Channel access method and apparatus, terminal, chip and storage medium

Abstract

Embodiments of the present application provide a channel access method. The method comprises: performing type-2 channel access on at least one first channel among a group of channels, wherein a channel access result obtained by performing type-2 channel access on the at least one first channel is used for determining whether the at least one first channel can be used for sending a sidelink synchronization signal block (S-SSB) in a first time slot, the group of channels are channels intended for sending the S-SSB in the first time slot, and the at least one first channel and the first time slot are contained in a channel occupancy time (COT). A channel listening duration is short in a type-2 channel access procedure, and therefore, type-2 channel access is performed on the at least one first channel contained in the COT, and on the basis of the channel access result, it is determined whether the at least one first channel can be used for sending the S-SSB, thereby being conducive to improving the probability that a first terminal successfully accesses the at least one first channel and sends the S-SSB on the at least one first channel, and further avoiding COT resource loss.

Description

Channel access method, device, terminal, chip and storage medium Technical Field

[0001] The embodiments of the present application relate to the field of communication technology, and specifically to a channel access method, device, terminal, chip, and storage medium. Background Art

[0002] When a user equipment (UE) sends S-SSB on multiple channels, it can use Type A (TypeA) or Type B (TypeB) multi-channel access to access the multiple channels. In the multi-channel access process of Type A, the UE needs to independently perform Type 1 (Type1) channel access on the multiple channels. If the access is successful on any one or more of the channels, the UE can send S-SSB on the one or more channels. In the multi-channel access process of Type B, the UE can randomly select one channel from the multiple channels to perform Type 1 channel access and perform Type 2 (Type2) channel access on the other channels. If Type 1 channel access is successful, the UE can send S-SSB on each channel where channel access is successful; if Type 1 channel access fails, the multiple channels are deemed unavailable.

[0003] In some scenarios, before sending an S-SSB, another UE may share its Channel Occupancy Time (COT) with the current UE. If the current UE sends an S-SSB on a channel included in the COT, it can prevent the COT resources from being preempted by users from other systems.

[0004] However, the above-mentioned multi-channel access methods of type A or type B cannot effectively prevent COT resources from being preempted by users of different systems. For example, when the UE adopts the multi-channel access method of type A, the UE needs to perform type 1 channel access on the channels included in the COT. Since the channel listening time during type 1 channel access is long, the probability of COT being preempted by users of different systems is relatively high. For another example, when the UE adopts the multi-channel access method of type B, if the UE performs type 1 channel access on one of the channels included in the COT, since the channel listening time during type 1 channel access is long, and whether other channels can be used to send S-SSB depends on the channel access results of the channel, the probability of COT being preempted by users of different systems is also relatively high.

[0005] Summary of the Invention

[0006] Embodiments of the present application provide a channel access method, device, terminal, chip, and storage medium.

[0007] In the first aspect, an embodiment of the present application provides a channel access method, which is applied to a first terminal, the method comprising: performing type 2 channel access on at least one first channel in a group of channels, and using the channel access result obtained by performing type 2 channel access on at least one first channel to determine whether the at least one first channel can be used to send a side link synchronization signal block S-SSB in the first time slot; wherein the group of channels is a channel planned to be used to send S-SSB in the first time slot, and at least one first channel and the first time slot are included in the channel occupancy time COT.

[0008] In second aspect, an embodiment of the present application provides a channel access device, which includes: a processing unit, configured to perform type 2 channel access on at least one first channel in a group of channels, and the channel access result obtained by performing type 2 channel access on at least one first channel is used to determine whether at least one first channel can be used to send a side link synchronization signal block S-SSB in a first time slot; wherein the group of channels is a channel planned to be used to send S-SSB in the first time slot, and at least one first channel and the first time slot are included in the channel occupancy time COT.

[0009] In a third aspect, an embodiment of the present application provides a terminal including a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to perform the above-mentioned channel access method.

[0010] In a fourth aspect, embodiments of the present application provide a chip for implementing the aforementioned channel access method. Specifically, the chip includes: a processor for calling and running a computer program from a memory, so that a device equipped with the chip executes the aforementioned channel access method.

