Communication method and device

Abstract

The embodiments of the present application disclose a communication method and apparatus, which can be applied to vehicle networking, V2X, V2V and other systems. The method includes: sending a channel state information reference signal CSI-RS to a second terminal device; wherein the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool, the resource pool is a set of time-frequency resources contained in the side link SL partial bandwidth BWP, the resource pool includes one or more continuous sub-channels in the frequency domain, a sub-channel of the resource pool includes one or more continuous physical resource blocks PRB, and the resource pool is determined in the time domain according to a periodic bit map. Through the method and apparatus of the embodiments of the present application, the first terminal device can obtain the channel state information CSI on each sub-channel in the resource pool, and allocate resources based on the CSI of each sub-channel on the resource pool, thereby improving the communication capacity in the SL scenario.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to communication methods and devices. Background Art

[0002] In the past few decades, wireless communication systems have undergone a technological evolution from the first generation of analog communications to new radio (NR). In wireless communication systems, in order to achieve goals such as channel measurement, the channel state information (CSI) process is introduced. The receiver calculates the CSI based on the channel state information-reference signal (CSI-RS) received from the transmitter and feeds back the CSI to the transmitter.

[0003] At present, there are at least two CSI schemes as follows: The first CSI scheme is the CSI scheme of the Uu interface (Uu interface, referred to as Uu port), which is mainly based on sub-band granularity for measurement. Considering that the sidelink (SL) does not introduce the concept of sub-band, the CSI scheme based on sub-band granularity is not applicable to SL. The second CSI scheme is the SL CSI scheme of the PC5 interface (PC5 interface, referred to as PC5 port) introduced by the R16 version of the 3rd Generation Partnership Project (3GPP). In the SL CSI scheme, the frequency domain bandwidth of the SL CSI-RS is required to be the same as the frequency domain bandwidth of the associated physical sidelink shared channel (PSSCH). In this way, the receiving end can only measure and calculate the CSI on the SL CSI-RS frequency band based on the SL CSI-RS, that is, it can only measure and calculate the CSI on one or more sub-channels (sub-channel) corresponding to the PSSCH associated with the SL CSI-RS. Furthermore, the transmitter can only obtain CSI on one or more subchannels corresponding to the PSSCH associated with the SL CSI-RS, which is not conducive to the transmitter to implement resource allocation based on CSI and cannot meet the communication requirements of SL.

[0004] It can be seen that the existing CSI solutions cannot meet the communication requirements of SL. Summary of the invention

[0005] The embodiments of the present application provide a communication method and device, which can be applied to the Internet of Vehicles, such as vehicle to everything (V2X) communication, long-term evolution-vehicle (LTE-V) communication, vehicle to vehicle (V2V) communication, etc., or can be used in the fields of intelligent driving, intelligent connected vehicles, etc., and can improve the communication capacity in SL scenarios.

[0006] In order to achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0007] In the first aspect, an embodiment of the present application provides a communication method, which can be executed by a first terminal device. The method includes: sending a channel state information reference signal CSI-RS to a second terminal device; wherein the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool, the resource pool is a set of time-frequency resources contained in the side link SL partial bandwidth BWP, the resource pool includes one or more continuous sub-channels in the frequency domain, a sub-channel of the resource pool includes one or more continuous physical resource blocks PRB, and the resource pool is determined in the time domain according to a periodic bitmap bitmap.

[0008] Thus, according to the communication method provided in the embodiment of the present application, in the SL scenario, since the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool, that is, the number of subchannels included in the frequency domain of the CSI-RS is the same as the number of subchannels included in the frequency domain of the resource pool, after the first terminal device sends the CSI-RS to the second terminal device, the second terminal device can measure and feed back the CSI on each subchannel in the resource pool to the first terminal device based on the CSI-RS. Furthermore, the first terminal device can reasonably select frequency domain resources according to the CSI of each subchannel in the resource pool, thereby improving the communication capacity in the SL scenario. On the other hand, according to the communication method provided in the embodiment of the present application, in the SL scenario, when the first terminal device determines that the channel quality of one or more subchannels used for the current transmission is poor and reliable transmission cannot be achieved, it can select other reasonable subchannels for transmission according to the CSI of each subchannel in the resource pool, thereby improving the transmission reliability in the SL scenario.

[0009] In one possible design, the method also includes: sending first indication information to the second terminal device, the first indication information is used to instruct the second terminal device to send channel state information CSI, and the first indication information is included in the second-level sidelink control information SCI.

[0010] In one possible design, the first indication information is also used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

[0011] In one possible design, the method also includes: sending second indication information to the second terminal device, the second indication information being used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

[0012] In one possible design, the second indication information is included in radio resource control RRC signaling.

[0013] The method provided in the embodiment of the present application indicates that the frequency domain bandwidth of the SL CSI-RS is the same as the frequency domain bandwidth of the resource pool through RRC signaling or the first indication information. Since the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool, that is, the number of subchannels included in the frequency domain of the CSI-RS is the same as the number of subchannels included in the resource pool in the frequency domain, after the first terminal device sends the CSI-RS to the second terminal device, the second terminal device can measure the CSI on each subchannel in the resource pool based on the CSI-RS and feed back the CSI on each subchannel in the resource pool to the first terminal device. Furthermore, the first terminal device can reasonably select frequency domain resources according to the CSI of each subchannel in the resource pool, thereby improving the communication capacity in the SL scenario.

[0014] In addition, compared with the prior art that configures the frequency domain bandwidth of CSI-RS through RRC signaling, which requires large signaling overhead and has strong restrictions on the frequency domain bandwidth of CSI-RS and the position of the starting physical resource block (PRB), the RRC signaling of the embodiment of the present application does not impose special restrictions on information such as the starting PRB, so part of the signaling overhead can be reduced. In addition, the signaling overhead of the first indication information is also small.

[0015] In one possible design, the CSI includes at least one of the following:

[0016] Wideband channel quality indicator CQI index, where the wideband CQI index is the CQI index corresponding to the frequency domain bandwidth of the CSI-RS;

[0017] The CQI values ​​of one or more sub-channels in the resource pool, the CQI value of a sub-channel in the resource pool corresponds to the CQI index of a sub-channel in the resource pool.

[0018] In the method provided by the embodiment of the present application, since the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool, the CSI obtained by the second terminal device measuring the CSI-RS includes a broadband CQI index and / or the CQI value of one or more sub-channels in the resource pool, that is, the second terminal device measures and feeds back the CSI of each sub-channel in the resource pool to the first terminal device. Furthermore, the first terminal device can select appropriate resources based on the CSI of each sub-channel in the resource pool to improve the communication capacity in the SL scenario.

[0019] Moreover, compared with the prior art, in which CSI is likely to include only 1-bit RI and 4-bit wideband CQI index (used to characterize the average channel quality of one or more subchannels), and the feedback CSI content is small, in the method provided in the embodiment of the present application, CSI includes a wideband CQI index and / or CQI values ​​of one or more subchannels in the resource pool, and the information content carried by CSI is richer, so that the first terminal device can obtain more information based on the CSI.

[0020] In a possible design, the CSI is carried in the medium access control layer control element MAC CE, and the number of bytes occupied by the MAC CE is related to the number of sub-channels in the resource pool. In other words, the size of the MAC CE provided by the present application is variable, and its design method is more flexible.

[0021] In one possible design, the MAC CE includes bytes;

[0022] in, is the round-up symbol, and y is the number of subchannels in the resource pool.

[0023] In one possible design, the power control factor β of the CSI-RS is CSI-RS,1 Satisfies the following relationship:

[0024]

[0025] in, is the power control factor of the physical sidelink shared channel PSSCH, W is the number of subchannels in the PSSCH bandwidth, Y is the number of subchannels in the resource pool, Y ≥ W, is the number of PSSCH layers scheduled, Q p is the number of CSI-RS ports.

[0026] It should be understood that in this implementation of the embodiment of the present application, the power control factor of the PSSCH is the same on the symbol used to transmit the CSI-RS and on each symbol not containing the CSI-RS (i.e., the symbol not used to transmit the CSI-RS). In addition, the power control factor of the CSI-RS is the same on the symbol containing the CSI-RS and on the symbol not containing the CSI-RS.

[0027] Among them, in the symbol containing CSI-RS, for the RE not used to send CSI-RS, the power on the RE remains unchanged, and for the RE used for CSI-RS transmission, the power on the RE is equivalent to extending from W subchannels to Y subchannels. It can be seen that the first terminal device reduces the transmission power of CSI-RS in a single PRB.

[0028] In one possible design, the power control factor β of the CSI-RS is CSI-RS,1 Satisfies the following relationship:

[0029]

[0030]

[0031] in, is the power control factor of the physical sidelink shared channel PSSCH on the symbol used to transmit the CSI-RS, is the power control factor of PSSCH on symbols not used for transmitting CSI-RS, W is the number of subchannels in the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, Y is the number of subchannels in the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the number of CSI-RS ports.

[0032] It should be understood that in this implementation, PSSCH uses a set of power control factors on symbols that do not contain CSI-RS, namely PSSCH uses another set of power control factors on symbols containing CSI-RS, namely Specifically, on the symbol containing CSI-RS, the power of PSSCH on the symbol is equivalent to expanding from W subchannels to "PSSCH of W subchannels + CSI-RS of Y subchannels". That is to say, on the symbol containing CSI-RS, the first terminal device reduces the transmission power of PSSCH.

[0033] And, because The power control factor of CSI-RS is That is, it is related to the power control factor of PSSCH on the symbol containing CSI-RS. When the power of PSSCH on the symbol containing CSI-RS decreases, it means that the power control factor of CSI-RS on the symbol containing CSI-RS also decreases, that is, the first terminal device also reduces the transmission power of CSI-RS.

[0034] Furthermore, the above two power control methods can reduce the probability of introducing AGC symbols.

[0035] In a second aspect, an embodiment of the present application provides a communication method, which can be executed by a second terminal device. The method includes: receiving a channel state information reference signal CSI-RS from a first terminal device; wherein the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of a resource pool, the resource pool is a set of time-frequency resources contained in the side link SL partial bandwidth BWP, the resource pool includes one or more continuous sub-channels in the frequency domain, a sub-channel of the resource pool includes one or more continuous physical resource blocks PRB, and the resource pool is determined in the time domain according to a periodic bit map.

[0036] In one possible design, the method further includes:

[0037] First indication information is received from a first terminal device, where the first indication information is used to instruct a second terminal device to send channel state information CSI, and the first indication information is included in second-level sidelink control information SCI.

[0038] In one possible design, the first indication information is also used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

[0039] In one possible design, the method further includes:

[0040] Second indication information is received from the first terminal device, where the second indication information is used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

[0041] In one possible design, the second indication information is included in radio resource control RRC signaling.

[0042] In one possible design, the CSI includes at least one of the following:

[0043] Wideband channel quality indicator CQI index, where the wideband CQI index is the CQI index corresponding to the frequency domain bandwidth of the CSI-RS;

[0044] The CQI values ​​of one or more sub-channels in the resource pool, the CQI value of a sub-channel in the resource pool corresponds to the CQI index of a sub-channel in the resource pool.

[0045] In a possible design, the CSI is carried in a medium access control layer control element MAC CE, and the number of bytes occupied by the MAC CE is related to the number of sub-channels in the resource pool.

[0046] In one possible design, the MAC CE includes bytes;

[0047] in, is the round-up symbol, and y is the number of subchannels in the resource pool.

[0048] In one possible design, the power control factor β of the CSI-RS is CSI-RS,1 Satisfies the following relationship:

[0049]

[0050] in, is the power control factor of the physical sidelink shared channel PSSCH, W is the number of subchannels in the PSSCH bandwidth, Y is the number of subchannels in the resource pool, Y ≥ W, is the number of PSSCH layers scheduled, Q p is the number of CSI-RS ports.

[0051] In one possible design, the power control factor β of the CSI-RS is CSI-RS,1 Satisfies the following relationship:

[0052]

[0053]

[0054] in, is the power control factor of the physical sidelink shared channel PSSCH on the symbol used to transmit the CSI-RS, is the power control factor of PSSCH on symbols not used for transmitting CSI-RS, W is the number of subchannels in the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, Y is the number of subchannels in the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the number of CSI-RS ports.

[0055] In a third aspect, an embodiment of the present application provides a communication method, which can be performed by a first terminal device. The method includes: sending first indication information to a second terminal device. The first indication information is used to indicate a frequency domain bandwidth of a CSI-RS.

[0056] According to the method provided in the embodiment of the present application, the first terminal device can flexibly configure the frequency domain bandwidth of the CSI-RS through the first indication information. Subsequently, the first terminal device can trigger the second terminal device to feedback the CSI of one or more subchannels (i.e., the subchannels corresponding to the CSI-RS frequency domain bandwidth) by sending a CSI-RS with configurable frequency domain bandwidth to the second terminal device. In this way, the first terminal device can select frequency domain resources based on the CSI on the one or more subchannels in the resource pool, so as to improve the communication capacity in the SL scenario.

[0057] In one possible design, the first indication information is included in PC5 RRC signaling.

[0058] In one possible design, the method also includes: sending CSI-RS to the second terminal device.

[0059] Among them, the power control factor of CSI-RS is CSI-RS,1 Satisfies the following relationship:

[0060]

[0061] in, is the power control factor of PSSCH on the OFDM symbol used to transmit SL CSI-RS; W is the number of subchannels in the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, and U is the number of overlapping subchannels in the frequency domain bandwidth of PSSCH and SL CSI-RS (exemplarily, as Fig.13 , U=1), Q p is the number of SL CSI-RS ports, y is the number of subchannels in the frequency domain bandwidth of SL CSI-RS, is the number of PSSCH layers scheduled, y is less than or equal to Y, and Y is the number of subchannels in the resource pool.

[0062] For the power control factor of PSSCH on the OFDM symbol used to transmit SL CSI-RS, that is, It satisfies the following relationship:

[0063]

[0064] in, is the power control factor of PSSCH in OFDM symbols not used for transmitting SL CSI-RS.

[0065] In one possible design, the method also includes: sending second indication information to a second terminal device.

[0066] The second indication information is used to trigger the second terminal device to measure the channel according to the SL CSI-RS and feed back the SL CSI.

[0067] Optionally, the second indication information is included in a second-level SCI.

[0068] In a fourth aspect, an embodiment of the present application provides a communication method, which can be performed by a second terminal device. The method includes: receiving first indication information from a first terminal device. The first indication information is used to indicate the frequency domain bandwidth of the SL CSI-RS.

[0069] In one possible design, the first indication information is included in PC5 RRC signaling.

[0070] In one possible design, the method also includes: receiving CSI-RS from the first terminal device.

