aspect, in some implementations of the second aspect, the first frequency domain resource is a resource block occupied by a physical sidelink feedback channel (PSFCH), and the method further includes: the network device sends first control information to the first terminal device, the first control information including third information, the third information indicating the first frequency domain resource, or the network device sends fourth information to the first terminal device, the fourth information indicating a first quantity M of downlink data in the first downlink data set, the first quantity being used to determine the first frequency domain resource, the first downlink data being one of M downlink data, and the M HARQ-ACK information corresponding to the M downlink data are all transmitted on the PSFCH, where M is a positive integer.

[0089] Regarding the second aspect, in some implementations of the second aspect, the first transmission resource is a resource used to transmit HARQ-ACK information of downlink data. In particular, for the relationship between M, the number of first resource blocks, and the number of second resource blocks, please refer to the description in the first aspect. Details will not be described again in this specification.

[0090] Regarding the second aspect, in some implementations of the second aspect, the first transmission resource is used to transmit HARQ-ACK information for downlink data and HARQ-ACK information for sidelink data. In particular, for the relationship between M, the first resource block quantity, the second resource block quantity, and the second quantity, please refer to the description in the first aspect. Details will not be described again in this specification.

[0091] Regarding the second aspect, in some implementations of the second aspect, the method further includes: the network device sends fourth configuration information to the first terminal device, the fourth configuration information is used to configure R resource pools, the first transmission resource is a resource in one of the R resource pools, and R is a positive integer.

[0092] Regarding the second aspect, in some implementations of the second aspect, the first downlink data includes a physical downlink shared channel (PDSCH), the first link is a link for communication based on a first communication interface, the second link is a link for communication based on a second communication interface, the third link is a link for communication based on a third communication interface, the first communication interface is a first Uu interface, the second communication interface is a PC5 interface, and the third communication interface is a second Uu interface.

[0093] For the technical effects of the method shown in the second embodiment and possible designs of the second embodiment, please refer to the technical effects of the first embodiment and possible designs of the first embodiment.

[0094] According to a third aspect, a terminal device is provided. The terminal device is configured to implement any one of the first aspect and the implementations of the first aspect. In particular, the terminal device includes a processor and a memory. The memory is configured to store a computer program. The processor is configured to call the computer program from the memory and run the computer program, thereby enabling the terminal device to implement any one of the first aspect and the implementations of the first aspect.

[0095] According to a fourth aspect, a network device is provided. The network device is configured to implement any one of the second aspect and the implementations of the second aspect. In particular, the network device includes a processor and a memory. The memory is configured to store a computer program. The processor is configured to call the computer program from the memory and run the computer program, thereby enabling the network device to implement any one of the second aspect and the implementations of the second aspect.

[0096] According to a fifth aspect, a communication device is provided. The communication device is configured to perform the method provided in any one of the first and second aspects and their implementations. In particular, the communication device may include units and / or modules (e.g., a processing unit and a transceiver unit) configured to perform the method provided in any one of the first and second aspects and their implementations.

[0097] In an implementation, the communication device is a terminal device. When the communication device is a terminal device, the transceiver unit may be a transceiver or an input / output interface. The processing unit may be at least one processor. Optionally, the transceiver may be a transceiver circuit. Optionally, the input / output interface may be an input / output circuit.

[0098] In another implementation, the communication device may be a chip, chip system, or circuit in a terminal device, in which case the transceiver unit may be an input / output interface, interface circuit, output circuit, input circuit, pin, related circuit, etc. on the chip, chip system, or circuit, and the processing unit may be at least one processor, processing circuit, logic circuit, etc.

[0099] According to a sixth aspect, the present application provides a processor configured to perform the methods provided in the first and second aspects.

[0100] The sending and acquiring / receiving operations related to the processor may be understood as operations such as output and receiving or input of the processor, or operations such as sending and receiving performed by the radio frequency circuit and antenna, unless otherwise specified or unless those operations contradict the actual function or internal logic of the operations in the relevant description, which is not limited in this application.

[0101] According to a seventh aspect, there is provided a computer-readable storage medium storing a computer program, the computer program being configured to enable a communication device to implement a method according to any one of the first and second aspects when run on the communication device.

[0102] According to an eighth aspect, there is provided a computer program product comprising instructions which, when run on a computer, enable the computer to carry out a method according to any one of the implementations of the first and second aspects.

[0103] According to a ninth aspect, a chip is provided, the chip including a processor and a communication interface, the processor reads instructions through the communication interface to perform the method according to any one of the implementations of the first and second aspects.

[0104] Optionally, in the implementation, the chip further includes a memory. The memory stores a computer program or instruction. The processor is configured to execute the computer program or instruction stored in the memory. When the computer program or instruction is executed, the processor is configured to perform a method according to any one of the implementations of the first and second aspects.

[0105] According to a tenth aspect, there is provided a communication system including the terminal device according to the third aspect and the network device according to the fourth aspect. [Brief explanation of the drawings]

[0106] [Figure 1] FIG. 1 is a diagram of a communication architecture according to an embodiment of the present application. [Figure 2] FIG. 1 is a diagram of a scenario in which XR glasses communicate with a network device through a mobile phone according to an embodiment of the present application. [Figure 3] 1 is a diagram of a slot structure according to an embodiment of the present application; [Figure 4] FIG. 2 is a diagram of the time relationship between PSSCH and PSFCH according to an embodiment of the present application. [Figure 5] FIG. 2 is a diagram of the frequency domain relationship between HARQ-ACK information of PSSCH and HARQ-ACK information of PSFCH according to an embodiment of the present application. [Figure 6] FIG. 1 is a diagram of code division multiplexing (CDM) according to an embodiment of the present application. [Figure 7] 1 is a schematic flowchart of a communication method according to an embodiment of the present application; [Figure 8] 4 is a schematic flowchart of another communication method according to an embodiment of the present application; [Figure 9] FIG. 1 is a diagram of a first time gap according to the present application. [Figure 10] 4 is a schematic flowchart of another communication method according to an embodiment of the present application; [Figure 11] FIG. 10 is a diagram of another first time gap according to an embodiment of the present application. [Figure 12] FIG. 10 is a diagram of another first time gap according to an embodiment of the present application. [Figure 13] FIG. 10 is a diagram of another first time gap according to an embodiment of the present application. [Figure 14] FIG. 2 is a diagram of a PDSCH transmission opportunity set according to an embodiment of the present application. [Figure 15] FIG. 10 is a diagram of another PDSCH transmission opportunity set according to an embodiment of the present application. [Figure 16] FIG. 10 is a diagram of another PDSCH transmission opportunity set according to an embodiment of the present application. [Figure 17] FIG. 10 is a diagram of allocating PRBs for PSFCH according to an embodiment of the present application. [Figure 18] FIG. 10 is another diagram of allocating PRBs for PSFCH according to an embodiment of the present application. [Figure 19] FIG. 10 is another diagram of allocating PRBs for PSFCH according to an embodiment of the present application. [Figure 20]FIG. 10 is another diagram of allocating PRBs for PSFCH according to an embodiment of the present application. [Figure 21] 1 is a block diagram of a communication device according to an embodiment of the present application; [Figure 22] FIG. 2 is a diagram of another communication device according to an embodiment of the present application. [Figure 23] FIG. 1 is a diagram of a chip system according to an embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0107] The following describes in detail the technical solutions in the embodiments of the present application with reference to the accompanying drawings.

[0108] The technical solutions in the embodiments of the present application may be applied to various communication systems, such as a 5th generation (5G) system or a new radio (NR) system, a long term evolution (LTE) system, an LTE frequency division duplex (FDD) system, and an LTE time division duplex (TDD) system. The technical solutions provided in the present application may further be applied to future communication systems, such as a sixth generation mobile communication system.

[0109] The real-time broadband communication (RTBC) scenario in the new 5G vision aims to support large bandwidth and low interaction latency. The goal is to improve bandwidth under given latency and specific reliability requirements and create an immersive experience during interaction between people and virtual worlds. XR services, with their ultra-high bandwidth and ultra-low latency requirements, pose more severe challenges to current 5G. XR services include multiple types of data, such as video, audio, and other control signals. Video data typically includes several ultra-high-definition images. Each image undergoes compression coding, such as High Efficiency Video Coding (HEVC). After coding, large data blocks are generated. Higher video definition typically indicates larger data blocks.

[0110] In a scenario where an XR device is connected to a base station, the XR device needs to communicate with a server through the base station. That is, the XR device sends uplink data, such as the XR device's pose information, audio data, and video data captured by the XR device's camera, to the server through the base station. After receiving the data, the server generates corresponding downlink data, such as video to be displayed on the XR device, and sends the downlink data to the XR device through the base station. In cellular communication, the base station is usually far away from the terminal device. Therefore, to ensure the uplink transmission communication quality, the terminal device needs to perform power amplification on the data signal before sending the data. As a result, the power consumption overhead of uplink transmission is relatively high. In XR devices, light weight causes battery capacity limitations, ultimately affecting the battery life of the XR device. Therefore, reducing power consumption is currently a difficult direction to improve the experience of XR devices. An architecture for reducing the power consumption overhead of uplink communication is proposed. Specifically, the XR device can send uplink information to the base station through the terminal device. For ease of understanding, the following briefly describes a communication architecture for reducing the power consumption overhead of uplink communication in this application with reference to FIGS.

[0111] 1 is a diagram of a communication architecture according to an embodiment of the present application, which includes a network device, a relay device, and a terminal device.

[0112] A terminal device (terminal equipment) in embodiments of the present application may be an access terminal, a subscriber unit, a subscriber station, a mobile station, a relay station, a remote station, a remote terminal, a mobile device, a user terminal, a user equipment (UE), a terminal, a wireless communication device, a user agent, or a user equipment. Alternatively, the terminal device may be a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication capabilities, a computing device, another processing device connected to a wireless modem, an in-vehicle device, a wearable device, a terminal device in a 5G network, a terminal device in a future evolved public land mobile network (PLMN), a terminal device in a future vehicular internet, etc. This is not limited in embodiments of the present application.

[0113] For example, in the embodiments of the present application, a wearable device, also referred to as a wearable intelligent device, is a general term for wearable devices, such as glasses, gloves, watches, clothing, and shoes, that are intelligently designed and developed for everyday wear by using wearable technology. A wearable device is a portable device that is worn directly on the body or integrated into a user's clothing or accessories. A wearable device is not only a hardware device, but also implements powerful functions through software support, data exchange, and cloud interaction. In a broad sense, a wearable intelligent device includes a full-function device, such as a smart watch or smart glasses, that can implement full or partial functions without relying on a smartphone. In addition, the device may alternatively be a portable device that is dedicated to only one type of application function and needs to be used with another device, such as a smartphone, such as various smart bands or smart jewelry for monitoring physical signs.

[0114] In addition, in the embodiment of the present application, the terminal device may alternatively be a terminal device in an IoT system. IoT is an important part of the future development of information technology. The main technical feature of IoT is that objects are connected to a network by using communication technology to implement an intelligent network of human-machine interconnection and object-object interconnection. In the embodiment of the present application, the IoT technology can implement large-scale connection, deep coverage, and terminal power saving by using, for example, narrow band (NB) technology.

[0115] In addition, in the embodiment of the present application, the terminal device may alternatively include a sensor, and its main functions include collecting data (some terminal devices), receiving control information and downlink data from network devices, sending electromagnetic waves, and sending uplink data to network devices.

[0116] The relay device in the embodiment of the present application may be a terminal device. See the above description of the terminal device. In other words, the relay device and the terminal device in the present application may be two different terminal devices, and these terminal devices may communicate directly with each other. For example, the direct communication between the terminal devices may be implemented by using device-to-device (D2D) technology. The relay device may relay information between the terminal device and the network device.

[0117] The network device in the embodiment of the present application may be any communication device that has wireless sending and receiving capabilities and is configured to communicate with a terminal device. The device may include, but is not limited to, an evolved NodeB (eNB), a radio network controller (RNC), a NodeB (NB), a home base station (HeNB, or home NodeB (HNB)), a baseband unit (BBU), or an access point (AP), a wireless relay node, a wireless backhaul node, a transmission point (TP), a transmission and reception point (TRP), etc. in a wireless fidelity (Wi-Fi) system, or may be a gNB or transmission point (TRP or TP) in a 5G system such as an NR system, or one antenna panel or a group of antenna panels (including multiple antenna panels) of a base station in a 5G system, or may be a network node forming a gNB or transmission point, for example, a baseband unit (BBU) or a distributed unit (DU).

[0118] The network devices and terminal devices may be deployed on land, including indoor or outdoor devices, handheld devices, or vehicle-mounted devices, or may be deployed on the water surface, or may be deployed on airplanes, balloons, or satellites in the air. The scenarios in which the network devices and terminal devices are deployed are not limited in the embodiments of the present application.

[0119] In an embodiment of the present application, a terminal device or a network device includes a hardware layer, an operating system layer running on the hardware layer, and an application layer running on the operating system layer. The hardware layer includes hardware such as a central processing unit, a memory management unit (MMU), and memory (also referred to as main memory). The operating system may be any one or more computer operating systems that implement service processing through processes, such as the Linux operating system, Unix operating system, Android operating system, iOS operating system, or Windows operating system. The application layer includes applications such as a browser, an address book, word processing software, and instant communication software.

[0120] Additionally, aspects or features of the present application may be implemented as a method, apparatus, or article of manufacture using standard programming and / or engineering techniques. The term "article of manufacture" as used herein covers a computer program accessible from any computer-readable component, carrier, or medium. For example, computer-readable media include, but are not limited to, magnetic storage components (e.g., hard disk drives, floppy disks, or magnetic tapes), optical disks (e.g., compact discs (CDs) or digital versatile discs (DVDs)), smart cards, and flash memory components (e.g., erasable programmable read-only memory (EPROM), cards, sticks, or key drives). Additionally, various storage media described herein may refer to one or more devices and / or other machine-readable media configured to store information. The term "machine-readable storage medium" may include, but is not limited to, wireless channels and various other media capable of storing, containing, and / or carrying instructions and / or data.

[0121] It should be understood that Figure 1 is merely a simplified example diagram for ease of understanding. The communication system 100 may further include another network device (not shown in Figure 1) or may further include another terminal device. For example, the communication system 100 may further include a core network device. The access network device provides a wireless access connection to the terminal device and may send data to the terminal device or receive data sent by the terminal device. In addition, the access network device may also be connected to a core network device and forward data received from the terminal device to the core network or receive data from the core network that needs to be sent to the terminal device.

[0122] For example, using the example in which the relay device shown in Fig. 1 is a mobile phone and the terminal device is an XR glass, we will describe how to reduce the power consumption overhead of the uplink communication of the XR glass, as shown in Fig. 2. Fig. 2 is a diagram of a scenario in which the XR glass communicates with a network device through a mobile phone according to an embodiment of the present application.

[0123] From Figure 2, it can be seen that the network device and the XR glasses may communicate with each other in a multipath manner. The multipath includes: (1) the XR glasses communicate directly with the network device through a communication interface (e.g., Uu#2); (2) the XR glasses communicate with the mobile phone via a short distance (e.g., sidelink, SL), and the mobile phone communicates with the network device through a communication interface (e.g., Uu#1).

[0124] In particular, the packet data convergence protocol (PDCP) layer of the network device is split into two bearers: one bearer (hereafter referred to as bearer #1) is from the XR glasses to the network device and is used to establish a link in which the mobile phone is used as a relay, and the other bearer (hereafter referred to as bearer #2) is a direct link between the XR glasses and the network device.

[0125] Regarding bearer #1, in downlink transmission (i.e., transmission from the network device to the XR glasses), bearer #1 forwards data with an added PDCP header to a sidelink relay adaptation protocol (SRAP) layer. After adding the corresponding header, the SRAP layer delivers the data to the corresponding radio link control (RLC) layer. After the header is added, the data is forwarded to the media access control (MAC) layer. The data is then transmitted to the mobile phone through a physical (PHY) layer (e.g., PHY #1 shown in FIG. 2). The mobile phone then transmits the data to the XR glasses through short-range communication (e.g., SL).

[0126] Similarly, for bearer #1, in the uplink, the XR glasses transmit data from the application layer through the SL to the mobile phone, and then the mobile phone transmits the data to the network device, the process of which is the reverse of the downlink transmission process described above, and the details will not be described again.

[0127] For bearer #2, downlink transmission (i.e., transmission from the network device to the XR glasses) does not require relaying through the mobile phone, so there is no SRAP layer in the protocol stack for bearer #2. PDCP delivers data to the RLC, and then the MAC transmits the data over the physical layer (e.g., PHY #2 shown in Figure 2) to the XR glasses.

[0128] Similarly, for bearer #2, in the uplink, the XR glasses transmit data directly from the application layer to the network device.

[0129] Uu#1 is the physical connection between the mobile phone and the base station, and Uu#2 is the physical connection between the glasses and the base station, and Uu#1 and Uu#2 may be in the same frequency band or different frequency bands. Furthermore, the mobile phone and the XR glasses implement an SL connection through a PC5 interface, and the frequency band of PC5 may be the same as or different from that of Uu#1 or Uu#2.

[0130] In order to reduce the uplink transmission power consumption of the XR glasses, for uplink data (e.g., pose information of the XR device, audio data, and video data captured by the camera of the XR device), the XR glasses may transmit the data to the mobile phone, and then the mobile phone transmits the data through Uu#1. Because the XR glasses and the mobile phone usually communicate with each other within a short distance, the distance from the XR glasses to the mobile phone is much smaller than the distance from the XR glasses to the base station. Therefore, the uplink transmission power consumption of the glasses is effectively reduced. In downlink communication, as shown in FIG. 2, data from the server can be sent to the XR glasses through two links (e.g., link #1 for transmission via Uu#1 and PC5, and link #2 for transmission via Uu#2). When Uu#1 and Uu#2 are in different frequency bands, using these two links is equivalent to increasing the link bandwidth, and therefore the transmission rate can be effectively improved.