[0011] In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium for storing a computer program, which enables a computer to execute the above-mentioned channel access method.

[0012] In a sixth aspect, an embodiment of the present application provides a computer program product, comprising computer program instructions, which enable a computer to execute the above-mentioned channel access method.

[0013] In a seventh aspect, an embodiment of the present application provides a computer program, which, when running on a computer, enables the computer to execute the above-mentioned channel access method.

[0014] Through the above technical solution, the first terminal can perform type 2 channel access on at least one first channel in a group of channels, and the obtained channel access result can be used to determine whether the at least one first channel can be used to send an S-SSB in the first time slot, wherein the group of channels is a channel planned to be used to send an S-SSB in the first time slot, and the at least one first channel and the first time slot are included in the COT. Since the channel listening duration in the type 2 channel access process is relatively short, performing type 2 channel access on at least one first channel included in the COT and determining whether the at least one first channel can be used to send an S-SSB based on the result of the channel access is beneficial to increasing the probability of the first terminal successfully accessing the at least one first channel and sending an S-SSB on the at least one first channel, thereby facilitating the maintenance of COT resource occupation to avoid COT resource loss (such as preventing COT resources from being preempted by users of other systems). BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0016] FIG1 is a schematic diagram of sideline communication within network coverage provided by an embodiment of the present application;

[0017] FIG2 is a schematic diagram of sideline communication with partial network coverage provided by an embodiment of the present application;

[0018] FIG3 is a schematic diagram of sideline communication outside network coverage provided by an embodiment of the present application;

[0019] FIG4 is a schematic diagram of sideline communication with a central control node provided in an embodiment of the present application;

[0020] FIG5 is a schematic diagram of a unicast transmission method provided in an embodiment of the present application;

[0021] FIG6 is a schematic diagram of a multicast transmission method provided in an embodiment of the present application;

[0022] FIG7 is a schematic diagram of a broadcast transmission method provided in an embodiment of the present application;

[0023] FIG8 is a schematic diagram of the time slot structure in NR-V2X provided in an embodiment of the present application;

[0024] FIG9 is a schematic diagram showing changes in the OFDM symbols available in a time slot of a PSSCH in different transmissions provided by an embodiment of the present application;

[0025] FIG10 is a schematic diagram of a second-order SCI mapping method provided in an embodiment of the present application;

[0026] FIG11 is a schematic diagram of the time-frequency domain position of a PSCCH DMRS provided in an embodiment of the present application;

[0027] FIG12 is a schematic diagram of the time domain position of 4 DMRS symbols when the PSSCH has 13 symbols provided in an embodiment of the present application;

[0028] FIG13 is a schematic diagram of a single-symbol DMRS frequency domain type 1 provided in an embodiment of the present application;

[0029] FIG14 is a schematic diagram of the time-frequency position of the SL CSI-RS provided in an embodiment of the present application;

[0030] FIG15 is a schematic diagram of an example of channel occupancy time and channel occupancy provided in an embodiment of the present application;

[0031] FIG16 is a schematic diagram of S-SSB time-frequency domain mapping provided in an embodiment of the present application;

[0032] FIG17 is a schematic diagram of channel access using a Type A multi-channel access method according to an embodiment of the present application;

[0033] FIG18 is a schematic diagram of channel access using a Type B multi-channel access method according to an embodiment of the present application;

[0034] FIG19 is a flow chart of a channel access method according to an embodiment of the present application;

[0035] FIG20 is a schematic diagram of an implementation scheme of the channel access method provided in an embodiment of the present application;

[0036] FIG21 is a second schematic diagram of an implementation scheme of the channel access method provided in an embodiment of the present application;

[0037] FIG22 is a third schematic diagram of an implementation scheme of the channel access method provided in an embodiment of the present application;

[0038] FIG23 is a schematic diagram of the structure of a channel access device provided in an embodiment of the present application;

[0039] FIG24 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0040] Figure 25 is a schematic structural diagram of the chip of an embodiment of the present application. DETAILED DESCRIPTION

[0041] The following will describe the technical solutions in the embodiments of this application in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0042] The technical solutions of the embodiments of the present application can be applied to various side communication systems. To facilitate understanding of the technical solutions of the embodiments of the present application, the relevant technologies of the embodiments of the present application are explained below. The following related technologies can be arbitrarily combined with the technical solutions of the embodiments of the present application as optional solutions, and they all fall within the protection scope of the embodiments of the present application.