[0071] Among them, the power control factor of CSI-RS is CSI-RS,1 Satisfies the following relationship:

[0072]

[0073] in, is the power control factor of PSSCH on the OFDM symbol used to transmit SL CSI-RS; W is the number of subchannels in the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, and U is the number of overlapping subchannels in the frequency domain bandwidth of PSSCH and SL CSI-RS (exemplarily, as Fig.13 , U=1), Q p is the number of SL CSI-RS ports, y is the number of subchannels in the frequency domain bandwidth of SL CSI-RS, is the number of PSSCH layers scheduled, y is less than or equal to Y, and Y is the number of subchannels in the resource pool.

[0074] For the power control factor of PSSCH on the OFDM symbol used to transmit SL CSI-RS, that is, It satisfies the following relationship:

[0075]

[0076] in, is the power control factor of PSSCH in OFDM symbols not used for transmitting SL CSI-RS.

[0077] In one possible design, the method also includes: receiving second indication information from the first terminal device.

[0078] The second indication information is used to trigger the second terminal device to measure the channel according to the SL CSI-RS and feed back the SL CSI.

[0079] Optionally, the second indication information is included in a second-level SCI.

[0080] In a fifth aspect, an embodiment of the present application provides a communication method, which can be executed by a first terminal device. The method includes: receiving CSI from a second terminal device.

[0081] CSI includes at least one of the following:

[0082] Wideband channel quality indicator CQI index, where the wideband CQI index is the CQI index corresponding to the frequency domain bandwidth of the CSI-RS;

[0083] The CQI values ​​of one or more sub-channels in the resource pool, the CQI value of a sub-channel in the resource pool corresponds to the CQI index of a sub-channel in the resource pool.

[0084] In one possible design, the method also includes: sending a channel state information reference signal CSI-RS to a second terminal device; wherein the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of a resource pool, the resource pool is a set of time-frequency resources contained in the side link SL partial bandwidth BWP, the resource pool includes one or more continuous sub-channels in the frequency domain, a sub-channel of the resource pool includes one or more continuous physical resource blocks PRB, and the resource pool is determined in the time domain according to a periodic bit map bitmap.

[0085] In one possible design, the method also includes: sending first indication information to the second terminal device, the first indication information is used to instruct the second terminal device to send channel state information CSI, and the first indication information is included in the second-level sidelink control information SCI.

[0086] In one possible design, the first indication information is also used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

[0087] In one possible design, the method also includes: sending second indication information to the second terminal device, the second indication information being used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

[0088] In one possible design, the second indication information is included in radio resource control RRC signaling.

[0089] In a possible design, the CSI is carried in a medium access control layer control element MAC CE, and the number of bytes occupied by the MAC CE is related to the number of sub-channels in the resource pool.

[0090] In one possible design, the MAC CE includes bytes;

[0091] in, is the round-up symbol, and y is the number of subchannels in the resource pool.

[0092] In one possible design, the power control factor β of the CSI-RS is CSI-RS1 Satisfies the following relationship:

[0093]

[0094] in, is the power control factor of the physical sidelink shared channel PSSCH, W is the number of subchannels in the PSSCH bandwidth, Y is the number of subchannels in the resource pool, Y ≥ W, is the number of PSSCH layers scheduled, Q p is the number of CSI-RS ports.

[0095] In one possible design, the power control factor β of the CSI-RS is CSI-RS,1 Satisfies the following relationship:

[0096]

[0097]

[0098] in, is the power control factor of the physical sidelink shared channel PSSCH on the symbol used to transmit the CSI-RS, is the power control factor of PSSCH on symbols not used for transmitting CSI-RS, W is the number of subchannels in the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, Y is the number of subchannels in the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the number of CSI-RS ports.

[0099] In a sixth aspect, an embodiment of the present application provides a communication method, which can be executed by a second terminal device. The method includes: sending CSI to a first terminal device.

[0100] CSI includes at least one of the following:

[0101] Wideband channel quality indicator CQI index, where the wideband CQI index is the CQI index corresponding to the frequency domain bandwidth of the CSI-RS;

[0102] The CQI values ​​of one or more sub-channels in the resource pool, the CQI value of a sub-channel in the resource pool corresponds to the CQI index of a sub-channel in the resource pool.

[0103] In one possible design, the method also includes: receiving a channel state information reference signal CSI-RS from a first terminal device; wherein the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of a resource pool, the resource pool is a set of time-frequency resources contained in the side link SL partial bandwidth BWP, the resource pool includes one or more continuous sub-channels in the frequency domain, a sub-channel of the resource pool includes one or more continuous physical resource blocks PRB, and the resource pool is determined in the time domain according to a periodic bit map bitmap.

[0104] In one possible design, the method also includes: receiving first indication information from the first terminal device, the first indication information is used to indicate the second terminal device to send channel state information CSI, and the first indication information is included in the second-level sidelink control information SCI.

[0105] In one possible design, the first indication information is also used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

[0106] In one possible design, the method also includes: receiving second indication information from the first terminal device, the second indication information being used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

[0107] In one possible design, the second indication information is included in radio resource control RRC signaling.

[0108] In a possible design, the CSI is carried in a medium access control layer control element MAC CE, and the number of bytes occupied by the MAC CE is related to the number of sub-channels in the resource pool.

[0109] In one possible design, the MAC CE includes bytes;

[0110] in, is the round-up symbol, and y is the number of subchannels in the resource pool.

[0111] In one possible design, the power control factor β of the CSI-RS is CSI-RS,1 Satisfies the following relationship:

[0112]

[0113] in, is the power control factor of the physical sidelink shared channel PSSCH, W is the number of subchannels in the PSSCH bandwidth, Y is the number of subchannels in the resource pool, Y ≥ W, is the number of PSSCH layers scheduled, Q p is the number of CSI-RS ports.

[0114] In one possible design, the power control factor β of the CSI-RS is CSI-RS,1 Satisfies the following relationship:

[0115]

[0116]

[0117] in, is the power control factor of the physical sidelink shared channel PSSCH on the symbol used to transmit the CSI-RS, is the power control factor of PSSCH on symbols not used for transmitting CSI-RS, W is the number of subchannels in the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, Y is the number of subchannels in the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the number of CSI-RS ports.

[0118] In a seventh aspect, an embodiment of the present application provides a communication device, which may be the first terminal device in any of the above aspects, or other devices supporting the functions of the first terminal device, such as a component in the first terminal device (such as a chip system). The device includes:

[0119] A communication interface for sending a channel state information reference signal CSI-RS to a second terminal device; wherein the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of a resource pool, the resource pool is a set of time-frequency resources contained in the side link SL partial bandwidth BWP, the resource pool includes one or more continuous sub-channels in the frequency domain, a sub-channel of the resource pool includes one or more continuous physical resource blocks PRB, and the resource pool is determined in the time domain according to a periodic bit map.

[0120] In one possible design, the communication interface is also used to send first indication information to the second terminal device, where the first indication information is used to instruct the second terminal device to send channel state information CSI, and the first indication information is included in the second-level sidelink control information SCI.

[0121] In one possible design, the first indication information is also used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

[0122] In one possible design, the communication interface is also used to send second indication information, where the second indication information is used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

[0123] In one possible design, the second indication information is included in radio resource control RRC signaling.

[0124] In one possible design, the CSI includes at least one of the following:

[0125] Wideband channel quality indicator CQI index, where the wideband CQI index is the CQI index corresponding to the frequency domain bandwidth of the CSI-RS;

[0126] The CQI values ​​of one or more sub-channels in the resource pool, the CQI value of a sub-channel in the resource pool corresponds to the CQI index of a sub-channel in the resource pool.

[0127] In a possible design, the CSI is carried in the medium access control layer control element MAC CE, and the number of bytes occupied by the MAC CE is related to the number of sub-channels in the resource pool. In other words, the size of the MAC CE provided by the present application is variable, and its design method is more flexible.

[0128] In one possible design, the MAC CE includes bytes;

[0129] in, is the round-up symbol, and y is the number of subchannels in the resource pool.

[0130] In one possible design, the power control factor β of the CSI-RS is CSI-RS,1 Satisfies the following relationship:

[0131]

[0132] in, is the power control factor of the physical sidelink shared channel PSSCH, W is the number of subchannels in the PSSCH bandwidth, Y is the number of subchannels in the resource pool, Y ≥ W, is the number of PSSCH layers scheduled, Q p is the number of CSI-RS ports.

[0133] In one possible design, the power control factor β of the CSI-RS is CSI-RS,1 Satisfies the following relationship:

[0134]

[0135]

[0136] in, is the power control factor of the physical sidelink shared channel PSSCH on the symbol used to transmit the CSI-RS, is the power control factor of PSSCH on symbols not used for transmitting CSI-RS, W is the number of subchannels in the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, Y is the number of subchannels in the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the number of CSI-RS ports.

[0137] In an eighth aspect, an embodiment of the present application provides a communication device, which may be a second terminal device of any of the above aspects, or other devices supporting the functions of the second terminal device, such as a component in the second terminal device (such as a chip system). The device includes:

[0138] A communication interface for receiving a channel state information reference signal CSI-RS from a first terminal device; wherein the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of a resource pool, the resource pool is a set of time-frequency resources contained in the side link SL partial bandwidth BWP, the resource pool includes one or more continuous sub-channels in the frequency domain, a sub-channel of the resource pool includes one or more continuous physical resource blocks PRB, and the resource pool is determined in the time domain according to a periodic bit map.

[0139] In one possible design, the communication interface is also used to receive first indication information from the first terminal device, where the first indication information is used to instruct the second terminal device to send channel state information CSI, and the first indication information is included in the second-level sidelink control information SCI.

[0140] In one possible design, the first indication information is also used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

[0141] In one possible design, the communication interface is also used to receive second indication information from the first terminal device, where the second indication information is used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

[0142] In one possible design, the second indication information is included in radio resource control RRC signaling.

[0143] In one possible design, the CSI includes at least one of the following:

[0144] Wideband channel quality indicator CQI index, where the wideband CQI index is the CQI index corresponding to the frequency domain bandwidth of the CSI-RS;

[0145] The CQI values ​​of one or more sub-channels in the resource pool, the CQI value of a sub-channel in the resource pool corresponds to the CQI index of a sub-channel in the resource pool.

[0146] In a possible design, the CSI is carried in a medium access control layer control element MAC CE, and the number of bytes occupied by the MAC CE is related to the number of sub-channels in the resource pool.

[0147] In one possible design, the MAC CE includes bytes;

[0148] in, is the round-up symbol, and y is the number of subchannels in the resource pool.

[0149] In one possible design, the power control factor β of the CSI-RS is CSI-RS,1 Satisfies the following relationship:

[0150]

[0151] in, is the power control factor of the physical sidelink shared channel PSSCH, W is the number of subchannels in the PSSCH bandwidth, Y is the number of subchannels in the resource pool, Y ≥ W, is the number of PSSCH layers scheduled, Q p is the number of CSI-RS ports.

[0152] In one possible design, the power control factor β of the CSI-RS is CSI-RS,1 Satisfies the following relationship:

[0153]

[0154]

[0155] in, is the power control factor of the physical sidelink shared channel PSSCH on the symbol used to transmit the CSI-RS, is the power control factor of PSSCH on symbols not used for transmitting CSI-RS, W is the number of subchannels in the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, Y is the number of subchannels in the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the number of CSI-RS ports.

[0156] In a ninth aspect, an embodiment of the present application provides a communication device, which may be the first terminal device in any of the above aspects, or other devices supporting the functions of the first terminal device, such as a component in the first terminal device (such as a chip system). The device includes:

[0157] A communication interface is used to send first indication information to a second terminal device, wherein the first indication information is used to indicate a frequency domain bandwidth of the SL CSI-RS.

[0158] In one possible design, the first indication information is included in PC5 RRC signaling.

[0159] In one possible design, the method also includes: sending CSI-RS to the second terminal device.

[0160] Among them, the power control factor of CSI-RS is CSI-RS,1 Satisfies the following relationship:

[0161]

[0162] in, is the power control factor of PSSCH on the OFDM symbol used to transmit SL CSI-RS; W is the number of subchannels in the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, and U is the number of overlapping subchannels in the frequency domain bandwidth of PSSCH and SL CSI-RS (exemplarily, as Fig.13 , U=1), Q p is the number of SL CSI-RS ports, y is the number of subchannels in the frequency domain bandwidth of SL CSI-RS, is the number of PSSCH layers scheduled, y is less than or equal to Y, and Y is the number of subchannels in the resource pool.

[0163] For the power control factor of PSSCH on the OFDM symbol used to transmit SL CSI-RS, that is, It satisfies the following relationship:

[0164]

[0165] in, is the power control factor of PSSCH in OFDM symbols not used for transmitting SL CSI-RS.

[0166] In one possible design, the method also includes: sending second indication information to a second terminal device.

[0167] The second indication information is used to trigger the second terminal device to measure the channel according to the SL CSI-RS and feed back the SL CSI.

[0168] Optionally, the second indication information is included in a second-level SCI.

[0169] In a tenth aspect, an embodiment of the present application provides a communication device, which may be a second terminal device of any of the above aspects, or other devices supporting the functions of the second terminal device, such as a component in the second terminal device (such as a chip system). The device includes:

[0170] The communication interface is used to receive third indication information from the first terminal device, wherein the third indication information is used to indicate the frequency domain bandwidth of the SL CSI-RS.

[0171] In one possible design, the first indication information is included in PC5 RRC signaling.

[0172] In one possible design, the method also includes: receiving CSI-RS from the first terminal device.

[0173] Among them, the power control factor of CSI-RS is CSI-RS,1 Satisfies the following relationship:

[0174]

[0175] in, is the power control factor of PSSCH on the OFDM symbol used to transmit SL CSI-RS; W is the number of subchannels in the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, and U is the number of overlapping subchannels in the frequency domain bandwidth of PSSCH and SL CSI-RS (exemplarily, as Fig.13 , U=1), Q p is the number of SL CSI-RS ports, y is the number of subchannels in the frequency domain bandwidth of SL CSI-RS, is the number of PSSCH layers scheduled, y is less than or equal to Y, and Y is the number of subchannels in the resource pool.

[0176] For the power control factor of PSSCH on the OFDM symbol used to transmit SL CSI-RS, that is, It satisfies the following relationship:

[0177]

[0178] in, is the power control factor of PSSCH in OFDM symbols not used for transmitting SL CSI-RS.

[0179] In one possible design, the method also includes: receiving second indication information from the first terminal device.

[0180] The second indication information is used to trigger the second terminal device to measure the channel according to the SL CSI-RS and feed back the SL CSI.

[0181] Optionally, the second indication information is included in a second-level SCI.

[0182] In an eleventh aspect, an embodiment of the present application provides a communication device, which may be the first terminal device in any of the above aspects, or other devices supporting the functions of the first terminal device, such as a component in the first terminal device (such as a chip system). The device includes:

[0183] The communication interface receives CSI from the second terminal device.

[0184] CSI includes at least one of the following:

[0185] Wideband channel quality indicator CQI index, where the wideband CQI index is the CQI index corresponding to the frequency domain bandwidth of the CSI-RS;

[0186] The CQI values ​​of one or more sub-channels in the resource pool, the CQI value of a sub-channel in the resource pool corresponds to the CQI index of a sub-channel in the resource pool.