[0131] To facilitate understanding of the embodiments of the present application, some basic concepts in the present application will be briefly described. The basic concepts described below will be explained by using the basic concepts specified in the NR protocol as an example, but it should be understood that the embodiments of the present application are not limited to being applied only to the NR system. Therefore, when the NR system is used as an example for explanation, all standard names that appear are functional descriptions, and specific names are not limited, but only indicate the functions of the device, and may be expanded to accommodate other future systems.

[0132] 1. HARQ-ACK information feedback in cellular networks: In a cellular network, after a network device schedules a physical downlink shared channel (PDSCH) for a terminal device by using downlink control information (DCI), the terminal device determines a physical uplink control channel (PUCCH) that carries HARQ-ACK information of the PDSCH based on the indication information in the DCI.

[0133] In particular, in addition to indicating the PDSCH, the DCI also carries a field indicating the PUCCH that carries the HARQ-ACK information corresponding to the PDSCH. For example, the k1 value, i.e., the offset time between the PDSCH and the PUCCH, is indicated by using the PDSCH-to-HARQ_feedback timing indicator field. Note that the offset time indicated in the DCI is an index, which refers to one of a group of offset times.

[0134] In particular, the network device configures a group of k1 values ​​for the terminal device by using higher layer signaling, for example, a radio resource control (RRC) message. When scheduling a PDSCH by using DCI, the network device indicates one k1 in the DCI, where the k1 is one of the above group of k1 values. In addition, the DCI also indicates a PUCCH resource that carries HARQ-ACK information. For example, the DCI indicates an index of the PUCCH resource to be used by using PUCCH resource indication information (PUCCH resource indicator).

[0135] For ease of understanding, the feedback of HARQ-ACK information for PDSCH will be described in detail with reference to Figure 3. Carriers with a time division duplex (TDD) configuration of 4:1 can be seen in Figure 3. Specifically, each TDD cycle has four downlink slots (e.g., DO, D1, D2, and D3 in the TDD cycle shown in Figure 3, and D4, D5, D6, and D7 in another TDD cycle) and one uplink slot (e.g., U0 in the TDD cycle shown in Figure 3 and U1 in another TDD cycle).

[0136] The network device configures a group of k1 values ​​or a group of PDSCH reception candidates (candidate PDSCH receptions) for the terminal device by using indication information (e.g., dl-DataToUL-ACK-r16) in a PUCCH configuration (PUCCH-Config) of higher layer signaling such as an RRC message, where the quantity typically does not exceed 8. For example, dl-DataToUL-ACK-r16={2,3,4,5,6,7}. In this case, for any uplink slot, e.g., U1 in FIG. 3, all HARQ-ACK information of {2,3,4,5,6,7} previous slots that can be used to transmit PDSCH can be fed back in U1.

[0137] In particular, U1 in Figure 3 is still used as an example. Before U1, the second slot is D6, the third slot is D5, the fourth slot is D4, the fifth slot is U0 (which cannot be used to transmit PDSCH, and therefore, the HARQ codebook does not need to be calculated), the sixth slot is D3, and the seventh slot is D2. All HARQ-ACK information of PDSCHs scheduled in D2 to D6 can be fed back in U1.

[0138] For example, a network device schedules a PDSCH in slot D2 by using a DCI, and the DCI further indicates a k1 index. For example, if PDSCH-to-HARQ_feedback timing indicator='000' (because dl-DataToUL-ACK-r16 contains 6 values, this indication field contains ceil(log2(quantity in dl-DataToUL-ACK-r16))=3 bits), it indicates that the first value in dl-DataToUL-ACK-r16, i.e., 2, is indicated. In other words, the HARQ of the PDSCH in D2 is fed back in U0. If PDSCH-to-HARQ_feedback timing indicator='101', i.e., the sixth value, i.e., 7, the HARQ-ACK information of the PDSCH in D2 is fed back in U1.

[0139] 2. PDSCH transmission opportunity: In this application, the PDSCH transmission opportunity refers to the number of HARQ-ACK information that can be transmitted on a time-frequency resource of the PDSCH, and multiple PDSCH transmission opportunities may be referred to as a PDSCH transmission opportunity set. For example, if the number of HARQ-ACK information that can be transmitted on a time-frequency resource #1 (e.g., PSSCH, PSFCH, or PUCCH) of the PDSCH is 2, the PDSCH transmission opportunity is 2.

[0140] 3. Semi-static codebook: HARQ-ACK information feedback on PUCCH is usually classified into two forms: semi-static codebook (also called type 1) and dynamic codebook (type 2).

[0141] The number of bits in the semi-static codebook for the PUCCH needs to consider all PDSCH transmission opportunities that can correspond to the PUCCH. As shown in Figure 3, the PUCCH codebook in U1 needs to consider reception candidates for the PDSCH transmitted in D2 to D6. It should be understood that because there is mini-slot scheduling (e.g., one slot contains 14 symbols, each PDSCH occupies only some symbols, and there may be multiple PDSCH transmission opportunities in one slot), the number of PDSCH candidates transmitted in D2 to D6 is not necessarily five and may be greater than five. For details, please refer to the PDSCH time domain resource allocation list configured by using higher layer messages. Table 1 shows a time domain indication scheme for time domain resource allocation (TDRA).

[0142] [Table 1]

[0143] In particular, Table 1 includes 16 rows, and each row is further divided into information such as a row index, a Type A demodulation reference signal (DMRS) position (dmrs-TypeA-Position), a PDSCH mapping type, k0, S, and L. DMRS is a demodulation reference channel used by the receiving end to estimate the channel and facilitate signal demodulation. dmrs-TypeA-Position is for when the PDSCH mapping type is Type A, and 2 or 3 indicates that the DMRS signal is located on the second or third symbol in the slot where the PDSCH is located. The PDSCH mapping type indicates the mapping type of the PDSCH. When the mapping type is Type A, the starting symbol of the PDSCH is any one of 0 to 3, i.e., the first to fourth symbols. When the mapping type is Type B, the starting symbol of the PDSCH is any one of 0 to 12, i.e., the first to thirteenth symbols. k0 represents the time offset of the PDSCH relative to the corresponding DCI, measured in slots; S represents the starting symbol position of the PDSCH, counted from 0; L represents the total number of symbols occupied by the PDSCH, counted from 1.

[0144] For example, when mapping type B is configured for a terminal device, according to Table 1, when the row index is 8, the corresponding PDSCH occupies seven symbols starting from the fifth symbol in one slot, i.e., symbols 5 to 11; or when the row index is 11, the corresponding PDSCH occupies two symbols starting from the twelfth symbol in one slot, i.e., symbols 12 and 13. It can be seen that the PDSCHs corresponding to row index 8 and row index 11 do not overlap in one slot. Therefore, multiple PDSCHs can exist in one slot. Therefore, for the semi-static codebook, please refer to the K1 set and the TDRA list together for the number of PDSCH candidates included in one PUCCH.

[0145] For simplicity, an example in which only mapping type A exists in Table 1 is used. In this case, one PUCCH semi-static codebook includes 5 bits, corresponding to PDSCHs in D2 to D6, respectively. When DCI and the corresponding PDSCH are received in the corresponding slot, the HARQ-ACK information bits are mapped based on the data channel decoding result of the PDSCH. If DCI is not detected in the slot, a NACK is fed back in the corresponding bit position.

[0146] 4. Dynamic Codebook: The drawback of the above semi-static codebook is that the codebook is fixed, which may cause resource waste. Therefore, a dynamic codebook is further proposed, which implements on-demand feedback based on the actual amount of received data. However, because the terminal device may miss detecting the DCI, to enable the dynamic codebook, a 2-bit downlink assignment index is usually added to the DCI so that the terminal device can detect the amount of received DCI.

[0147] For example, see the feedback state shown in Figure 3. A network device schedules three PDSCHs in slots D4, D5, and D6 by using three DCIs, respectively, and the downlink assignment indexes (DAIs) corresponding to the DCIs are "01," "10," and "11," respectively. A terminal device receives a DCI in D4 of Figure 3, and the corresponding DAI index is "01." The terminal device fails to detect a DCI in D5 and receives a DCI in D6, and the corresponding index is "11." In this case, the terminal device indicates that the DCI is missing in the detection between D4 and D6, and therefore feeds back three bits of HARQ-ACK information corresponding to the PDSCHs corresponding to D4, D5, and D6. Because the DCI is missing in the detection in D5, the terminal device feeds back a NACK in the corresponding bits.

[0148] 5. HARQ-ACK Information Feedback on Sidelink: In a sidelink scenario (i.e., communication between terminal devices), for example, in the scenario of communication between a relay device and a terminal device shown in FIG. 1 or communication between an XR glass and a mobile phone shown in FIG. 2, the sending terminal device may transmit data to the peer end through a physical sidelink shared channel (PSSCH) and receive the decoding result fed back by the terminal device on a physical sidelink feedback channel (PSFCH). The PSFCH is configured by using higher layer signaling and has periodicity, and the periodicity value of the PSFCH is

[0149]

number

[0150] , 0 indicates that there is no PSFCH. In addition, one PSFCH is included in every one, two, or four slots, and the PSFCH occupies the penultimate symbol in the slot. Because the received power of a terminal device may vary over the orthogonal frequency division multiplexing (OFDM) symbol in which the PSFCH is located, the penultimate symbol in the slot is also used to send the PSFCH to help the receiving terminal device perform automatic gain control (AGC) adjustment. In addition, the terminal devices that send the PSFCH and the PSFCH are different. Therefore, for the sending / receiving conversion of the terminal device, an additional symbol (i.e., the penultimate symbol) needs to be added before the two PSFCHs.

[0151] FIG. 4 shows the time relationship between PSSCH and PSFCH.

[0152]

number

[0153] is 4, i.e., one PSFCH appears for every four PSSCHs, and the PSFCH and PSSCH share 14 symbols of one slot. In addition, considering that a terminal device needs processing time after receiving data, for example, time from decoding the PSSCH after receiving it to generating information such as corresponding HARQ, in this case, higher layer signaling indicates the minimum slot offset of the PSFCH carrying the HARQ-ACK information of the PSSCH by using the minimum slot offset of the sidelink PSFCH (sl-minTimeGapPSFCH) parameter. That is, the HARQ-ACK information of the PSSCH needs to be fed back on the PSFCH at least in the slot after sl-minTimeGapPSFCH. As shown in FIG. 4, when sl-minTimeGapPSFCH=2, HARQ-ACK information feedback of the PSSCH in S0 and S1 may be transmitted through the first PSFCH, and HARQ-ACK information feedback of the PSSCH in S2 to S5 may be transmitted through the second PSFCH. The number of PSSCHs corresponding to each PSFCH is usually determined by the PSFCH period.

[0154]

number

[0155] However, cases may occur where there is no PSFCH. For example, if a sidelink synchronization signal block (S-SSB) is sent in the slot or if the sidelink control information (SCI) indicates that the PSFCH is canceled, the PSFCH period is lost. In this case, one PSFCH may correspond to more than four PSSCH HARQs. The specific quantity depends on the number of PSSCHs that satisfy sl-minTimeGapPSFCH.

[0156] For example, if the first PSFCH in FIG. 4 does not exist for a specific reason, all HARQ-ACK information feedback corresponding to the PSSCH in S0 to S5 is transmitted on the second PSFCH.

[0157] Figure 4 shows the time-domain relationship between the HARQ of the PSSCH and the HARQ of the PSFCH. Furthermore, Figure 5 shows the frequency-domain relationship between the HARQ-ACK information of the PSSCH and the HARQ-ACK information of the PSFCH, i.e., the HARQ bits of the PSSCH are transmitted over specific frequency-domain resources of the PSFCH, such as physical resource blocks (PRBs) (hereinafter also referred to as resource blocks (RBs)). As shown in Figure 5, one PSFCH PRB set includes 16 PRBs, and this parameter can be configured by using higher layer signaling. For example, the sidelink resource pool configuration (SL-PSFCH-Config-r16) parameter in the sidelink resource pool (SL-ResourcePool) signaling in the RRC message is used to configure the number of PRBs of the PSFCH. In particular, the PSFCH transmission resource set is divided into multiple subsets based on the PSFCH period parameter in the resource pool configuration information and the number of subchannels that can be used for PSSCH transmission, and the PSFCH transmission resource in each subset corresponds to PSSCH transmission in one slot and one subchannel.

[0158] For example, if the PSFCH period is

[0159]

number

[0160] and the resource pool is N subch The number of PRBs in the PSFCH is

[0161]

number

[0162] Then, the number of PRBs of the PSFCH corresponding to one PSSCH subchannel in one slot is

[0163]

number

[0164] For a PSSCH sent on the jth subchannel in the ith slot, the available PRBs of the PSFCH corresponding to the PSSCH are

[0165]

number

[0166] These PRBs form a PSFCH transmission resource subset. As shown in Figure 5, the PSFCH period is four slots, i.e., one PSFCH slot corresponds to four PSFCH slots, the resource pool includes two subchannels, and the resource pool configuration information configures 16 PRBs for transmitting the PSFCH. Therefore, one subchannel corresponds to two PSFCH PRBs, and the correspondence between the PSSCH subchannels and the PSFCH PRBs is first in the time domain sequence and then in the frequency domain sequence. As shown in Figure 5, subchannel 0 in slot 0 corresponds to PSFCH PRB0 and PRB1, subchannel 0 in slot 1 corresponds to PSFCH PRB2 and PRB3, and so on.

[0167] In addition, for the PRB of the PSFCH, the feedback results of the PSFCHs of multiple UEs may be multiplexed into the PRB of the PSFCH by code division multiplexing (CDM). The number of PSFCHs available for CDM in one PRB is determined by the parameter

[0168]

number

[0169] This parameter may be configured by using higher layer signaling. The transmission resource set of the PSFCH corresponding to the PSSCH is determined by

[0170]

number

[0171] When the PSFCH transmission resource is determined based on the index of the starting subchannel occupied by the PSSCH,

[0172]

number

[0173] For example, when the PSSCH occupies slot 0, the transmission resources of the PSFCH corresponding to the PSSCH are PRB0 and PRB1, regardless of whether the PSSCH occupies subchannel 0 or subchannels 0 and 1. When the transmission resources of the PSFCH are determined based on the indexes of all subchannels occupied by the PSSCH,

[0174]

number

[0175] and

[0176]

number

[0177] is the number of subchannels occupied by the PSSCH. For example, if the PSSCH occupies subchannel 0 in slot 0, the PSFCH corresponding to the PSSCH is PRB0 and PRB1. If the PSSCH occupies subchannel 0 and subchannel 1 in slot 0, the transmission resources of the corresponding PSFCH are PRB0, PRB1, PRB8, and PRB9. One PSFCH is

[0178]

number

[0179] The terminal selects the transmission resource corresponding to the PSFCH in the PSFCH transmission resource set according to the following equation:

[0180]

number

[0181] Determine P ID indicates the ID information of the UE sending the PSSCH, i.e., the source ID carried in SCI format 2-A or 2-B, and M ID indicates the ID of the receiving UE in the communication group and can be determined by using the destination ID in SCI format 2-A or 2-B. In unicast or the second feedback scheme above (PSFCH transmission resource is determined based on the indexes of all subchannels occupied by the PSSCH), M ID = 0. Therefore, the receiving ends in the group can determine different PSFCH transmission resources according to the IDs.

[0182] As shown in FIG. 6, the PSFCH corresponding to one PSSCH subchannel occupies four PRBs, and each PRB has:

[0183]

number

[0184] The UE first uses the frequency domain scheme and then the code domain scheme.

[0185]

number

[0186] Based on the results of

[0187]

number

[0188] If , then the fifth PRB (calculated from 0) based first on the frequency domain and then on the code domain, namely PRB1, is used to transmit the PSFCH.

[0189] 6. Sidelink Scheduling: Currently, sidelink scheduling is classified into two modes: Mode 1 and Mode 2. In Mode 1, the network device controls the transmission of the SL, i.e., the network device indicates to the sending terminal device (txUE) that it will send data to the receiving terminal device (rxUE) over the PSSCH by using a DCI. In particular, in a 5G new radio (NR) sidelink, the network device indicates the sending of the txUE by using DCI format 3_0. In a long term evolution (LTE) sidelink, the network device indicates the sending of the txUE by using DCI format 3_1. Each DCI can indicate N (usually 3 or less) PSSCH sendings at a time. Using NR as an example, the indication field of DCI format 3_0 includes:

[0190] (1) Resource pool index: A network device may configure multiple resource pools and corresponding indexes for a terminal device. When scheduling a side transmission resource by using a DCI, the network device needs to indicate resource pool index information in the DCI. Based on the resource pool index information, the terminal device determines the resource pool to which the side transmission resource scheduled by using the DCI belongs. Different parameters, such as the number of subchannels and subchannel size, may be configured for different resource pools.

[0191] (2) Time gap: Used to determine the time gap between the first sidelink transmission resource and the slot in which the DCI is located. The time-domain location of the first sidelink transmission resource may be determined based on such information and the time-domain location of the DCI received by the txUE.

[0192] (3) Time resource assignment: This information field indicates the time domain in the same manner as in SCI format 1-A. This parameter is used to determine the slot gap between the first sidelink transmission resource and the N-1 sidelink transmission resources other than the first sidelink transmission resource.

[0193] (4) Frequency-domain starting subchannel indicator for initial transmission (low index of subchannel allocation for initial transmission): Indicates the lowest index of the subchannel occupied by the first sidelink transmission resource. The frequency-domain starting positions of the PSCCH and PSSCH are aligned. Therefore, the frequency-domain starting positions of the PSCCH and PSSCH can be determined based on such information.

[0194] (5) Frequency resource assignment: The manner in which such information indicates frequency domain resources is the same as in SCI format 1-A, and this parameter is used to determine the frequency domain resource size (number of subchannels) of the sidelink transmission resource and the frequency domain starting positions of the N-1 sidelink transmission resources other than the first sidelink transmission resource.