[0043] 1. Sideline communication in different network coverage environments

[0044] In side communication, according to the network coverage of the communicating terminal, it can be divided into side communication within the network coverage, side communication with partial network coverage, side communication outside the network coverage, and side communication with a central control node, as shown in Figures 1, 2, 3 and 4 respectively.

[0045] As shown in FIG1 , in sideline communications within network coverage, all terminals performing sideline communications are within the coverage of the same base station. Thus, the above terminals can perform sideline communications based on the same sideline configuration by receiving configuration signaling from the base station.

[0046] As shown in Figure 2, in the case of sidelink communication with partial network coverage, some terminals performing sidelink communication are located within the coverage of the base station. These terminals can receive the configuration signaling from the base station and perform sidelink communication according to the configuration of the base station. However, terminals located outside the network coverage cannot receive the configuration signaling from the base station. In this case, the terminals outside the network coverage will determine the sidelink configuration based on the pre-configuration information and the information carried in the Physical Sidelink Broadcast Channel (PSBCH) sent by the terminals within the network coverage, thereby performing sidelink communication.

[0047] As shown in FIG3 , for sideline communications outside network coverage, all terminals performing sideline communications are located outside network coverage, and all terminals determine sideline configurations according to pre-configured information and perform sideline communications.

[0048] As shown in Figure 4 , for sideline communication with a central control node, multiple terminals form a communication group, which includes a central control node, such as UE1 in Figure 4 . The central control node can also be called a cluster header (CH). The central control node has at least one of the following functions, but is not limited to: establishing the communication group; managing the joining and leaving of group members; coordinating resources, allocating sideline transmission resources to other terminals, receiving sideline feedback information from other terminals, and coordinating resources with other communication groups.

[0049] 2. Device to Device (D2D) / Vehicle to Everything (V2X)

[0050] Device-to-device communication is a sidelink transmission technology based on D2D. Unlike traditional cellular systems, where communication data is received or sent via base stations, it offers higher spectrum efficiency and lower transmission latency. The connected vehicle system utilizes direct end-to-end communication. The 3rd Generation Partnership Project (3GPP) defines two transmission modes: Mode 1 and Mode 2.

[0051] Mode 1: The terminal's transmission resources are allocated by the base station, and the terminal transmits data on the sidelink based on the allocated resources. The base station can allocate resources for either single transmissions or semi-static transmissions. As shown in Figure 1, when the terminal is within network coverage, the network allocates transmission resources for sidelink transmissions.

[0052] Mode 2: The terminal selects a resource from the resource pool for data transmission. As shown in Figure 3, when the terminal is outside the cell coverage area, it autonomously selects a transmission resource from the pre-configured resource pool for sidelink transmission. Alternatively, as shown in Figure 1, the terminal autonomously selects a transmission resource from the network-configured resource pool for sidelink transmission.

[0053] 3. New Radio-Vehicle to Everything (NR-V2X)

[0054] In NR-V2X, autonomous driving needs to be supported, which places higher requirements on data interaction between vehicles, such as higher throughput, lower latency, higher reliability, larger coverage, and more flexible resource allocation.

[0055] LTE-V2X supports broadcast transmission, while NR-V2X introduces unicast and multicast transmission modes. For unicast transmission, there is only one receiving terminal. For example, in Figure 5, unicast transmission is performed between UE1 and UE2. For multicast transmission, the receiving terminals are all terminals in a communication group, or all terminals within a certain transmission distance. As shown in Figure 6, UE1, UE2, UE3, and UE4 form a communication group, where UE1 transmits data, and the other terminal devices in the group are all receiving terminals. For broadcast transmission, the receiving terminal is any terminal around the transmitting terminal. As shown in Figure 7, UE1 is the transmitting terminal, and the other terminals around it, UE2 to UE6, are all receiving terminals.