[0187] In one possible design, the method also includes: sending a channel state information reference signal CSI-RS to a second terminal device; wherein the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of a resource pool, the resource pool is a set of time-frequency resources contained in the side link SL partial bandwidth BWP, the resource pool includes one or more continuous sub-channels in the frequency domain, a sub-channel of the resource pool includes one or more continuous physical resource blocks PRB, and the resource pool is determined in the time domain according to a periodic bit map bitmap.

[0188] In one possible design, the method also includes: sending first indication information to the second terminal device, the first indication information is used to instruct the second terminal device to send channel state information CSI, and the first indication information is included in the second-level sidelink control information SCI.

[0189] In one possible design, the first indication information is also used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

[0190] In one possible design, the method also includes: sending second indication information to the second terminal device, the second indication information being used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

[0191] In one possible design, the second indication information is included in radio resource control RRC signaling.

[0192] In a possible design, the CSI is carried in a medium access control layer control element MAC CE, and the number of bytes occupied by the MAC CE is related to the number of sub-channels in the resource pool.

[0193] In one possible design, the MAC CE includes bytes;

[0194] in, is the round-up symbol, and y is the number of subchannels in the resource pool.

[0195] In one possible design, the power control factor β of the CSI-RS is CSI-RS,1 Satisfies the following relationship:

[0196]

[0197] in, is the power control factor of the physical sidelink shared channel PSSCH, W is the number of subchannels in the PSSCH bandwidth, Y is the number of subchannels in the resource pool, Y ≥ W, is the number of PSSCH layers scheduled, Q p is the number of CSI-RS ports.

[0198] In one possible design, the power control factor β of the CSI-RS is CSI-RS,1 Satisfies the following relationship:

[0199]

[0200]

[0201] in, is the power control factor of the physical sidelink shared channel PSSCH on the symbol used to transmit the CSI-RS, is the power control factor of PSSCH on symbols not used for transmitting CSI-RS, W is the number of subchannels in the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, Y is the number of subchannels in the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the number of CSI-RS ports.

[0202] In a twelfth aspect, an embodiment of the present application provides a communication device, which may be a second terminal device of any of the above aspects, or other devices supporting the functions of the second terminal device, such as a component in the second terminal device (such as a chip system). The device includes:

[0203] The communication interface sends the CSI to the first terminal device.

[0204] CSI includes at least one of the following:

[0205] Wideband channel quality indicator CQI index, where the wideband CQI index is the CQI index corresponding to the frequency domain bandwidth of the CSI-RS;

[0206] The CQI values ​​of one or more sub-channels in the resource pool, the CQI value of a sub-channel in the resource pool corresponds to the CQI index of a sub-channel in the resource pool.

[0207] In one possible design, the method also includes: receiving a channel state information reference signal CSI-RS from a first terminal device; wherein the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of a resource pool, the resource pool is a set of time-frequency resources contained in the side link SL partial bandwidth BWP, the resource pool includes one or more continuous sub-channels in the frequency domain, a sub-channel of the resource pool includes one or more continuous physical resource blocks PRB, and the resource pool is determined in the time domain according to a periodic bit map bitmap.

[0208] In one possible design, the method also includes: receiving first indication information from the first terminal device, the first indication information is used to indicate the second terminal device to send channel state information CSI, and the first indication information is included in the second-level sidelink control information SCI.

[0209] In one possible design, the first indication information is also used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

[0210] In one possible design, the method also includes: receiving second indication information from the first terminal device, the second indication information being used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

[0211] In one possible design, the second indication information is included in radio resource control RRC signaling.

[0212] In a possible design, the CSI is carried in a medium access control layer control element MAC CE, and the number of bytes occupied by the MAC CE is related to the number of sub-channels in the resource pool.

[0213] In one possible design, the MAC CE includes bytes;

[0214] in, is the round-up symbol, and y is the number of subchannels in the resource pool.

[0215] In one possible design, the power control factor β of the CSI-RS is CSI-RS,1 Satisfies the following relationship:

[0216]

[0217] in, is the power control factor of the physical sidelink shared channel PSSCH, W is the number of subchannels in the PSSCH bandwidth, Y is the number of subchannels in the resource pool, Y ≥ W, is the number of PSSCH layers scheduled, Q p is the number of CSI-RS ports.

[0218] In one possible design, the power control factor β of the CSI-RS is CSI-RS,1 Satisfies the following relationship:

[0219]

[0220]

[0221] in, is the power control factor of the physical sidelink shared channel PSSCH on the symbol used to transmit the CSI-RS, is the power control factor of PSSCH on symbols not used for transmitting CSI-RS, W is the number of subchannels in the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, Y is the number of subchannels in the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the number of CSI-RS ports.

[0222] In a thirteenth aspect, the present application provides a communication device for implementing the function of the first terminal device in any of the above aspects, or for implementing the function of the second terminal device in any of the above aspects.

[0223] In a fourteenth aspect, the present application provides a communication device having the function of implementing any of the communication methods in any of the above aspects. The function can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

[0224] In a fifteenth aspect, a communication device is provided, comprising: a processor and a memory; the memory is used to store computer execution instructions, and when the communication device is running, the processor executes the computer execution instructions stored in the memory to enable the communication device to perform a communication method as described in any one of the above aspects.

[0225] In a sixteenth aspect, a communication device is provided, comprising: a processor; the processor is used to couple with a memory, and after reading instructions in the memory, execute a communication method as described in any one of the above aspects according to the instructions.

[0226] In the seventeenth aspect, an embodiment of the present application provides a communication device, comprising: a processor and an interface circuit; the interface circuit is used to receive code instructions and transmit them to the processor; the processor is used to run the code instructions to execute a communication method such as any one of the above aspects.

[0227] In an eighteenth aspect, an embodiment of the present application provides a communication device, which may be a chip system, which includes a processor and, optionally, a memory, for implementing the functions of the method described in any of the above aspects. The chip system may be composed of a chip, or may include a chip and other discrete devices.

[0228] In a nineteenth aspect, a communication device is provided, which may be a circuit system, the circuit system including a processing circuit, and the processing circuit is configured to execute a communication method as described in any one of the above aspects.

[0229] In the twentieth aspect, an embodiment of the present application also provides a computer-readable storage medium, comprising instructions, which, when executed on a computer, enables the computer to execute any of the methods described above.

[0230] In the twenty-first aspect, an embodiment of the present application also provides a computer program product, comprising instructions, which, when executed on a computer, enables the computer to execute any of the above methods.

[0231] In the twenty-second aspect, an embodiment of the present application provides a system, the system comprising a first terminal device and a second terminal device of any aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0232] Figure 1 (a) is a schematic diagram of a channel measurement architecture provided in an embodiment of the present application, Figure 1 (b) is a schematic diagram of a channel measurement architecture provided in an embodiment of the present application;

[0233] Figure 2 A schematic diagram of a bandwidth provided in an embodiment of the present application;

[0234] Figure 3 A schematic diagram of a communication system architecture provided in an embodiment of the present application;

[0235] Figure 4 A schematic diagram of the structure of a communication device provided in an embodiment of the present application;

[0236] Figure 5 A flow chart of a communication method provided in an embodiment of the present application;

[0237] Figure 6 (a) is a schematic diagram of a resource pool provided in an embodiment of the present application, Figure 6 (b) is a schematic diagram of another bandwidth provided in an embodiment of the present application;

[0238] Figure 7 A schematic diagram of a MAC CE provided in an embodiment of the present application;

[0239] Figure 8 A schematic diagram of another MAC CE provided in an embodiment of the present application;

[0240] Fig. 9 A schematic diagram of another MAC CE provided in an embodiment of the present application;

[0241] Fig.10 A flowchart of another communication method provided in an embodiment of the present application;

[0242] Fig.11 A flowchart of another communication method provided in an embodiment of the present application;

[0243] Fig.12 A flowchart of another communication method provided in an embodiment of the present application;

[0244] Fig.13 A schematic diagram of another bandwidth provided in an embodiment of the present application;

[0245] Fig.14 A schematic diagram of the structure of a communication device provided in an embodiment of the present application;

[0246] Fig.15 A schematic diagram of the structure of another communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0247] The terms "first" and "second" and the like in the specification and drawings of this application are used to distinguish different objects, or to distinguish different processing of the same object, rather than to describe a specific order of objects.

[0248] "At least one" means one or more.

[0249] "Plurality" means two or more.

[0250] "And / or" describes the association relationship of associated objects, indicating that there can be three types of relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural.

[0251] The character “ / ” generally indicates that the related objects are in an “or” relationship. For example, A / B can mean A or B.

[0252] In addition, the terms "including" and "having" and any variations thereof mentioned in the description of the present application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but may optionally include other steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products or devices.

[0253] It should be noted that, in the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0254] In the specification and drawings of this application, "of", "corresponding, relevant" and "corresponding" may sometimes be used interchangeably. It should be pointed out that when the distinction is not emphasized, the meanings to be expressed are consistent.

[0255] First, some technical terms involved in the embodiments of the present application are introduced:

[0256] 1. Channel measurement

[0257] In order to obtain the channel status, etc., the communication system introduces a channel measurement process. In the NR system, the uplink (UL) channel measurement is implemented through the sounding reference signal (SRS) framework. Figure 1 (a) Downlink (DL) channel measurement is achieved through a flexible CSI-RS framework. SL channel measurement is achieved through a CSI-RS framework.

[0258] This application embodiment mainly introduces the channel measurement process of SL. Figure 1 (b) takes the transmitting end (i.e., the side that sends CSI-RS) as UE1 and the receiving end (i.e., the side that receives CSI-RS) as UE3 as an example. In SL, the CSI-RS framework is mainly implemented as follows: UE1 sends CSI-RS to UE3, UE3 measures the channel based on the CSI-RS, calculates CSI, and feeds back CSI to UE1.

[0259] At the transmitting end, i.e. UE1, CSI is used to calculate appropriate transmission parameters to optimize the utilization efficiency of the wireless channel. At the receiving end, i.e. UE3, CSI is used to achieve correct signal reception.

[0260] 2. CSI process of Uu interface

[0261] Uu interface refers to the interface between network equipment and terminal equipment, for example, Figure 1 In (a), the interface between the base station and UE2 is the Uu interface.

[0262] The CSI process at the Uu interface includes a configuration phase and a channel measurement phase. In the configuration phase, the base station configures CSI-RS resources for the UE. In the channel measurement phase, the base station sends CSI-RS to the UE, and the UE feeds back CSI to the base station based on the CSI-RS.

[0263] In the configuration phase, the base station (such as gNB) configures one or more CSI-RS patterns for the UE through radio resource control (RRC) signaling. The configuration parameters of each CSI-RS pattern include resource ID, resource mapping parameters, etc. Among them, the resource mapping parameters further include the number of ports, frequency domain position, time domain position, frequency domain bandwidth, etc. of the CSI-RS. The gNB sends the CSI-RS to the UE, the UE measures the CSI-RS, calculates the CSI, and feeds the CSI back to the gNB.

[0264] In the configuration parameters of the above CSI-RS resources, the frequency domain bandwidth of the CSI-RS is configured by the CSI-FrequencyOccupation information element (IE) in the RRC signaling. Exemplarily, the configuration information included in the CSI-FrequencyOccupation IE is as follows:

[0265]

[0266] The meaning of each field in the CSI-FrequencyOccupation IE is as follows: startingRB indicates the position of the starting physical resource block (PRB) of the CSI-RS resource in the frequency domain relative to the common resource block #0 (CRB#0 for short) within the resource block (RB) grid. The value range of startingRB is greater than or equal to 0 and less than or equal to maxNrofPhysicalResourceBlocks-1, and startingRB is an integer multiple of 4. The value of maxNrofPhysicalResourceBlocks is defined by the standard as 275, so the value range of startingRB is {0, 4, 8, ...}.

[0267] It should be noted that PRB and RB can be considered to have the same meaning, that is, both represent 12 consecutive subcarriers in the frequency domain. The above CRB#0 represents the common reference point of the RB grid. For any PRB, its frequency domain position can be determined by its offset relative to CRB#0.

[0268] nrofRBs indicates the number of PRBs covered by the CSI-RS resource (span). The value of nrofRBs must be an integer multiple of 4. The minimum configurable nrofRBs value is: the minimum value between 24 and the bandwidth of the bandwidth part (BWP) associated with the CSI-RS, and the maximum configurable nrofRBs value is: maxNrofPhysicalResourceBlocksPlus1, and the value of maxNrofPhysicalResourceBlocksPlus1 is defined by the standard as 276. When the configured nrofRBs value is greater than the bandwidth of the BWP associated with the CSI-RS, the UE will assume that the actual bandwidth of the CSI-RS resource is the same as the bandwidth of the BWP.

[0269] It should be noted that the above BWP represents a subset of the carrier bandwidth or the system bandwidth. The bandwidth of the BWP can be represented by the number of PRBs.

[0270] Based on the above RRC signaling, the gNB configures the frequency domain bandwidth of a certain CSI-RS resource for the UE.

[0271] During the channel measurement phase, when the UE feeds back CSI to the gNB, if the gNB configures the UE to feed back the channel quality indicator (CQI) corresponding to the sub-band, the UE feeds back the sub-band differential CQI value corresponding to each sub-band in multiple sub-bands based on the sub-band granularity. Specifically, when the UE feeds back the sub-band differential CQI to the gNB, it also needs to feed back the wideband CQI index.

[0272] The differential CQI value corresponding to a subband is determined by the subband CQI index and the wideband CQI index. The differential CQI value is 2 bits. The CQI index (including the wideband CQI index and the subband CQI index) is 4 bits, and the CQI index is an integer from 0 to 15. The larger the value of the CQI index, the better the quality of the channel, and vice versa. The size of a single subband is configured by RRC signaling, and the value is one of {4, 8, 16, 32}, and the unit is PRB.

[0273] The differential CQI value is determined by the subband CQI index and the wideband CQI index, specifically including the following steps: for the subband with index s, according to its subband CQI index and the wideband CQI index, the subband offset level is determined according to the following formula:

[0274] Subband offset level(s)=subband CQI index(s)−wideband CQI index.

[0275] Where s represents the index of the subband. Thus, the subband offset level (s) represents the subband offset level of the subband indexed as s, and the subband CQI index (s) represents the subband CQI index of the subband indexed as s. For any subband, according to its subband offset level, its differential CQI value is determined as shown in Table 1, for example.

[0276] Table 1

[0277] Differential CQI value Subband offset level 0 0 1 1 2 ≥2 3 ≤-1

[0278] For example, when the UE calculates the CSI based on the CSI-RS from the gNB, the wideband CQI index is 13, and the subband CQI index of subband 0 is 11, then the corresponding subband offset level is 11-13=-2. According to the above Table 1, when the subband offset level is less than or equal to 1, the differential CQI value is 3, so the 2-bit differential CQI value corresponding to subband 0 can be expressed as 11.