[0195] (6) PUCCH resource indicator: The base station configures a PUCCH resource set and a corresponding index by using upper layer signaling, and the PUCCH transmission resource is determined in the resource set by using this information field in the DCI.

[0196] (7) Slot Gap Between PSFCH and PUCCH (PSFCH-to-HARQ Feedback Timing Indicator): Used to determine the time gap between PSFCH and PUCCH. PSFCH is used to carry HARQ-ACK information feedback of PSSCH indicated by DCI. If the sidelink transmission resources allocated by the base station (network device) correspond to at least one PSFCH, the slot gap indicates the slot gap between the transmission resource of the last PSFCH and the PUCCH transmission resource.

[0197] (8) HARQ process number: Indicates the HARQ process number corresponding to the sidelink transmission resource allocated to the terminal by the network.

[0198] (9) New Data Indicator (NDI): Indicates whether new sidelink data scheduled by DCI is to be transmitted. NDI is toggled when new sidelink data scheduled by DCI format 3_0 is to be transmitted. Otherwise, NDI is not toggled.

[0199] (10) Configuration Index: When a sidelink configuration scheduling radio network temporary identifier (SL-CS-RNTI) is configured for the UE, DCI format 3_0 can be used to activate or release a type-2 sidelink configured grant. The network may configure multiple type-2 sidelink configured grants. The configuration index indicates which sidelink configured grant is activated or released by the DCI. When a SL-CS-RNTI is not configured for the UE, this field (information field) is not present or has a 0 bit.

[0200] (11) Counter sidelink assignment index: The counter sidelink assignment index is cumulatively sent by the network and indicates the number of DCIs used to schedule sidelink transmission resources. Based on this information, the terminal determines the number of information bits during the generation of the HARQ-ACK codebook.

[0201] When a terminal device receives DCI format 3_0, the PSSCH is scheduled through the PSCCH on the time-frequency domain resources indicated by the DCI (e.g., in SCI format 1-A). The same information fields in DCI format 3_0 may be used for time resource allocation and frequency resource allocation during the SCI.

[0202] Additionally, the following explanations are provided to facilitate understanding of the embodiments of the present application.

[0203] First, in this application, "indicate" may include "directly indicate" and "indirectly indicate." When indication information is described as indicating A, the indication information may directly indicate A or indirectly indicate A, but this does not mean that the indication information necessarily includes A.

[0204] The information indicated by the indication information is called information to be indicated. In a specific implementation process, there are multiple ways to indicate the information to be indicated. The information to be indicated may be sent as a whole, or may be divided into multiple pieces of sub-information and sent separately. In addition, the sending periods and / or sending opportunities of the sub-information may be the same or different. The specific sending method is not limited in the present application. The sending periods and / or sending opportunities of the sub-information may be predefined, for example, according to a protocol, or may be configured by the transmitting end device by sending configuration information to the receiving end device. The configuration information may include, but is not limited to, one of radio resource control signaling, MAC layer signaling, and physical layer signaling, or a combination of at least two of them. The radio resource control signaling may include, for example, RRC signaling, the MAC layer signaling may include, for example, MAC CE, and the physical layer signaling may include, for example, DCI.

[0205] Second, "at least one" as used herein means one or more, and "multiple" means two or more. In addition, in the embodiments of the present application, "first," "second," and various numerical numbers (e.g., "#1" and "#2") are used merely for distinction purposes for ease of description and are not used to limit the scope of the embodiments of the present application. The sequence numbers of the following processes do not indicate the sequence of execution. The execution sequence of the processes should be determined according to the functions and internal logic of the processes and should not constitute any limitation on the implementation process of the embodiments of the present application. It should be understood that objects described in such a manner can be interchangeable where appropriate to describe solutions other than the embodiments of the present application. In addition, in the embodiments of the present application, words such as "710" and "720" are merely identifiers for ease of description and do not limit the sequence of performing steps.

[0206] Third, in this application, words such as "example" or "for example" are used to denote providing an example, illustration, or explanation. Any embodiment or design solution described in this application as an "example" or "for example" should not be construed as preferred or advantageous over other embodiments or design solutions. In particular, words such as "example" or "for example" are used to present related concepts in a particular manner.

[0207] Fourth, "storage" in the embodiments of the present application may be storage in one or more memories. The one or more memories may be disposed separately or integrated into an encoder or decoder, a processor, or a communication device. Alternatively, a portion of the one or more memories may be disposed separately, and a portion of the one or more memories may be integrated into a decoder, a processor, or a communication device. The type of memory may be any form of storage medium. This is not limited in the present application.

[0208] Fifth, the "protocol" in the embodiments of the present application may be a standard protocol in the communication field, for example, the LTE protocol, the NR protocol, and related protocols applied to future communication systems, which are not limited in the present application.

[0209] Sixth, in the embodiments of this application, "if," "when," and "if" are sometimes used interchangeably. Please note that when their differences are not emphasized, the meaning to be expressed is consistent.

[0210] Seventh, in the embodiments of the present application, all terms and English acronyms and abbreviations, such as Radio Resource Control (RRC), are examples provided for ease of explanation and should not be considered as any limitation to the present application. The present application does not exclude the possibility of defining other terms that can implement the same or similar functions in existing or future protocols.

[0211] Eighth, the term "and / or" in this specification merely indicates an association relationship between associated objects, and indicates that three relationships may exist. For example, A and / or B may indicate three cases: only A exists, both A and B exist, and only B exists. In addition, the character " / " in this specification generally indicates an "or" relationship between associated objects.

[0212] 1, the above briefly describes scenarios to which the communication methods provided in the embodiments of the present application can be applied, describes basic concepts that can be used in the embodiments of the present application, and describes HARQ-ACK information feedback in sidelinks and HARQ-ACK information feedback in cellular networks in the basic concepts. Currently, after receiving a PDSCH, a terminal device feeds back HARQ-ACK information to a network device through a communication interface (e.g., Uu) between the terminal device and the network device, causing high uplink power consumption overhead. In order to reduce the uplink power consumption overhead of the terminal device, the present application provides a communication method in which, after receiving a PDSCH, the terminal device may feed back HARQ-ACK information to a network device through a relay device.

[0213] It should be understood that the communication method provided in the embodiments of the present application may be applied to a system in which communication is implemented by using multi-antenna technology, such as the communication system 100 shown in Fig. 1. The communication system may include at least one network device, at least one terminal device, and at least one relay device.

[0214] It should be further understood that the specific structure of the execution body of the method provided in the embodiment of the present application is not particularly limited in the embodiments shown below, provided that a program recording a code for the method provided in the embodiment of the present application can be run to perform communication according to the method provided in the embodiment of the present application. For example, the method provided in the embodiment of the present application may be performed by a terminal device, or may be performed by a functional module in the terminal device that can call and execute a program.

[0215] 7 is a schematic flowchart of a communication method according to the present application. The method includes the following steps:

[0216] S710: The network device sends first downlink data to the first terminal device through the first link. In other words, the first terminal device receives the first downlink data from the network device through the first link.

[0217] For example, the first downlink data may be the PDSCH described above, or may be other downlink data (e.g., PDCCH) sent by the network device to the first terminal device. The specific format of the first downlink data is not limited in this embodiment. For ease of explanation, an example in which the first downlink data is PDSCH#1 is used below for explanation.

[0218] In particular, the first terminal device may be any terminal device that communicates with the network device. For example, in this embodiment, the first terminal device may be the terminal device shown in Figure 1 above, or the XR glasses shown in Figure 2 above.

[0219] The first link is a communication link between the first terminal device and the network device. For example, the first link is a link for communication based on communication interface #1 (e.g., Uu #2) and may also be referred to as a first communication channel. The term "first channel" is used to describe a communication channel for direct communication between the first terminal device and the network device.

[0220] In a possible implementation, in this embodiment, the network device sending PDSCH#1 to the first terminal device through the first link may be understood as follows: The network device sends DCI#1 to the first terminal device through the first link, and the DCI#1 is used to schedule PDSCH#1 for the terminal device.

[0221] Furthermore, after receiving PDSCH#1, the terminal device may decode PDSCH#1 to obtain a first decoding result. The method procedure shown in Figure 7 further includes the following steps.

[0222] S720: The first terminal device decodes the first downlink data to obtain a first decoding result.

[0223] In particular, in this embodiment, the process of how the first terminal device decodes PDSCH#1 to obtain the first decoding result is not described in detail.For details, please refer to the description in the current related art that the terminal device performs decoding and obtains the decoding result after receiving the PDSCH scheduled by the network device.The details are not described in this specification.

[0224] In this embodiment, the first terminal device obtains a first decoding result and generates first HARQ-ACK information based on the first decoding result (e.g., generates an acknowledgment (ACK) or a negative acknowledgment (NACK)). After the first HARQ-ACK information is generated, in this embodiment, the first terminal device may not directly feed back the first HARQ-ACK information to the network device, but sends the first HARQ-ACK information to the second terminal device, and the second terminal device forwards the first HARQ-ACK information to the network device, thereby reducing the power consumption required for the first terminal device to feed back the first HARQ-ACK information. The method procedure shown in FIG. 7 further includes the following steps:

[0225] S730: The first terminal device sends first information to the second terminal device through the second link. In other words, the second terminal device receives first information from the first terminal device through the second link. The first information includes first HARQ-ACK information.

[0226] In particular, the second terminal device may be any terminal device that establishes communication with the network device and the first terminal device. For example, in this embodiment, the second terminal device may be the relay device shown in Figure 1 above, or the mobile phone shown in Figure 2 above.

[0227] The second link is a communication link between the first terminal device and the second terminal device. For example, the second link is a link for communication based on communication interface #2 (e.g., PC5) and may also be referred to as a second communication channel. The second channel etc. is used to describe a communication channel for direct communication between the first terminal device and the second terminal device.

[0228] Furthermore, in this embodiment, after receiving the first HARQ-ACK information of the first terminal device for PDSCH#1, the second terminal device forwards the first HARQ-ACK information to the network device. The method procedure shown in Figure 7 further includes the following steps:

[0229] S740: The second terminal device sends fifth information to the network device through the third link. In other words, the network device receives fifth information from the second terminal device through the third link. The fifth information includes the first HARQ-ACK information.

[0230] The third link is a communication link between the second terminal device and the network device. For example, the third link is a link for communication based on communication interface #3 (e.g., Uu #1), and may also be referred to as a third communication channel. The third channel, etc., is used to describe a communication channel for direct communication between the second terminal device and the network device.

[0231] In this embodiment, how the second terminal device forwards the first HARQ-ACK information for the first terminal device to the network device is not limited, and the first HARQ-ACK information may be forwarded on the transmission resources allocated to the second terminal device by the network device. In this embodiment, how the network device configures the transmission resources for forwarding the first HARQ-ACK information is not limited, and the transmission resources allocated to the second terminal device may be reused, or the transmission resources may be configured separately for the first HARQ-ACK information.

[0232] It should be understood that in this embodiment, a prerequisite for the first terminal device to send the first HARQ-ACK information to the second terminal device through the second link is that the first terminal device knows the first transmission resource that can be used to transmit the first HARQ-ACK information on the second link. In this embodiment, the first terminal device may know the first transmission resource that is used to transmit the first HARQ-ACK information on the second link in the following two ways.

[0233] Scheme 1.1: The network device indicates the first transmission resource by dynamic indication. With reference to Figure 8, the following will describe in detail how the first terminal device learns the first transmission resource in the case described in Scheme 1.1.

[0234] Scheme 1.2: The network device indicates the first transmission resource in a semi-static manner. With reference to Figure 10, the following will describe in detail how the first terminal device learns the first transmission resource in the case described in Scheme 1.2.

[0235] It should be understood that the above Scheme 1.1 and Scheme 1.2 are merely examples for describing a scheme for the first terminal device to determine the first transmission resource for transmitting the first HARQ-ACK information on the second link, and do not constitute any limitation on the scope of protection of the present application. The first transmission resource may be an unlicensed spectrum resource. In the present application, it is mainly considered that the first terminal device learns the first transmission resource based on an indication from the network device.

[0236] 7, after receiving the PDSCH, the first terminal device transmits corresponding HARQ-ACK information to the second terminal device through a second link (e.g., PC5), and then the second terminal device transmits the HARQ-ACK information to the network device. This prevents the first terminal device from directly sending the HARQ-ACK information to the network device, thereby reducing the power consumption overhead caused by the uplink HARQ-ACK information feedback performed by the first terminal device.

[0237] 8 is a schematic flowchart of another communication method according to the present application. The method includes the following steps:

[0238] S810: The network device sends first control information to the first terminal device. In other words, the first terminal device receives the first control information from the network device.

[0239] In particular, determining a first transmission resource for transmitting the first HARQ-ACK information by the first terminal device includes determining a specific time for transmitting the first HARQ-ACK information, for example, the first terminal device determines a first time unit in which the first terminal device sends the first information through the second link.

[0240] It should be understood that the first time unit determined by the first terminal device is a time unit for sending the first information and the first HARQ-ACK information. The first terminal device may be understood to determine that the time unit for sending the first HARQ-ACK information is the first time unit. For example, if the first terminal device determines to send the first HARQ-ACK information in a slot, the first terminal device sends the first information carrying the first HARQ-ACK information in that slot.

[0241] For example, the first terminal device may determine the first time unit by determining a first time gap, where the first time gap is less than or equal to the time gap between the first time unit and the second time unit, and the second time unit is the time unit at which the first terminal device receives first downlink data or the time unit at which the first terminal device receives first control information, and the first control information may be further used to schedule the first downlink data.

[0242] In a possible implementation, the first time gap is a time offset between the first time unit and the second time unit. In this implementation, the first time unit is the first time unit that is a time offset after the second time unit. The time gap between the first time unit and the second time unit may be understood to be equal to the time offset.

[0243] In another possible implementation, the first time gap is a minimum time gap (minTimeGap) between the first time unit and the second time unit, and in this implementation, the time gap between the first time unit and the second time unit is equal to or greater than the minimum time gap.

[0244] In the embodiment shown in Figure 8, the network device may dynamically indicate the size of the first time gap by using first control information. The first time gap is the time gap between the first time unit in which the first terminal device sends the first HARQ-ACK information and the time unit in which the first terminal device receives PDSCH#1, or the first time gap is the time gap between the first time unit in which the first terminal device sends the first HARQ-ACK information and the time unit in which the first terminal device receives information for scheduling PDSCH#1 (e.g., DCI#1). For ease of explanation, the following description will be given using an example in which the first control information is DCI#1 and DCI#1 indicates the time gap between the first time unit and the time unit for receiving DCI#1.

[0245] For example, the first control information is DCI#1 in the communication method shown in Figure 7. DCI#1 is used to schedule PDSCH#1 and further indicates a first time gap (also referred to as a first time domain offset) between the time domain location of the SL resource (e.g., PSSCH or PSFCH) carrying the first HARQ-ACK information of PDSCH#1 and the time domain location at which DCI#1 is received.

[0246] In a possible implementation, in this embodiment, DCI#1 includes a field used to indicate a time offset between the time unit for receiving PDSCH#1 and the SL resource carrying the first HARQ-ACK information of PDSCH#1. For example, DCI#1 includes a PDSCH-to-HARQ-feedback-on-PSSCH timing indicator field or a PDSCH-to-HARQ-feedback-on-PSFCH timing indicator field. This newly added field indicates a first time gap between the time domain location of the resource for receiving PDSCH#1 and the time domain location of the SL resource carrying the first HARQ-ACK information of PDSCH#1.

[0247] In another possible implementation, in this embodiment, the PDSCH-to-HARQ feedback indicator field in downlink DCI format 1_0 or format 1_1 is reused to indicate a first time gap between the time domain location of the resources for receiving PDSCH#1 and the time domain location of the SL resources carrying the first HARQ-ACK information of PDSCH#1.

[0248] Optionally, the above field (newly added or reused) indicating the first time gap may be used together with higher layer signaling to indicate the first time gap. For example, before the network device sends the first control information to the first terminal device, the network device sends second configuration information to the first terminal device, and the second configuration information is used to configure a time gap set, and the first time gap is one time gap in the time gap set. The method procedure shown in FIG. 8 further includes the following steps.

[0249] S811: The network device sends second setting information to the first terminal device. In other words, the first terminal device receives the second setting information from the network device.

[0250] The second configuration information may be higher layer signaling (e.g., an RRC message), for example, the higher layer signaling may configure multiple time gap candidates for the first terminal device (e.g., the network device configures a total of four time gap candidates {3, 4, 5, 8} for the first terminal device, where the unit is a slot).

[0251] Optionally, when the first control information reuses the PDSCH-to-HARQ feedback indicator field in DCI format 1_0 or format 1_1, the bit width of the PDSCH-to-HARQ feedback indicator field may be ceil(log24)=2 bits, where ceil(·) is the ceiling (or

[0252]

number

[0253] may be replaced by

[0254]

number

[0255] indicates a ceiling operation), and 4 indicates the quantity of time gap candidates constructed (e.g., a total of four time gap candidates {3, 4, 5, 8} are constructed above).

[0256] For example, the PDSCH-to-HARQ feedback indicator field may be an index, which corresponds to a value among the above time gap candidates. For example, index "00" represents the first value, which is "3", i.e., the first time gap is three slots, and the first HARQ-ACK information of PDSCH#1 is fed back three slots after PDSCH#1 is received.

[0257] It should be noted that the above listed implementations are merely examples for describing how to indicate the first time gap by using the first control information, and do not constitute any limitation on the scope of protection of the present application. Alternatively, the first time gap may be dynamically indicated in another manner, for example, the first time gap is indicated by adding signaling, or the first time gap is indicated in a pre-configured manner (described below with reference to FIG. 10). Examples are not described herein.

[0258] For ease of understanding, how the first control information indicates the first time gap will be briefly described with reference to (a) and (b) of FIG.