[0056] 4. NR-V2X system frame structure

[0057] The time slot structure in NR-V2X is shown in Figure 8:

[0058] FIG8(a) is a schematic diagram of a time slot structure in which a physical sidelink feedback channel (PSFCH) is not included in the time slot; FIG8(b) is a schematic diagram of a time slot structure in which a PSFCH is included.

[0059] The NR-V2X Physical Sidelink Control Channel (PSCCH) starts at the second sidelink symbol of the timeslot in the time domain, occupies 2 or 3 Orthogonal Frequency Division Multiplexing (OFDM) symbols, and can occupy {10, 12, 15, 20, 25} Physical Resource Blocks (PRBs) in the frequency domain. To reduce the complexity of blind detection of the PSCCH by the user equipment (UE), only one number of PSCCH symbols and PRBs is allowed to be configured in a resource pool. In addition, because the subchannel is the minimum granularity for the allocation of physical sidelink shared channel (PSSCH) resources in NR-V2X, the number of PRBs occupied by the PSCCH must be less than or equal to the number of PRBs contained in a subchannel in the resource pool to avoid additional restrictions on PSSCH resource selection or allocation. In the time domain, the PSSCH also begins with the second sidelink symbol of the timeslot. The last time-domain symbol in the timeslot is the guard period (GP) symbol, and the remaining symbols are mapped to the PSSCH. The first sidelink symbol in the timeslot is a repetition of the second sidelink symbol. The receiving terminal typically uses the first sidelink symbol as an automatic gain control (AGC) symbol; the data on this symbol is not typically used for data demodulation. In the frequency domain, the PSSCH occupies K subchannels, each consisting of N consecutive PRBs.

[0060] 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, as shown in FIG8 (b).

[0061] 5. Sidelink PSSCH

[0062] In NR-V2X, the PSSCH is used to carry second-order sidelink control information (SCI) (SCI 2-A or SCI 2-B) and data information. The second-order SCI uses polarization coding and fixed quadrature phase shift keying (QPSK) modulation. The data portion of the PSSCH uses low-density parity check (LDPC) code and supports a maximum modulation order of 256QAM.

[0063] In NR-V2X, PSSCH supports up to two stream transmissions and uses a unit precoding matrix to map data on two layers to two antenna ports. At most, only one transport block (TB) can be sent in a 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.

[0064] 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 PSFCH resources is 2 or 4, the available OFDM symbols in the time slot where different transmissions of a PSSCH are located may change, as shown in Figure 9. If calculated based on the actual number of OFDM symbols in a time slot The difference in the number of symbols available for PSSCH transmission in a time slot may cause Q′ SCI2 Different, and Q′ SCI2 The change of will lead to the change of the size of the TB carried by PSSCH. In order to ensure that the transmission block size (TBS) remains unchanged during multiple transmissions of 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.

[0065] The code rate of the second-order SCI can be dynamically adjusted within a certain range. The specific code rate used is indicated by the first-order SCI, so the receiver does not need to perform blind detection of the second-order SCI even after the code rate changes. The modulation symbols of the second-order SCI are mapped in the frequency domain first and then in the time domain, starting from the symbol containing the first PSSCH DMRS. In the OFDM symbol containing the DMRS, the second-order SCI is mapped to the REs not occupied by the DMRS, as shown in Figure 10.

[0066] The data portion of the PSSCH within a resource pool can use multiple different modulation and coding scheme (MCS) tables, including the conventional 64QAM MCS table, the 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. To control the Peak to Average Power Ratio (PAPR), the PSSCH must be transmitted using contiguous PRBs. Since the subchannel is the minimum frequency-domain resource granularity of the PSSCH, this requires that the PSSCH must occupy contiguous subchannels.

