Communication method and communication device

Abstract

Provided are a communication method and a communication device, the method comprising: a first terminal device sending first information to a second terminal device, the first information being used for indicating a first reference value in a first time slot, the first reference value being used for the first terminal device to calculate a reference orthogonal frequency division multiplexing (OFDM) symbolic number when determining a transport block size (TBS). According to the method in the embodiment of the invention, correct receiving of the data can be ensured.

Description

[0001] Cross-references

[0002] This application is a divisional application of a patent application filed on October 23, 2024, with application number 202280095301.X and application name “Communication Method and Communication Device”. Technical Field

[0003] The present application relates to the field of communication technology, and more specifically, to a communication method and a communication device. Background Art

[0004] With the development of communication technology, some communication systems support transmission using unlicensed frequency bands to improve the spectrum utilization of the system. However, there are still some problems when performing sidelink (SL) transmission on unlicensed frequency bands. Summary of the invention

[0005] The present application provides a communication method and a communication device. The following introduces various aspects involved in the embodiments of the present application.

[0006] In a first aspect, a communication method is provided, the method comprising: a first terminal device sends first information to a second terminal device, the first information being used to indicate a first reference value within a first time slot, the first reference value being used to calculate a reference orthogonal frequency division multiplexing OFDM symbol number when the first terminal device determines a transmission block size TBS.

[0007] In a second aspect, a communication method is provided, which includes: a second terminal device receives first information sent by a first terminal device, the first information is used to indicate a first reference value in a first time slot, and the first reference value is used to calculate a reference orthogonal frequency division multiplexing OFDM symbol number when the first terminal device determines a transmission block size TBS.

[0008] According to a third aspect, a communication device is provided, comprising: a sending unit, configured to send first information to a second terminal device, wherein the first information is used to indicate a first reference value within a first time slot, and the first reference value is used to calculate a reference orthogonal frequency division multiplexing OFDM symbol number when the device determines a transmission block size TBS.

[0009] In a fourth aspect, a communication device is provided, which includes: a receiving unit, used to receive first information sent by a first terminal device, the first information is used to indicate a first reference value in a first time slot, and the first reference value is used to calculate a reference orthogonal frequency division multiplexing OFDM symbol number when the first terminal device determines a transmission block size TBS.

[0010] In a fifth aspect, a communication device is provided, comprising a memory, a transceiver and a processor, wherein the memory is used to store programs, the transceiver is used to send and receive data, and the processor is used to call the program in the memory to execute the method described in the first aspect or the second aspect.

[0011] In a sixth aspect, a communication device is provided, comprising a processor for calling a program from a memory to execute the method described in the first aspect or the second aspect.

[0012] In a seventh aspect, a chip is provided, comprising a processor for calling a program from a memory so that a device equipped with the chip executes the method described in the first aspect or the second aspect.

[0013] According to an eighth aspect, a computer-readable storage medium is provided, on which a program is stored, wherein the program enables a computer to execute the method described in the first aspect or the second aspect.

[0014] According to a ninth aspect, a computer program product is provided, comprising a program, wherein the program enables a computer to execute the method described in the first aspect or the second aspect.

[0015] According to a tenth aspect, a computer program is provided, wherein the computer program enables a computer to execute the method described in the first aspect or the second aspect.

[0016] In an embodiment of the present application, a first terminal device sends first information to a second terminal device, where the first information is used to indicate a first reference value in a first time slot, and the first reference value is used to calculate a reference number of orthogonal frequency division multiplexing OFDM symbols when the first terminal device determines a transmission block size TBS. This ensures that the TBS determined by the sender and the receiver during the transmission of the same TB are the same, thereby ensuring correct reception of data. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is an example diagram of a wireless communication system applied in an embodiment of the present application.

[0018] Figure 2 This is an example diagram of a wireless communication system applied in another embodiment of the present application.

[0019] Figure 3 This is an example diagram of a wireless communication system applied in yet another embodiment of the present application.

[0020] Figure 4 This is an example diagram of a wireless communication system applied in yet another embodiment of the present application.

[0021] Figure 5 This is an example diagram of unicast transmission in an embodiment of the present application.

[0022] Figure 6This is an example diagram of multicast transmission in an embodiment of the present application.

[0023] Figure 7 This is an example diagram of broadcast transmission in an embodiment of the present application.

[0024] Figure 8 This is an example diagram of the time slot structure in V2X in an embodiment of the present application.

[0025] Fig. 9 It is a schematic diagram of PSFCH resources and the corresponding number of OFDM symbols in a time slot.

[0026] Fig.10 It is a schematic diagram of the mapping method of the second-order SCI.

[0027] Fig.11 It is a schematic diagram of the time-frequency domain position of DMRS in PSCCH.

[0028] Fig.12 This is a schematic diagram of the time domain positions of 4 DMRS symbols when the number of PSSCH symbols is 13.

[0029] Fig.13 This is a schematic diagram of single-symbol DMRS frequency domain type 1.

[0030] Fig.14 It is a schematic diagram of the time-frequency position of SL CSI-RS.

[0031] Fig.15 It is a schematic diagram of channel occupation time and channel occupancy.

[0032] Fig.16 is a schematic diagram of LBT on unlicensed spectrum.

[0033] Fig.17 It is a schematic flow chart of a communication method provided by an embodiment of the present application.

[0034] Fig.18 It is a schematic diagram of the starting point position and the number of OFDM symbols in one embodiment of the present application.

[0035] Fig.19 It is a schematic diagram of the starting point position and the number of OFDM symbols in another embodiment of the present application.

[0036] Fig. 20 This is a schematic diagram of the starting point position and the number of OFDM symbols in another embodiment of the present application.

[0037] Fig.21 It is a schematic structural diagram of a communication device provided in one embodiment of the present application.

[0038] Fig. 22It is a schematic structural diagram of a communication device provided in another embodiment of the present application.

[0039] Fig.23 It is a schematic structural diagram of a device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0040] The technical solution in this application will be described below in conjunction with the accompanying drawings.

[0041] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as: the fifth generation (5th generation, 5G) system or new radio (new radio, NR), long term evolution (long term evolution, LTE) system, LTE frequency division duplex (frequency division duplex, FDD) system, LTE time division duplex (time division duplex, TDD), etc. The technical solutions provided by the present application can also be applied to future communication systems, such as the sixth generation mobile communication system, satellite communication system, etc.

[0042] The user equipment (UE) in the embodiments of the present application may also be referred to as terminal equipment, access terminal, user unit, user station, mobile station, mobile station (MS), mobile terminal (MT), remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device. The UE in the embodiments of the present application may refer to a device that provides voice and / or data connectivity to a user, and may be used to connect people, objects and machines, such as a handheld device with a wireless connection function, a vehicle-mounted device, etc. The UE in the embodiments of the present application can be a mobile phone, a tablet computer, a laptop, a PDA, a mobile internet device (MID), a wearable device, a virtual reality (VR) device, an augmented reality (AR) device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical surgery, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, etc. Optionally, the UE can be used to act as a base station. For example, the UE can act as a scheduling entity, which provides sidelink signals between UEs in vehicle to everything (V2X) or device to device (D2D). For example, a cellular phone and a car communicate with each other using a sidelink signal. Cellular phones and smart home devices communicate without relaying communication signals through a base station.