[0279] In this CSI process, based on the subband granularity, the size of a single subband is one of {4, 8, 16, 32}, and as described above, the frequency domain bandwidth of CSI-RS must be a multiple of 4. The concept of subchannels is introduced in NR. According to the 3GPP R16 protocol, the number of PRBs corresponding to a single subchannel can be optionally 10, 15, 20, 25, 50, 75, 100, etc. After multiplying this number by the number of subchannels corresponding to PSSCH, it cannot be guaranteed to be a multiple of 4. Therefore, the existing method of configuring the CSI-RS frequency domain bandwidth in the Uu interface is not applicable to NR. In addition, considering that NR does not introduce the concept of subbands, the differential CQI value is also not applicable to NR.

[0280] 3. CSI process of PC5 interface

[0281] In the configuration phase, the transmitting UE configures a CSI-RS pattern for the receiving UE via PC5 RRC signaling, wherein the configuration parameters of the CSI-RS pattern include the number of CSI-RS ports, frequency domain position, and time domain position.

[0282] Different from the CSI process of the Uu interface mentioned above, in the current CSI process of the PC5 interface, the base station does not configure the frequency domain bandwidth of the CSI-RS pattern. This is because the 3GPP R16 protocol stipulates that there is SL CSI-RS on each PRB corresponding to the physical sidelink shared channel (PSSCH), which means that the frequency domain bandwidth of the SL CSI-RS is the same as the frequency domain bandwidth of the associated PSSCH.

[0283] The PSSCH associated with the SL CSI-RS can be understood as the PSSCH that transmits the SL CSI-RS.

[0284] It should be noted that PSSCH is a channel used to transmit SL data. The frequency domain bandwidth of PSSCH can be represented by the number of PRBs. Specifically, the frequency domain bandwidth of PSSCH is composed of one or more sub-channels in the resource pool, and a sub-channel is composed of multiple consecutive PRBs. Multiply the number of sub-channels corresponding to PSSCH and the number of PRBs corresponding to a sub-channel to obtain the number of PRBs contained in PSSCH. Among them, the resource pool refers to a set of time-frequency resources that can be used for SL transmission, specifically in the form of multiple orthogonal frequency division multiplexing (OFDM) symbols in the time domain and a set corresponding to multiple consecutive PRBs in the frequency domain.

[0285] For example, in Figure 2 In the , the resource pool contains 4 subchannels, each subchannel contains 10 PRBs, and the PSSCH includes 2 subchannels, that is, 20 PRBs, so the frequency domain bandwidth of the PSSCH is 20 PRBs. Since the protocol stipulates that the frequency domain bandwidth of the SL CSI-RS is the same as the frequency domain bandwidth of the associated PSSCH, the frequency domain bandwidth of the SL CSI-RS is also 20 PRBs. Figure 2 The figure shows the time-frequency resource occupancy of SL CSI-RS in one subchannel of PSSCH. It can be seen that SL CSI-RS exists on all 10 PRBs corresponding to the subchannel. In each PRB, the number of ports, time domain position, and frequency domain position of SL CSI-RS are the same.

[0286] During the channel measurement phase, the transmitting UE sends sidelink control information (SCI) to the receiving UE. The SCI includes a first-stage SCI (1st stage SCI) and a second-stage SCI (2nd stage SCI), the first-stage SCI is carried in the physical sidelink control channel (PSCCH), and the second-stage SCI is carried in the PSSCH. One bit in the second-stage SCI is used to trigger the receiving UE to feedback CSI. The transmitting UE sends a SL CSI-RS to the receiving UE, the receiving UE measures and calculates the CSI based on the SL CSI-RS, and feeds back the CSI to the transmitting UE through the media access control (MAC) control element (CE).

[0287] Different from the CSI process of the above-mentioned Uu interface, in the current CSI process of the PC5 interface, when the receiving UE feeds back CSI to the transmitting UE, the 3GPP R16 protocol stipulates that the differential CQI value shall not be fed back. Therefore, the receiving UE feeds back a 1-bit rank indicator (RI) and a 4-bit wideband CQI index (without feeding back the differential CQI value) to the transmitting UE through the medium access control control element (MAC CE).

[0288] In the existing CSI process of the PC5 interface, the frequency domain bandwidth of the SL CSI-RS is the same as the frequency domain bandwidth of the associated PSSCH, so the receiving end can only measure and calculate the CSI on one or more subchannels corresponding to the associated PSSCH. Figure 2 As shown in the figure, SL CSI-RS only exists on the PRBs of the shaded sub-channels, so the receiver can only measure and calculate the CSI on these sub-channels. This will result in the following disadvantages:

[0289] (1) When the transmitting UE selects other subchannels (unshaded subchannels) to send PSSCH, since the receiving UE does not measure and feedback the CSI of the other subchannels, the transmitting UE cannot know the specific situation of the other subchannels. As a result, the transmitting UE may not be able to reasonably adjust the modulation and coding scheme (MCS) used to send PSSCH.

[0290] (2) The transmitting UE determines one or more subchannels (such as Figure 2 The channel quality of the two sub-channels filled with shadows is very poor, but due to the lack of other sub-channels (such as Figure 2 The transmitting UE cannot determine whether the other subchannels in the resource pool can realize reliable PSSCH transmission. Therefore, it is likely that the reliability of PSSCH transmission cannot be improved by switching subchannels.

[0291] From the above analysis, it can be seen that in the current CSI scheme of the PC5 interface, according to the CSI fed back by the receiving UE, the transmitting UE may still be unable to reasonably allocate resources, which is not conducive to achieving effective frequency hopping communication in SL.

[0292] In addition, in the current CSI solution of the PC5 interface, the CSI carries 1-bit RI and 4-bit wideband CQI index, the fed-back CSI content is small, and it is not conducive to achieving effective frequency hopping communication in SL.

[0293] It can be seen that the current CSI solutions for the Uu interface and PC5 interface are not suitable for NR.

[0294] In order to solve the above technical problems, an embodiment of the present application provides a communication method. The communication method can be applied to SL scenarios. Including scenarios of direct communication between various terminal devices. For example, including but not limited to V2X, device to device (D2D) communication, vehicle to vehicle (V2V) communication, etc.

[0295] Figure 3 A V2X communication system is provided in an embodiment of the present application, such as Figure 3 As shown, the V2X communication system may include: multiple terminal devices (such as Figure 3 The terminal device 1, terminal device 2, terminal device 3, ... are shown in the figure). A direct communication link can be established between the terminal device and the surrounding terminal devices to realize direct communication, such as: terminal device 1 can communicate directly with terminal device 2. Exemplarily, the direct communication link established between the terminal devices can be defined as SL, and the interface for direct communication between the terminal device and the surrounding terminal devices can be called PC5 port. Figure 3 The V2X communication system shown may also include a network device. The terminal device may send a V2X message to the opposite terminal device by means of a network device or access the network through the network device. For example, terminal device 1 may send a V2X message to the network device, and the network device may send the V2X message to terminal device 2. Exemplarily, the interface between the terminal device and the network device may be referred to as a Uu interface. Optionally, Figure 3 The network architecture shown is only an exemplary architecture diagram, and the embodiments of this application are not limited to Figure 3 The number of network elements included in the V2X communication system shown. Figure 3 In addition to the network functional entities shown, Figure 3 The communication system shown may also include other functional entities, such as application servers, core network equipment, etc., without limitation.

[0296] Figure 3 The network equipment in it is mainly used to realize functions such as wireless physical control functions, resource scheduling and wireless resource management, wireless access control and mobility management. The network equipment can be an access network (AN) / radio access network (RAN) equipment, or it can be a device composed of multiple 5G-AN / 5G-RAN nodes, or it can be any node in a base station (nodeB, NB), an evolved base station (evolution nodeB, eNB), a next generation base station (generation nodeB, gNB), a transmission receive point (TRP), a transmission point (TP) and some other access nodes. In the embodiment of the present application, the device for realizing the function of the network device can be a network device, or it can be a device that can support the network device to realize the function, such as a chip system. In the technical solution provided in the embodiment of the present application, the technical solution provided in the embodiment of the present application is described by taking the device for realizing the function of the network device as a network device as an example.

[0297] The terminal device is a terminal that is connected to the V2X communication system and has a wireless transceiver function or a chip that can be set in the terminal. Figure 3 The vehicle shown is not limited to any type of vehicle such as a car, bicycle, electric car, airplane, ship, train, high-speed rail, etc. The vehicle may include an on-board device that can directly communicate with other devices. The on-board device can be called user equipment (UE) or terminal equipment.

[0298] The terminal device may also be a user device, an access terminal, a user unit, a user station, a mobile station, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent or a user device. For example, the terminal device in the embodiments of the present application may be a mobile phone, a tablet computer, a computer with a wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, a vehicle-mounted terminal, an RSU with terminal function, etc. The terminal device of the present application can also be a vehicle-mounted module, vehicle-mounted module, vehicle-mounted component, vehicle-mounted chip or vehicle-mounted unit built into the vehicle as one or more components or units. The vehicle can implement the communication method provided by the present application through the built-in vehicle-mounted module, vehicle-mounted module, vehicle-mounted component, vehicle-mounted chip or vehicle-mounted unit.

[0299] In the embodiment of the present application, the device for realizing the function of the terminal device may be the terminal device itself, or a device capable of supporting the terminal device to realize the function, such as a chip system. In the embodiment of the present application, the chip system may be composed of a chip, or may include a chip and other discrete devices.

[0300] The system architecture and business scenarios described in this application are intended to more clearly illustrate the technical solutions of this application, and do not constitute the sole limitation on the technical solutions provided by this application. A person of ordinary skill in the art will appreciate that, with the evolution of the system architecture and the emergence of new business scenarios, the technical solutions provided by this application are equally applicable to similar technical problems.

[0301] Optionally, the terminal device in the embodiment of the present application can be Figure 4 The communication device of the described structure is implemented. Figure 4 The structure diagram of a communication device provided in an embodiment of the present application is shown in FIG. 400 . The communication device 400 includes at least one processor 401 , a memory 403 , and at least one communication interface 404 . The memory 403 may also be included in the processor 401 .

[0302] The processor 401 may be composed of one or more processing units, which may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of the program of the present application.

[0303] There are communication lines between the above components for transmitting information between the components.

[0304] Communication interface 404, used to communicate with other devices. In the embodiment of the present application, the communication interface can be a module, a circuit, an interface or other device capable of implementing a communication function, used to communicate with other devices. Optionally, the communication interface can be an independently arranged transmitter, which can be used to send information to other devices, and the communication interface can also be an independently arranged receiver, which is used to receive information from other devices. The communication interface can also be a component that integrates the functions of sending and receiving information, i.e., a transceiver. The embodiment of the present application does not limit the specific implementation of the communication interface.

[0305] The memory 403 may be a read-only memory (ROM) or other types of storage modules that can store static information and instructions, a random access memory (RAM) or other types of storage modules that can dynamically store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), an optical disk, a magnetic disk or other magnetic storage device. The memory may be independent and connected to the processor via a communication line. The memory may also be integrated with the processor.

[0306] The memory 403 is used to store computer-executable instructions, and the computer-executable instructions can be called by one or more processing units in the processor 401 to execute corresponding steps in each method provided in the following embodiments.

[0307] Optionally, the computer-executable instructions in the embodiments of the present application may also be referred to as application code, instructions, computer program or other names, which are not specifically limited in the embodiments of the present application.

[0308] In a specific implementation, as an embodiment, the communication device 400 may include multiple processors, such as Figure 4401 and processor 407 in the embodiment. Each of these processors may be a single-core processor or a multi-core processor. The processor herein may refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions).

[0309] In a specific implementation, as an embodiment, the communication device 400 may further include an output device 405 and an input device 406. The output device 405 communicates with the processor 401 and may display information in a variety of ways. For example, the output device 405 may be a liquid crystal display (LCD), a light emitting diode (LED) display device, a cathode ray tube (CRT) display device, or a projector. The input device 406 communicates with the processor 401 and may receive user input in a variety of ways. For example, the input device 406 may be a mouse, a keyboard, a touch screen device, or a sensor device.

[0310] like Figure 4 It should be understood that the communication device shown in the figure is only an example, and in actual application, the communication device may have more Figure 4 More or fewer components may be shown, two or more components may be combined, or there may be a different configuration of components.

[0311] The communication device 400 may be a general device or a dedicated device, and the embodiment of the present application does not limit the type of the communication device 400. The terminal device may be a Figure 4 Devices of similar structure.

[0312] The communication method provided in the embodiments of the present application is described below with reference to the accompanying drawings.

[0313] It should be noted that the embodiments of the present application are mainly used in SL scenarios, that is, in the process of communication between terminal devices through the PC5 interface. Figure 5 The communication method provided in the embodiment of the present application includes the following steps:

[0314] S501. A first terminal device sends first indication information to a second terminal device.

[0315] Correspondingly, the second terminal device receives the first indication information from the first terminal device.

[0316] The first indication information is used to instruct the second terminal device to send SL CSI. The first indication information may also be referred to as trigger information. As a possible implementation, the first indication information is included in the second-level SCI, for example, the first indication information may be 1 bit in the second-level SCI.

[0317] In the embodiment of the present application, the first terminal device refers to a terminal device that sends SL CSI-RS, and the second terminal device refers to a terminal device that receives SL CSI-RS, measures SL CSI based on SL CSI-RS, and feeds back SL CSI to the first terminal device. It should be understood that in different scenarios, the roles of the first terminal device and the second terminal device can be interchanged.

[0318] S502. The first terminal device sends a SL CSI-RS to the second terminal device.

[0319] Correspondingly, the second terminal device receives the SL CSI-RS from the first terminal device.

[0320] The frequency domain bandwidth of the SL CSI-RS is the same as the frequency domain bandwidth of the resource pool.

[0321] As a possible implementation method, the resource pool is a set of time-frequency resources contained in the SL BWP, the resource pool includes one or more continuous sub-channels in the frequency domain, a sub-channel of the resource pool includes one or more continuous PRBs, and the resource pool is determined in the time domain according to a periodic bitmap.

[0322] Optionally, BWP represents a subset of a carrier bandwidth or a system bandwidth.

[0323] Optionally, the number of subchannels included in the resource pool, the number of PRBs included in a subchannel in the resource pool, and the bit map are determined according to high-level signaling. The high-level signaling is RRC signaling from a network device, or pre-configuration information of the first terminal device.

[0324] Optionally, the resource pool may be used for transmission of PSSCH or for reception of PSSCH. The resource pool may be associated with one of SL resource allocation mode 1 or SL resource allocation mode 2.

[0325] Resource allocation mode 1 and resource allocation mode 2 may also have other names, which are not limited in the embodiments of the present application.

[0326] For example, see Figure 6 (a), BWP is a subset of the carrier bandwidth of the SL carrier. The time-frequency resources in BWP include the time-frequency resource sets corresponding to resource pool 1, resource pool 2...resource pool n. Among them, Figure 6 (a) shows the frequency domain resources included in resource pool 2, that is, 4 subchannels in the frequency domain, each subchannel includes one or more PRBs, and some time domain resources included in resource pool 2. Time domain resources include but are not limited to time slots and symbols. Among them, the time domain resources included in resource pool 2 are determined according to a bit map. The bit map is 00000111, indicating that with 8 time slots as a period, only the last three time slots in every 8 time slots can be used for SL transmission.