[0067] 6. Sidelink transmission block size

[0068] PSSCH follows the transport block size (TBS) determination mechanism of the physical downlink shared channel (PDSCH) and physical uplink shared channel (PUSCH) in the New Radio (NR), that is, the TBS is determined based on the reference value of the number of REs used for PSSCH in the time slot where the 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 used. RE Determine according to formula (1):

[0069] where 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′ RErepresents the number of reference REs that can be used for PSSCH in a PRB, which is determined by formula (2):

[0070] in: Indicates the number of subcarriers in a PRB; Indicates the number of symbols available for sidelink 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 Radio Resource Control (RRC) layer parameters and is used to indicate the reference value of the number of REs occupied by PT-RS and CSI-RS. It represents the average number of DMRS REs in a time slot and is related to the DMRS patterns allowed in the resource pool, as shown in Table 1.

[0071] Table 1 DMRS patterns allowed in the resource pool and The corresponding relationship

[0072] 7. Sidelink DMRS

[0073] In NR-V2X, the DMRS pattern of the PSCCH is the same as that of the NR physical downlink control channel (PDCCH). That is, the DMRS exists in each OFDM symbol of the PSCCH and is located in the frequency domain at {#1, #5, #9} REs of a PRB, as shown in Figure 11. The DMRS sequence of the PSCCH is generated by formula (3):

[0074] 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 pre-configured by the network.

[0075] NR-V2X draws on the design of the NR Uu interface and adopts multiple time-domain PSSCH DMRS patterns. The number of available DMRS patterns within a resource pool 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 within the pattern are shown in Table 2. Figure 12 shows a schematic diagram of the time-domain position of four DMRS symbols when the PSSCH has 13 symbols.

[0076] Table 2 Number and position of DMRS symbols under different PSSCH and PSCCH symbol numbers

[0077] If multiple time-domain DMRS patterns are configured within the resource pool, the transmitting UE selects the specific time-domain DMRS pattern to use and indicates this in the first-order SCI. This design allows high-speed UEs to select a high-density DMRS pattern, thereby ensuring accurate channel estimation, while low-speed UEs can use a low-density DMRS pattern, thereby improving spectrum efficiency.

[0078] The generation method of the PSSCH DMRS sequence is almost identical to 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 cyclic redundancy check (CRC) of the PSCCH that schedules the PSSCH, where L=24 is the number of bits of the PSCCH CRC.

[0079] NR PDSCH and PUSCH support two frequency domain DMRS patterns, namely DMRS frequency domain type 1 and DMRS frequency domain type 2. 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 a maximum of two DMRS ports, only single symbol DMRS frequency domain type 1 is supported, as shown in Figure 13.

[0080] 8. Sidelink Channel State Information Reference Signal (CSI-RS)

[0081] To better support unicast communication, NR-V2X supports SL CSI-RS. SL CSI-RS is sent only when the following three conditions are met:

[0082] 1) The UE sends the corresponding PSSCH, that is, the UE cannot only send SL CSI-RS;

[0083] 2) Sidelink CSI reporting is activated by higher-layer signaling;

[0084] 3) When sidelink CSI reporting is activated by higher layer signaling, the corresponding bit in the second-order SCI sent by the UE triggers the sidelink CSI reporting.

[0085] The maximum number of ports supported by SL CSI-RS is two. For two ports, SL CSI-RSs from different ports are code-division multiplexed across two adjacent REs in the same OFDM symbol. Within a PRB, the number of SL CSI-RSs per port is one, meaning the density is one. Therefore, within a PRB, an SL CSI-RS appears in at most one OFDM symbol, the specific location of which is determined by the transmitting terminal. To avoid impacting the resource mapping of the PSCCH and second-order SCI, the SL CSI-RS cannot be located in the same OFDM symbol as the PSCCH and second-order SCI. Because the channel estimation accuracy of the OFDM symbol where the PSSCH DMRS resides is higher, and the SL CSI-RSs for two ports occupy two consecutive REs in the frequency domain, the SL CSI-RS cannot be transmitted in the same OFDM symbol as the PSSCH DMRS. The OFDM symbol location of the SL CSI-RS is indicated by the sl-CSI-RS-FirstSymbol parameter in the PC5RRC protocol.