[0043] The network device in the embodiment of the present application may be a device for communicating with a UE, and the network device may also be referred to as an access network device or a radio access network device, such as a base station. The network device in the embodiment of the present application may refer to a radio access network (RAN) node (or device) that accesses a UE to a wireless network. The base station can broadly cover various names as follows, or be replaced with the following names, such as: NodeB, evolved NodeB (eNB), next generation NodeB (gNB), relay station, access point, transmission point (TRP), transmission point (TP), master station MeNB, secondary station SeNB, multi-standard radio (MSR) node, home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, base band unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), positioning node, etc. The base station can be a macro base station, a micro base station, a relay node, a donor node or the like, or a combination thereof.

[0044] It should be understood that all or part of the functions of the network device and UE in the present application can also be implemented by software functions running on hardware, or by virtualization functions instantiated on a platform (such as a cloud platform).

[0045] It should be understood that the terms "system" and "network" are often used interchangeably in this article. The term "and / or" in this article is only a description of the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0046] The terms used in the implementation mode of this application are only used to explain the specific embodiments of this application, and are not intended to limit this application. The terms "first", "second", "third" and "fourth" in the specification and claims of this application and the drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0047] It should be understood that the "indication" mentioned in the embodiments of the present application can be a direct indication, an indirect indication, or an indication of an association relationship. For example, A indicates B, which can mean that A directly indicates B, for example, B can be obtained through A; it can also mean that A indirectly indicates B, for example, A indicates C, and B can be obtained through C; it can also mean that there is an association relationship between A and B.

[0048] In the description of the embodiments of the present application, the term "corresponding" may indicate a direct or indirect correspondence between two items, or an association relationship between the two items, or a relationship between indication and being indicated, configuration and being configured, and the like.

[0049] In this application, "pre-definition" can be implemented by pre-saving corresponding codes, tables or other methods that can be used to indicate relevant information in a device (for example, including a terminal device and a network device), and this application does not limit its specific implementation method. For example, pre-definition can refer to what is defined in the protocol.

[0050] In this application, the "protocol" may refer to a standard protocol in the communication field, for example, it may include an LTE protocol, a NR protocol, and related protocols used in future communication systems, and this application does not limit this.

[0051] The technical solution in the embodiments of the present application can be applied to side communication. The side communication will be introduced in detail below.

[0052] In sideline communication, according to the different network coverage conditions of the communicating terminal devices, it can be divided into sideline communication within network coverage, sideline communication with partial network coverage, and sideline communication outside network coverage. Figure 1 , Figure 2 , Figure 3 and Figure 4 shown.

[0053] In the case of sideline communication within the network coverage, all terminal devices performing sideline communication are within the coverage of the same base station. Figure 1 As shown, both terminal devices 120 and 130 are within the network coverage of network device 110, can receive the sidewalk configuration sent by network device 110, and perform sidewalk communication based on the sidewalk configuration.

[0054] In the case of partial network coverage of sideline communication, some terminal devices performing sideline communication are located within the coverage of the network device. Figure 2 As shown, the terminal device 220 can receive the sidelink configuration of the network device 210 and perform sidelink communication based on the sidelink configuration, while the terminal device 230 located outside the network coverage cannot receive the sidelink configuration of the network device 210. In this case, the terminal device 230 outside the network coverage can determine the sidelink configuration based on the pre-configuration information and the information carried in the physical sidelink broadcast channel (PSBCH) sent by the terminal device 220, and perform sidelink communication based on the sidelink configuration.

[0055] For sideline communications outside the network coverage, all terminal devices performing sideline communications are located outside the network coverage. Figure 3 As shown, both terminal devices 310 and 320 are located outside the network coverage. At this time, terminal devices 310 and 320 can respectively determine the sidewalk configuration according to the pre-configuration information and perform sidewalk communication based on the sidewalk configuration.

[0056] In sideline communication, multiple terminal devices can also form a communication group, which has a central control node, which can also be a cluster header terminal (CH). The central control node has one of the following functions: responsible for the establishment of the communication group; controlling the joining and leaving of group members; coordinating resources, allocating sideline transmission resources to other terminal devices in the communication group, receiving sideline feedback information from other terminal devices; coordinating resources with other communication groups, etc. Figure 4 As shown, terminal devices 410, 420 and 430 form a communication group, terminal device 410 is the central control node of the communication group, terminal devices 420 and 430 are group members, and terminal device 410 can allocate side transmission resources to terminal devices 420 and 430.

[0057] Device-to-device communication is a sidelink (SL) transmission technology based on D2D. Unlike the traditional cellular system where communication data is received or sent by network devices, device-to-device communication has higher spectrum efficiency and lower transmission latency. For example, the Internet of Vehicles system can communicate in a terminal-to-terminal communication manner. Currently, the 3rd Generation Partnership Project (3GPP) defines two transmission modes for device-to-device communication: the first mode and the second mode.

[0058] The first mode: The transmission resources of the terminal device are allocated by the network device, and the terminal device sends data on the sidelink according to the resources allocated by the network device; the network device can allocate resources for a single transmission to the terminal device, or it can allocate resources for semi-static transmission to the terminal device. For example, Figure 1 As shown, the terminal device is located within the coverage of the network, and the network device allocates transmission resources for side transmission to the terminal device.

[0059] Second mode: The terminal device selects a resource in the resource pool to transmit data. Figure 3 In the case where the terminal device is outside the network coverage, the terminal device can autonomously select transmission resources from the pre-configured resource pool for side transmission; or Figure 1 As shown, the terminal device can also autonomously select transmission resources from the resource pool configured by the network for side transmission.

[0060] New radio vehicle to everything (NR-V2X) is a sidelink transmission technology used in vehicle wireless communications. In NR-V2X, unicast, multicast and broadcast transmission modes are supported. For unicast transmission, there is only one receiving terminal, such as Figure 5 As shown, unicast transmission is performed between terminal device 510 and terminal device 520; for multicast transmission, the receiving end is all terminal devices in a communication group, or all terminal devices within a certain transmission distance, such as Figure 6 As shown, terminal devices 610, 620, 630 and 640 constitute a communication group, wherein terminal device 610 sends data, and other terminal devices in the communication group are receiving terminal devices; for the broadcast transmission mode, the receiving end is any terminal around the sending terminal device, such as Figure 7 As shown, terminal device 710 is a transmitting terminal device, and terminal devices 720-760 are receiving terminal devices around terminal device 710. Terminal device 710 can send data to terminal devices 720-760.

[0061] The time slot structure in NR-V2X can be as follows Figure 8 As shown. Among them, Figure 8 Part (a) shows the time slot structure in which the physical sidelink feedback channel (PSFCH) is not included in the time slot; Figure 8 Part (b) shows the time slot structure including PSFCH.

[0062] like Figure 8As shown, the physical sidelink control channel (PSCCH) in NR-V2X starts from the second sidelink symbol of the time slot in the time domain, occupies 2 or 3 orthogonal frequency division multiplexing (OFDM) symbols, and can occupy {10, 1215, 20, 25} physical resource blocks (PRBs) in the frequency domain. In order to reduce the complexity of UE's blind detection of PSCCH, only one number of PSCCH symbols and PRBs can be configured in a resource pool. In addition, because the subchannel is the minimum granularity of physical sidelink shared channel (PSSCH) resource allocation in NR-V2X, the number of PRBs occupied by PSCCH can be less than or equal to the number of PRBs contained in a subchannel in the resource pool, so as to avoid additional restrictions on PSSCH resource selection or allocation. PSSCH also starts from the second side symbol of the time slot in the time domain. The last time domain symbol in the time slot is the guard period (GP) symbol, and the remaining symbols are mapped to PSSCH. The first side symbol in the time slot is a repetition of the second side symbol. Usually, the receiving terminal device uses the first side symbol as an automatic gain control (AGC) symbol, and the data on this symbol is usually not used for data demodulation. PSSCH can occupy K subchannels in the frequency domain, and each subchannel can include M consecutive PRBs, where K and M are integers.