[0259] 9(a), it can be seen that the first terminal device receives DCI#1 and corresponding PDSCH#1 in slot D1, where DCI#1 indicates that the first HARQ-ACK information of PDSCH#1 is transmitted on the PSSCH two slots later.

[0260] 9(b), it can be seen that the first terminal device receives DCI#1 and corresponding PDSCH#1 in slot D1, where DCI#1 indicates that the first HARQ-ACK information of PDSCH#1 is transmitted on the PSFCH two slots later.

[0261] Furthermore, when the first time gap is measured in slots, a subcarrier spacing (SCS) corresponding to the number of slots in the first time gap needs to be determined. For example, the SCS corresponding to the second link is different from the SCS corresponding to the first link. Therefore, the duration of each slot on the second link is different from the duration of each slot on the first link. For example, the SCS of the first link is 15 kHz, and the duration of each uplink or downlink slot is 1 ms, while the SCS of the second link is 30 kHz, and the duration of each slot on the second link is 0.5 ms. Therefore, when the first time gap is measured in slots, it needs to be specified whether the first time gap indicated by the first control information is a slot on the second link or a slot on the first link.

[0262] For example, the first terminal device determines, based on the first parameter, that the SCS referenced by the first time gap is the SCS corresponding to the first link or the SCS corresponding to the second link.

[0263] Optionally, the first parameter may be configured by the network device. For example, the first parameter may be 1-bit information newly added to DCI#1. For example, a 1-bit field may be added to DCI#1 to indicate that the SCS indicated by DCI#1 and referenced by the first time gap is the SCS corresponding to the first link or the SCS corresponding to the second link. In another example, the first parameter may be configured by using higher layer signaling. For example, an RRC message indicates the first parameter, and the first parameter is used to configure the SCS indicated by DCI#1 and referenced by the first time gap as the SCS corresponding to the first link or the SCS corresponding to the second link.

[0264] Optionally, the first parameter is pre-programmed into the first terminal device. It may be understood that the first parameter is pre-configured in the first terminal device before delivery.

[0265] For example, the first parameter may be preconfigured, i.e., preconfigured before delivery, such that the SCS indicated by DCI#1 and referenced by the first time gap is the SCS corresponding to the first link or the SCS corresponding to the second link.

[0266] Optionally, the first parameter is determined by the first terminal device and the network device through negotiation.

[0267] It should be noted that if the first time gap is not measured in slots but in absolute time (e.g., in units of milliseconds (ms)), then no additional first parameter is required to indicate that the SCS referenced by the first time gap is the SCS corresponding to the first link or the SCS corresponding to the second link.

[0268] Furthermore, after determining the first time unit, the first terminal device further needs to determine a first transmission resource specifically used for transmitting the first HARQ-ACK information, where the first transmission resource includes a first time domain resource and a first frequency domain resource, and the first time domain resource is the time domain resource of the first time unit.

[0269] With reference to Scheme 2.1 and Scheme 2.2, the following describes in detail how the first terminal device determines the first time domain resource and the first frequency domain resource when the first transmission resource is a PSSCH and a PSFCH.

[0270] Scheme 2.1: The first transmission resource is a PSSCH (as shown in FIG. 9(a)). In this implementation, the first terminal device determining the first time domain resource and the first frequency domain resource includes:

[0271] S821: The network device sends the second information to the first terminal device. In other words, the first terminal device receives the second information from the network device.

[0272] In particular, the second information indicates a first time domain resource and a first frequency domain resource. For example, if the second information is information included in the first control information, steps S810 and S821 are one step, or the second information is different from the first control information. For ease of explanation, an example in which the second information is included in the first control information is used below for explanation.

[0273] For example, the second information is information included in DCI#1 of the communication method shown in Figure 7. DCI#1 is used to schedule PDSCH#1 and further indicates a PSSCH carrying first HARQ-ACK information for PDSCH#1. The first terminal device may determine the PSSCH for transmitting the first HARQ-ACK information based on the indication of DCI#1.

[0274] For example, the network device configures one or more resource pools for the first terminal device by using higher layer signaling such as an RRC message, and each resource pool has a corresponding resource pool index. The indication field #1 of DCI #1 indicates that the transmission resource of the first HARQ-ACK information is one of these resource pools by using the index. The resource pool in this embodiment may be a resource pool dedicated to transmitting the HARQ-ACK information of the PDSCH, or may be the same as the existing PSSCH resource pool.

[0275] For example, the resource pool may be configured by using the SL-ResourcePool field in an existing RRC message. For example, the network device may configure several SL resource pools and corresponding indices for the first terminal device and the second terminal device, and DCI#1 may indicate the resource pool to which the PSSCH carrying the first HARQ-ACK information belongs by indicating the index.

[0276] In another example, the network device may configure a separate resource pool carrying the HARQ-ACK information of the PDSCH and a corresponding index by using other higher layer signaling. For example, multiple resource pools (sl-PDSCH-HARQ-Pools) are configured, and each sl-PDSCH-HARQ-Pool corresponds to an index. The indication field #1 of DCI #1 indicates the index, thereby indicating the resource pool to which the PSSCH for transmitting the first HARQ-ACK information by the first terminal device belongs.

[0277] In the case shown in Scheme 2.1, after the indication field #1 of DCI #1 indicates a resource pool to which a PSSCH for transmitting the first HARQ-ACK information belongs, DCI #1 may further indicate a first time domain resource and a first frequency domain resource corresponding to the PSSCH in the resource pool. For example, second information is added to DCI #1, and the second information indicates the first time domain resource and the first frequency domain resource.

[0278] Optionally, the second information includes a first field and a second field, where the first field is a time resource assignment field and the second field is a frequency resource assignment field.

[0279] Optionally, a field indicating the time resource allocation and frequency resource allocation in DCI#1 may be further added to SCI format 1A of the PSSCH for the second terminal device to determine a specific location of the PSSCH for transmitting the first HARQ-ACK information.

[0280] Furthermore, in the case shown in Scheme 2.1, the first terminal device sending the first HARQ-ACK information to the second terminal device through the second link includes:

[0281] The first terminal device sends a MAC CE to the second terminal device on a first transmission resource on the second link, and the MAC CE includes the first HARQ-ACK information. In other words, the first information in the embodiment shown in FIG. 7 may be a MAC CE.

[0282] For example, after decoding PDSCH#1, the first terminal device may transmit first HARQ-ACK information in the form of MAC CE on the PSSCH indicated by DCI#1. The MAC CE includes a 6-bit logical channel ID (LCID), and multiple additional bits are used to carry the first HARQ-ACK information. The LCID is present in the MAC CE subheader and indicates that the function of the MAC CE is to carry the first HARQ-ACK information.

[0283] For example, the decimal value of a 6-bit LCID is 0 to 63. Considering that some LCID values ​​are defined for other functions and 20 to 55 are not currently defined, when the LCID is X (X is any value from 20 to 55), the LCID indicates that the MAC CE indicates HARQ-ACK information of the first terminal device, and the HARQ-ACK information carried in the MAC CE includes 1 bit of information (e.g., ACK or NACK).

[0284] Optionally, in the case shown in Scheme 2.1, the first terminal device may feedback HARQ-ACK information by using MAC CE. When the first terminal device fails to detect DCI (for example, when the network device sends DCI#1 and DCI#2 to the first terminal device, and the first terminal device receives DCI#1 but not DCI#2), the first terminal device may not transmit second HARQ-ACK information of PDSCH#2 corresponding to the missing DCI#2 during detection. For example, the first terminal device does not send MAC CE corresponding to the second HARQ-ACK information to the second terminal device. In this case, confusion may occur when the second terminal device receives and feeds back HARQ-ACK information.

[0285] For example, the network device may send two PDSCHs, but the first terminal device may only detect one DCI and feed back one HARQ-ACK information (one MAC CE). During reception, the second terminal device may generate an inaccurate HARQ codebook. To prevent the second terminal device from generating an inaccurate HARQ codebook, in the case shown in scheme 2.1, the first terminal device may indicate whether DCI is missing during detection in the following possible implementation.

[0286] In a possible implementation, the MAC CE sent by the first terminal device to the second terminal device further carries a HARQ process number to inform the second terminal device of the HARQ process whose feedback result is the MAC CE.

[0287] In another possible implementation, the first terminal device may determine the number of PDSCHs corresponding to the HARQ-ACK information transmitted on the PSSCH and generate a corresponding number of MAC CEs. Upon receiving the PDSCH at the corresponding slot position, the first terminal device feeds back the HARQ-ACK information on the corresponding MAC CE. If the PDSCH is not received, a non-reception indication is fed back.

[0288] For example, if the quantity of PDSCHs corresponding to the HARQ-ACK information transmitted on the PSSCH indicates four PDSCHs, PDSCH#0, PDSCH#1, PDSCH#2, and PDSCH#3, the first terminal device sends four MAC CEs, MAC CE#0, MAC CE#1, MAC CE#2, and MAC CE#3, on the PSSCH. When the first terminal device receives PDSCHs only at slot positions corresponding to PDSCH#2 and PDSCH#3, PDSCH#2 is successfully decoded, PDSCH#3 fails to be decoded (because PDSCHs are not received), and NACKs are fed back in MAC CE#0 and MAC CE#1, an ACK is fed back in MAC CE#2, and a NACK is fed back in MAC CE#3 (decoding fails).

[0289] Alternatively, Discontinuous transmission (DTX) is fed back in MAC CE#0 and MAC CE#1 to indicate that PDSCH is not received, ACK is fed back in MAC CE#2, and NACK is fed back in MAC CE#3. In this case, 1-bit feedback is insufficient and must be extended to 2 bits, e.g., 00-DTX, 01-ACK, 10-NACK, and 11-reserved.

[0290] Scheme 2.2: The first transmission resource is a PSFCH (as shown in FIG. 9(b)). In this implementation, the first terminal device's determining the first time domain resource and the first frequency domain resource includes:

[0291] S822: The network device sends the third information to the first terminal device. In other words, the first terminal device receives the third information from the network device.

[0292] In particular, the third information indicates a first frequency domain resource. For example, if the third information is information included in the first control information, steps S810 and S822 are one step, or the third information is different from the first control information. For ease of explanation, an example in which the third information is included in the first control information is used below for explanation.

[0293] For example, the network device may add an indication field (i.e., third information) to DCI #1 to indicate a PSFCH for transmitting the first HARQ-ACK information. The first terminal device may determine a PSFCH for transmitting the first HARQ-ACK information based on the indication of DCI #1.

[0294] For example, the network device configures one or more resource pools for the first terminal device by using higher layer signaling (such as an RRC message), and each resource pool has a corresponding resource pool index. The indication field of DCI#1 indicates that the transmission resource of the first HARQ-ACK information is one of these resource pools by using the index. The resource pool in this embodiment may be a resource pool dedicated to transmitting the HARQ-ACK information of the PDSCH, or may be the same as the existing PSFCH resource pool.

[0295] For example, the resource pool may be configured by using the SL-ResourcePool field in an existing RRC message. For example, the network device configures several SL resource pools and corresponding indices for the first terminal device and the second terminal device, and each SL-ResourcePool configures a PSFCH for the first terminal device and the second terminal device by using sl-PSFCH-Config-r16. The indication field #2 of DCI #1 indicates an index to indicate the resource pool to which the PSFCH for transmitting the first HARQ-ACK information by the first terminal device belongs.

[0296] In another example, the network device may configure a separate resource pool carrying the HARQ-ACK information of the PDSCH and a corresponding index by using other higher layer signaling. For example, multiple resource pools (sl-PDSCH-HARQ-Pools) are configured, and each sl-PDSCH-HARQ-Pool corresponds to an index. The indication field #2 of DCI #1 indicates the index, thereby indicating the resource pool to which the PSFCH for transmitting the first HARQ-ACK information by the first terminal device belongs.

[0297] In the case shown in Scheme 2.2, when HARQ-ACK information for multiple PDSCHs is transmitted in the same slot, for example, DCI#0 indicates that PDSCH#0 is scheduled in slot D1 and HARQ-ACK information feedback is performed on PSFCH in the fourth slot, and DCI#1 indicates that PDSCH#1 is scheduled in slot D2 and HARQ-ACK information feedback is also performed on PSFCH in the fourth slot. In this case, the PSFCHs indicated by DCI#0 and DCI#1 may be the same PSFCH or different PSFCHs. For example, DCI#0 indicates resource pool index 0 (or dedicated resource pool 0), and DCI#1 indicates resource pool index 1 (or dedicated resource pool 1). In this case, different PSFCHs are indicated by using DCIs, and therefore, HARQ-ACK information for multiple PDSCHs can be transmitted in one slot.

[0298] Optionally, HARQ-ACK information for multiple PDSCHs may alternatively be transmitted on the same PSFCH. For example, DCI#0 and DCI#1 schedule PDSCH#0 and PDSCH#1, respectively, but DCI#0 and DCI#1 indicate the same PSFCH. In this case, the PRBs of the PSFCH may be divided into a corresponding number of subsets based on the number of HARQ-ACK information pieces that need to be carried (e.g., 2).

[0299] For example, if 20 PRBs are configured for one PSFCH by using higher layer signaling, when two PDSCHs are received, the 20 PRBs are divided into two PSFCH sets, e.g., uniformly divided into two PSFCH subsets, each PSFCH subset containing 10 PRBs, and each PSFCH is used to transmit HARQ-ACK information for each of PDSCH#0 and PDSCH#1.

[0300] Furthermore, if HARQ-ACK information for PDSCH#0, PDSCH#1, PDSCH#2, and PDSCH#3 is fed back in the same slot, but DCI indicates that PDSCH#0 and PDSCH#1 are transmitted by the same PSFCH#0, and PDSCH#2 and PDSCH#3 are transmitted by PDSCH#1, PRBs for PSFCH#0 may be grouped to carry HARQ-ACK information for PDSCH#0 and PDSCH#1, and PRBs for PSFCH#1 may be grouped to carry HARQ-ACK information for PDSCH#2 and PDSCH#3.

[0301] Optionally, in the case shown in Scheme 2.2, if the first terminal device fails to detect the DCI, the first terminal device cannot receive the PDSCH scheduled by using the DCI. This may cause a problem in allocating resource blocks for the PSFCH. For example, a network device sends two DCIs (DCI#1 and DCI#2), and the two DCIs indicate the same PSFCH. However, the first terminal device only successfully decodes one DCI. In this case, the PSFCH is not segmented. Therefore, a mismatch problem between the receiving end and the transmitting end occurs, which affects the second terminal device when decoding the PSFCH. In the case shown in Scheme 2.2, the first terminal device may indicate whether the DCI is missing during detection in the following possible implementation.

[0302] In a possible implementation, indication information #1 is added to the DCI to indicate the quantity of PDSCHs or to indicate that the PDSCH is a specific PDSCH.

[0303] For example, the indication information #1 may be a relay-downlink assignment index (R-DAI) used to indicate the accumulation index of the PDSCH indicated by the DCI. When the indication field is x bits, the value of the accumulation index that may be indicated by the indication field is [0, 2 x -1]. It should be understood that this does not represent the actual quantity of scheduling DCIs. For example, when x=2 bits, the index value ranges from 0 to 3. When a network device sends 6 DCIs, the R-DAIs of the DCIs are 00, 01, 10, 11, 00, and 01, respectively, and the corresponding decimal R-DAIs are 0, 1, 2, 3, 4, and 5.

[0304] Table 2 shows the mapping relationship between the value of R-DAI and the quantity (Y) of PDCCH transmission opportunities for scheduling PDSCH.

[0305] [Table 2]

[0306] Table 2 can be understood as follows: when the value of R-DAI is 1, the corresponding PDCCH monitoring opportunities are 1, 5, and 9, or when the value of R-DAI is 2, the corresponding PDCCH monitoring opportunities are 2, 6, and 10, and so on.

[0307] Therefore, the second terminal device may determine the number of PDSCHs on which HARQ-ACK information is transmitted on one PUCCH, i.e., the size of the HARQ codebook and whether DCI detection misses occur, based on the R-DAI parameter. For example, when the second terminal device detects that the two DCIs indicate that the R-DAI values ​​are "01" and "11", respectively, the second terminal device may determine that detection misses occur in the DCI indicating that the R-DAI is "10", and thus determine that the size of the HARQ-ACK information codebook is 3 bits.

[0308] In the communication method shown in Figure 8, the network device indicates the SL resource (e.g., the PSSCH or PSFCH shown above) used to transmit HARQ-ACK information in a dynamic indication manner. The present application further provides another method for determining the SL resource used to transmit HARQ-ACK information. The following provides a detailed description of Figure 10.

[0309] 10 is a schematic flowchart of another communication method according to the present application. The method includes the following steps:

[0310] S1010: The network device sends first setting information to the first terminal device. In other words, the first terminal device receives the first setting information from the network device. Before sending PDSCH#1 to the first terminal device, the network device sends the first setting information to the first terminal device, where the first setting information indicates a first time gap.

[0311] In particular, determining a first transmission resource for transmitting the first HARQ-ACK information by the first terminal device includes determining a specific time for transmitting the first HARQ-ACK information. For example, the first terminal device determines a first time unit in which the first terminal device sends the first information through the second link.

[0312] It should be understood that the first time unit determined by the first terminal device is a time unit for sending the first information and the first HARQ-ACK information. It can be understood that the first terminal device determines that the time unit for sending the first HARQ-ACK information is the first time unit. For example, when the first terminal device determines to send the first HARQ-ACK information in a slot, the first terminal device sends the first information carrying the first HARQ-ACK information in the slot.

[0313] For example, the first terminal device may determine the first time unit by determining a first time gap, where the first time gap is less than or equal to the time gap between the first time unit and the second time unit, and the second time unit is the time unit at which the first terminal device receives first downlink data or the time unit at which the first terminal device receives first control information, and the first control information may be further used to schedule the first downlink data.

[0314] In a possible implementation, the first time gap is a time offset between the first time unit and the second time unit. In this implementation, the first time unit is a first time unit that is a later time offset than the second time unit. It can be understood that the time gap between the first time unit and the second time unit is equal to the time offset.