[0086] The position of the first RE occupied by the SL CSI-RS within a PRB is indicated by the sl-CSI-RS-FreqAllocation parameter in the PC5RRC. If the SL CSI-RS is a single port, this parameter is a 12-bit bitmap corresponding to the 12 REs within a PRB. If the SL CSI-RS is a dual port, this parameter is a 6-bit bitmap. In this case, the 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 bitmap. The frequency domain position of the SL CSI-RS is also determined by the transmitting terminal, but the determined frequency domain position of the SL CSI-RS cannot conflict with the PT-RS. FIG14 shows a schematic diagram of the time-frequency position of an SL CSI-RS. In FIG14 , the number of SL CSI-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].

[0087] 9. 5G unlicensed (unlicensed) spectrum communications (NR-unlicensed, NR-U)

[0088] The NR system introduced by the 3GPP 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 Long Term Evolution (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), was discussed.

[0089] 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, such as 5925-7125MHz in the United States, or 5925-6425MHz in Europe. In the R16 standard, band 46 (5150MHz-5925MHz) is newly defined for use as unlicensed spectrum.

[0090] Unlicensed spectrum is spectrum designated by countries and regions for use by radio equipment. This spectrum is generally considered shared spectrum, meaning that as long as communications devices meet national or regional regulatory requirements for the spectrum, they can use it without having to apply for exclusive spectrum authorization from the national or regional spectrum management agency. Because the use of unlicensed spectrum must comply with specific national and regional regulations, such as the "Listen Before Talk" (LBT) principle, NR technology requires corresponding enhancements to meet regulatory requirements for unlicensed frequency bands and efficiently utilize unlicensed spectrum to provide services. The 3GPP Release 16 standard primarily standardizes the following aspects of NR-U technology: channel sensing process; initial access process; control channel design; Hybrid Automatic Repeat Request (HARQ) and scheduling; and scheduling-free grant transmission.

[0091] 10. Channel monitoring: LBT

[0092] To ensure the harmonious coexistence of various communication systems using unlicensed spectrum for wireless communications, some countries and regions have established regulatory requirements for the use of unlicensed spectrum. For example, according to European regulations, when communicating on unlicensed spectrum, communication devices must adhere to the "LBT" principle. This means that before transmitting signals on a channel in the unlicensed spectrum, they must first perform LBT, or channel sensing. Only if the channel sensing result indicates that the channel is idle, or if LBT is successful, can the communication device transmit signals on that channel. If the channel sensing result indicates that the channel is busy, or if LBT fails, the communication device cannot transmit signals on that channel. Furthermore, to ensure fair use of shared spectrum resources, if a communication device successfully performs LBT on an unlicensed spectrum channel, the duration for which it can use that channel for communication cannot exceed a certain limit. This mechanism, by limiting the maximum duration of communication after a successful LBT, ensures that different communication devices have the opportunity to access the shared channel, thereby enabling harmonious coexistence of different communication systems on the shared spectrum.

[0093] Although channel sensing is not a global regulatory requirement, it can provide interference avoidance and friendly coexistence benefits for communication transmissions between communication systems on shared spectrum. Therefore, in the design of NR systems on unlicensed spectrum, channel sensing is a feature that must be supported by the communication equipment in the system. From the perspective of system networking, channel sensing includes two mechanisms: load-based equipment (LBE) LBT, also known as dynamic channel sensing or dynamic channel occupancy, and frame-based equipment (FBE) LBT, also known as semi-static channel sensing or semi-static channel occupancy.

[0094] 11. Dynamic channel monitoring

[0095] 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 Type 1 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 (Channel Access Priority Class, CAPC) p can be selected according to the priority of the service to be transmitted. The Type 2 channel access method is a channel access method based on a fixed-length monitoring time slot, wherein the Type 2 channel access method includes Type 2A channel access, Type 2B channel access and Type 2C channel access. The Type 1 channel access method is mainly used for communication equipment to initiate channel occupancy, and the Type 2 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 synchronization signal / physical broadcast channel (SS / PBCH) block within the Discovery Reference Symbol (DRS) window and the DRS window does not include UE 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.

[0096] FIG15 shows an example 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.

[0097] 12. Default channel access mode on the base station side: Type 1 channel access

[0098] 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. In Table 3, m p It refers to the number of fallback slots corresponding to the channel access priority p, and CWp refers to the contention window (CW) size corresponding to the channel access priority p. min,p Refers to the CW corresponding to the channel access priority p p Minimum value, CW max,p Refers to the CW corresponding to the channel access priority p p The maximum value, T mcot,p It refers to the maximum channel occupancy time corresponding to the channel access priority p.