[0063] like Figure 8 As shown in part (b), when a time slot contains a PSFCH channel, the second to last and third to last symbols in the time slot are used for PSFCH channel transmission, and a time domain symbol before the PSFCH channel is used as a GP symbol.

[0064] In NR-V2X, PSSCH is used to carry the second-order sidelink control information (SCI) (such as SCI 2-A or SCI 2-B, see the subsequent description for details) and data information. The second-order SCI adopts Polar coding and fixedly adopts quadrature phase shift keying (QPSK) modulation. The data part of PSSCH adopts low-density parity check (LDPC) code, and the highest modulation order supported is 256 quadrature amplitude modulation (QAM).

[0065] In NR-V2X, PSSCH supports up to two stream transmissions, and uses a unit precoding matrix to map the data on the two layers to two antenna ports. At most, only one transport block (TB) can be sent in one PSSCH. However, unlike the transmission method of the PSSCH data part, when PSSCH adopts a dual-stream transmission method, the modulation symbols sent by the second-order SCI on the two streams are exactly the same. This design can ensure the reception performance of the second-order SCI in highly correlated channels.

[0066] Since the maximum number of retransmissions of a PSSCH in NR-V2X is 32, if there are PSFCH resources in the resource pool and the configuration period of the PSFCH resources is 2 or 4, the available OFDM symbols in the time slots where different transmissions of a PSSCH are located may change, such as Fig. 9 As shown. If calculated according to the actual number of OFDM symbols in a time slot ( The reference value of the number of symbols occupied by PSSCH) may be caused by the different number of symbols available for PSSCH transmission in a time slot. S ' CI2 Different, but Q S ' CI 2 will result in a change in the size of the TB carried by the PSSCH, as described below. In order to ensure that the transmission block size (TBS) remains unchanged during multiple transmissions of the PSSCH, The actual number of PSFCH symbols is not used. The number of resource elements (REs) occupied by the PSSCH demodulation reference signal (DMRS) and the number of REs occupied by the phase tracking reference signal (PT-RS), which may change during the retransmission process, are not taken into account. Fig. 9 Where n and l are integers.

[0067] The code rate of the second-order SCI can be dynamically adjusted within a certain range. The specific code rate is indicated by the first-order SCI, so the receiver does not need to perform blind detection on the second-order SCI even after the code rate changes. The modulation symbols of the second-order SCI are mapped from the symbol where the first PSSCH DMRS is located in the frequency domain first and then in the time domain. On the OFDM symbol where the DMRS is located, the second-order SCI is mapped to the RE not occupied by the DMRS, such as Fig.10 shown.

[0068] The data part of PSSCH in a resource pool can use multiple different modulation and coding scheme (MCS) tables, including the conventional 64QAM MCS table, 256QAM MCS table, and the low spectrum efficiency 64QAM MCS table. The specific MCS table used in a transmission is indicated by the "MCS table indication" field in the first-order SCI. In order to control the peak to average power ratio (PAPR), PSSCH must be sent using continuous PRBs. Since the subchannel is the minimum frequency domain resource granularity of PSSCH, this requires that PSSCH must occupy continuous subchannels.

[0069] PSSCH follows the NR PDSCH and PUSCH transport block size (TBS) determination mechanism, that is, the TBS is determined based on the reference value of the number of REs used for PSSCH in the time slot where PSSCH is located, so that the actual code rate is as close to the target code rate as possible. The purpose of using the reference value of the number of REs instead of the actual number of REs here is to ensure that the number of REs used to determine the TBS remains unchanged during the PSSCH retransmission process, so that the determined TBS size is the same. To achieve this goal, the reference value N of the number of REs occupied by PSSCH in the TBS determination process is set. RE Determine according to the following formula (1):

[0070]

[0071] Among them, n PRB is the number of PRBs occupied by PSSCH, is the number of REs occupied by the first-order SCI (including the REs occupied by the DMRS of the PSCCH), is the number of REs occupied by the second-order SCI, N′ RE Indicates the number of reference REs that can be used for PSSCH in a PRB. N' RE It can be determined by the following formula (2):

[0072]

[0073] in: Indicates the number of subcarriers in a PRB; Indicates the number of symbols available for sideline in a time slot, excluding the last GP symbol and the first symbol used for AGC; or 3, the specific value is indicated by the "PSFCH symbol number" field in the first-order SCI, which is the reference value of the number of symbols occupied by PSFCH; The value of is configured by the RRC layer parameters and is used to indicate the reference value of the number of REs occupied by the PT-RS and the channel state information reference signal (CSI-RS); It represents the average number of DMRS REs in a time slot, and is related to the DMRS pattern allowed in the resource pool. The corresponding relationship can be shown in the following Table 1.

[0074] Table 1 DMRS patterns allowed in the resource pool and The corresponding relationship

[0075]

[0076] In NR-V2X, the DMRS pattern of PSCCH is the same as that of the NR physical downlink control channel (PDCCH), that is, DMRS exists on each OFDM symbol of PSCCH and is located in {#1, #5, #9} REs of a PRB in the frequency domain, such as Fig.11 The DMRS sequence of PSCCH is generated by the following formula (3):

[0077]

[0078] Among them, the pseudo-random sequence c(m) is given by Initialize, where l is the index of the OFDM symbol where the DMRS is located in the time slot, is the index of the time slot where the DMRS is located in the system frame, Indicates the number of OFDM symbols in a time slot, N ID ∈{0,1,…,65535}, in a resource pool N ID The specific value is configured or preconfigured by the network.

[0079] NR-V2X draws on the design in the NR Uu interface and uses multiple time-domain PSSCH DMRS patterns. In a resource pool, the number of available DMRS patterns is related to the number of PSSCH symbols in the resource pool. For a specific number of PSSCH symbols (including the first AGC symbol) and PSCCH symbols, the available DMRS patterns and the position of each DMRS symbol in the pattern are shown in Table 2 below. Fig.12 A schematic diagram of the time domain position of 4 DMRS symbols when the number of PSSCH symbols is 13 is given in FIG.

[0080] Table 2 Number and position of DMRS symbols under different PSSCH and PSCCH symbol numbers

[0081]

[0082] If multiple time-domain DMRS patterns are configured in the resource pool, the specific time-domain DMRS pattern to be used is selected by the transmitting UE and indicated in the first-order SCI. This design allows high-speed UEs to select high-density DMRS patterns to ensure the accuracy of channel estimation, while for low-speed UEs, low-density DMRS patterns can be used to improve spectrum efficiency.

[0083] The generation method of the PSSCH DMRS sequence is almost the same as that of the PSCCH DMRS sequence. The only difference is the initialization formula c(m) of the pseudo-random sequence. init middle, p i The i-th CRC of the PSCCH that schedules the PSSCH, where L=24 is the number of bits of the PSCCH CRC.