[0315] In another possible implementation, the first time gap is a minimum time gap (minTimeGap) between the first time unit and the second time unit, and in this implementation, it can be understood that the time gap between the first time unit and the second time unit is equal to or greater than the minimum time gap.

[0316] In the embodiment shown in Figure 10, the network device may statically configure the first time gap by using first configuration information. The first time gap is the time gap between the first time unit in which the first terminal device sends the first HARQ-ACK information and the time unit in which the first terminal device receives PDSCH #1, or the first time gap is the time gap between the first time unit in which the first terminal device sends the first HARQ-ACK information and the time unit in which the first terminal device receives information for scheduling PDSCH #1 (e.g., DCI #1). For ease of explanation, an example in which the first configuration information is used to configure the time gap between the first time unit and the time unit for receiving DCI #1 will be used below for explanation.

[0317] For example, if the first transmission resource is a PSSCH, the first configuration information may be used to configure a first time gap between DCI#1 and the PSSCH used to transmit the first HARQ-ACK information. For example, the network device configures the first time gap by sending higher layer signaling (e.g., an RRC message). The first time gap may be measured in slots or in milliseconds.

[0318] For example, the time gap between DCI #1 and the first time unit is referred to as timeGap, and indicates to the first terminal device that when the first terminal device receives the PSSCH in the timeGap-th slot after DCI #1, it will send first HARQ-ACK information corresponding to PDSCH #1 scheduled by DCI #1. For example, the first HARQ-ACK information of PDSCH #1 scheduled by DCI #1 received in D0 is transmitted on the PSSCH in the second slot (i.e., the third S slot) after D0.

[0319] When the time gap is measured in slots, the subcarrier spacing (SCS) corresponding to the number of slots in the first time gap must be determined. For example, the SCS corresponding to the second link may be different from the SCS corresponding to the first link. As a result, the duration of each slot on the second link may be different from the duration of each slot on the first link. For example, the SCS of the first link may be 15 kHz, and the duration of each uplink or downlink slot may be 1 ms. The SCS of the second link may be 30 kHz, and the duration of each slot on the second link may be 0.5 ms. Therefore, when the offset of the first time gap is in slots, it must be specified whether the time gap indicated by DCI#1 refers to slots on the second link or slots on the first link.

[0320] Optionally, the first configuration information indicating the first time gap may be used together with higher layer signaling to indicate the first time gap. For example, before the network device sends the first configuration information to the first terminal device, the network device sends second configuration information to the first terminal device, the second configuration information is used to configure a time gap set, and the first time gap is one time gap in the time gap set.

[0321] For ease of understanding, with reference to (a) to (c) of Figure 11, a brief description will be given of how the first configuration information configures the first time gap between DCI#1 and the PSSCH used to transmit the first HARQ-ACK information.

[0322] From (a) of Figure 11, it can be seen that when the time gap timeGap between DCI#1 and PSSCH is equal to 2 and the first terminal device receives PSSCH in the second slot after DCI#1, the first terminal device sends the first HARQ-ACK information corresponding to PDSCH#1 scheduled by using DCI#1.

[0323] From Figure 11(b), it can be seen that the SCS of the first link is 15 kHz, the duration of each slot is 1 ms, and the SCS of the second link is 30 kHz, the duration of each slot is 0.5 ms. If timeGap = 2 slots and the SCS of the second link is used as the reference for timeGap, after PDSCH is received in D1, transmission is performed on PSSCH, which is 2 slots away from D1 on the second link (i.e., the 6th S slot).

[0324] From (c) of Figure 11, it can be seen that if the SCS of the first link is used as a reference for the timeGap, i.e., timeGap = two slots on the first link, after receiving the PDSCH in slot D0 on the first link, the first terminal device transmits HARQ-ACK information for the PDSCH on the PSSCH in a slot on the second link that is two slots away from D0 on the first link. As shown in (c) of Figure 11, the slot separated from D0 by two slots on the first link, i.e., slot D2, corresponds to two slots on the second link. For example, in this scenario, the first slot on the second link corresponding to D2 is used to transmit HARQ-ACK information for the PDSCH.

[0325] Note that the slots on the first link may not be aligned with the slots on the second link as shown in the figure. For example, the first S slot in Figure 11 may be slightly later than slot D0. In this case, the terminal device (e.g., the first terminal device or the second terminal device) may report a timing alignment quantity to the network device to determine the difference between the slots on the second link and the slots on the first link, so that the network device and the terminal device are synchronized in the slots on the first link and the second link.

[0326] Furthermore, timeGap may reuse the existing sl-minTimeGapPSFCH (the minimum gap between a PSFCH and an associated PSSCH, which is typically two or three slots). When this parameter is reused, the parameter no longer indicates the slot gap between the PSFCH and PSSCH, but may be used to indicate the minimum slot gap between the PSSCH and PDSCH (or DCI or PDCCH), i.e., the PSSCH carrying HARQ-ACK information for the PDSCH can be determined by using the PDSCH (or DCI) and the sl-minTimeGapPSFCH parameter.

[0327] For example, if the first transmission resource is a PSFCH, the first configuration information may be used to configure a first time gap between DCI#1 and the PSFCH used to transmit the first HARQ-ACK information. For example, the network device configures the first time gap by sending higher layer signaling (e.g., an RRC message). The first time gap may be measured in slots or in milliseconds.

[0328] After receiving PDSCH#1, the first terminal device may also use PSFCH to transmit the first HARQ-ACK information of PDSCH#1, which is the same as the PSSCH above. When the first HARQ-ACK information of PDSCH#1 is transmitted using PSFCH, the resource and slot position of PSFCH also need to be indicated.

[0329] First, the network device semi-statically configures the time gap between the PSFCH carrying the first HARQ-ACK information of PDSCH#1 and PDSCH#1 by using higher layer signaling (e.g., RRC message). For example, a new parameter, timeGap, is introduced into the higher layer signaling (RRC message) to determine the time gap between the PSFCH and PDSCH#1 (or DCI#1). The unit may be a slot, etc.

[0330] Alternatively, the network device may reuse sl-minTimeGapPSFCH in the PSFCH configuration in existing higher layer signaling, where sl-minTimeGapPSFCH indicates the minimum gap between the PSFCH and PDSCH#1 (or DCI#1).

[0331] For ease of understanding, how the first configuration information configures the first time gap between DCI#1 and the PSFCH used to transmit the first HARQ-ACK information will be briefly described with reference to Figure 12. It can be seen from Figure 12 that timeGap = 2 slots.

[0332] In this implementation, similar to the above description where the first transmission resource is the PSSCH, it should be understood that the unit of timeGap can alternatively be another time unit, for example, milliseconds. When the first time gap is measured in slots, the subcarrier spacing (SCS) corresponding to the number of slots in the first time gap needs to be further determined. The timeGap can use the SCS of the first link as a reference or the SCS of the second link as a reference. In FIG. 12, the SCS of the first link and the second link are the same, for example, both are 30 kHz, timeGap=2 slots, and the PSFCH period is also two slots. Therefore, the HARQ-ACK information of the PDSCH transmitted in DO and D1 can be the first PSFCH at least two slots apart, i.e., the PSFCH in the fourth slot. For D2 and D3, transmission is performed on the first PSFCH at least two slots apart, i.e., the PSFCH in the sixth slot.

[0333] Furthermore, after determining the first time gap, the first terminal device further needs to determine a first transmission resource specifically used for transmitting the first HARQ-ACK information, where the first transmission resource includes a first time domain resource and a first frequency domain resource, and the first time domain resource is a time domain resource of a first time unit.

[0334] Referring to Scheme 3.1 and Scheme 3.2, the following describes in detail how the first terminal device determines the first time domain resource and the first frequency domain resource in this embodiment when the first transmission resource is a PSSCH and a PSFCH.

[0335] Scheme 3.1: The first transmission resource is a PSSCH (as shown in (a) to (c) of FIG. 11). In this implementation, the first terminal device determining the first time domain resource and the first frequency domain resource includes:

[0336] S1021: The network device sends third configuration information to the first terminal device. In other words, the first terminal device receives third configuration information from the network device. Before sending PDSCH#1 to the first terminal device, the network device sends the third configuration information to the first terminal device, where the third configuration information indicates a first time domain resource and a first frequency domain resource.

[0337] In particular, the third configuration information is used to configure the PSSCH. For example, the frequency domain resource configured by using the third configuration information may include a subchannel number (sl-NumSubchannel) indicating the number of subchannels, a subchannel size (sl-SubchannelSize) indicating the number of consecutive PRBs included in one subchannel, a subchannel start RB index (sl-StartRB-Subchannel) indicating the start PRB index of the first subchannel in the resource pool, and a PSCCH frequency domain resource indicator (sl-FreqResourcePSCCH) indicating the frequency domain resource of the PSCCH corresponding to the PSSCH, for example, the size of the frequency domain resource of the PSCCH. For example, the value range is {10, 12, 15, 20, 25} PRB.

[0338] For example, the frequency domain resource configured by using the third configuration information includes at least a start symbol (sl-StartSymbol) and a number of symbols (sl-LengthSymbols) of the PSCCH in the PC5 slot. Optionally, the third configuration information may further configure a time domain resource (sl-TimeResourcePSCCH) of the PSCCH to indicate the number of symbols occupied by the PSCCH.

[0339] Optionally, the third configuration information is an RRC message.

[0340] Furthermore, in the case shown in Scheme 3.1, the first terminal device sending the first HARQ-ACK information to the second terminal device through the second link includes:

[0341] The first terminal device sends a MAC CE to the second terminal device on a first transmission resource on the second link, and the MAC CE includes the first HARQ-ACK information. For a specific implementation, refer to the embodiment shown in Figure 8 in which the first terminal device sends a MAC CE to the second terminal device. Details will not be described again here.

[0342] Scheme 3.2: The first transmission resource is a PSFCH (as shown in FIG. 12). In this implementation, the first terminal device's determining the first time domain resource and the first frequency domain resource includes:

[0343] S1022: The first terminal device determines a first frequency domain resource based on a first quantity, where the first quantity is a quantity M of downlink data included in a first downlink data set to which the first downlink data belongs, and M pieces of HARQ-ACK information corresponding to the M pieces of downlink data are all transmitted on the PSFCH, and M is a positive integer.

[0344] It should be understood that in this application, the example in which one downlink data corresponds to one HARQ-ACK information is mainly used for explanation. In some cases, one downlink data may correspond to multiple HARQ-ACK information. In other words, M downlink data may correspond to L HARQ-ACK information, where L is a positive integer equal to or greater than M. If one downlink data corresponds to multiple HARQ-ACK information, the first quantity in this embodiment should be replaced with L.

[0345] As shown in Figure 12, each PSFCH may transmit HARQ-ACK information for two or more PDSCHs, so the problem of how to allocate PRBs in one PSFCH to transmit HARQ-ACK information for multiple PDSCHs needs to be further solved.

[0346] It should be understood that a prerequisite for determining how to allocate PRBs in one PSFCH to transmit HARQ-ACK information of multiple PDSCHs is to determine the quantity of HARQ-ACK information of PDSCHs that can be transmitted through one PSFCH. In particular, in this embodiment, the following schemes (Scheme 3.2.1, Scheme 3.2.2, and Scheme 3.2.3 below) are provided for determining the quantity of HARQ-ACK information of PDSCHs that are transmitted through one PSFCH.

[0347] Scheme 3.2.1: The quantity of HARQ-ACK information for PDSCHs that can be transmitted on each PSFCH (also called the PDSCH transmission opportunity set or the quantity of PDSCH transmission opportunities) is determined based on the PSFCH period and the SCS of the first link and the second link.

[0348] In the case shown in scheme 3.2.1, the quantity of HARQ-ACK information of PDSCH that can be carried in each PSFCH depends on the PSFCH period and the SCS of the first link and the second link. In particular, the following steps are included:

[0349] Step 1: Determine the slot position of a PDSCH corresponding to one PSFCH based on a first time gap (timeGap or sl-minTimeGapPSFCH). Using FIG. 12 as an example, timeGap=2 slots, and the PDSCH corresponding to one PSFCH is at least two slots away from the PSFCH. For example, the earliest slot of the PDSCH corresponding to the second PSFCH is D1 (in other words, the PSFCH carries HARQ-ACK information for the PDSCH transmitted in and before slot D1), and the third PSFCH carries HARQ-ACK information for the PDSCH transmitted in and before slot D3.

[0350] Step 2: PSFCH period

[0351]

number

[0352] A first quantity M of HARQ-ACK information for PDSCHs transmitted on the PSFCH may be determined according to a PDSCH transmission opportunity set (hereinafter denoted as M)

[0353]

number

[0354] 12 as an example, according to step 1, it may be determined that the slot corresponding to the second PSFCH is calculated from D1 in advance, and then according to the PSFCH period being 2, it may be determined that the HARQ-ACK information of the PDSCH in the slot of the first link corresponding to the two slots of the second link is transmitted on the PSFCH, that is, the PDSCH transmission opportunity set corresponding to one PSFCH in FIG.

[0355]

number

[0356] is.

[0357] Furthermore, since the SCS of the first link and the second link may be different, the PDSCH corresponding to the PSFCH may not be equal to the PSFCH period.

[0358] For example, as shown in Figure 13(a), the SCS of the first link is half that of the second link. For example, the SCS of the first link is 30 kHz, and the SCS of the second link is 60 kHz. When the timeGap is two second link slots and the PSFCH period is 2, one PSFCH corresponds to a transmission opportunity in only one downlink slot. Alternatively, when the timeGap is two PC5 slots and the PSFCH period is 4, one PSFCH corresponds to a transmission opportunity in two downlink slots.

[0359] For example, as shown in Figure 13(b), the SCS of the first link is twice that of the second link. For example, the SCS of the first link is 60 kHz, and the SCS of the second link is 30 kHz. It is still used as an example that the time gap is two slots of the second link. In this case, one PSFCH corresponds to PDSCH transmission opportunities in four downlink slots.

[0360] It should be understood that the number of downlink slots corresponding to one PSFCH does not represent the PDSCH transmission opportunity set. Referring to the related description of Table 1, there may be two or more PDSCHs in one slot. Therefore, the number of downlink slots corresponding to one PSFCH may not be exactly equal to the size of the PDSCH transmission candidate set M. Using (b) of FIG. 13 as an example, when multiple, for example, X=2 PDSCHs can be transmitted in one downlink slot, the size of the PDSCH transmission candidate set M for one PSFCH is:

[0361]

number

[0362] Furthermore, since configurations such as uplink slots and flexible slots exist in Uu, it can be seen in FIG. 13(b) that the third PSFCH corresponds to only three downlink slots. In this case, the PSFCH may construct a HARQ codebook for transmitting PDSCHs only for three downlink slots. It should be understood that each PSFCH may correspond to a different quantity of PDSCH transmission candidates.

[0363] In some cases, for example, when each DCI schedules only one PDSCH, the PDSCH transmission opportunity set corresponding to each PSFCH is given by the formula

[0364]

number

[0365] where X represents the number of PDSCHs that can be transmitted in each slot. For example, when only Type A PDSCH mapping scheme is supported, X=1. Furthermore, u PC5 and u Uu As shown in Table 3, PC5 and Uu2 represent the subcarrier configurations, respectively.

[0366] [Table 3]

[0367] Scheme 3.2.2: The HARQ-ACK information of the PDSCH that may be transmitted on each PSFCH is determined based on the configuration of higher layer signaling.

[0368] In the case shown in scheme 3.2.2, the quantity of PDSCH HARQ-ACK information carried in each PSFCH depends on the configuration of higher layer signaling. In particular, the above basic concept describes that in the case of PUCCH, the quantity of PDSCH that can be transmitted by PUCCH depends on higher layer signaling, for example, dl-DataToULACKr16. This parameter usually includes several slot offsets and is used to determine the time gap between PUCCH and PDSCH.

[0369] In particular, in this embodiment, the network device configures a time gap set including a first time gap for the first terminal device by using higher layer signaling. The time gap set includes at least one element, and each element is a positive integer and corresponds to one time gap. The unit may be a slot. Therefore, the quantity of HARQ-ACK information of the PDSCH that can be transmitted on the PSFCH can be determined based on the slot position of the PSFCH and the above time gap set.

[0370] For example, the PDSCH-to-PSFCH time gap list contains three elements: {2, 3, 5}. For the PSFCH, the PDSCHs corresponding to the second, third, and fifth slots before the slot in which the PSFCH is located form the PDSCH transmission opportunity set, as shown in Figure 14.

[0371] 14, based on the PDSCH-to-PSFCH time gap set, the HARQ-ACK information of the PDSCH that may be transmitted on the third PSFCH is the PDSCH received in DO, D2, and D3, and the HARQ-ACK information of the PDSCH that may be transmitted on the fourth PSFCH is the PDSCH received in D2, U, and D4. Because U is an uplink slot in which PDSCH cannot be transmitted, U may not be included in the HARQ-ACK information of the PDSCH that may be transmitted on the fourth PSFCH.

[0372] Manner 3.2.3: The network device sends fourth information to the first terminal device, where the fourth information indicates a first quantity M of downlink data in the first downlink data set, which is a PDSCH transmission opportunity set

[0373]

number

[0374] The first terminal device determines the quantity of HARQ-ACK information of the PDSCH that can be transmitted on each PSFCH based on the fourth information. For example, the network device explicitly indicates the DAI by using DCI. For the transmission opportunity index, refer to the DAI information in the DCI, and the DAI can be directly reused as the PDSCH transmission opportunity index.

[0375] After the number of PDSCH transmission opportunities is determined, the HARQ-ACK information of the PDSCH can be fed back in the manner of a dynamic or semi-static codebook.