[0327] It should be noted that, for the convenience of description, the SL CSI-RS in the embodiment of the present application may also be referred to as CSI-RS, and similarly, the SL CSI may also be referred to as CSI. They are described uniformly here.

[0328] It should be understood that the transmitting UE sends the SL CSI-RS to the receiving UE on a certain resource pool, so it can be considered that the resource pool is associated with the SL CSI-RS. The frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool. Exemplarily, if the frequency domain bandwidth of the resource pool is X PRBs, then the frequency domain bandwidth of the SL CSI-RS sent on the resource pool is also X PRBs, where X is a positive integer. Furthermore, if the resource pool contains Y subchannels, and 1 subchannel of the Y subchannels contains Z PRBs, where Y and Z are positive integers, then X=Y*Z.

[0329] It should be understood that the frequency domain bandwidth of the CSI-RS represents the frequency domain bandwidth corresponding to all subchannels where the SL CSI-RS exists, or the frequency domain bandwidth corresponding to all PRBs where the SL CSI-RS exists.

[0330] Exemplarily, the first terminal device is Figure 6 The CSI-RS is sent on the resource pool shown in (b), which contains 4 subchannels (i.e., the 4 subchannels filled with shaded areas), each subchannel contains 10 PRBs, and the frequency domain bandwidth of the resource pool is 4*10=40 PRBs. In this resource pool, the frequency domain bandwidth of PSSCH is 2 subchannels, i.e., 20 PRBs. The frequency domain bandwidth of SL CSI-RS is the same as the frequency domain bandwidth of the associated resource pool (i.e., the resource pool used to send the SL CSI-RS), i.e., 40 PRBs. Among them, Figure 6(b) shows the time-frequency resource occupancy of the SL CSI-RS in one of the subchannels. It can be seen that the SL CSI-RS exists on all 10 PRBs corresponding to the subchannel. And in each PRB, the number of ports, time domain position, and frequency domain position of the SL CSI-RS are the same.

[0331] Optionally, in an embodiment of the present application, in order to avoid introducing additional automatic gain control (AGC) symbols, it is necessary to ensure that the receiving power of the receiving end, that is, the second terminal device, on each orthogonal frequency division multiplexing (OFDM) symbol is the same. Therefore, the transmitting end, that is, the first terminal device, needs to adjust the transmitting power when sending SL CSI-RS.

[0332] Among them, the receiving end can perform AGC processing. To avoid problems such as signal saturation and reduce the processing performance of the receiving end. In the AGC processing flow, the AGC symbol is an OFDM symbol used for AGC. As a possible implementation method, the transmitting end sends a short training sequence to the receiving end in certain OFDM symbols, and the receiving end receives the short training sequence from the corresponding symbol and performs AGC processing. The symbol of the short training sequence received by the receiving end can be regarded as an AGC symbol. Of course, there can be other implementation methods.

[0333] As a possible implementation, the power control factor β of CSI-RS CSI-RS,1 Satisfies the following relationship:

[0334]

[0335] in, is the power control factor of the physical sidelink shared channel PSSCH, W is the number of subchannels in the PSSCH bandwidth, Y is the number of subchannels in the resource pool, Y ≥ W, is the number of PSSCH layers scheduled, Q p is the number of CSI-RS ports.

[0336] In the existing CSI scheme of the PC5 interface, the power control factor of the SL CSI-RS having the same frequency domain bandwidth as the PSSCH is:

[0337]

[0338] It can be found that

[0339] It should be understood that in this implementation of the embodiment of the present application, the power control factor of the PSSCH is the same on the symbol containing the CSI-RS (i.e., the symbol used to transmit the CSI-RS) and on each symbol not containing the CSI-RS (i.e., the symbol not used to transmit the CSI-RS). In addition, the power control factor of the CSI-RS is the same on the symbol containing the CSI-RS and on the symbol not containing the CSI-RS.

[0340] Among them, in the symbol containing CSI-RS, for the RE not used to send CSI-RS, the power on the RE remains unchanged, and for the RE used for CSI-RS transmission, the power on the RE is equivalent to extending from W subchannels to Y subchannels. It can be seen that the first terminal device reduces the transmission power of CSI-RS in a single PRB.

[0341] As another possible implementation, the power control factor β of CSI-RS CSI-RS，1 Satisfies the following relationship:

[0342]

[0343]

[0344] in, is the power control factor of the physical sidelink shared channel PSSCH on the symbol used to transmit the CSI-RS, is the power control factor of PSSCH on symbols not used for transmitting CSI-RS, W is the number of subchannels in the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, Y is the number of subchannels in the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the number of CSI-RS ports.

[0345] It should be understood that in this implementation, PSSCH uses a set of power control factors on symbols that do not contain CSI-RS, namely PSSCH uses another set of power control factors on symbols containing CSI-RS, namely Specifically, on the symbol containing CSI-RS, the power of PSSCH on the symbol is equivalent to expanding from W subchannels to "PSSCH of W subchannels + CSI-RS of Y subchannels". That is to say, on the symbol containing CSI-RS, the first terminal device reduces the transmission power of PSSCH.

[0346] And, because The power control factor of CSI-RS is That is, it is related to the power control factor of PSSCH on the symbol containing CSI-RS. When the power of PSSCH on the symbol containing CSI-RS decreases, it means that the power control factor of CSI-RS on the symbol containing CSI-RS also decreases, that is, the first terminal device also reduces the transmission power of CSI-RS.

[0347] The embodiment of the present application does not limit the execution order between S501 and S502. S501 may be executed first, S502 may be executed first, or S501 and S502 may be executed simultaneously.

[0348] S503. The second terminal device determines CSI according to CSI-RS.

[0349] Specifically, since the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool, the second terminal device measures the CSI-RS of all sub-channels included in the resource pool to obtain the CSI corresponding to all sub-channels. In the embodiment of the present application, the specific content included in the CSI may be different in different implementation methods. Two possible implementation methods are introduced as follows. It should be noted that other methods besides these two implementation methods may also be used in actual implementation, and the embodiments of the present application are not limited thereto.

[0350] Mode 1: The CSI includes at least one of the following parameters: a wideband CQI index, and a CQI value of one or more sub-channels in a resource pool.

[0351] Among them, the wideband CQI index is the CQI index corresponding to the frequency domain bandwidth of the CSI-RS. Since the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool, here, the wideband CQI index refers to the CQI index corresponding to the frequency domain bandwidth of the resource pool. The wideband CQI index can be used to characterize the overall channel quality of the resource pool. The larger the CQI index, the better the overall channel quality of the resource pool.

[0352] The CQI value of a subchannel in the resource pool corresponds to the CQI index of a subchannel in the resource pool. The CQI value corresponding to the subchannel is determined by the subchannel CQI index and the broadband CQI index of the subchannel. The subchannel CQI index of a subchannel is used to characterize the subchannel quality of the subchannel. The larger the CQI index, the better the subchannel quality of the subchannel.

[0353] Optionally, the subchannel CQI index and the wideband CQI index may be 4 bits. The CQI value is k bits. k may be one of {2, 3}.

[0354] Exemplarily, if the frequency domain bandwidth of the SL CSI-RS corresponds to y subchannels, where y is a positive integer, when the frequency domain bandwidth of the SLCSI-RS is the same as the frequency domain bandwidth of the resource pool, the number of subchannels corresponding to the resource pool Y=y. Then the CQI calculated by the receiving end, i.e., the second terminal device, includes, for example, a 4-bit wideband CQI index, and / or a y*k-bit CQI value. CSI includes CQI, and a rank indicator (RI) such as 1 bit.

[0355] It should be noted that the second terminal device can refer to the prior art for calculating the broadband CQI index. The second terminal device calculates the subchannel CQI index, which can be implemented as follows: the second terminal device measures the subchannel CQI indexes corresponding to all subchannels in the resource pool with subchannel as the granularity.

[0356] As follows, a specific method for determining a subchannel CQI value based on a wideband CQI index and a subchannel CQI index is introduced. For a subchannel with an index of s (s is a non-negative integer), the subchannel offset level is determined according to its subchannel CQI index and wideband CQI index according to the following formula: Subchannel offset level (s) = subchannel CQI index (s) – wideband CQI index. Next, for a subchannel with an index of s, its CQI value is determined according to its subchannel offset level according to the following Table 2.

[0357] Table 2

[0358] CQI value Subchannel offset level 0 0 1 1 2 ≥2 3 ≤-1

[0359] Mode 2: CSI includes at least one of the following parameters: wideband CQI index, subchannel CQI index of one or more subchannels in the resource pool. The calculation method of the wideband CQI index and the subchannel CQI index can refer to the calculation method in the above embodiment mode 1, which will not be repeated here.

[0360] Exemplarily, in this implementation, if the frequency domain bandwidth of the SL CSI-RS corresponds to y subchannels, where y is a positive integer, when the frequency domain bandwidth of the SL CSI-RS is the same as the frequency domain bandwidth of the resource pool, the number of subchannels corresponding to the resource pool Y=y, then the CQI calculated by the receiving end, i.e., the second terminal device includes, for example, a 4-bit wideband CQI index, and / or a 4*y-bit subchannel CQI index.

[0361] In the method provided by the embodiment of the present application, since the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool, the CSI obtained by the second terminal device measuring the CSI-RS includes a broadband CQI index and / or the CQI value of one or more sub-channels in the resource pool, that is, the second terminal device measures and feeds back the CSI of each sub-channel in the resource pool to the first terminal device. Furthermore, the first terminal device can select appropriate resources based on the CSI of each sub-channel in the resource pool, so as to optimize frequency hopping communication in the SL scenario and improve the communication capacity in the SL scenario.

[0362] Moreover, compared with the prior art, in which CSI is likely to include only 1-bit RI and 4-bit wideband CQI index (used to characterize the average channel quality of one or more subchannels), and the feedback CSI content is small, in the method provided in the embodiment of the present application, CSI includes a wideband CQI index and / or CQI values ​​of one or more subchannels in the resource pool, and the information content carried by CSI is richer, so that the first terminal device can obtain more information based on the CSI.

[0363] S504. The second terminal device sends CSI to the first terminal device.

[0364] Correspondingly, the first terminal device receives CSI from the second terminal device.

[0365] The CSI is carried in the MAC CE, or the CSI is carried by the MAC CE. That is, S504 can be implemented as: the second terminal device sends a MAC CE to the first terminal device, and the MAC CE carries the CSI. Correspondingly, the first terminal device receives the MAC CE from the second terminal device.

[0366] For a MAC CE carrying CSI, the number of octets occupied by the MAC CE is related to the number of sub-channels in the resource pool. That is, in the embodiment of the present application, the MAC CE is of variable size.

[0367] Usually, one byte occupies 8 bits.

[0368] As a possible implementation, corresponding to the above-mentioned method 1, the CSI includes a wideband CQI index and / or a CQI value of one or more subchannels in the resource pool. Optionally, the MAC CE carrying the CSI includes 1+[y / 4] bytes (octets). Among them, is a rounded-up symbol, and y is the number of subchannels in the resource pool. That is, the MAC CE carrying the CSI may be 1+[y / 4] bytes, or may be greater than 1+[y / 4] bytes. This embodiment of the present application does not limit this.

[0369] As a possible implementation, corresponding to the above-mentioned method 1, the MAC CE includes the first byte and Bytes. The first byte corresponds to the RI and wideband CQI index. In other words, the first byte occupied by MAC CE carries the RI and wideband CQI index. The bytes correspond to (or carry) one or more sub-channel CQI values, wherein any CQI value among the one or more sub-channel CQI values ​​is indicated by 2 bits.

[0370] For example, it is assumed that the number of subchannels included in the resource pool is y=4, and the CQI value occupies k=2 bits. Figure 7 In the MAC CE shown, the first byte is Oct 1, which carries, for example, a 1-bit RI and a 4-bit wideband CQI index.

[0371] It should be noted that the position of the 1-bit RI and the wideband CQI index such as 4 bits in Oct 1 is not limited in the embodiment of the present application. For example, the 5 bits may be located at the first 5 bit positions, or the last 5 bit positions, or other positions of Oct 1. In addition, the remaining 3 bits in the first byte are not limited in the embodiment of the present application. Optionally, the remaining 3 bits may be reserved bits, represented by R, or used for other purposes.

[0372] For the bytes other than the first byte in the MAC CE, such as Figure 7 As shown in Oct 2, the 8 bits T0, T1, ..., T7 in Oct 2 carry a total of 8 bits of CQI value, and the specific carrying method is not limited in the embodiment of the present application. For example, for y=4 subchannels with indexes 0, 1, 2, and 3, the T0 and T1 bits carry the CQI value of the subchannel with index 0, the T2 and T3 bits carry the CQI value of the subchannel with index 1, and so on.

[0373] In other embodiments, considering that the precoding matrix indicator (PMI) and / or reference signal receiving power (RSRP), and / or other information may be carried in the CSI in the future, the number of bytes of the MAC CE carrying the CSI may be greater than 1+[y / 4].

[0374] As a possible implementation, corresponding to the above-mentioned method 2, the CSI includes a wideband CQI index and / or one or more subchannel CQI indexes in the resource pool. Optionally, the MAC CE carrying the CSI includes a second byte and a third byte set, and the number of bytes included in the third byte set is less than or equal to in, is the round-up symbol, and y is the number of subchannels in the resource pool.

[0375] For example, when y=3, the MAC CE carrying the CSI includes the second byte and another byte (1 is less than ). That is, when y=3, it is possible that only 2 bytes are needed to transmit CSI, instead of bytes.

[0376] As a possible implementation, corresponding to the above-mentioned method 2, the first part of the second byte carries the RI, and the second part of the second byte carries a sub-channel CQI index. The third byte set carries the remaining y-1 sub-channel CQI indexes.

[0377] For example, assuming that the number of subchannels in the resource pool is y = 4, the structure of MAC CE is as follows: Figure 8 As shown, the MAC CE includes the second byte, namely Oct1, and the byte other than Oct1. bytes, namely Oct2 and Oct3.

[0378] The 4 bits in Oct1 carry 1 bit of RI. The remaining 3 bits of the 4 bits are not limited in the embodiment of the present application and can be reserved bits, represented by R. The remaining 4 bits T0, T1, T2, T3 in Oct1 carry 4 bits, that is, a subchannel CQI index.

[0379] In Oct2, 8 bits T4, T5, ..., T11 carry 8 bits, ie, two sub-channel CQI indexes.

[0380] In Oct3, 4 bits T12, T13, T14, and T15 carry 4 bits, namely, a subchannel CQI index. The remaining 4 bits of Oct3 are not limited in the embodiment of the present application and can be reserved bits, denoted by R.