[0084] NR PDSCH and PUSCH support two frequency domain DMRS patterns, namely DMRS frequency domain type 1 and DMRS frequency domain type 2, and for each frequency domain type, there are two different types: single DMRS symbol and double DMRS symbol. Single symbol DMRS frequency domain type 1 supports 4 DMRS ports, single symbol DMRS frequency domain type 2 can support 6 DMRS ports, and in the case of double DMRS symbols, the number of supported ports is doubled. However, in NR-V2X, since PSSCH only needs to support two DMRS ports at most, only single symbol DMRS frequency domain type 1 is supported, such as Fig.13 shown.

[0085] To better support unicast communication, NR-V2X supports SL CSI-RS. SL CSI-RS will only be sent when the following three conditions are met:

[0086] (1) The UE sends the corresponding PSSCH, that is, the UE cannot only send the SL CSI-RS;

[0087] (2) Sidelink CSI reporting is activated by high-level signaling;

[0088] (3) When the sidelink CSI reporting is activated by high-layer signaling, the corresponding bit in the second-order SCI sent by the UE triggers the sidelink CSI reporting.

[0089] The maximum number of ports supported by SL CSI-RS is 2. When there are two ports, the SL CSI-RS of different ports are multiplexed by code division on two adjacent REs of the same OFDM symbol. The number of SLCSI-RS of each port in a PRB is 1, that is, the density is 1. Therefore, SL CSI-RS will appear in at most one OFDM symbol in a PRB. The specific position of this OFDM symbol is determined by the transmitting terminal. In order to avoid affecting the resource mapping of PSCCH and the second-order SCI, SLCSI-RS cannot be located in the same OFDM symbol as PSCCH and the second-order SCI. Since the channel estimation accuracy of the OFDM symbol where the PSSCH DMRS is located is high, and the SL CSI-RS of the two ports will occupy two consecutive REs in the frequency domain, the SL-CSI-RS cannot be sent on the same OFDM symbol as the PSSCH DMRS. The position of the OFDM symbol where the SL CSI-RS is located is indicated by the sl-CSI-RS-FirstSymbol parameter in PC5 RRC.

[0090] The position of the first RE occupied by SL CSI-RS in a PRB is indicated by the sl-CSI-RS-FreqAllocation parameter in PC5 RRC. If SL CSI-RS is one port, this parameter is a bitmap with a length of 12, corresponding to 12 REs in a PRB. If SL CSI-RS is two ports, this parameter is a bitmap with a length of 6. In this case, SL CSI-RS occupies two REs, 2f(1) and 2f(1)+1, where f(1) represents the index of the bit with a value of 1 in the above bitmap. The frequency domain position of SL CSI-RS is also determined by the transmitting terminal, but the determined frequency domain position of SL CSI-RS cannot conflict with PT-RS. Fig.14 A schematic diagram of the time-frequency position of SL CSI-RS is given. Fig.14In the example, the number of SLCSI-RS ports is 2, the sl-CSI-RS-FirstSymbol is 8, and the sl-CSI-RS-FreqAllocation is [b5, b4, b3, b2, b1, b0] = [0, 0, 0, 1, 0, 0].

[0091] The NR system introduced in the 3GPP Release 15 (R15) standard is a communication technology for use on existing and new licensed spectrum. The NR system can achieve seamless coverage, high spectrum efficiency, high peak rate and high reliability of cellular networks. In the LTE system, unlicensed spectrum (or unlicensed spectrum) has been used as a supplementary frequency band to the licensed spectrum for cellular networks. Similarly, the NR system can also use unlicensed spectrum as part of 5G cellular network technology to provide services to users. In the 3GPP R16 standard, the NR system for unlicensed spectrum, called NR-unlicensed (NR-U), is discussed.

[0092] The NR-U system supports two networking modes: licensed spectrum assisted access and unlicensed spectrum independent access. The former requires the use of licensed spectrum to access the network, and the unlicensed spectrum is used as a secondary carrier; the latter can be independently networked through unlicensed spectrum, and the UE can directly access the network through the unlicensed spectrum. The range of unlicensed spectrum used by the NR-U system introduced in 3GPP R16 is concentrated in the 5GHz and 6GHz frequency bands, for example, 5925–7125MHz in the United States, or 5925–6425MHz in Europe. In the R16 standard, band 46 (5150MHz-5925MHz) is also newly defined for use as an unlicensed spectrum.

[0093] Unlicensed spectrum is a spectrum that can be used for radio equipment communication divided by countries and regions. This spectrum is generally considered to be a shared spectrum, that is, as long as the communication equipment meets the regulatory requirements set by the country or region on the spectrum, it can use the spectrum without applying for exclusive spectrum authorization from the exclusive spectrum management agency of the country or region. Since the use of unlicensed spectrum needs to meet the specific regulatory requirements of each country and region, such as communication equipment using unlicensed spectrum in accordance with the principle of "listen before talk" (LBT). Therefore, NR technology needs to be enhanced accordingly to adapt to the regulatory requirements of unlicensed frequency bands, while efficiently using unlicensed spectrum to provide services. In the 3GPP R16 standard, the standardization of NR-U technology in the following aspects is mainly completed: channel monitoring process; initial access process; control channel design; HARQ and scheduling; scheduling-free authorization transmission, etc. This chapter will introduce these technologies in detail.

[0094] Dynamic channel monitoring can also be considered as an LBT method based on LBE, and its channel monitoring principle is that the communication equipment performs LBT on the carrier of the unlicensed spectrum after the service arrives, and starts sending signals on the carrier after the LBT is successful. The LBT method of dynamic channel monitoring includes type 1 (Type1) channel access method and type 2 (Type2) channel access method. The Type1 channel access method is a multi-slot channel detection with random backoff based on the adjustment of the contention window size, wherein the corresponding channel access priority class (CAPC) p can be selected according to the priority of the service to be transmitted. The Type2 channel access method is a channel access method based on a fixed-length monitoring time slot, wherein the Type2 channel access method includes Type2A channel access, Type2B channel access and Type2C channel access. The Type1 channel access method is mainly used for communication equipment to initiate channel occupancy, and the Type2 channel access method is mainly used for communication equipment to share channel occupancy. A special case that needs to be explained is that when the base station initiates channel occupancy for the transmission of the SS / PBCH block in the discovery reference symbol (DRS) and the DRS window does not include the UE's unicast data transmission, if the length of the DRS window does not exceed 1ms and the duty cycle of the DRS window transmission does not exceed 1 / 20, then the base station can use Type2A channel access to initiate channel occupancy.

[0095] Fig.15 An example is given of a channel occupancy time obtained by a communication device after successful LBT on a channel of an unlicensed spectrum and signal transmission using resources within the channel occupancy time.

[0096] The default channel access mode on the base station side is Type 1 channel access. Taking the base station as an example, the channel access parameters corresponding to the channel access priority p on the base station side are shown in Table 3 below. If the channel access process is completed, the base station can use the channel to transmit the service to be transmitted. The maximum time length that the base station can use the channel for transmission cannot exceed T mcot,p .

[0097] Table 3 Channel access parameters corresponding to different channel priorities

[0098]

[0099] Among them, in the above Table 1, m p Indicates the number of fallback time slots corresponding to the channel access priority, CW p Indicates the size of the contention window corresponding to the channel access priority, CW min,p Indicates the CW corresponding to the channel access priorityp The minimum value, CW max,p Indicates the CW corresponding to the channel access priority p The maximum value, T mcot,p Indicates the maximum channel occupation time corresponding to the channel access priority.