[0376] In a possible implementation, the HARQ-ACK information of the PDSCH may be transmitted on the second link in a dynamic codebook manner, or when the DCI explicitly indicates the accumulation index of each DCI (or PDSCH), the PRB allocation scheme of the PSFCH may be determined based on the indication information of the DCI. Figure 14 is used as an example. The transmission set of the PDSCH corresponding to one PSFCH includes three candidates. However, if the first terminal device determines based on the DCI indication information that two DCIs (or PDSCHs) are received, the PRBs of the PSFCH may be divided based on the actual situation, i.e., two PDSCHs.

[0377] In another possible implementation, the HARQ-ACK information of the PDSCH may be transmitted on the second link in a semi-static codebook manner. For example, when the DCI does not explicitly indicate the respective accumulation indexes of the DCI, the PRBs of the PSFCH need to be divided based on the number of PDSCH candidates. For example, in FIG. 14, the third PSFCH includes three PDSCH transmission opportunities and is therefore used for HARQ of the three PDSCHs, and the fourth PSFCH includes two PDSCH transmission opportunities and is therefore used for HARQ-ACK information transmission of the two PDSCHs.

[0378] Note that in the case of two PSFCHs, the PDSCH in slot D2 is used as a transmission opportunity. In this case, the two PSFCHs need to reserve feedback PRBs for transmission opportunities in the slot. After decoding the PDSCH in slot D2, the first terminal device may simultaneously perform feedback on the two PSFCHs. Alternatively, the DCI explicitly indicates the time gap from the PDSCH to the PSFCH. For example, if the DCI for scheduling the PDSCH in D2 indicates that the time gap is 3, the HARQ-ACK information of the PDSCH in D2 is transmitted on the third PSFCH, and the NACK is fed back on the PSFCH PRB reserved for the slot on the fourth PSFCH.

[0379] Furthermore, note that the SCS of the first link and the second link in Figure 14 are the same. However, there may be cases where the SCS of the first link and the second link are different. When the SCS is different, there is no impact if the time gap is in time units such as ms. However, if the time gap is still measured in slots, it needs to be specified whether the slot on the first link or the slot on the second link is used when the first time gap is measured in slots.

[0380] When the first time gap uses the first link as a reference, using FIG. 15(a) as an example, if the SCS of the second link is greater than the SCS of the first link, the slot on the first link corresponding to the last PSFCH is n sl , for example, D4, the corresponding PDSCH transmission opportunity slots are D0, D2, and D3, respectively. sl -2, n sl -3, and n sl -5. n sl -2 is the starting point sl can be understood as a forward offset of two slots by using sl -3 is the starting point sl can be understood as a forward offset of three slots by using n sl -5 is the starting point sl Using FIG. 15(b) as an example, the SCS of the second link is smaller than the SCS of the first link, and the slot on the first link corresponding to the last PSFCH is n sl , for example, D8, and the corresponding PDSCH transmission opportunity slots are D5, D7, and U, respectively. sl -2, n sl -3, and n sl −5, where U is an uplink slot and may not be included in the PDSCH transmission opportunity.

[0381] When the second link is used as a reference for the first time gap, a time gap list of {2,3,5} is still used as an example, as shown in Figure 16(a) (the SCS of the second link is larger than that of the first link) and Figure 16(b) (the SCS of the second link is smaller than that of the first link). In Figure 16(a), using the last PSFCH as an example, the PDSCH slot corresponding to the last PSFCH is U (when the gap is 2 or 3) and D3 (when the gap is 5). In Figure 16(b), the PDSCH slots corresponding to the last PSFCH are D5 and D6 (when the gap is 2), D4 and U (when the gap is 3), and D0 and D1 (when the gap is 5). Therefore, when PC5 is used as a reference, the number of slots corresponding to the PDSCH time gap list candidates corresponding to each PSFCH is

[0382]

number

[0383] For example, in FIG. 16(a), using an example where Uu SCS is 15 kHz (uUL=0) and PC5 SCS is 30 kHz (uSL=1), each candidate in the time gap list corresponds to one slot. In FIG. 16(b), using an example where Uu SCS is 30 kHz (uUL=1) and PC5 SCS is 15 kHz (uSL=0), the PDSCH time gap list candidates corresponding to each PSFCH are

[0384]

number

[0385] is.

[0386] After the HARQ codebook size is determined for the PSFCH, the frequency domain resource for the HARQ-ACK information of each PDSCH needs to be determined. For example, the PSFCH PRB used to transmit the HARQ-ACK information of the PDSCH can be configured separately or shared with the PSSCH, including the following two schemes (Scheme 4.1 and Scheme 4.2 below).

[0387] Scheme 4.1: The PSFCH PRB used for transmitting the HARQ-ACK information of the PDSCH is configured separately, that is, the first transmission resource is dedicated to transmitting the HARQ-ACK information of the downlink data.

[0388] In particular, the network device configures the frequency domain resources, e.g., PRB resources, used to carry the PDSCH by using higher layer signaling (e.g., RRC messages). For example, parameter #1, such as the sl-PSFCH-RB-Set-PDSCH parameter, is added to the higher layer signaling to configure the resource (denoted as K below).

[0389]

number

[0390] 1 indicates a PRB for transmitting HARQ-ACK information of a PDSCH indicated as

[0391] In a possible implementation, parameter #1 may be in the form of a bitmap, as shown below: sl-PSFCH-RB-Set-PDSCH BIT STRING(SIZE(10...275))

[0392] The bit string represents a bitmap, and the length of the bit string can be 10 to 275 bits. Each bit indicates whether the PRB at the corresponding position can be used for the PSFCH, and the calculation starts from the least significant bit RB index of the resource pool. Bit "0" indicates that the corresponding PRB is not used for the PSFCH, and bit "1" indicates that the corresponding PRB is used for the PSFCH.

[0393] For example, the parameter includes 10 bits, i.e., an individual PSFCH may include 10 consecutive PRBs calculated from the least significant bit PRB index of the resource pool in which the PSFCH is located, but not all PRBs may be used for the PSFCH. For example, when the 10 bits are "1100111000", it indicates that the third, fourth, eighth, ninth, and tenth PRBs among the 10 consecutive PRBs calculated from the least significant bit PRB index of the resource pool in which the PSFCH is located are not used for the PSFCH, or the PSFCH does not include these PRBs.

[0394] For example, the left side (or most significant bit (MSB)) in the bit sequence corresponds to the index of the smallest PRB in the resource pool. The resource pool in which the PSFCH is located may be determined by using another parameter, for example, configured by using sl-ResourcePool signaling in the base station's RRC message, and sl-PSFCH-RB-Set-PDSCH may be used as the signaling parameter.

[0395] Compared to the PSFCH index depending on the index of the smallest RB in the resource pool, the RB index of an independently configured PSFCH can also be calculated starting from the largest RB index of the existing PSFCH resources, i.e., in the frequency domain, the smallest RB index of the PRB of the PSFCH used to transmit HARQ-ACK information of the PDSCH is larger than the largest RB index of the PSFCH used to carry HARQ-ACK information of the PSSCH.

[0396] For example, the smallest RB index of the PRB of the PSFCH for transmitting the HARQ-ACK information of the PDSCH is the next adjacent index of the largest RB index of the existing PSFCH for carrying the HARQ-ACK information of the PSSCH. For example, the number of RBs allocated to the existing PSFCH is 100, that is, 100 bits are used to indicate the RB index of the PSFCH, for example, from 0 to 99, respectively. The index used to carry the HARQ-ACK information of the PDSCH may start from the RB with index 100. In this case, the PSFCH carrying the HARQ-ACK information of the PDSCH may also use the above bitmap format, but the starting reference position of the index is changed. In this case, the PRBs of the PSFCH may be discontinuous.

[0397] In another possible implementation, the PSFCH carrying the HARQ-ACK information for the PDSCH is configured as a group of consecutive PRBs as shown below. sl-PSFCH-RB-Set-PDSCH ENUMERATED{10,20,30,40,50,60,70,...} OPTIONAL

[0398] Each of 10, 20, etc. represents the quantity of RBs available for the PSFCH and may indicate a segment of contiguous RBs. The starting index of the RBs is the next value after the highest index of the RBs of the PSFCH for transmitting PSSCH HARQ (if configured), or is calculated starting from the smallest index in the resource pool, e.g., 0.

[0399] After the PRB resource of the PSFCH is determined, the PRB resource corresponding to each PDSCH in the PDSCH in which HARQ-ACK information is transmitted through the same PSFCH may be further determined, including the following steps:

[0400] Step 1: According to the above description, for each PSFCH used to carry HARQ-ACK information of a PDSCH, a PDSCH transmission opportunity set M corresponding to the PSFCH may be obtained (e.g., the transmission opportunity set M is determined by the above scheme 3.2.1, scheme 3.2.2, or scheme 3.2.3).

[0401] Step 2: The PSFCH resource (PRB) K is divided into multiple PRB subsets based on the PDSCH transmission opportunity set, and each PRB subset is used to transmit PDSCH HARQ-ACK information in one PDSCH set.

[0402] Step 3: The PRB subset (denoted as N below) occupied by each PDSCH

[0403]

number

[0404] is the expression

[0405]

number

[0406] where:

[0407]

number

[0408] is the floor operation.

[0409] For example, as shown in Figure 17, if the total number of PRBs of the PSFCH for transmitting HARQ-ACK information of the PDSCH is configured as K = 10 according to higher layer signaling and the PDSCH transmission opportunity set is M = 2, each PDSCH transmission opportunity may correspond to 5 PRBs. Alternatively, no rounding operation may be performed, and N = K / M. In this case, M is required to be divisible by K.

[0410] Since only one PRB is required to transmit the HARQ-ACK information of a PDSCH, when multiple PRBs of a PSFCH are used to transmit the HARQ-ACK information of one PDSCH, the PRB in which one bit of the HARQ-ACK information is located is designated.

[0411] In a possible implementation, it may be specified that the HARQ-ACK information of the PDSCH is in the PRB with the smallest index number in the PRB subset. For example, the HARQ-ACK information of PDSCH 0 is transmitted on PRB 0, and the HARQ-ACK information of PDSCH 1 is transmitted on PRB 5. In this way, PRB 0 and PRB 5 are separated by four PRBs, thereby effectively avoiding interference with the decoding of the PSFCH caused by in-band leakage.

[0412] In another possible implementation, the HARQ-ACK information of the PDSCH may alternatively be in the PRB with the highest index number in each PRB subset.

[0413] In another possible implementation, the HARQ-ACK information of the PDSCH may alternatively be in a random PRB in each PRB subset, in which case the receiving end needs to blindly detect each PRB in the PRB subset of each PSFCH to determine whether HARQ-ACK information is present.

[0414] Optionally, in step 3, N may alternatively be obtained in another manner, for example, M is a PDSCH transmission opportunity set, K is a PRB set for transmitting HARQ-ACK information of the PDSCH, M=K / M modulo is defined, K is ceil(K / M2), K is floor(K / M2), and M=min(M,K).

[0415] For the m-th PDSCH transmission opportunity, when M>0, where m is an integer from 1 to M, the PRB index number corresponding to the HARQ-ACK information of the m-th PDSCH is (m-1)*K to m*K, It should be understood that the index number is a relative index number in the PRB set.

[0416] When the value of m is any integer between M1+1 and M, the PRB index number for HARQ feedback during the mth PDSCH transmission opportunity is M1*K1+(m-M1-1)*K2+k2 (the value of k2 is an integer between 0 and K2-1), i.e., M1*K1+(m-M1-1)*K2 to M1*K1+(m-M1-1)*K2+K2-1.

[0417] For example, M=3 and K=11 are used as an example, with M2=3, M1=2, K1=4, and K2=3. Since M1>0, for the first to M1 PDSCH transmission opportunities, the corresponding PRB relative index numbers are (m-1)*K1 to m*K1-1. For example, for the (m=1) PDSCH, the PRB relative index numbers are 0 to 3. When m=2, the PRB index numbers are 4 to 7. When m=3, the PRB relative index numbers are M1*K1+(m-M1-1)*K2 to M1*K1+(m-M1-1)*K2+K2-1, i.e., 8 to 10.

[0418] Note that the index may be a relative index value rather than an absolute index value of the PRB. For example, when the configured PSFCH PRB indexes include 11 PRBs 10, 11, 12, 15, 16, 17, 25, 35, 54, 76, and 99, the index 0 in the above formula may be understood as 10 here, and the index 5 in the above formula may be understood as 17 here, i.e., the PRBs of the first PDSCH are 10, 11, 12, and 15, and so on.

[0419] Optionally, if M2 = M, then min(M,K) = M. In the case shown in Scheme 4.1, M, the number of first resource blocks, and the number of second resource blocks satisfy the following relationship and the following possible implementations concluded:

[0420] In a possible implementation, M, the number of first resource blocks, and the number of second resource blocks satisfy the following relationship:

[0421]

number

[0422] where N represents the number of second resource blocks, K represents the number of first resource blocks,

[0423]

number

[0424] represents a floor operation, and the N resource blocks corresponding to the m-th downlink data among the M downlink data are the resource blocks with indexes (m-1)*N to m*N-1 among the K resource blocks; or or M, the number of first resource blocks, and the number of second resource blocks satisfy the following relationship:

[0425]

number

[0426] where M is divisible by K, and the N resource blocks corresponding to the m-th downlink data among the M downlink data are the resource blocks with indices (m-1)*N to m*N-1 among the K resource blocks; or or In the case where M1>0, when m is any integer from 1 to M1, the N resource blocks corresponding to the m-th downlink data among the M downlink data are the resource blocks with indexes (m-1)*K1 to m*K1-1 among the K resource blocks, or when m is any integer from M1 to M, the N resource blocks corresponding to the m-th downlink data among the M downlink data are the resource blocks with indexes [M1*K1+(m-M1-1)*K2] to [M1*K1+(m-M1-1)*K2+K2-1] among the K resource blocks, or When M1=0, the N resource blocks corresponding to the m-th downlink data among the M downlink data are the [M1*K1+(m-M1-1)*K2]-th resource block to the [M1*K1+(m-M1-1)*K2+K2-1]-th resource block among the K resource blocks, where: K1 is

[0427]

number

[0428] and K2 is

[0429]

number

[0430] and M1 is

[0431]

number

[0432] is the remainder of

[0433]

number

[0434] is the ceiling operation.

[0435] The PSFCH PRB corresponding to each PDSCH transmission opportunity may be determined by using the above steps. However, it should be understood that the PDSCH transmission opportunity does not necessarily indicate that the network device will perform scheduling at these times. Therefore, there may be cases where the PDSCH does not appear during some PDSCH transmission opportunities (e.g., DCI is not detected, the network device does not send DCI, or the first terminal device fails to detect DCI). When the first terminal device correctly decodes the PDSCH during the PDSCH transmission opportunity, the first terminal device transmits an ACK on the corresponding PSFCH PRB; otherwise, when the first terminal device does not correctly decode the PDSCH during the PDSCH transmission opportunity (e.g., DCI is not received or the PDSCH fails to be decoded), the first terminal device transmits a NACK on the corresponding PSFCH PRB.

[0436] Scheme 4.2: The shared PSFCH is used to transmit HARQ-ACK information of the PDSCH and HARQ-ACK information of the PSSCH, i.e., the first transmission resource is used to transmit HARQ-ACK information of the downlink data and HARQ-ACK information of the sidelink data.

[0437] In this implementation, the PSFCH carrying the HARQ-ACK information of the PDSCH may be directly multiplexed with the resource pool of the PSSCH, i.e., the PSFCH and the PSSCH share a resource pool. In other words, for the PRBs of the PSFCH, the PRBs are allocated to the PDSCH and the PSSCH according to the PDSCH and PSSCH transmission opportunity sets.

[0438] Step 1: Number of subchannels corresponding to one PSFCH slot

[0439]

number

[0440] Determine.

[0441] Step 2: A PDSCH transmission opportunity set (which may be denoted as M below) corresponding to one PSFCH slot

[0442]

number

[0443] Determine.

[0444] Therefore, each PSSCH subchannel / PDSCH transmission opportunity is

[0445]

number

[0446] where:

[0447]

number

[0448] is the number of configured PSFCH PRBs (denoted as K below), or each PSSCH subchannel / PDSCH transmission opportunity is

[0449]

number

[0450] In this case,

[0451]

number

[0452] teeth,

[0453]

number

[0454] It is required that it be divisible by

[0455] Step 3: Allocate PRBs from low index to high index in the sequence of first PSSCH, then PDSCH (or first PDSCH, then PSSCH). For example, the PSFCH PRB set includes 12 PRBs corresponding to two PSSCH subchannels and two PDSCH transmission opportunities. As shown in Figure 18, each PSSCH subchannel / PDSCH transmission opportunity corresponds to three PRBs, where PRBs 0 to 5 are used to transmit HARQ-ACK information for PSSCH, and PRBs 6 to 11 are used to transmit HARQ for PDSCH.

[0456] Optionally, in the case shown in Scheme 4.2, M, the first resource block quantity, the second resource block quantity, and the second quantity satisfy the following relationship:

[0457]

number

[0458] where N represents the second number of resource blocks, K represents the first number of resource blocks, and A represents a second number, which is for sidelink data and is the number of HARQ-ACK information transmitted on the PSFCH;

[0459]

number

[0460] represents a floor operation, and N resource blocks corresponding to m-th downlink data among M downlink data and A sidelink data are resource blocks with indices (m-1)*N to m*N-1 among K resource blocks; or or M, the number of first resource blocks, the number of second resource blocks, and the second number satisfy the following relationship:

[0461]

number

[0462] where M+A is divisible by K, and the N resource blocks corresponding to the m-th downlink data among the M downlink data and the A sidelink data are the resource blocks with indices (m-1)*N to m*N-1 among the K resource blocks; or or In the case where M1>0, when m is any integer from 1 to M1, the N resource blocks corresponding to the m-th downlink data among the M downlink data and the A sidelink data are the resource blocks with indices (m-1)*K1 to m*K1-1 among the K resource blocks, or when m is any integer from M1 to M, the N resource blocks corresponding to the m-th downlink data among the M downlink data are the resource blocks with indices [M1*K1+(m-M1-1)*K2] to [M1*K1+(m-M1-1)*K2+K2-1] among the K resource blocks, or When M1=0, the N resource blocks corresponding to the m-th downlink data among the M downlink data and the A sidelink data are the [M1*K1+(m-M1-1)*K2]-th resource block to the [M1*K1+(m-M1-1)*K2+K2-1]-th resource block among the K resource blocks, where K1 is

[0463]

number

[0464] and K2 is

[0465]

number

[0466] and M1 is

[0467]

number

[0468] is the remainder of

[0469]

number

[0470] is the ceiling operation.