[0381] As a possible implementation manner, corresponding to the above-mentioned manner 2, the second byte carries the RI, and the third byte set carries the sub-channel CQI index.

[0382] For example, the number of subchannels included in the resource pool is y=4, and the MAC CE structure is as follows Fig. 9 As shown, the MAC CE includes the second byte (ie, Oct1) and other bytes (i.e. Oct2 and Oct3).

[0383] Oct1 carries RI such as 1 bit, and the remaining 7 bits of Oct1 are not limited in the embodiment of the present application, and can be reserved bits, represented by R. In Oct2 and Oct3, 16 bits, namely 4 sub-channel CQI indexes, are carried by 16 bits T0, T1, ..., T15 respectively. The specific carrying method of Oct2 and Oct3 is not limited in the embodiment of the present application. For example, for y=4 sub-channels with indexes 0, 1, 2, and 3, the bits T0, T1, T2, and T3 carry the sub-channel CQI index corresponding to the sub-channel with index 0, and the bits T4, T5, T6, and T7 carry the sub-channel CQI index corresponding to the sub-channel with index 1, and so on.

[0384] In other embodiments, considering that PMI, RSRP and other information may be carried in CSI in the future, corresponding to mode 1, the number of bytes included in MAC CE may be greater than

[0385] In the communication method provided by the embodiment of the present application, in the SL scenario, since the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool, that is, the number of subchannels included in the frequency domain of the CSI-RS is the same as the number of subchannels included in the frequency domain of the resource pool, after the first terminal device sends the CSI-RS to the second terminal device, the second terminal device can measure the CSI on each subchannel in the resource pool based on the CSI-RS and feed back the CSI on each subchannel in the resource pool to the first terminal device. Furthermore, the first terminal device can reasonably select frequency domain resources according to the CSI of each subchannel in the resource pool, so as to optimize frequency hopping communication in the SL scenario, improve resource utilization, and improve communication capacity in the SL scenario.

[0386] At the same time, according to the method provided in the embodiment of the present application, when the first terminal device determines that the channel quality of one or more sub-channels used for the current transmission is very poor, it can determine whether other sub-channels in the resource pool can achieve reliable transmission based on the CSI of all sub-channels in the resource pool, and then switch to other sub-channels for transmission, thereby improving transmission reliability in the SL scenario.

[0387] Optionally, the embodiment of the present application also provides at least two methods for indicating that the CSI-RS frequency domain bandwidth is the same as the frequency domain bandwidth of the resource pool. Fig.10 , a method for indicating that the frequency domain bandwidth of a CSI-RS is the same as the frequency domain bandwidth of a resource pool provided in an embodiment of the present application. The method comprises the following steps:

[0388] S1000. A first terminal device sends first indication information to a second terminal device.

[0389] Correspondingly, the second terminal device receives the first indication information from the first terminal device.

[0390] It should be understood that in this implementation, the first indication information may be 1 bit in the second-level SCI which is the same as that in the prior art, that is, the specific implementation of the first indication information may refer to the prior art.

[0391] Specifically, the implementation of step S1000 can refer to step S501, which will not be repeated here.

[0392] S1001. A first terminal device sends second indication information to a second terminal device.

[0393] Correspondingly, the second terminal device receives second indication information from the first terminal device.

[0394] The second indication information is used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool. Optionally, the second indication information is included in RRC signaling. In the SL scenario, the RRC signaling may be PC5 RRC signaling.

[0395] It should be understood that in order for the receiving end, that is, the second terminal device, to know that the frequency domain bandwidth of the SL CSI-RS is the same as the frequency domain bandwidth of the associated resource pool, the sending end, that is, the first terminal device, needs to indicate that the frequency domain bandwidth of the SL CSI-RS is the same as the frequency domain bandwidth of the resource pool when configuring the SLCSI-RS pattern for the second terminal device through PC5 RRC signaling.

[0396] As a possible implementation manner, the second indication information corresponds to the sl-CSI-RS-freqBand field in the PC5 RRC signaling, and the first terminal device indicates the frequency domain bandwidth corresponding to the SL CSI-RS pattern through this field:

[0397] sl-CSI-RS-freqBand ENUMERATED{txPSSCH,txResourcePool}

[0398] Among them, ENUMERATED means selecting one of multiple parameters, txPSSCH is used to indicate that the frequency domain bandwidth of SL CSI-RS is the same as the frequency domain bandwidth of the associated PSSCH, and txResourcePool is used to indicate that the frequency domain bandwidth of SL CSI-RS is the same as the frequency domain bandwidth of the associated resource pool. The first terminal device sets the sl-CSI-RS-freqBand field to txResourcePool, so that the second terminal device knows that the frequency domain bandwidth of SL CSI-RS is the same as the frequency domain bandwidth of the associated resource pool.

[0399] In this way, after receiving the second indication information, the second terminal device can determine that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

[0400] S1002. The first terminal device sends a SL CSI-RS to the second terminal device.

[0401] Correspondingly, the second terminal device receives the SL CSI-RS from the first terminal device.

[0402] Specifically, the implementation of step S1002 can refer to step S502, which will not be repeated here.

[0403] S1003. The second terminal device determines CSI according to CSI-RS.

[0404] Specifically, the implementation of step S1003 may refer to step S503, which will not be described in detail here.

[0405] It should be understood that after the second terminal device receives the CSI-RS, it can measure the channel quality of all sub-channels in the resource pool.

[0406] S1004. The second terminal device sends CSI to the first terminal device.

[0407] Correspondingly, the first terminal device receives CSI from the second terminal device.

[0408] Specifically, the implementation of step S1004 may refer to step S504, which will not be described in detail here.

[0409] It should be noted that the embodiment of the present application does not limit the execution order of S1000, S1001, and S1002.

[0410] From the above, it can be seen that compared with Figure 5 The process, Fig.10 The sending and receiving actions of the second indication information are added to the process, and the first terminal device indicates the frequency domain bandwidth of the CSI-RS through the second indication information.

[0411] See also Fig.11 , as another method provided in an embodiment of the present application to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool. The frequency domain bandwidth of the CSI-RS can be indicated by the above-mentioned first indication information. The method comprises the following steps:

[0412] S1101. A first terminal device sends first indication information to a second terminal device.

[0413] Correspondingly, the second terminal device receives the first indication information from the first terminal device.

[0414] The first indication information is used to instruct the second terminal device to send CSI, and is also used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

[0415] and Fig.10 The corresponding embodiments are different. In this embodiment, the first indication information is 1 bit in the second-level SCI which is different from the prior art. For example, Fig.10 In the corresponding embodiment, the first indication information may be 1 bit in the prior art, while in this embodiment, the first indication information is 1 bit different from the prior art. When the second terminal device receives the 1 bit different from the prior art, it considers that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the associated resource pool.

[0416] S1102. The first terminal device sends a SL CSI-RS to the second terminal device.

[0417] Correspondingly, the second terminal device receives the SL CSI-RS from the first terminal device.

[0418] Specifically, the implementation of step S1102 may refer to step S502, which will not be described in detail here.

[0419] S1103. The second terminal device determines CSI according to CSI-RS.

[0420] Specifically, the implementation of step S1103 may refer to step S503, which will not be described in detail here.

[0421] It should be understood that after the second terminal device receives the CSI-RS, it can measure the channel quality of all sub-channels in the resource pool.

[0422] S1104. The second terminal device sends CSI to the first terminal device.

[0423] Correspondingly, the first terminal device receives CSI from the second terminal device.

[0424] Specifically, the implementation of step S1104 can refer to step S504, which will not be described in detail here. It should be noted that the embodiment of the present application does not limit the execution order of S1101 and S1102.

[0425] It can be seen that Figure 5 Compared with the process Fig.11 In the process, the first indication information not only instructs the second terminal device to send CSI, but also indicates that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

[0426] Compared with the prior art, in which the frequency domain bandwidth of CSI-RS is configured through RRC signaling, which requires large signaling overhead and has strong restrictions on the frequency domain bandwidth of CSI-RS and the position of the starting PRB, in an embodiment of the present application, PC5 RRC signaling is used, or the first indication information is used to indicate that the frequency domain bandwidth of SL CSI-RS is the same as the frequency domain bandwidth of the resource pool, thereby saving signaling overhead.

[0427] The embodiment of the present application also provides a communication method, in which the frequency domain bandwidth of the CSI-RS can be flexibly indicated. Fig.12 , the method comprises the following steps:

[0428] S1201. A first terminal device sends first indication information to a second terminal device.

[0429] Correspondingly, the second terminal device receives the first indication information from the first terminal device.

[0430] It should be noted that Fig.12 The first indication information in the corresponding embodiment is not the same as the first indication information in other parts of other embodiments. Figure 5 , Fig.10 , Fig.11 In a corresponding embodiment, the first indication information is used to instruct the second terminal device to send CSI. Fig.12 In a corresponding embodiment, the first indication information is used to indicate the frequency domain bandwidth of the SL CSI-RS. Optionally, the first indication information is included in PC5 RRC signaling.

[0431] Optionally, the first indication information in the PC5 RRC signaling is as follows:

[0432]

[0433] Among them, sl-CSI-FrequencyOccupation is used to indicate the frequency domain bandwidth of SL CSI-RS; startingSubChannel indicates the position of the starting subchannel of SL CSI-RS in the frequency domain in the resource pool. The value range of this parameter is greater than or equal to 0 and less than or equal to M, and the value of this parameter is an integer, M is a positive integer, optional, M=26; nrofSubChannels indicates the number of subchannels corresponding to the frequency domain bandwidth of SL CSI-RS. The value range of this parameter is greater than or equal to 1 and less than or equal to N. The value of this parameter is an integer, N is a positive integer, optional, N=27.

[0434] For example, in Fig.13In the example, the resource pool contains 4 subchannels, each of which contains 10 PRBs. The frequency domain bandwidth of PSSCH is 2 subchannels, i.e., 20 PRBs. In the frequency domain bandwidth parameters of SL CSI-RS, startingSubChannel is 0, nrofSubChannels is 3, i.e., the number of subchannels corresponding to the frequency domain bandwidth of SL CSI-RS is y=3, and SL CSI-RS exists on the 0th, 1st, and 2nd subchannels of the resource pool. Fig.10 The figure shows the time-frequency resource occupancy of SL CSI-RS in one of the sub-channels. It can be seen that SL CSI-RS exists in all 10 PRBs corresponding to the sub-channel. In each PRB, the port number, time domain position and frequency domain position of SL CSI-RS are the same.

[0435] S1202. The first terminal device sends second indication information to the second terminal device.

[0436] Correspondingly, the second terminal device receives second indication information from the first terminal device.

[0437] It should be noted that Fig.12 The second indication information in the corresponding embodiment is different from the second indication information in other embodiments of the present application. In other embodiments of the present application, for example Figure 5 , Fig.10 , Fig.11 In a corresponding embodiment, the second indication information is used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool. Fig.12 In a corresponding embodiment, the second indication information is used to trigger the second terminal device to measure the channel according to the SL CSI-RS and feedback the SL CSI. Fig.10 The first indication information in the corresponding embodiments is the same.

[0438] For the specific implementation of S1202, please refer to Fig.10 Related content.

[0439] S1203. The first terminal device sends SL CSI-RS to the second terminal device.

[0440] Correspondingly, the second terminal device receives the SL CSI-RS from the first terminal device.

[0441] For example, the frequency domain bandwidth of the SL CSI-RS is as follows: Fig.13 shown.

[0442] Optionally, if the frequency domain bandwidth of SL CSI-RS is different from the frequency domain bandwidth of PSSCH, in order to avoid introducing additional AGC symbols, it is necessary to ensure that the receiving power of the second terminal device on each OFDM symbol is the same. Therefore, the first terminal device needs to adjust the transmission power when sending SL CSI-RS.

[0443] In a possible implementation, the first terminal device calculates the power control factor β of the CSI-RS using the following formula: CSI-RS,1 :

[0444]

[0445] in is the power control factor of PSSCH on the OFDM symbol used to transmit SL CSI-RS; W is the number of subchannels in the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, and U is the number of overlapping subchannels in the frequency domain bandwidth of PSSCH and SL CSI-RS (exemplarily, as Fig.13 , U=1), Q p is the number of SL CSI-RS ports, y is the number of subchannels in the frequency domain bandwidth of SL CSI-RS, is the number of PSSCH layers scheduled, y is less than or equal to Y, and Y is the number of subchannels in the resource pool.

[0446] For the power control factor of PSSCH on the OFDM symbol containing SL CSI-RS, that is, Its expression is:

[0447]

[0448] in, is the power control factor of PSSCH in OFDM symbols not used for transmitting SL CSI-RS.

[0449] The embodiment of the present application does not limit the execution order of S1201, S1202, and S1203.

[0450] S1204. The second terminal device determines the SL CSI according to the SL CSI-RS.

[0451] Specifically, the second terminal device measures the subchannel corresponding to the frequency domain bandwidth according to the frequency domain bandwidth of the SL CSI-RS. Fig.13 For example, the second terminal device measures the three sub-channels filled with shadows and determines the SL CSI corresponding to the three sub-channels.

[0452] S1205. The second terminal device feeds back SL CSI to the first terminal device.

[0453] Correspondingly, the first terminal device receives SL CSI from the second terminal device.

[0454] As a possible implementation manner, the second terminal device determines the CSI with a sub-channel as a granularity.

[0455] Optionally, the SL CSI includes at least one of the following parameters: a wideband CQI index, and a CQI value of one or more subchannels corresponding to the SL CSI-RS frequency domain bandwidth. The wideband CQI index is the CQI index corresponding to the SL CSI-RS frequency domain bandwidth.

[0456] For example, Fig.13 The SL CSI includes a wideband CQI index (a CQI index corresponding to the total bandwidth of the three sub-channels filled with shadows) and / or CQI values ​​corresponding to the three sub-channels filled with shadows.

[0457] Optionally, the SL CSI includes at least one of the following parameters: a wideband CQI index, and one or more subchannel CQI indexes corresponding to the SL CSI-RS frequency domain bandwidth. Fig.13 , the SL CSI includes a wideband CQI index, and / or, subchannel CQI indexes corresponding to the three subchannels filled with shadows.

[0458] Among them, the specific definitions of the wideband CQI index, CQI value, and sub-channel CQI index can be found above.

[0459] In an embodiment of the present application, the first terminal device can trigger the second terminal device to feedback the SL CSI of one or more sub-channels (i.e., the sub-channels corresponding to the SL CSI-RS frequency domain bandwidth) by sending the SL CSI-RS that can flexibly indicate the frequency domain bandwidth to the second terminal device. In this way, the first terminal device can select frequency domain resources based on the CSI on the one or more sub-channels in the resource pool, so as to optimize frequency hopping communication in the SL scenario and improve the communication capacity in the SL scenario.

[0460] In addition, compared with the prior art in which the frequency domain bandwidth of CSI-RS is configured through RRC signaling, which has strong restrictions on the frequency domain bandwidth of CSI-RS and the position of the starting PRB, in an embodiment of the present application, the frequency domain bandwidth of SL CSI-RS is configured through PC5 RRC signaling, without restricting parameters such as the starting PRB.