[0100] When the base station initiates the channel occupying time (COT), in addition to using the resources in the COT for downlink transmission, the resources in the COT can also be shared with the UE for uplink transmission. When the resources in the COT are shared with the UE for uplink transmission, the channel access method that the UE can use is Type 2A channel access, Type 2B channel access or Type 2C channel access, among which Type 2A channel access, Type 2B channel access and Type 2C channel access are all channel access methods based on fixed-length monitoring time slots. Type 2 channel access is channel detection based on fixed-length channel monitoring time slots. Type 2 channel access can include the following:

[0101] Type 2A channel access: The channel detection method of the terminal device is 25μs single-slot channel detection. Specifically, under Type 2A channel access, the terminal device can monitor the channel for 25μs before starting transmission, and transmit data after the channel monitoring is successful.

[0102] Type 2B channel access: The channel detection method of the terminal device is 16μs single-slot channel detection. Specifically, under Type 2B channel access, the terminal device can monitor the channel for 16μs before the start of transmission, and transmit after the channel monitoring is successful. Among them, the gap between the start position of the transmission and the end position of the previous transmission is 16μs.

[0103] Type 2C channel access: The terminal device transmits without performing channel detection after the gap ends. Specifically, under Type 2C channel access, the terminal device can directly transmit, wherein the gap between the start position of the transmission and the end position of the previous transmission is less than or equal to 16μs. The length of the transmission does not exceed 584μs.

[0104] In SL communication based on licensed spectrum or dedicated spectrum, the number of symbols available for SL transmission in different time slots will not change significantly. The terminal can determine the size of the transport block TB sent in a time slot based on the average number of OFDM symbols available in a time slot and the resource bandwidth. The average number of OFDM symbols available in a time slot can be known in advance based on the configuration of the resource pool. The receiving terminal can calculate the same TBS based on the resource pool configuration information and the indication information in the SCI to ensure correct reception.

[0105] When Sidelink technology works on an unlicensed spectrum, it is necessary to continue to support the existing SL sensing mechanism to avoid resource conflicts with other SL users; in addition, it is also necessary to support the LBT channel sensing mechanism to avoid resource conflicts with users of other systems (such as WiFi). However, due to the uncertainty of LBT, the UE may succeed in LBT at any position within a time slot. Therefore, the number of OFDM symbols available for TB transmission in a time slot will also fluctuate greatly. Since a TB may need to be retransmitted, due to LBT, the number of OFDM symbols available for TB transmission in the retransmission time slot will also be different from the time slot where the TB was previously transmitted. For example Fig.16 As shown, the terminal may succeed in LBT after the 4th OFDM symbol of time slot n, and succeed in LBT before the start of time slot n+1 and time slot n+2. In this case, how to ensure that the TBS remains unchanged during the new transmission and reselection process is an urgent problem to be solved.

[0106] In order to solve one or more of the above technical problems, the present application proposes a communication method and a communication device, which can ensure that the TBS determined by the sender and the receiver during the transmission of the same TB is the same, thereby ensuring the correct reception of data. Figures 17 to 20 The embodiments of the present application are described in detail with examples.

[0107] Fig.17 It is a schematic flowchart of the communication method of an embodiment of the present application. Fig.17 The method 1700 shown may include steps S1710 and S1720, which are specifically as follows:

[0108] S1710, the first terminal device sends first information to the second terminal device.

[0109] The first terminal device can send the first information to the second terminal device in the unlicensed frequency band.

[0110] The first information may be used to indicate a first reference value in the first time slot. The first reference value may be used to calculate the reference number of OFDM symbols in the first time slot. For example, the first reference value may be used to calculate the reference number of OFDM symbols when the first terminal device determines the TBS; or, the first reference value may also be used to calculate the reference number of OFDM symbols when the second terminal device determines the TBS. Optionally, the first reference value may be determined by the first terminal device, pre-specified by the protocol, configured by the network, or pre-configured by the network.

[0111] It should be noted that the reference number of OFDM symbols mentioned here may not be the actual number of OFDM symbols in the first time slot, but is a reference value set to ensure that the TBS determined by the sender and receiver during the PSSCH retransmission process remains unchanged.

[0112] The above TBS may refer to the TB size of the sideline data sent by the first terminal device to the second terminal device. That is, the first reference value may be used to calculate the reference OFDM symbol number when the first terminal device sends the sideline data, and may also be used to calculate the reference OFDM symbol number when the second terminal device receives the sideline data.

[0113] In some embodiments, the first information may be carried in sidelink control information (SCI). For example, the first information may be carried in a PSFCH overhead indication field in the SCI; or, the first information may also be carried in other fields in the SCI, which is not limited in the present application.

[0114] In an embodiment of the present application, a first terminal device sends first information to a second terminal device, where the first information is used to indicate a first reference value in a first time slot, and the first reference value is used to calculate a reference number of orthogonal frequency division multiplexing OFDM symbols when the first terminal device determines a transmission block size TBS. This ensures that the TBS determined by the sender and the receiver during the transmission of the same TB are the same, thereby ensuring correct reception of data.

[0115] In some embodiments, method 1700 may further include step S1720, which is as follows:

[0116] S1720: The first terminal device sends sidewalk information to the second terminal device at the first starting point.

[0117] The first terminal device may send sidelink information to the second terminal device at a first starting point in an unlicensed frequency band.

[0118] The first starting point position may be one of one or more sideline transmission starting points in the first time slot.

[0119] In some embodiments, the starting position S1 may be the first starting position of one or more sideline transmission starting positions in the first time slot. Optionally, the starting position S1 may be determined according to the configuration or pre-configuration of the sideline SL bandwidth part (BWP) where the resource pool is located, or the starting position S1 may also be determined according to the configuration or pre-configuration of the resource pool. Wherein, S1 is a positive integer.

[0120] The first time slot may also include a starting position S2. Optionally, the starting position S2 may be predetermined (e.g., specified by a protocol), network configured, or network preconfigured. Wherein, S2 is an integer greater than S1. Optionally, in the first time slot, the number N1 of OFDM symbols available for sideline transmission starting from the starting position S2 is not less than 6, and N1 is a positive integer.

[0121] In some embodiments, no PSFCH resources may be configured in the resource pool to which the first time slot belongs. At this time, if the first starting point position is the starting point position S1 or S2 in the first time slot, the first reference value of the first terminal device when determining the TBS may be 0 or S2-S1. Accordingly, the second terminal device may determine the first reference value according to the indication of the first information, and determine the TBS using the same reference OFDM symbol number as the first terminal device. Therefore, it can be ensured that the TBS determined by the sender and the receiver during the transmission of the same TB are the same, thereby ensuring the correct reception of the data.

[0122] In some embodiments, the configuration period of the PSFCH resources in the resource pool to which the first time slot belongs is 1, that is, each time slot contains PSFCH resources. At this time, if the first starting position is the starting position S1 or S2 in the first time slot, the first reference value of the first terminal device when determining the TBS can be 3 or S2-S1+3. Accordingly, the second terminal device can determine the first reference value according to the indication of the first information, and determine the TBS using the same reference OFDM symbol number as the first terminal device.