[0099] 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 .

[0100] Table 3 Channel access parameters corresponding to different channel access priorities p

[0101] 13. Channel occupancy time sharing on the base station side

[0102] When the base station initiates the Channel Occupancy Time (COT), in addition to using the resources within the COT for downlink transmission, the resources within the COT can also be shared with the UE for uplink transmission. When the resources within the COT are shared with the UE for uplink transmission, the channel access mode that the UE can use is Type 2A channel access, Type 2B channel access, or Type 2C channel access. Among them, Type 2A channel access, Type 2B channel access, and Type 2C channel access are all channel access modes based on fixed-length monitoring time slots.

[0103] Type 2A channel access:

[0104] The UE uses a 25μs single-slot channel detection method. Specifically, under Type 2A channel access, the UE can monitor the channel for 25μs before starting transmission and transmit after successful channel monitoring.

[0105] Type 2B channel access:

[0106] The UE uses a 16μs single-slot channel detection method. Specifically, in Type 2B channel access, the UE can monitor the channel for 16μs before starting transmission and transmit after successful channel monitoring. The gap between the start position of each transmission and the end position of the previous transmission is 16μs.

[0107] Type 2C channel access:

[0108] The UE transmits after the gap ends without performing channel detection. Specifically, under Type 2C channel access, the UE can directly transmit, where 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.

[0109] 14. Channel access for transmission(s) on multiple channels

[0110] When the system supports multiple channels (multiple RB sets), the UE needs to access multiple channels separately, that is, LBT channel listening. When the NR-U downlink (DL) multi-channel access mechanism is adopted, the UE can transmit on any channel with successful channel access. In the sidelink unlicensed system, for the transmission of PSFCH and S-SSB, the following multi-channel access methods are supported:

[0111] 1) Type A multi-channel access

[0112] When a UE wants to send a PSFCH or S-SSB on C channels (RB sets), it needs to perform a Type 1 channel access procedure independently on each of the C channels. If access is successful on any one or more of the channels, the UE can send a PSFCH or S-SSB on the one or more corresponding channels.

[0113] 2) Type B multi-channel access

[0114] When a UE wants to transmit a PSFCH or S-SSB on C channels (RB sets), it randomly selects one of the C channels and uses Type 1 channel access. The remaining channels are accessed using Type 2 channels. Only after successful Type 1 channel access can the UE transmit on the channel where Type 2 channel access was successful. If Type 1 channel access fails, all channels accessed using Type 2 channels are considered unavailable.

[0115] 15. Channel access parameter indication (including cyclic prefix extension (CPE))

[0116] In the NR-U system, when the UE is scheduled to transmit the Physical Uplink Shared Channel (PUSCH) or the Physical Uplink Control Channel (PUCCH), the base station can indicate the channel access method corresponding to the PUSCH or PUCCH by carrying the downlink control information (DCI) of the uplink grant (UL grant) or downlink grant (DL grant). Since some channel access methods need to meet the gap requirements of 16μs or 25μs, the UE can ensure the gap size between two transmissions by transmitting an extended cyclic prefix (CPE). Accordingly, the base station can indicate the CPE length of the first symbol of the UE's uplink transmission.

[0117] When specifically indicating, the base station can explicitly indicate channel access parameters such as CPE length, channel access mode or channel access priority to the UE through joint coding. The following describes the characteristics of the indication mode of channel access parameters introduced in different DCI formats.

[0118] 1) Fallback uplink grant for scheduling PUSCH transmission (DCI format 0_0):

[0119] The standard pre-sets a set of joint channel access mode and CPE length indications, as shown in Table 4. The fallback uplink grant includes 2-bit LBT indication information, which is used to indicate the jointly coded channel access mode and CPE length from the set shown in Table 4. The channel access mode and CPE length are used for PUSCH transmission. If the channel access mode is Type 1 channel access, the UE selects the channel access priority (CAPC) based on the service priority.