[0461] An embodiment of the present application also provides a communication method, in which the second terminal device can calculate the CQI with sub-channel as the granularity.

[0462] The method comprises the following steps:

[0463] 1. The first terminal device sends first indication information to the second terminal device.

[0464] Correspondingly, the second terminal device receives the first indication information from the first terminal device.

[0465] It should be noted that the first indication information in this method can be Fig.10 The first indication information is shown.

[0466] 2. The first terminal device sends SL CSI-RS to the second terminal device.

[0467] Correspondingly, the second terminal device receives the SL CSI-RS from the first terminal device.

[0468] Optionally, the SL CSI-RS may be the SL CSI-RS in the prior art, that is, the frequency domain bandwidth is the same as the frequency domain bandwidth of the PSSCH.

[0469] The embodiment of the present application does not limit the execution order of step 1 and step 2.

[0470] 3. The second terminal device calculates the SL CSI based on the SL CSI-RS with the sub-channel as the granularity.

[0471] Optionally, the SL CSI includes at least one of the following parameters: a wideband CQI index, and a CQI value of one or more sub-channels corresponding to the SL CSI-RS frequency domain bandwidth.

[0472] Optionally, the SL CSI includes at least one of the following parameters: a wideband CQI index, and one or more sub-channel CQI indexes corresponding to the SL CSI-RS frequency domain bandwidth.

[0473] The specific implementation of this step may refer to the above embodiments, such as step S503.

[0474] 4. The second terminal device feeds back SL CSI to the first terminal device.

[0475] Correspondingly, the first terminal device receives SL CSI from the second terminal device.

[0476] The specific implementation of this step may refer to the above embodiments, such as step S504.

[0477] Optionally, the method for calculating CQI at subchannel granularity may also be combined with the above-mentioned embodiment method, for example, the frequency domain bandwidth of SLCSI-RS is the same as the frequency domain bandwidth of the associated PSSCH, or the same as the frequency domain bandwidth of the associated resource pool. Fig.12 In the corresponding embodiment, the frequency domain bandwidth of the SL CSI-RS can be flexibly indicated.

[0478] In the embodiment of the present application, the second terminal device feeds back the SL CSI measured with subchannel granularity to the first terminal device, so that the first terminal device can determine the channel quality on one or more subchannels. In this way, the first terminal device can optimize resource allocation according to the channel quality of the one or more subchannels, improve the resource utilization efficiency of the resource pool in the SL scenario, and improve the communication capacity in the SL scenario.

[0479] At the same time, according to the method provided in the embodiment of the present application, when the first terminal device determines that the channel quality of one or more sub-channels currently used for transmission is very poor, it can try to switch to other sub-channels for transmission, thereby improving transmission reliability in the SL scenario.

[0480] It is understandable that the first terminal device and the second terminal device in the embodiment of the present application include hardware structures and / or software modules corresponding to the execution of each function in order to realize the above functions. In combination with the units and algorithm steps of each example described in the embodiment disclosed in this application, the embodiment of the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the technical solution of the embodiment of the present application.

[0481] The embodiment of the present application can divide the functional units of the first terminal device and the second terminal device according to the above method example. For example, each functional unit can be divided according to each function, or two or more functions can be integrated into one processing unit. The above integrated unit can be implemented in the form of hardware or in the form of software functional units. It should be noted that the division of units in the embodiment of the present application is schematic and is only a logical functional division. There may be other division methods in actual implementation.

[0482] Fig.14 A schematic block diagram of a communication device provided in an embodiment of the present application is shown, and the communication device may be the first terminal device mentioned above, or a device (such as a chip system) that supports the functions of the first terminal device. The communication device 700 may exist in the form of software, or may be a chip that can be used for a device. The communication device 700 includes: a processing unit 702 and a transceiver unit 703. Optionally, the transceiver unit 703 may also be divided into a sending unit (not shown in FIG. 1 ). Fig.14 ) and the receiving unit (not shown in Fig.14 The sending unit is used to support the communication device 700 to send information to other network elements. The receiving unit is used to support the communication device 700 to receive information from other network elements.

[0483] Optionally, the communication device 700 may further include a storage unit 701 for storing program codes and data of the communication device 700 . The data may include but is not limited to original data or intermediate data.

[0484] The processing unit 702 can be used to support the first terminal device to determine the CSI-RS, the first indication information, the second indication information, the third indication information, and / or other processes for the scheme described in this document.

[0485] The transceiver unit 703 is configured to send a CSI-RS to a second terminal device;

[0486] Among them, the frequency domain bandwidth of CSI-RS is the same as the frequency domain bandwidth of the resource pool. The resource pool is a set of time-frequency resources contained in the side link SL partial bandwidth BWP. The resource pool includes one or more continuous sub-channels in the frequency domain. A sub-channel of the resource pool includes one or more continuous physical resource blocks PRB. The resource pool is determined in the time domain according to a periodic bit map.

[0487] In a possible design, the transceiver unit 703 is also used to send first indication information to the second terminal device, where the first indication information is used to instruct the second terminal device to send channel state information CSI, and the first indication information is included in the second-level sidelink control information SCI.

[0488] In one possible design, the first indication information is also used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

[0489] In one possible design, the transceiver unit 703 is also used to send second indication information to the second terminal device, and the second indication information is used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

[0490] In one possible design, the second indication information is included in radio resource control RRC signaling.

[0491] In one possible design, the CSI includes at least one of the following:

[0492] Wideband channel quality indicator CQI index, where the wideband CQI index is the CQI index corresponding to the frequency domain bandwidth of the CSI-RS;

[0493] The CQI values ​​of one or more sub-channels in the resource pool, the CQI value of a sub-channel in the resource pool corresponds to the CQI index of a sub-channel in the resource pool.

[0494] In a possible design, the CSI is carried in a medium access control layer control element MAC CE, and the number of bytes occupied by the MAC CE is related to the number of sub-channels in the resource pool.

[0495] In one possible design, the MAC CE includes bytes, of which is the round-up symbol, and y is the number of subchannels in the resource pool.

[0496] In one possible design, the power control factor β of the CSI-RS is CSI-RS,1 Satisfies the following relationship:

[0497]

[0498] in, is the power control factor of the physical sidelink shared channel PSSCH, W is the number of subchannels in the PSSCH bandwidth, Y is the number of subchannels in the resource pool, Y ≥ W, is the number of PSSCH layers scheduled, Q p is the number of CSI-RS ports.

[0499] In one possible design, the power control factor β of the CSI-RS is CSI-RS,1 Satisfies the following relationship:

[0500]

[0501]

[0502] in, is the power control factor of the physical sidelink shared channel PSSCH on the symbol used to transmit the CSI-RS, is the power control factor of PSSCH on symbols not used for transmitting CSI-RS, W is the number of subchannels in the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, Y is the number of subchannels in the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the number of CSI-RS ports.

[0503] Fig.15 Schematic diagram of the structure of another communication device provided in an embodiment of the present application, the communication device may be the second terminal device mentioned above, or a device (such as a chip system) that supports the function of the second terminal device. The communication device 800 may exist in the form of software, or may be a chip that can be used for a device. The communication device 800 includes: a processing unit 802 and a transceiver unit 803. Optionally, the transceiver unit 803 may also be divided into a sending unit (not shown in FIG. 1 ). Fig.15) and the receiving unit (not shown in Fig.15 The sending unit is used to support the communication device 800 to send information to other network elements. The receiving unit is used to support the communication device 800 to receive information from other network elements.

[0504] Optionally, the communication device 800 may further include a storage unit 801 for storing program codes and data of the communication device 800 . The data may include but is not limited to original data or intermediate data.

[0505] The processing unit 802 may be configured to support the second terminal device in determining CSI based on the CSI-RS, and / or for other processes of the solution described herein.

[0506] The transceiver unit 803 is configured to receive a channel state information reference signal CSI-RS from a first terminal device;

[0507] Among them, the frequency domain bandwidth of CSI-RS is the same as the frequency domain bandwidth of the resource pool. The resource pool is a set of time-frequency resources contained in the side link SL partial bandwidth BWP. The resource pool includes one or more continuous sub-channels in the frequency domain. A sub-channel of the resource pool includes one or more continuous physical resource blocks PRB. The resource pool is determined in the time domain according to a periodic bit map.

[0508] In one possible design, the transceiver unit 803 is also used to receive first indication information from the first terminal device, where the first indication information is used to instruct the second terminal device to send channel state information CSI, and the first indication information is included in the second-level sidelink control information SCI.

[0509] In one possible design, the first indication information is also used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

[0510] In one possible design, the transceiver unit 803 is also used to receive second indication information from the first terminal device, and the second indication information is used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

[0511] In one possible design, the second indication information is included in radio resource control RRC signaling.

[0512] In one possible design, the CSI includes at least one of the following:

[0513] Wideband channel quality indicator CQI index, where the wideband CQI index is the CQI index corresponding to the frequency domain bandwidth of the CSI-RS;

[0514] The CQI values ​​of one or more sub-channels in the resource pool, the CQI value of a sub-channel in the resource pool corresponds to the CQI index of a sub-channel in the resource pool.

[0515] In a possible design, the CSI is carried in a medium access control layer control element MAC CE, and the number of bytes occupied by the MAC CE is related to the number of sub-channels in the resource pool.

[0516] In one possible design, the MAC CE includes bytes, of which is the round-up symbol, and y is the number of subchannels in the resource pool.

[0517] In one possible design, the power control factor β of the CSI-RS is CSI-RS,1 Satisfies the following relationship:

[0518]

[0519] in, is the power control factor of the physical sidelink shared channel PSSCH, W is the number of subchannels in the PSSCH bandwidth, Y is the number of subchannels in the resource pool, Y ≥ W, is the number of PSSCH layers scheduled, Q p is the number of CSI-RS ports.

[0520] In one possible design, the power control factor β of the CSI-RS is CSI-RS,1 Satisfies the following relationship:

[0521]

[0522]

[0523] in, is the power control factor of the physical sidelink shared channel PSSCH on the symbol used to transmit the CSI-RS, is the power control factor of PSSCH on symbols not used for transmitting CSI-RS, W is the number of subchannels in the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, Y is the number of subchannels in the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the number of CSI-RS ports.

[0524] In one possible embodiment, the processing unit 802 may be a controller or Figure 4The processor 401 or processor 407 shown may be, for example, a central processing unit (CPU), a general-purpose processor, a digital signal processing (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. It may implement or execute various exemplary logic blocks, modules and circuits described in conjunction with the contents disclosed in this application. The processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, and so on. The transceiver unit 803 may be Figure 4 The communication interface 404 shown may also be a transceiver circuit, etc. The storage unit 801 may be Figure 4 The memory 403 is shown.

[0525] It will be appreciated by those skilled in the art that in the above embodiments, the embodiments may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, the embodiments may be implemented in whole or in part 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 process or function according to the embodiment of the present application is 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. The computer instructions may be stored in a computer-readable storage medium, or may be transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from a website site, a computer, a server, or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server, or data center. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or a data center that includes one or more available media integrated therein. Available media may be magnetic media (eg, floppy disks, hard disks, magnetic tapes), optical media (eg, digital video discs (DVD)), or semiconductor media (eg, solid state disks (SSD)).

[0526] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical or other forms.

[0527] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network devices (such as terminal devices). Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0528] In addition, each functional unit in each embodiment of the present application can be integrated into one processing unit, or each functional unit can exist independently, or two or more units can be integrated into one unit. The above integrated unit can be implemented in the form of hardware or in the form of hardware plus software functional units.

[0529] Through the description of the above implementation methods, the technicians in the relevant field can clearly understand that the present application can be implemented by means of software plus necessary general hardware, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a readable storage medium, such as a computer floppy disk, hard disk or optical disk, etc., and includes a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0530] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application shall be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A communication method, characterized in that: include: Sending a channel state information reference signal CSI-RS to the second terminal device; The frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool, the resource pool is a set of time-frequency resources contained in the side link SL part bandwidth BWP, the resource pool includes one or more continuous sub-channels in the frequency domain, one sub-channel of the resource pool includes one or more continuous physical resource blocks PRB, and the resource pool is determined in the time domain according to a periodic bit map; First indication information is sent to the second terminal device, where the first indication information is used to instruct the second terminal device to send channel state information CSI, and the first indication information is included in the second-level sidelink control information SCI.

2. The method according to claim 1, characterized in that The first indication information is further used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

3. The method according to claim 1, characterized in that The method further comprises: Send second indication information to the second terminal device, where the second indication information is used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

4. The method according to claim 3, characterized in that The second indication information is included in radio resource control RRC signaling.

5. The method according to any one of claims 1 to 4, characterized in that The CSI includes at least one of the following: A wideband channel quality indicator CQI index, where the wideband CQI index is a CQI index corresponding to the frequency domain bandwidth of the CSI-RS; The CQI values ​​of one or more sub-channels in the resource pool, wherein the CQI value of a sub-channel in the resource pool corresponds to a CQI index of a sub-channel in the resource pool.

6. The method according to any one of claims 1 to 4, characterized in that The CSI is carried in a medium access control layer control element MAC CE, and the number of bytes occupied by the MAC CE is related to the number of sub-channels in the resource pool.

7. The method according to claim 5, characterized in that The CSI is carried in a medium access control layer control element MAC CE, and the number of bytes occupied by the MAC CE is related to the number of sub-channels in the resource pool.

8. The method according to claim 6, characterized in that The MAC CE includes bytes, of which, is the round-up symbol, and y is the number of sub-channels in the resource pool.

9. The method according to claim 7, characterized in that: The MAC CE includes bytes, of which, is the round-up symbol, and y is the number of sub-channels in the resource pool.

10. The method according to any one of claims 1-4, 7-9, characterized in that: Power control factor β of CSI-RS CSI-RS,1 Satisfies the following relationship: in, is the power control factor of the physical sidelink shared channel PSSCH, W is the number of subchannels in the PSSCH bandwidth, Y is the number of subchannels in the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the port number of the CSI-RS.

11. The method according to claim 5, characterized in that Power control factor β of CSI-RS CSI-RS,1 Satisfies the following relationship: in, is the power control factor of the physical sidelink shared channel PSSCH, W is the number of subchannels in the PSSCH bandwidth, Y is the number of subchannels in the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the port number of the CSI-RS.

12. The method according to claim 6, characterized in that Power control factor β of CSI-RS CSI-RS,1 Satisfies the following relationship: in, is the power control factor of the physical sidelink shared channel PSSCH, W is the number of subchannels in the PSSCH bandwidth, Y is the number of subchannels in the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the port number of the CSI-RS.

13. The method according to any one of claims 1-4, 7-9, characterized in that: Power control factor β of CSI-RS CSI-RS,1 Satisfies the following relationship: in, is the power control factor of the physical sidelink shared channel PSSCH on the symbol used to transmit the CSI-RS, is the power control factor of the PSSCH on the symbol not used for transmitting CSI-RS, W is the number of subchannels of the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, Y is the number of subchannels of the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the port number of the CSI-RS.