[0123] In some embodiments, the configuration period of the PSFCH resources in the resource pool to which the first time slot belongs is greater than 1, that is, only part of the time slots contain PSFCH resources. At this time, if the first time slot does not contain PSFCH resources, the first starting position may be the starting position S1 or S2 in the first time slot; if the first time slot contains PSFCH resources, the first starting position may be the starting position S1 in the first time slot. Optionally, the first reference value of the first terminal device when determining the TBS may be 0 or 3. Accordingly, the second terminal device may determine the first reference value according to the indication of the first information, and determine the TBS using the same reference OFDM symbol number as the first terminal device.

[0124] The following describes several implementations of the present application scheme in detail according to whether PSFCH resources are configured in the resource pool. For ease of understanding, the following embodiments are described by taking a time slot as an example with a maximum of two starting positions, and the present application does not limit the number of starting positions contained in a time slot.

[0125] Method 1: No PSFCH resources are configured in the resource pool, and the terminal device can start side transmission at multiple starting positions within the time slot.

[0126] If no PSFCH resource is configured in the resource pool, that is, the period of the PSFCH resource is configured as 0, then all time slots may not contain PSFCH resources. At this time, the terminal device may start side transmission at two starting positions in the time slot.

[0127] The first starting point position S1 can be determined by the terminal device according to the configuration or pre-configuration of the SL BWP where the resource pool is located, or it can also be determined by the terminal device according to the configuration or pre-configuration of the resource pool. The second starting point position S2 can be defined by the communication protocol, network configuration or pre-configuration. For example, the value of S2 can be defined as S1+3 by the standard, or the value of S2 can also be configured or pre-configured by the network to other values.

[0128] Optionally, it can be ensured that the number of OFDM symbols available for sideline transmission starting from S2 (including S2) is not less than 6. In this way, large fluctuations in code rate when transmitting the same TB in different time slots can be avoided, thereby improving the stability and reliability of sideline transmission.

[0129] If the terminal device determines that the resource pool allows the sideline transmission to start from multiple starting points according to the resource pool configuration or pre-configuration, a specific field can be included in the PSCCH sent in the resource pool to indicate the starting point position. For example, the "PSFCH overhead indication" field in SCI format 1-A can be reused, or a new field can be introduced, and the value of the field can be 1 bit. For ease of description, it is assumed in the subsequent embodiments that the field is set to 0 for S1 and set to 1 for S2. When the terminal determines the TBS, N' can be calculated according to formula (2) RE At this time, unlike the prior art, Or S2-S1. Among them, It can be indicated by the "PSFCH symbol number" field in the SCI, which can represent the reference value of the PSFCH symbol number.

[0130] For the sending terminal (i.e., the first terminal device), if If the starting position indicator field is set to S2-S1, or the initial transmission of a TB is sent from S2, the starting position indicator field can be set to 1 when sending the PSCCH that schedules the new transmission and retransmission of the TB. If the value of the starting position indication field is set to 0, or the initial transmission of a TB is sent from S1, the value of the starting position indication field can be set to 0 when sending the PSCCH that schedules the new transmission and retransmission of the TB. Calculate the TBS, or set the starting point indication field to 0, and the sending terminal cannot send a new transmission and / or retransmission of the TB from other starting points other than S1.

[0131] For the receiving terminal (i.e., the second terminal device), if the value of the starting point indication field in the received PSCCH is 0, then when calculating the TBS of the TB scheduled by the PSCCH, Set to 0; otherwise, Set to S2-S1.

[0132] Method 2: When PSFCH resources are configured in the resource pool and the PSFCH configuration period is 1, the terminal device can start side transmission at multiple starting positions within the time slot.

[0133] In this embodiment, if the configuration or pre-configuration information of the resource pool indicates that the resource pool allows the sideline transmission to start at multiple starting points, the terminal device can start the sideline transmission at two starting points in one time slot.

[0134] The first starting point position S1 may be determined by the terminal device according to the configuration or pre-configuration of the SL BWP where the resource pool is located, or may also be determined by the terminal device according to the configuration or pre-configuration of the resource pool. The second starting point position S2 may be defined by a standard, configured by a network, or pre-configured. For example, the value of S2 may be configured by the network or pre-configured to other values.

[0135] Optionally, it can be ensured that the number of OFDM symbols available for sideline transmission from S2 (including S2) to the GP symbol before the PSFCH symbol is not less than 6, such as Fig.18 In this way, it is possible to avoid large fluctuations in the code rate when the same TB is transmitted in different time slots, thereby improving the stability and reliability of the side transmission.

[0136] If the terminal determines that the resource pool allows the sideline transmission to start from multiple starting points according to the resource pool configuration or pre-configuration, a specific field exists in the PSCCH transmitted in the resource pool for indicating the starting point position. For example, the "PSFCH overhead indication" field in SCI format 1-A can be reused, or a new field can be introduced, and the value of the field can be 1 bit. For ease of description, it is assumed in the subsequent embodiments that the field is set to 0 for S1 and set to 1 for S2. When the terminal determines the TBS, N' is calculated according to formula (2) RE . Different from the previous one, Or S2-S1+3.

[0137] For the transmitting terminal, if TBS is calculated using If the transmission start point is set to S2-S1+3, or the initial transmission of a TB is sent from S2, the transmission start point indication field should be set to 1 when sending the PSCCH that schedules the new transmission and retransmission of the TB. If the transmission start point indication field is set to 3, or the initial transmission of a TB is sent from S1, the transmission start point indication field can be set to 0 when sending the PSCCH for scheduling the new transmission and retransmission of the TB. If the TBS is calculated or the starting point indication field is set to 0, the sending terminal cannot send a new transmission and / or retransmission of the TB from other starting points other than S1.

[0138] For the receiving terminal, if the value of the starting point indication field in the received PSCCH is 0, then when calculating the TBS of the TB scheduled by the PSCCH, Set to 3; otherwise, Set to S2-S1+3.

[0139] Method 3: When PSFCH resources are configured in the resource pool and the PSFCH resource period is 2 or 4, in a time slot where there are no PSFCH resources, the terminal device can start side transmission from multiple starting positions within the time slot. In a time slot where there are PSFCH resources, the terminal device can only start side transmission from one starting position.

[0140] In this embodiment, PSFCH resources exist in some time slots within the resource pool, and PSFCH resources do not exist in other time slots. In time slots without PSFCH resources, the terminal device can start side transmission from two starting positions within a time slot. Among them, the first position S1 can be determined by the terminal device according to the configuration or pre-configuration of the SL BWP where the resource pool is located, or it can also be determined by the terminal device according to the configuration or pre-configuration of the resource pool. The second position S2 can be defined by the standard, configured by the network, or pre-configured. For example, the value of S2 can be defined by the standard as S1+3, or the value of S2 can also be configured by the network or pre-configured to other values.

[0141] Optionally, it can be ensured that the number of OFDM symbols available for sideline transmission starting from S2 (including S2) is not less than 6. In this way, large fluctuations in code rate when transmitting the same TB in different time slots can be avoided, thereby improving the stability and reliability of sideline transmission.

[0142] When the terminal determines TBS, N' is calculated according to formula (2): RE , the difference is, or 3.

[0143] For the transmitting terminal, if TBS is calculated using If it is set to 3, the "PSFCH overhead indication" field should be set to 1 when sending the PSCCH that schedules this TB. If set to 0, the value of the "PSFCH overhead indication" field can be set to 0 when sending the PSCCH that schedules this TB.