[0471] The resource configuration methods shown in Figures 8 and 10 mainly consider the case where a first terminal device transmits HARQ-ACK information of a PDSCH to a second terminal device through PC5. For example, only one XR glass transmits HARQ-ACK information of a PDSCH through PC5.

[0472] Furthermore, in a scenario where multiple first terminal devices are within a certain range and need to transfer HARQ-ACK information for PDSCHs through PC5, the network device may separately schedule PDSCHs for the multiple first terminal devices in the same slot through the first link, and the multiple first terminal devices may transmit PSFCHs on the same PRB in the same PSFCH subset. Therefore, interference occurs, and the receiving end cannot recover information sent by any of the first terminal devices. Transmission interference between the multiple first terminal devices can be avoided in the following manner.

[0473] In a possible implementation, the network device configures a different individual PSFCH PRB for each of a plurality of first terminal devices, and the PSFCH PRBs are unrelated to each other. When the number of first terminal devices that require PC5 to transmit HARQ-ACK information of the PDSCH increases, the number of required PRBs also increases, which may result in wasted PRB resources.

[0474] In another possible implementation, the network device semi-statically configures a PRB index for each first terminal device by using higher layer signaling to indicate the PRB in the PSFCH PRB subset on which the HARQ-ACK information of the PDSCH is transmitted by the first terminal device. For example, in FIG. 17, the network device separately schedules PDSCHs for UE#0 and UE#1 in slot D0. If the PRB index of UE#0 is configured as 0 and the PRB index of UE#1 is configured as 2 by using higher layer signaling, it is determined based on the PRB index that the HARQ-ACK information of the PDSCH of UE#0 is transmitted on PRB0 and the HARQ-ACK information of the PDSCH of UE#1 is transmitted on PRB2.

[0475] In another possible implementation, the HARQ-ACK information of the PDSCHs of multiple first terminal devices can be transmitted by using a group of PRBs in a code division multiplexing manner. The SCI for sending the PSSCH indicates the PID and MID, which respectively indicate the IDs of the transmitting UE and the receiving UE. The PRB index is expressed by the formula

[0476]

number

[0477] and determine the position of the PRB corresponding to the HARQ-ACK information of the PSSCH.

[0478] However, since there is no SCI when the PSFCH corresponding to the PDSCH is sent, the PID and MID cannot be determined according to the prior art.

[0479]

number

[0480] cannot be obtained. Therefore, the method needs to be modified. For example, compared with the method of obtaining the PRB index by using a formula, the higher layer signaling may semi-statically configure the PRB index for each first terminal device, and the index may directly indicate the PRB on which the HARQ-ACK information of the PDSCH of the UE is transmitted.

[0481] For example, the network device adds a parameter indicating a PSFCH PRB index, e.g., sl-PDSCH-to-PSFCH-PRB-Index, for the first terminal device by using higher layer signaling (e.g., RRC signaling), and determines, first in the frequency domain and then in the code domain, that the fifth PRB in the PRB set is used to carry HARQ-ACK information feedback for the glass PDSCH.

[0482] For example, Figure 19 is used as an example. When sl-PDSCH-to-PSFCH-PRB-Index=5, the PRB with index 5 (i.e., PRB 01) is used to transmit HARQ-ACK information of the PDSCH in a sequence first in the frequency domain and then in the code domain. Furthermore, the code domain size in Figure 19

[0483]

number

[0484] , ...

[0485] When the sl-PDSCH-to-PSFCH-PRB-Index is also configured for the second terminal device, the second terminal device may determine the PSFCH PRB on which detection is performed based on the parameter, thereby preventing the second terminal device from blindly detecting all PRBs. Because there may be a scenario in which one second terminal device forwards HARQ-ACK information of PDSCHs of multiple first terminal devices, the sl-PDSCH-to-PSFCH-PRB-IndexList may be configured for the second terminal device to indicate multiple PRB indexes, and the second terminal device may determine the PRB for transmitting the HARQ-ACK information of PDSCH based on an indication of the list.

[0486] In another possible implementation, the HARQ-ACK information of the UE's PDSCH is multiplexed into the same group of PSFCH in a CDM manner.

[0487] First, the network device uses upper layer signaling to determine a PSFCH transmission resource of the PSFCH for the first terminal device.

[0488]

number

[0489] and cyclic shift pair

[0490]

number

[0491] and configure the PSFCH transmission resource set

[0492]

number

[0493] , i.e., determine the total number of available PRB resources. As shown in Figure 20,

[0494]

number

[0495] PRBs are configured for one PSFCH to transmit HARQ data for PDSCH, and the number of cyclic shift pairs is

[0496]

number

[0497] is configured by using higher layer signaling. Therefore, the total number of PDSCHs that can be used to transmit HARQ-ACK information is

[0498]

number

[0499] There are transmission resources, and the transmission resources correspond to PRB index numbers from 0 to 29. For example, sorting is performed first in the frequency domain and then in the time domain.

[0500] For example, the network device configures an index for each first terminal device to transmit HARQ-ACK information of the PDSCH, and the PDSCH of the first terminal device is transmitted on a PRB corresponding to the index.

[0501] Alternatively, considering that one PSFCH corresponds to multiple PDSCH transmission opportunities, a group of indices or an index list may be configured, and the number of elements in the list may correspond to the number of elements in the PDSCH transmission opportunity set, and thus each PDSCH has a corresponding PRB index.

[0502] Alternatively, the number of elements in the list is not limited, and the PDSCH transmission opportunities then correspond to the indexes in the list. For example, the number of PDSCH transmission opportunities is three, and the index list includes two indexes. Thus, the first PDSCH transmission opportunity corresponds to the first index in the index list, the second PDSCH corresponds to the second index, and then the third PDSCH corresponds to the third index.

[0503] Alternatively, the PRB corresponding to each PDSCH transmission opportunity is determined based on information such as the transmitting UE ID and the receiving UE ID. Each PSFCH may correspond to multiple PDSCH transmission opportunities. Therefore, the PDSCH transmission opportunity also needs to be considered in PRB selection.

[0504] In the scenario of FIG. 2, the PRB corresponding to the PDSCH transmission opportunity of any XR glass is determined by the ID of the XR glass, the ID of the mobile phone, and the PDSCH transmission opportunity.

[0505] In particular, the PDSCH transmission opportunities may be determined in a semi-static manner as shown in scheme 3.2.1 above. For example, after the PDSCH transmission opportunity set is determined according to the PSFCH period and the SCS of Uu and PC5, sorting is performed based on the sequence (e.g., a time sequence that may be a descending or ascending order of the time gap from the PSFCH), and corresponding indexes are assigned.

[0506] Alternatively, the PDSCH transmission opportunity may be determined based on higher layer signaling, as shown in scheme 3.2.2 above. For example, the PDSCH transmission opportunity set is determined based on the time gap between the PDSCH and the PSFCH, and then the corresponding index is allocated.

[0507] Alternatively, the PDSCH transmission opportunity may be indicated by the network device by using the fourth information shown in scheme 3.2.3 above. For example, when the DCI explicitly indicates the DAI, the transmission opportunity index may refer to the DAI information in the DCI. For example, the DAI may be directly reused as the PDSCH transmission opportunity index.

[0508] XR Glass TID (T ID (shown as) ID and mobile phone (R ID The ID (denoted as T ) may be obtained by using higher layer signaling. For example, the network device configures the IDs for the XR glasses and the mobile phone separately by using higher layer signaling (e.g., RRC messages), and the PRB index corresponding to the PDSCH is obtained by the formula (T ID +R ID +i PDSCH )mod

[0509]

number

[0510] where i PDSCH can be understood as the sequence number in the PDSCH transmission set.

[0511] It should be understood that the sequence numbers of the above processes do not mean the sequence of execution, and the sequence of execution of the processes should be determined according to the functions and internal logic of the processes, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0512] Furthermore, in the embodiments of the present application, unless otherwise specified or there is no logical conflict, the terms and / or descriptions between different embodiments are consistent and can be cross-referenced, and it should be understood that the technical features in different embodiments can be combined into new embodiments based on their internal logical relationships.

[0513] Furthermore, it should be understood that in some of the above embodiments, devices in existing network architectures are mainly used as examples (e.g., network devices or terminal devices) for explanation purposes. It should be understood that the specific form of the device is not limited in the embodiments of the present application. For example, all devices that can implement the same function in the future are applicable to the embodiments of the present application.

[0514] In the above method embodiments, it may be understood that the methods and operations implemented by a device (e.g., a network device or a terminal device) may also be implemented by a component (e.g., a chip or circuit) of the device.

[0515] The communication methods provided in the embodiments of the present application have been described in detail above with reference to Figures 7 to 20. The above communication methods are mainly described in terms of interactions between terminal devices and network devices. It can be understood that to implement the above functions, the terminal devices and network devices include corresponding hardware structures and / or software modules for performing the functions.

[0516] Those skilled in the art should recognize that, with respect to the exemplary units and algorithm steps described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is implemented by hardware or by hardware driven by computer software depends on a specific application and the design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but the implementation should not be deemed to go beyond the scope of the present application.

[0517] The communication device provided in this application will be described in detail below with reference to Figures 21 and 23. It should be understood that the description of the device embodiment corresponds to the description of the method embodiment. Therefore, for content that is not described in detail, please refer to the above method embodiment. For the sake of brevity, some content will not be described again.

[0518] In the embodiments of the present application, the transmitting end device or the receiving end device may be divided into functional modules according to the above-mentioned method example. For example, each functional module may be obtained through division based on its corresponding function, or two or more functions may be integrated into one processing module. The integrated module may be implemented in the form of hardware or in the form of a software functional module. It should be noted that the division into modules in the embodiments of the present application is an example and is merely a logical functional division. In actual implementation, there may be other division methods. An example in which each functional module is obtained through division based on its corresponding function is used below for explanation.

[0519] 21 is a block diagram of a communication device 10 according to an embodiment of the present application. The device 10 includes a transceiver module 11 and a processing module 12. The transceiver module 11 may implement corresponding communication functions. The processing module 12 is configured to perform data processing. In other words, the transceiver module 11 is configured to perform operations related to transmission and reception. The processing module 12 is configured to perform operations other than transmission and reception. The transceiver module 11 may also be referred to as a communication interface or a communication unit.

[0520] Optionally, the apparatus 10 may further include a storage module 13. The storage module 13 may be configured to store instructions and / or data. The processing module 12 may read the instructions and / or data in the storage module, so that the apparatus implements the device actions in the above method embodiments.

[0521] In design, the apparatus 10 may correspond to the first terminal device in the above method embodiments, or may be a component (eg, a chip) of the first terminal device.

[0522] The apparatus 10 may implement corresponding steps or procedures performed by the terminal device in the above method embodiments. The transceiver module 11 may be configured to perform operations related to transmission and reception of the first terminal device in the above method embodiments. The processing module 12 may be configured to perform operations related to processing of the first terminal device in the above method embodiments.

[0523] In one possible implementation, the transceiver module 11 is configured to receive first downlink data from a network device through a first link, the processing module 12 is configured to decode the first downlink data to obtain a first decoding result, and the transceiver module 11 is further configured to send first information to a second terminal device through a second link, the first information including first hybrid automatic repeat request (HARQ-ACK) information indicating the first decoding result. The first link is a transmission link between the first terminal device and the network device, and the second link is a transmission link between the first terminal device and the second terminal device.

[0524] When apparatus 10 is configured to perform the method of FIG. 7, transceiver module 11 may be configured to perform the information transmitting and receiving steps in the method, e.g., steps S710 and S730, and processing module 12 may be configured to perform the processing steps in the method, e.g., step S720.

[0525] When apparatus 10 is configured to perform the method of FIG. 8, transceiver module 11 may be configured to perform the steps of transmitting and receiving information in the method, e.g., steps S811, S810, S821, and S822, and processing module 12 may be configured to perform the processing steps in the method.

[0526] When apparatus 10 is configured to perform the method of FIG. 10, transceiver module 11 may be configured to perform steps of transmitting and receiving information in the method, e.g., steps S1010 and S1021, and processing module 12 may be configured to perform processing steps in the method, e.g., step S1022.

[0527] In another design, apparatus 10 may correspond to or be a component (eg, a chip) of a network device in the above method embodiments.

[0528] The apparatus 10 may implement the steps or procedures corresponding to those performed by the network device in the above method embodiments. The transceiver module 11 may be configured to perform operations related to the transmission and reception of the network device in the above method embodiments. The processing module 12 is configured to perform operations related to the processing of the network device in the above method embodiments.

[0529] In a possible implementation, the transceiver module 11 is configured to send first downlink data to a first terminal device through a first link, and the transceiver module 11 is configured to receive fifth information from a second terminal device through a third link, the fifth information including first hybrid automatic repeat request acknowledgement (HARQ-ACK) information, and the first HARQ-ACK information indicating a first decoding result corresponding to the first downlink data.

[0530] When apparatus 10 is configured to perform the method of FIG. 7, transceiver module 11 may be configured to perform steps of transmitting and receiving information in the method, e.g., steps S710 and S740, and processing module 12 may be configured to perform processing steps in the method.

[0531] When apparatus 10 is configured to perform the method of FIG. 8, transceiver module 11 may be configured to perform the steps of transmitting and receiving information in the method, e.g., steps S811, S810, S821, and S822, and processing module 12 may be configured to perform the processing steps in the method.

[0532] When apparatus 10 is configured to perform the method of FIG. 10, transceiver module 11 may be configured to perform steps of transmitting and receiving information in the method, e.g., steps S1010 and S1021, and processing module 12 may be configured to perform processing steps in the method.

[0533] It should be understood that the specific processes by which the units perform the above corresponding steps are described in detail in the above method embodiments, and for the sake of brevity, the details will not be described herein.

[0534] It should be understood that the apparatus 10 herein is implemented in the form of a functional module. The term "module" herein may refer to an application-specific integrated circuit (ASIC), an electronic circuit, a memory, a processor (such as a shared processor, a dedicated processor, or a group of processors) configured to execute one or more software or firmware programs, a combined logic circuit, and / or another suitable component supporting the described functionality. Those skilled in the art will understand that, in an optional example, the apparatus 10 may be, in particular, a mobility management network element in the above embodiments and configured to perform procedures and / or steps corresponding to the mobility management network element in the above method embodiments. Alternatively, the apparatus 10 may be, in particular, a terminal device in the above embodiments and configured to perform procedures and / or steps corresponding to the terminal device in the above method embodiments. To avoid repetition, details will not be described again herein.

[0535] The apparatus 10 in the above solution has functions for implementing corresponding steps performed by a device (e.g., a terminal device or a network device) in the above method. The functions may be implemented by using hardware or by using hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the aforementioned functions. For example, to perform the transmission and reception operations and related processing operations in the method embodiments, respectively, a transceiver module may be replaced with a transceiver (e.g., a transmitting unit in the transceiver module may be replaced with a transmitter, and a receiving unit in the transceiver module may be replaced with a receiver), and another unit such as a processing module may be replaced with a processor.

[0536] Furthermore, the transceiver module 11 may alternatively be a transceiver circuit (eg, a transceiver circuit may include a receiver circuit and a transmitter circuit), and the processing module may be a processing circuit.

[0537] 22 is a diagram of another communication device 20 according to an embodiment of the present application. The device 20 includes a processor 21. The processor 21 is configured to execute computer programs or instructions stored in a memory 22 or read data / signaling stored in the memory 22 to implement the methods in the above method embodiments. Optionally, there are one or more processors 21.

[0538] Optionally, as shown in Figure 22, the device 20 further includes a memory 22. The memory 22 is configured to store computer programs or instructions and / or data. The memory 22 and the processor 21 may be integrated together or may be disposed separately. Optionally, there are one or more memories 22.

[0539] Optionally, as shown in Figure 22, the device 20 may further include a transceiver 23. The transceiver 23 is configured to receive and / or send signals. For example, the processor 21 is configured to control the transceiver 23 to receive and / or send signals.

[0540] In the solution, the apparatus 20 is configured to implement the operations performed by the terminal device in the above method embodiments.

[0541] It is understood that the processor in embodiments of the present application may be a central processing unit (CPU), or may be another general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, etc. The general-purpose processor may be a microprocessor, or the processor may be any conventional processor, etc.

[0542] Furthermore, it should be understood that the memory referred to in the embodiments of the present application may be volatile memory and / or nonvolatile memory. Nonvolatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory may be random access memory (RAM). For example, RAM may be used as an external cache. By way of example and not limitation, RAM includes multiple forms such as static random access memory (static RAM, SRAM), dynamic random access memory (dynamic RAM, DRAM), synchronous dynamic random access memory (synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (double data rate SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (enhanced SDRAM, ESDRAM), synchlink dynamic random access memory (synchlink DRAM, SLDRAM), and direct rambus random access memory (direct rambus RAM, DR RAM).

[0543] It should be noted that when the processor is a general-purpose processor, a DSP, an ASIC, an FPGA or another programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, the memory (storage module) may be integrated into the processor.

[0544] It should be further noted that memory as described herein is intended to include, without being limited to, these and any other suitable types of memory.

[0545] 23 is a diagram of a chip system 30 according to one embodiment of the present application. The chip system 30 (sometimes referred to as a processing system) includes a logic circuit 31 and an input / output interface 32.