14. The method according to claim 5, characterized in that Power control factor β of CSI-RS CSI-RS,1 Satisfies the following relationship: in, is the power control factor of the physical sidelink shared channel PSSCH on the symbol used to transmit the CSI-RS, is the power control factor of the PSSCH on the symbol not used for transmitting CSI-RS, W is the number of subchannels of the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, Y is the number of subchannels of the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the port number of the CSI-RS.

15. The method according to claim 6, characterized in that Power control factor β of CSI-RS CSI-RS,1 Satisfies the following relationship: in, is the power control factor of the physical sidelink shared channel PSSCH on the symbol used to transmit the CSI-RS, is the power control factor of the PSSCH on the symbol not used for transmitting CSI-RS, W is the number of subchannels of the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, Y is the number of subchannels of the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the port number of the CSI-RS.

16. A communication method, characterized in that: include: Receiving a channel state information reference signal CSI-RS from a first terminal device; The frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool, the resource pool is a set of time-frequency resources contained in the side link SL part bandwidth BWP, the resource pool includes one or more continuous sub-channels in the frequency domain, one sub-channel of the resource pool includes one or more continuous physical resource blocks PRB, and the resource pool is determined in the time domain according to a periodic bit map; First indication information is received from the first terminal device, where the first indication information is used to instruct the second terminal device to send channel state information CSI, and the first indication information is included in the second-level sidelink control information SCI.

17. The method according to claim 16, characterized in that The first indication information is further used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

18. The method according to claim 16, characterized in that The method further comprises: Second indication information is received from the first terminal device, where the second indication information is used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

19. The method according to claim 18, characterized in that The second indication information is included in radio resource control RRC signaling.

20. The method according to any one of claims 16 to 19, characterized in that The CSI includes at least one of the following: A wideband channel quality indicator CQI index, where the wideband CQI index is a CQI index corresponding to the frequency domain bandwidth of the CSI-RS; The CQI values ​​of one or more sub-channels in the resource pool, wherein the CQI value of a sub-channel in the resource pool corresponds to a CQI index of a sub-channel in the resource pool.

21. The method according to any one of claims 16 to 19, characterized in that The CSI is carried in a medium access control layer control element MAC CE, and the number of bytes occupied by the MAC CE is related to the number of sub-channels in the resource pool.

22. The method according to claim 20, characterized in that The CSI is carried in a medium access control layer control element MAC CE, and the number of bytes occupied by the MAC CE is related to the number of sub-channels in the resource pool.

23. The method according to claim 21, characterized in that The MAC CE includes bytes, of which, is the round-up symbol, and y is the number of sub-channels in the resource pool.

24. The method according to claim 22, characterized in that The MAC CE includes bytes, of which, is the round-up symbol, and y is the number of sub-channels in the resource pool.

25. The method according to any one of claims 16-19, 22-24, characterized in that: Power control factor β of CSI-RS CSI-RS,1 Satisfies the following relationship: in, is the power control factor of the physical sidelink shared channel PSSCH, W is the number of subchannels in the PSSCH bandwidth, Y is the number of subchannels in the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the port number of the CSI-RS.

26. The method according to claim 20, characterized in that Power control factor β of CSI-RS CSI-RS,1 Satisfies the following relationship: in, is the power control factor of the physical sidelink shared channel PSSCH, W is the number of subchannels in the PSSCH bandwidth, Y is the number of subchannels in the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the port number of the CSI-RS.

27. The method according to claim 21, characterized in that Power control factor β of CSI-RS CSI-RS,1 Satisfies the following relationship: in, is the power control factor of the physical sidelink shared channel PSSCH, W is the number of subchannels in the PSSCH bandwidth, Y is the number of subchannels in the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the port number of the CSI-RS.

28. The method according to any one of claims 16-19, 22-24, characterized in that: Power control factor β of CSI-RS CSI-RS,1 Satisfies the following relationship: in, is the power control factor of the physical sidelink shared channel PSSCH on the symbol used to transmit the CSI-RS, is the power control factor of the PSSCH on the symbol not used for transmitting CSI-RS, W is the number of subchannels of the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, Y is the number of subchannels of the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the port number of the CSI-RS.

29. The method according to claim 20, characterized in that Power control factor β of CSI-RS CSI-RS,1 Satisfies the following relationship: in, is the power control factor of the physical sidelink shared channel PSSCH on the symbol used to transmit the CSI-RS, is the power control factor of the PSSCH on the symbol not used for transmitting CSI-RS, W is the number of subchannels of the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, Y is the number of subchannels of the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the port number of the CSI-RS.

30. The method according to claim 21, characterized in that Power control factor β of CSI-RS CSI-RS,1 Satisfies the following relationship: in, is the power control factor of the physical sidelink shared channel PSSCH on the symbol used to transmit the CSI-RS, is the power control factor of the PSSCH on the symbol not used for transmitting CSI-RS, W is the number of subchannels of the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, Y is the number of subchannels of the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the port number of the CSI-RS.

31. A communication device, characterized in that: include: A transceiver unit, configured to send a channel state information reference signal CSI-RS to a second terminal device; The frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool, the resource pool is a set of time-frequency resources contained in the side link SL part bandwidth BWP, the resource pool includes one or more continuous sub-channels in the frequency domain, one sub-channel of the resource pool includes one or more continuous physical resource blocks PRB, and the resource pool is determined in the time domain according to a periodic bit map; The transceiver unit is further used to send first indication information to the second terminal device, where the first indication information is used to instruct the second terminal device to send channel state information CSI, and the first indication information is included in the second-level sidelink control information SCI.

32. The device according to claim 31, characterized in that The first indication information is further used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

33. The device according to claim 31, characterized in that The transceiver unit is also used to send second indication information to the second terminal device, and the second indication information is used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

34. The device according to claim 33, characterized in that The second indication information is included in radio resource control RRC signaling.

35. The device according to any one of claims 31 to 34, characterized in that The CSI includes at least one of the following: A wideband channel quality indicator CQI index, where the wideband CQI index is a CQI index corresponding to the frequency domain bandwidth of the CSI-RS; The CQI values ​​of one or more sub-channels in the resource pool, wherein the CQI value of a sub-channel in the resource pool corresponds to a CQI index of a sub-channel in the resource pool.

36. The device according to any one of claims 31 to 34, characterized in that The CSI is carried in a medium access control layer control element MAC CE, and the number of bytes occupied by the MAC CE is related to the number of sub-channels in the resource pool.

37. The device according to claim 35, characterized in that The CSI is carried in a medium access control layer control element MAC CE, and the number of bytes occupied by the MAC CE is related to the number of sub-channels in the resource pool.

38. The device according to claim 36, characterized in that The MAC CE includes bytes, of which, is the round-up symbol, and y is the number of sub-channels in the resource pool.

39. The device according to claim 37, characterized in that The MAC CE includes bytes, of which, is the round-up symbol, and y is the number of sub-channels in the resource pool.

40. The device according to any one of claims 31-34, 37-39, characterized in that Power control factor β of CSI-RS CSI-RS,1 Satisfies the following relationship: in, is the power control factor of the physical sidelink shared channel PSSCH, W is the number of subchannels in the PSSCH bandwidth, Y is the number of subchannels in the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the port number of the CSI-RS.

41. The device according to claim 35, characterized in that Power control factor β of CSI-RS CSI-RS,1 Satisfies the following relationship: in, is the power control factor of the physical sidelink shared channel PSSCH, W is the number of subchannels in the PSSCH bandwidth, Y is the number of subchannels in the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the port number of the CSI-RS.

42. The device according to claim 36, characterized in that Power control factor β of CSI-RS CSI-RS,1 Satisfies the following relationship: in, is the power control factor of the physical sidelink shared channel PSSCH, W is the number of subchannels in the PSSCH bandwidth, Y is the number of subchannels in the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the port number of the CSI-RS.

43. The device according to any one of claims 31-34, 37-39, characterized in that Power control factor β of CSI-RS CSI-RS,1 Satisfies the following relationship: in, is the power control factor of the physical sidelink shared channel PSSCH on the symbol used to transmit the CSI-RS, is the power control factor of the PSSCH on the symbol not used for transmitting CSI-RS, W is the number of subchannels of the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, Y is the number of subchannels of the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the port number of the CSI-RS.

44. The device according to claim 35, characterized in that Power control factor β of CSI-RS CSI-RS,1 Satisfies the following relationship: in, is the power control factor of the physical sidelink shared channel PSSCH on the symbol used to transmit the CSI-RS, is the power control factor of the PSSCH on the symbol not used for transmitting CSI-RS, W is the number of subchannels of the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, Y is the number of subchannels of the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the port number of the CSI-RS.

45. The device according to claim 36, characterized in that Power control factor β of CSI-RS CSI-RS,1 Satisfies the following relationship: in, is the power control factor of the physical sidelink shared channel PSSCH on the symbol used to transmit the CSI-RS, is the power control factor of the PSSCH on the symbol not used for transmitting CSI-RS, W is the number of subchannels of the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, Y is the number of subchannels of the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the port number of the CSI-RS.

46. ​​A communication device, characterized in that: include: A transceiver unit, configured to receive a channel state information reference signal CSI-RS from a first terminal device; The frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool, the resource pool is a set of time-frequency resources contained in the side link SL part bandwidth BWP, the resource pool includes one or more continuous sub-channels in the frequency domain, one sub-channel of the resource pool includes one or more continuous physical resource blocks PRB, and the resource pool is determined in the time domain according to a periodic bit map; The transceiver unit is further used to receive first indication information from the first terminal device, where the first indication information is used to instruct the second terminal device to send channel state information CSI, and the first indication information is included in the second-level sidelink control information SCI.

47. The device according to claim 46, characterized in that The first indication information is further used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

48. The device according to claim 46, characterized in that The transceiver unit is also used to receive second indication information from the first terminal device, where the second indication information is used to indicate that the frequency domain bandwidth of the CSI-RS is the same as the frequency domain bandwidth of the resource pool.

49. The device according to claim 48, characterized in that The second indication information is included in radio resource control RRC signaling.

50. The device according to any one of claims 46 to 49, characterized in that The CSI includes at least one of the following: A wideband channel quality indicator CQI index, where the wideband CQI index is a CQI index corresponding to the frequency domain bandwidth of the CSI-RS; The CQI values ​​of one or more sub-channels in the resource pool, wherein the CQI value of a sub-channel in the resource pool corresponds to a CQI index of a sub-channel in the resource pool.

51. The device according to any one of claims 46 to 49, characterized in that The CSI is carried in a medium access control layer control element MAC CE, and the number of bytes occupied by the MAC CE is related to the number of sub-channels in the resource pool.

52. The device according to claim 50, characterized in that The CSI is carried in a medium access control layer control element MAC CE, and the number of bytes occupied by the MAC CE is related to the number of sub-channels in the resource pool.

53. The device according to claim 51, characterized in that The MAC CE includes bytes, of which, is the round-up symbol, and y is the number of sub-channels in the resource pool.

54. The device according to claim 52, characterized in that The MAC CE includes bytes, of which, is the round-up symbol, and y is the number of sub-channels in the resource pool.

55. The device according to any one of claims 46-49, 52-54, characterized in that Power control factor β of CSI-RS CSI-RS,1 Satisfies the following relationship: in, is the power control factor of the physical sidelink shared channel PSSCH, W is the number of subchannels in the PSSCH bandwidth, Y is the number of subchannels in the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the port number of the CSI-RS.

56. The device according to claim 50, characterized in that Power control factor β of CSI-RS CSI-RS,1 Satisfies the following relationship: in, is the power control factor of the physical sidelink shared channel PSSCH, W is the number of subchannels in the PSSCH bandwidth, Y is the number of subchannels in the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the port number of the CSI-RS.

57. The device according to claim 51, characterized in that Power control factor β of CSI-RS CSI-RS,1 Satisfies the following relationship: in, is the power control factor of the physical sidelink shared channel PSSCH, W is the number of subchannels in the PSSCH bandwidth, Y is the number of subchannels in the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the port number of the CSI-RS.

58. The device according to any one of claims 46-49, 52-54, characterized in that Power control factor β of CSI-RS CSI-RS,1 Satisfies the following relationship: in, is the power control factor of the physical sidelink shared channel PSSCH on the symbol used to transmit the CSI-RS, is the power control factor of the PSSCH on the symbol not used for transmitting CSI-RS, W is the number of subchannels of the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, Y is the number of subchannels of the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the port number of the CSI-RS.

59. The device according to claim 50, characterized in that Power control factor β of CSI-RS CSI-RS,1 Satisfies the following relationship: in, is the power control factor of the physical sidelink shared channel PSSCH on the symbol used to transmit the CSI-RS, is the power control factor of the PSSCH on the symbol not used for transmitting CSI-RS, W is the number of subchannels of the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, Y is the number of subchannels of the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the port number of the CSI-RS.

60. The device according to claim 51, characterized in that Power control factor β of CSI-RS CSI-RS,1 Satisfies the following relationship: in, is the power control factor of the physical sidelink shared channel PSSCH on the symbol used to transmit the CSI-RS, is the power control factor of the PSSCH on the symbol not used for transmitting CSI-RS, W is the number of subchannels of the PSSCH bandwidth, Z is the number of PRBs included in a subchannel of the resource pool, Y is the number of subchannels of the resource pool, Y≥W, is the number of PSSCH layers scheduled, Q p is the port number of the CSI-RS.

61. A communication device, characterized in that: The device comprises a processor and a memory, wherein a computer program is stored in the memory, and the processor executes the computer program stored in the memory so that the device performs the method according to any one of claims 1 to 15.

62. A communication device, characterized in that: The device comprises a processor and a memory, wherein a computer program is stored in the memory, and the processor executes the computer program stored in the memory so that the device performs the method according to any one of claims 16 to 30.

63. A communication device, characterized in that: include: processor and interface circuits; The interface circuit is used to receive code instructions and transmit them to the processor; The processor is configured to run the code instructions to execute the method according to any one of claims 1-15.

64. A communication device, characterized in that: include: processor and interface circuits; The interface circuit is used to receive code instructions and transmit them to the processor; The processor is configured to run the code instructions to execute the method according to any one of claims 16-30.

65. A computer-readable storage medium for storing instructions, characterized in that: When the instructions are executed, the method according to any one of claims 1 to 15 is implemented.

66. A computer-readable storage medium for storing instructions, characterized in that: When the instructions are executed, the method according to any one of claims 16 to 30 is implemented.

67. A computer program product, characterized in that The computer program product comprises a program or an instruction. When the computer program product is run on a communication device, the communication device executes the method according to any one of claims 1 to 15, or executes the method according to any one of claims 16 to 30.

68. A chip system, characterized in that: The method comprises a processor configured to perform the method as claimed in any one of claims 1 to 15, or to perform the method as claimed in any one of claims 16 to 30.

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