[0144] For the receiving terminal, if the value of the "PSFCH overhead indication" field in the received PSCCH is 0, then the TBS of the TB scheduled by the PSCCH can be calculated by Set to 0, otherwise, Set to 3.

[0145] Method 4: When PSFCH resources are configured in the resource pool and the PSFCH resource period is 2 or 4, the terminal device can start side transmission from multiple starting positions in each time slot, but the second starting position is different in the time slot with PSFCH resources and the time slot without PSFCH resources.

[0146] In this embodiment, PSFCH resources exist in some time slots in the resource pool, and PSFCH resources do not exist in other time slots.

[0147] In a time slot without PSFCH resources, the terminal can start side transmission at two positions in a time slot. The first starting position S1 can be determined by the terminal device according to the configuration or pre-configuration of the SL BWP where the resource pool is located, or it can also be determined by the terminal according to the configuration or pre-configuration of the resource pool. The second starting position S2 can be defined by the standard, configured by the network, or pre-configured. For example, the value of S2 can be defined by the standard or configured or pre-configured by the network to be other values.

[0148] Optionally, it can be ensured that the number of OFDM symbols N1 available for sideline transmission starting from S2 (including S2) is not less than 6, for example, Fig.19 shown.

[0149] In a time slot where PSFCH resources exist, the terminal device can start side transmission at two starting positions in a time slot. Among them, the first starting position S1 can be determined by the terminal device according to the configuration or pre-configuration of the SL BWP where the resource pool is located, or it can also be determined by the terminal device according to the configuration or pre-configuration of the resource pool. The second position S2 can be defined by the standard, configured by the network, or pre-configured. For example, the value of S2 can be defined by the standard or configured / pre-configured by the network to be other values.

[0150] Optionally, it can be ensured that the number of OFDM symbols N2 available for sideline transmission between S2 (including S2) and the GP symbol before the PSFCH symbol is not less than 6, for example, Fig. 20 In this way, it is possible to avoid large fluctuations in the code rate when the same TB is transmitted in different time slots, thereby improving the stability and reliability of the side transmission.

[0151] Furthermore, it can be ensured that N1=N2. In this way, it is possible to further avoid large fluctuations in the code rate when transmitting the same TB in different time slots.

[0152] When the terminal device determines TBS, N′ can be calculated according to formula (2): RE . Different from the prior art, or S2-S1.

[0153] For the transmitting terminal, if TBS is calculated using If N is set to N1, the "PSFCH overhead indication" field can be set to 1 when sending the PSCCH that schedules the TB. If set to 0, the value of the "PSFCH overhead indication" field can be set to 0 when sending the PSCCH that schedules this TB.

[0154] For the receiving terminal, if the value of the "PSFCH overhead indication" field in the received PSCCH is 0, then the TBS of the TB scheduled by the PSCCH can be calculated by Set to 0; otherwise, Set to S2-S1.

[0155] Combination of the above Figures 1 to 20 , describes the method embodiment of the present application in detail, and the following is combined with Figure 21 to Figure 23 , describes the device embodiment of the present application in detail. It should be understood that the description of the method embodiment corresponds to the description of the device embodiment, so the parts not described in detail can refer to the previous method embodiment.

[0156] Fig.21 is a schematic structural diagram of a communication device provided in an embodiment of the present application. Fig.21 As shown, the device 2100 includes a sending unit 2110, which is specifically as follows:

[0157] The sending unit 2110 is used to send first information to the second terminal device, where the first information is used to indicate a first reference value in a first time slot, and the first reference value is used to calculate the reference orthogonal frequency division multiplexing OFDM symbol number when the device determines the transmission block size TBS.

[0158] Optionally, the sending unit 2110 is further used to: send sideline information to the second terminal device at a first starting point position, where the first starting point position is one of one or more sideline sending starting points in the first time slot.

[0159] Optionally, the starting position S1 is the first starting position of one or more sideline transmission starting positions in the first time slot, and the starting position S1 is determined according to the configuration or pre-configuration of the sideline SL bandwidth part BWP where the resource pool is located, or the starting position S1 is determined according to the configuration or pre-configuration of the resource pool, and S1 is a positive integer.

[0160] Optionally, the first time slot also includes a starting position S2, and the starting position S2 is predetermined, network configured or network preconfigured, and S2 is an integer greater than S1.

[0161] Optionally, in the first time slot, the number N1 of symbols available for side transmission starting from the starting position S2 is not less than 6, and N1 is a positive integer.

[0162] Optionally, the first information is carried in side control information SCI.

[0163] Optionally, the first information is carried in a physical sidelink feedback channel PSFCH overhead indication field or other fields in the SCI.

[0164] Optionally, no physical side feedback channel PSFCH resources are configured in the resource pool to which the first time slot belongs. If the first starting position is the starting position S1 or S2 in the first time slot, then when determining TBS, the first reference value is 0 or S2-S1, S1 is a positive integer, and S2 is an integer greater than S1.

[0165] Optionally, the resource configuration period of the physical side feedback channel PSFCH in the resource pool to which the first time slot belongs is 1. If the first starting position is the starting position S1 or S2 in the first time slot, then when determining TBS, the first reference value is 3 or S2-S1+3, S1 is a positive integer, and S2 is an integer greater than S1.

[0166] Optionally, the physical side feedback channel PSFCH resource configuration period in the resource pool to which the first time slot belongs is greater than 1. If the first time slot does not contain PSFCH resources, the first starting position is the starting position S1 or S2 in the first time slot. If the first time slot contains PSFCH resources, the first starting position is the starting position S1 in the first time slot.

[0167] Optionally, the first reference value is 0 or 3 when determining TBS.

[0168] Fig. 22 It is a schematic structural diagram of a communication device provided in one embodiment of the present application. Fig. 22 The communication device 2200 in the embodiment includes a receiving unit 2210, which is specifically as follows:

[0169] The receiving unit 2210 is used to receive first information sent by a first terminal device, where the first information is used to indicate a first reference value in a first time slot, and the first reference value is used to calculate a reference orthogonal frequency division multiplexing OFDM symbol number when the first terminal device determines a transmission block size TBS.

[0170] Optionally, the receiving unit 2210 is further used to: receive sideline information sent by the first terminal device at a first starting point position, where the first starting point position is one of one or more sideline sending starting points in the first time slot.

[0171] Optionally, the starting position S1 is the first starting position of one or more sideline transmission starting positions in the first time slot, and the starting position S1 is determined according to the configuration or pre-configuration of the sideline SL bandwidth part BWP where the resource pool is located, or the starting position S1 is determined according to the configuration or pre-configuration of the resource pool, and S1 is a positive integer.

[0172] Optionally, the first time slot also includes a starting position S2, and the starting position S2 is predetermined, network configured or network preconfigured, and S2 is an integer greater than S1.

[0173] Optionally, in the first time slot, the number N1 of symbols available for side transmission starting from the starting position S2 is not less than 6, and N1 is a positive integer.

[0174] Optionally, the first information is carried in side control information SCI.

[0175] Optionally, the first information is carried in a physical sidelink feedback channel PSFCH overhead indication field or other fields in the SCI.