[0546] The logic circuit 31 may be a processing circuit in the chip system 30. The logic circuit 31 is coupled to a storage unit and invokes instructions in the storage unit, so that the chip system 30 can implement the methods and functions in the embodiments of the present application. The input / output interface 32 may be an input / output circuit in the chip system 30, which outputs information processed by the chip system 30 or inputs data or signaling information to be processed into the chip system 30 for processing.

[0547] In the solution, the chip system 30 is configured to implement the operations performed by the terminal device in the above method embodiments.

[0548] For example, the logic circuit 31 is configured to implement operations related to the processing performed by the terminal device in the above method embodiments, and the input / output interface 32 is configured to implement operations related to the receiving performed by the terminal device in the above method embodiments.

[0549] An embodiment of the present application further provides a computer-readable storage medium, which stores computer instructions used to implement the method performed by the device in the above method embodiment. For example, when the computer program is executed by a computer, the computer can implement the method performed by the terminal device or network device in the above method embodiment.

[0550] An embodiment of the present application further provides a computer program product including instructions, which, when executed by a computer, implement the methods performed by the terminal device or network device in the above method embodiments.

[0551] An embodiment of the present application further provides a communication system including the above terminal device and a network device.

[0552] For the description of the relevant contents and beneficial effects of any one of the above-provided devices, please refer to the corresponding method embodiments provided above, and the details will not be described again here.

[0553] In some embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the described apparatus embodiments are merely examples. For example, the division into units is merely a logical functional division. In actual implementation, there may be other division manners. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not implemented. Furthermore, the shown or described mutual couplings or direct couplings or communication connections may be implemented through some interfaces, and indirect couplings or communication connections between apparatuses or units may be implemented in electrical, mechanical, or other forms.

[0554] All or part of the above embodiments may be implemented by software, hardware, firmware, or any combination thereof. When software is used to implement an embodiment, all or part of the embodiment may be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the procedures or functions according to the embodiments of the present application are generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. For example, the computer may be a personal computer, a server, or a network device. The computer instructions may be stored in a computer-readable storage medium or transmitted from a computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website, computer, server, or data center to another website, computer, server, or data center via a wired (e.g., coaxial cable, optical fiber, or digital subscriber line (DSL)) or wireless (e.g., infrared, radio, or microwave) method. The computer-readable storage medium may be any available medium accessible by a computer or data storage device, such as a server or data center, that integrates one or more available media. The usable medium may be a magnetic medium (e.g., a floppy disk, a hard disk, or a magnetic tape), an optical medium (e.g., a DVD), a semiconductor medium (e.g., a solid state disk (SSD)), etc. For example, the usable medium includes, but is not limited to, any medium that can store program code, for example, a USB flash drive, a removable hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0555] The above description is merely a specific implementation of the present application. However, the scope of protection of the present application is not limited thereto. Any modifications or replacements that can be easily conceived by those skilled in the art within the technical scope disclosed in the present application shall fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be subject to the scope of protection of the claims.

Claims

1. 1. A communication method comprising: receiving, by a first terminal device, first downlink data from a network device over a first link; decoding, by the first terminal device, the first downlink data to obtain a first decoding result; sending, by the first terminal device, first information to a second terminal device over a second link, the first information including first hybrid automatic repeat request (HARQ-ACK) information, the first HARQ-ACK information indicating the first decoding result; the first link is a transmission link between the first terminal device and the network device, and the second link is a transmission link between the first terminal device and the second terminal device; Communication method.

2. Prior to the step of sending the first information by the first terminal device to the second terminal device over the second link, the method further comprises: determining, by the first terminal device, a first time unit in which the first terminal device sends the first information; The method of claim 1 further comprising:

3. The step of determining, by the first terminal device, the first time unit in which the first terminal device sends the first information includes: determining, by the first terminal device, a first time gap, the first time gap being less than or equal to a time gap between the first time unit and a second time unit; determining, by the first terminal device, the first time unit based on the first time gap and the second time unit; the second time unit is a time unit in which the first terminal device receives the first downlink data or a time unit in which the first terminal device receives first control information, and the first control information is used to schedule the first downlink data; The method of claim 2.

4. The step of determining, by the first terminal device, the first time gap comprises: receiving, by the first terminal device, the first control information from the network device, the first control information further indicating the first time gap; or receiving, by the first terminal device, first configuration information from the network device before receiving the first downlink data; and determining the first time gap based on the first configuration information. The method of claim 3, comprising:

5. Before the step of receiving, by the first terminal device, the first control information from the network device, the method further comprises: receiving, by the first terminal device, second configuration information from the network device, the second configuration information being used to configure a time gap set, the first time gap being one time gap in the time gap set; The method of claim 4 further comprising:

6. The step of determining, by the first terminal device, the first time gap when the first time gap is measured in a slot, comprises: determining, by the first terminal device, that a subcarrier spacing SCS referenced by the first time gap is a first SCS or a second SCS, wherein the first SCS is an SCS corresponding to the first link, the second SCS is an SCS corresponding to the second link, and the first link is different from the second link; The method of any one of claims 3 to 5, further comprising:

7. determining, by the first terminal device, that the SCS referenced by the first time gap is the first SCS or the second SCS, determining, by the first terminal device, based on a first parameter, that the SCS referenced by the first time gap is the first SCS or the second SCS, wherein the first parameter indicates the first SCS or the second SCS; the first parameter is configured by the network device, the first parameter is determined through negotiation by the first terminal device and the network device, or the first parameter is pre-programmed into the first terminal device; The method of claim 6.

8. The method comprises: determining, by the first terminal device, a first transmission resource used to transmit the first information, the first transmission resource including a first time domain resource and a first frequency domain resource, the first time domain resource being in the first time unit; The method of any one of claims 2 to 7, further comprising:

9. The first transmission resource is a physical sidelink shared channel (PSSCH), and the step of determining the first transmission resource by the first terminal device comprises: receiving, by the first terminal device, the first control information from the network device, the first control information including second information, the second information indicating the first time domain resource and the first frequency domain resource; determining, by the first terminal device, the first transmission resource based on the second information; or determining, by the first terminal device, the first time domain resource and the first frequency domain resource based on third configuration information, the third configuration information being information received by the first terminal device from the network device before the first terminal device receives the first downlink data; The method of claim 8, comprising:

10. 10. The method of claim 9, wherein the second information includes a first field and a second field, the first field indicating a time resource allocation and the second field indicating a frequency resource allocation.

11. 10. The method of claim 9, wherein the third configuration information includes information indicating a quantity of subchannels, information indicating a subchannel size, information indicating a starting resource block of a subchannel, information indicating a starting symbol of the first time domain resource in the first time unit, and information indicating a quantity of symbols occupied by the first time domain resource.

12. The method according to any one of claims 9 to 11, wherein the first information is a Medium Access Control Control Element (MAC CE).

13. The first frequency domain resource is a resource block occupied by a physical sidelink feedback channel (PSFCH), and the step of determining, by the first terminal device, the first transmission resource comprises: receiving, by the first terminal device, the first control information from the network device, the first control information including third information, the third information indicating the first frequency domain resource; determining, by the first terminal device, the first frequency domain resource based on the third information; The method of claim 8, comprising:

14. The first frequency domain resource is a resource block included in a physical sidelink feedback channel (PSFCH), and the step of determining the first transmission resource by the first terminal device comprises: determining, by the first terminal device, a first quantity M of downlink data in a first downlink data set, where the first downlink data is one of the M downlink data, and M HARQ-ACK information corresponding to the M downlink data are all transmitted on the PSFCH, where M is a positive integer; determining, by the first terminal device, a second number of resource blocks based on the first number and a first number of resource blocks, wherein the first number of resource blocks is the number of resource blocks included in the PSFCH and the second number of resource blocks is the number of resource blocks included in the first frequency domain resource; determining, by the first terminal device, a location of the second number of resource blocks within the first number of resource blocks based on a location of the first downlink data in the downlink data set; The method of claim 8, comprising:

15. The method of claim 14 , wherein the first transmission resource is used to transmit HARQ-ACK information for downlink data.

16. M, the number of first resource blocks, and the number of second resource blocks satisfy the following relationship: [Equation 1] N represents the number of second resource blocks, K represents the number of first resource blocks, [Equation 2] represents a floor operation, and N resource blocks corresponding to m-th downlink data among the M downlink data are resource blocks with indices from (m-1)*N to m*N-1 among the K resource blocks; or M, the number of first resource blocks, and the number of second resource blocks satisfy the following relationship: [Equation 3] M is divisible by K, and N resource blocks corresponding to m-th downlink data among the M downlink data are resource blocks with indexes from (m-1)*N to m*N-1 among the K resource blocks; or In the case where M1>0, when m is any integer from 1 to M1, the N resource blocks corresponding to the m-th downlink data among the M downlink data are resource blocks with indices (m-1)*K1 to m*K1-1 among the K resource blocks, or when m is any integer from M1 to M, the N resource blocks corresponding to the m-th downlink data among the M downlink data are resource blocks with indices [M1*K1+(m-M1-1)*K2] to [M1*K1+(m-M1-1)*K2+K2-1] among the K resource blocks, or When M1=0, the N resource blocks corresponding to the m-th downlink data among the M downlink data are the [M1*K1+(m-M1-1)*K2]-th resource block to the [M1*K1+(m-M1-1)*K2+K2-1]-th resource block among the K resource blocks; K1 is [Equation 4] and K2 is [Equation 5] and M1 is [Equation 6] is the remainder of [Equation 7] denotes the ceiling operation, 16. The method of claim 15.

17. The method of claim 14 , wherein the first transmission resource is used to transmit HARQ-ACK information for downlink data and HARQ-ACK information for sidelink data.

18. M, the number of first resource blocks, the number of second resource blocks, and the second quantity satisfy the following relationship: [Equation 8] N represents the second number of resource blocks, K represents the first number of resource blocks, and A represents the second quantity, which is for the sidelink data and is the number of HARQ-ACK information transmitted on the PSFCH; [Equation 9] represents a floor operation, and N resource blocks corresponding to m-th downlink data among the M downlink data and A sidelink data are resource blocks with indices from (m−1)*N to m*N−1 among K resource blocks; or M, the number of first resource blocks, the number of second resource blocks, and the second quantity satisfy the following relationship: [Equation 10] M+A is divisible by K, and N resource blocks corresponding to m-th downlink data among the M downlink data and A sidelink data are resource blocks with indices ranging from (m-1)*N to m*N-1 among the K resource blocks; or In the case where M1>0, when m is any integer from 1 to M1, the N resource blocks corresponding to the m-th downlink data among the M downlink data and the A sidelink data are resource blocks with indices (m-1)*K1 to m*K1-1 among the K resource blocks, or when m is any integer from M1 to M, the N resource blocks corresponding to the m-th downlink data among the M downlink data are resource blocks with indices [M1*K1+(m-M1-1)*K2] to [M1*K1+(m-M1-1)*K2+K2-1] among the K resource blocks, or When M1=0, the N resource blocks corresponding to the m-th downlink data among the M downlink data and the A sidelink data are the [M1*K1+(m-M1-1)*K2]-th resource block to the [M1*K1+(m-M1-1)*K2+K2-1]-th resource block among the K resource blocks; K1 is [0011] and K2 is [0012] and M1 is [0013] is the remainder of [0014] denotes the ceiling operation, 18. The method of claim 17.

19. The step of determining, by the first terminal device, the first quantity includes: receiving, by the first terminal device, fourth information from the network device, the fourth information indicating the first quantity; or by the first terminal device, the time gap set, the time domain resource allocation TDRA of the first link, the subcarrier spacing of the first link, the subcarrier spacing of the second link, the duration of the first transmission resource, or the first time unit, wherein the first time unit is one time gap in the time gap set; determining the first quantity based on at least one of the following information:

19. The method of any one of claims 14 to 18, comprising:

20. When the first terminal device does not receive second downlink data in the downlink data set, the method includes: skipping, by the first terminal device, transmitting HARQ-ACK information on a second transmission resource corresponding to the second downlink data, or feeding back a negative acknowledgement (NACK) on the second transmission resource.

20. The method of any one of claims 14 to 19, further comprising:

21. When the first terminal device is one of a plurality of terminal devices that feed back HARQ-ACK information through the second terminal device, the method includes: sending, by the first terminal device, the first HARQ-ACK information to the second terminal device on the first transmission resource in a code division multiplexing manner; 21. The method of any one of claims 14 to 20, further comprising:

22. Prior to receiving the first downlink data from the network device, the method further comprises: receiving, by the first terminal device, fourth configuration information from the network device, the fourth configuration information being used to configure R resource pools, the first transmission resource being a resource in one of the R resource pools, where R is a positive integer; 22. The method of any one of claims 8 to 21, further comprising:

23. 23. The method of claim 1, wherein the first downlink data comprises a physical downlink shared channel (PDSCH), the first link is a link for communication based on a first communication interface, the second link is a link for communication based on a second communication interface, the first communication interface is a first Uu interface, the second communication interface is a PC5 interface, the first terminal device comprises an extended reality XR device, and the second terminal device comprises a mobile terminal.

24. 1. A communication method comprising: sending, by the network device, first downlink data over the first link to the first terminal device; receiving, by the network device, fifth information from a second terminal device through a third link, the fifth information including first hybrid automatic repeat request (HARQ-ACK) information, the first HARQ-ACK information indicating a first decoding result corresponding to the first downlink data; the first link is a transmission link between the first terminal device and the network device, and the third link is a transmission link between the second terminal device and the network device; Communication method.

25. The method comprises: configuring, by the network device, first transmission resources for the first terminal device over the first link, the first transmission resources being used by the first terminal device to send first information to the second terminal device over a second link, the first information including the first HARQ-ACK information, and the second link being a transmission link between the first terminal device and the second terminal device; 25. The method of claim 24, further comprising:

26. The first transmission resource includes a first time domain resource and a first frequency domain resource, the first time domain resource being in a first time unit, and the method further comprises: sending, by the network device, first control information to the first terminal device, the first control information indicating a first time gap; or before sending the first downlink data to the first terminal device, sending first configuration information by the network device to the first terminal device, the first configuration information indicating a first time gap; the first time gap is equal to or less than a time gap between the first time unit and a second time unit, the second time unit being a time unit in which the first terminal device receives the first downlink data or a time unit in which the first terminal device receives the first control information, and the first control information is further used to schedule the first downlink data; 26. The method of claim 25.

27. Before the step of sending the first control information by the network device to the first terminal device, the method further comprises: sending, by the network device, second configuration information to the first terminal device, the second configuration information being used to configure a time gap set, the first time gap being one time gap in the time gap set; 27. The method of claim 26, further comprising:

28. When the first time gap is measured in a slot, the method further comprises: sending, by the network device, a first parameter to the first terminal device, the first parameter indicating that a subcarrier spacing SCS referenced by the first time gap is a first SCS or a second SCS, the first SCS being an SCS corresponding to the first link, the second SCS being an SCS corresponding to the second link, and the first link being different from the second link; 28. The method of claim 26 or 27, further comprising:

29. The first transmission resource is a physical sidelink shared channel (PSSCH), and the method comprises: sending, by the network device, the first control information to the first terminal device, the first control information including second information, the second information indicating the first time domain resource and the first frequency domain resource; or sending, by the network device, third configuration information to the first terminal device before sending the first downlink data to the first terminal device, the third configuration information indicating the first time domain resource and the first frequency domain resource.

29. The method of any one of claims 26 to 28, further comprising:

30. The first frequency domain resource is a resource block occupied by a physical sidelink feedback channel (PSFCH), and the method comprises: sending, by the network device, the first control information to the first terminal device, the first control information including third information, the third information indicating the first frequency domain resource; or sending fourth information to the first terminal device by the network device before the network device sends the first downlink data to the first terminal device, the fourth information indicating a first quantity M of downlink data in a first downlink data set, the first quantity being used to determine the first frequency domain resource; the first downlink data is one of the M downlink data, and M HARQ-ACK information corresponding to the M downlink data are all transmitted on the PSFCH, where M is a positive integer; 29. The method of any one of claims 26 to 28.

31. The method comprises: sending, by the network device, fourth configuration information to the first terminal device, the fourth configuration information being used to configure R resource pools, the first transmission resource being a resource in one of the R resource pools, where R is a positive integer; 31. The method of claim 29 or 30, further comprising:

32. 32. The method of claim 25, wherein the first downlink data comprises a physical downlink shared channel (PDSCH), the first link is a link for communication based on a first communication interface, the second link is a link for communication based on a second communication interface, and the third link is a link for communication based on a third communication interface, the first communication interface being a first Uu interface, the second communication interface being a PC5 interface, and the third communication interface being a second Uu interface.

33. 24. A terminal device comprising a processor and a memory, the processor coupled to the memory, the memory configured to store a computer program, the terminal device being capable of performing the method of any one of claims 1 to 23 when the processor runs the computer program.

34. 33. A network device comprising a processor and a memory, the processor coupled to the memory, the memory configured to store a computer program, the network device being capable of performing a method according to any one of claims 24 to 32 when the processor runs the computer program.

35. 32. A computer-readable storage medium storing computer instructions that, when run on a terminal device, enable the terminal device to perform the method of any one of claims 1 to 23, or that, when run on a network device, enable the network device to perform the method of any one of claims 24 to 32.

36. 34. A computer program product comprising instructions, when the computer instructions are run on a terminal device, that enable the terminal device to perform the method of any one of claims 1 to 23, or when the computer instructions are run on a network device, that enable the network device to perform the method of any one of claims 24 to 32.

37. A chip comprising a processor and a communication interface, the processor reading instructions through the communication interface and executing the instructions, such that when the chip is installed in a terminal device, the terminal device is enabled to perform the method of any one of claims 1 to 23, or when the chip is installed in a network device, the network device is enabled to perform the method of any one of claims 24 to 32.

38. 32. A communication system comprising a terminal device and a network device, the terminal device configured to perform the method of any one of claims 1 to 23 and the network device configured to perform the method of any one of claims 24 to 32.

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