[0176] Optionally, no physical side feedback channel PSFCH resources are configured in the resource pool to which the first time slot belongs. If the first starting position is the starting position S1 or S2 in the first time slot, then when determining TBS, the first reference value is 0 or S2-S1, S1 is a positive integer, and S2 is an integer greater than S1.

[0177] Optionally, the resource configuration period of the physical side feedback channel PSFCH in the resource pool to which the first time slot belongs is 1. If the first starting position is the starting position S1 or S2 in the first time slot, then when determining TBS, the first reference value is 3 or S2-S1+3, S1 is a positive integer, and S2 is an integer greater than S1.

[0178] Optionally, the physical side feedback channel PSFCH resource configuration period in the resource pool to which the first time slot belongs is greater than 1. If the first time slot does not contain PSFCH resources, the first starting position is the starting position S1 or S2 in the first time slot. If the first time slot contains PSFCH resources, the first starting position is the starting position S1 in the first time slot.

[0179] Optionally, the first reference value is 0 or 3 when determining TBS.

[0180] Fig.23 It is a schematic structural diagram of a device provided in one embodiment of the present application. Fig.23 The dotted line in the figure indicates that the unit or module is optional. The device 2300 can be used to implement the method described in the above method embodiment. The device 2300 can be a chip or a communication device.

[0181] The device 2300 may include one or more processors 2310. The processor 2310 may support the device 2300 to implement the method described in the foregoing method embodiment. The processor 2310 may be a general-purpose processor or a special-purpose processor. For example, the processor may be a central processing unit (CPU). Alternatively, the processor may also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0182] The apparatus 2300 may further include one or more memories 2320. The memory 2320 stores a program, which can be executed by the processor 2310, so that the processor 2310 executes the method described in the above method embodiment. The memory 2320 may be independent of the processor 2310 or integrated in the processor 2310.

[0183] The apparatus 2300 may further include a transceiver 2330. The processor 2310 may communicate with other devices or chips through the transceiver 2330. For example, the processor 2310 may transmit and receive data with other devices or chips through the transceiver 2330.

[0184] The present application also provides a computer-readable storage medium for storing a program. The computer-readable storage medium can be applied to the communication device provided in the present application, and the program enables a computer to execute the method executed by the communication device in each embodiment of the present application.

[0185] The embodiment of the present application also provides a computer program product. The computer program product includes a program. The computer program product can be applied to the communication device provided in the embodiment of the present application, and the program enables the computer to execute the method performed by the communication device in each embodiment of the present application.

[0186] The embodiment of the present application also provides a computer program. The computer program can be applied to the communication device provided in the embodiment of the present application, and the computer program enables a computer to execute the method executed by the communication device in each embodiment of the present application.

[0187] It should be understood that in the embodiment of the present application, "B corresponding to A" means that B is associated with A, and B can be determined according to A. However, it should also be understood that determining B according to A does not mean determining B only according to A, and B can also be determined according to A and / or other information.

[0188] It should be understood that the term "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0189] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0190] 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 the units is only a logical function division. There may be other division methods in actual implementation, such as 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, mechanical or other forms.

[0191] 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 distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0192] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0193] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can 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 described in 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 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, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (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 can be read by a computer or a data storage device such as a server or data center that includes one or more available media integrated. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a digital video disc (DVD)), or a semiconductor medium (eg, a solid state disk (SSD)).

[0194] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A communication method, characterized in that: include: The first terminal device sends first information to the second terminal device, where the first information is used to indicate a first reference value in a first time slot, and the first reference value is used to calculate a reference number of orthogonal frequency division multiplexing OFDM symbols when the first terminal device determines a transmission block size TBS.

2. The method according to claim 1, characterized in that The method further comprises: The first terminal device sends sideline information to the second terminal device at a first starting point, where the first starting point is one of one or more sideline transmission starting points in the first time slot.

3. The method according to claim 2, characterized in that The starting position S1 is the first starting position among one or more sideline transmission starting positions in the first time slot, and the starting position S1 is determined according to the configuration or pre-configuration of the sideline SL bandwidth part BWP where the resource pool is located, or the starting position S1 is determined according to the configuration or pre-configuration of the resource pool, and S1 is a positive integer.

4. The method according to claim 3, characterized in that The first time slot also includes a starting position S2, and the starting position S2 is predetermined, network configured or network preconfigured, and S2 is an integer greater than S1.

5. The method according to claim 4, characterized in that The number N1 of symbols available for sideline transmission starting from the starting position S2 in the first time slot is not less than 6, and N1 is a positive integer.

6. The method according to any one of claims 1 to 5, characterized in that The first information is carried in sideline control information SCI.

7. The method according to claim 6, characterized in that The first information is carried in a physical sidelink feedback channel PSFCH overhead indication field or other fields in the SCI.

8. The method according to any one of claims 2 to 7, characterized in that The physical side feedback channel PSFCH resource configuration period in the resource pool to which the first time slot belongs is greater than 1. If the first time slot does not contain PSFCH resources, the first starting position is the starting position S1 or S2 in the first time slot. If the first time slot contains PSFCH resources, the first starting position is the starting position S1 in the first time slot.

9. The method according to claim 8, characterized in that The first reference value is 0 or 3 when determining TBS.

10. A communication method, characterized in that: include: The second terminal device receives the first information sent by the first terminal device, where the first information is used to indicate a first reference value in a first time slot, and the first reference value is used to calculate the reference orthogonal frequency division multiplexing OFDM symbol number when the first terminal device determines the transmission block size TBS.

11. The method according to claim 10, characterized in that The method further comprises: The second terminal device receives the sideline information sent by the first terminal device at a first starting point position, where the first starting point position is one of the one or more sideline sending starting points in the first time slot.

12. The method according to claim 11, characterized in that The starting position S1 is the first starting position among one or more sideline transmission starting positions in the first time slot, and the starting position S1 is determined according to the configuration or pre-configuration of the sideline SL bandwidth part BWP where the resource pool is located, or the starting position S1 is determined according to the configuration or pre-configuration of the resource pool, and S1 is a positive integer.

13. The method according to claim 12, characterized in that The first time slot also includes a starting position S2, and the starting position S2 is predetermined, network configured or network preconfigured, and S2 is an integer greater than S1.

14. The method according to claim 13, characterized in that The number N1 of symbols available for sideline transmission starting from the starting position S2 in the first time slot is not less than 6, and N1 is a positive integer.

15. The method according to any one of claims 10 to 14, characterized in that The first information is carried in sideline control information SCI.

16. The method according to claim 15, characterized in that The first information is carried in a physical sidelink feedback channel PSFCH overhead indication field or other fields in the SCI.

17. The method according to any one of claims 11 to 16, characterized in that The physical side feedback channel PSFCH resource configuration period in the resource pool to which the first time slot belongs is greater than 1. If the first time slot does not contain PSFCH resources, the first starting position is the starting position S1 or S2 in the first time slot. If the first time slot contains PSFCH resources, the first starting position is the starting position S1 in the first time slot.

18. The method according to claim 17, characterized in that The first reference value is 0 or 3 when determining TBS.

19. A communication device, characterized in that: The invention comprises a memory, a transceiver and a processor, wherein the memory is used to store programs, the transceiver is used to send and receive data, and the processor is used to call the program in the memory to execute the method according to any one of claims 1 to 18.

20. A computer-readable storage medium, characterized in that: A program is stored thereon, the program causing a computer to execute the method according to any one of claims 1 to 18.

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