[0120] 2) Fallback downlink grant for scheduling PDSCH transmission (DCI format 1_0):

[0121] The standard presets a set of joint indications of channel access mode and CPE length, as shown in Table 4. The fallback downlink grant includes 2-bit LBT indication information, which is used to indicate the jointly coded channel access mode and CPE length from the set shown in Table 4. The channel access mode and CPE length are used for PUCCH transmission, where the PUCCH can carry a positive acknowledgment (ACK) or negative acknowledgment (NACK) corresponding to the PDSCH. If the channel access mode is Type 1 channel access, the UE determines the channel access priority CAPC = 1 for transmitting the PUCCH.

[0122] Table 4 Channel access mode and CPE length joint indication set

[0123] In Table 4, the value of C1 is specified by the protocol. When the subcarrier spacing is 15 kHz and 30 kHz, C1 = 1; when the subcarrier spacing is 60 kHz, C1 = 2. The values ​​of C2 and C3 are configured by higher-layer parameters. When the subcarrier spacing is 15 kHz and 30 kHz, the values ​​of C2 and C3 range from 1 to 28; when the subcarrier spacing is 60 kHz, the values ​​of C2 and C3 range from 2 to 28.

[0124] 3) Non-fallback uplink grant for scheduling PUSCH transmission (DCI format 0_1):

[0125] The higher layer configures an LBT parameter indication set, which includes at least one jointly coded channel access method, CPE length, and CAPC. The non-fallback uplink grant includes LBT indication information, which is used to indicate the jointly coded channel access method, CPE length, and CAPC from the above-mentioned LBT parameter indication set. The channel access method, CPE length, and CAPC are used for PUSCH transmission. If the indicated channel access method is Type 2 channel access, the CAPC indicated at the same time is the CAPC used by the base station when obtaining the COT. The LBT indication information includes a maximum of 6 bits.

[0126] 4) Non-fallback downlink grant for scheduling PDSCH transmission (DCI format 1_1):

[0127] The high layer configures an LBT parameter indication set, and the LBT parameter indication set includes at least one jointly coded channel access method and CPE length. The non-fallback downlink authorization includes LBT indication information, and the LBT indication information is used to indicate the jointly coded channel access method and CPE length from the above-mentioned LBT parameter indication set. The channel access method and CPE length are used for PUCCH transmission, wherein the PUCCH can carry ACK or NACK information corresponding to the PDSCH. If the channel access method is Type 1 channel access, the UE determines that the channel access priority CAPC=1 for transmitting the PUCCH. The LBT indication information includes a maximum of 4 bits.

[0128] In addition to the above explicit indications, the base station can also implicitly indicate the channel access method within the COT. When the UE receives an UL grant or DL ​​grant sent by the base station indicating that the channel access type corresponding to the PUSCH or PUCCH is Type 1 channel access, if the UE can determine that the PUSCH or PUCCH belongs to the COT of the base station, for example, the UE receives a DCI format 2_0 sent by the base station and determines that the PUSCH or PUCCH belongs to the COT of the base station based on the DCI format 2_0, then the UE can update the channel access type corresponding to the PUSCH or PUCCH to Type 2A channel access instead of Type 1 channel access.

[0129] 16. S-SSB time-frequency domain mapping

[0130] Based on the current Release 18SL technology, the time-frequency domain mapping of S-SSBs is shown in Figure 16. Within an S-SSB period (160ms), there are both Type 1 and Type 2 S-SSBs. Type 1 S-SSBs are the S-SSB time slot resources configured in Release 16 / 17SL, while Type 2 S-SSBs are the additional S-SSB time slot resources newly defined in Release 18. Within the frequency domain resources corresponding to an S-SSB time slot, if the frequency domain contains four resource block (RB) sets, the UE can attempt to map / transmit the S-SSB on one or more of these RB sets. This attempt means that the UE first performs LBT on one RB set. If it detects that the RB set is unoccupied / available, it maps / transmits the S-SSB on that RB set. If transmission on multiple RB sets is required, LBT is performed on each of these RB sets, and the LBT results on each RB set determine whether the S-SSB can be transmitted on that RB set. Within an RB set, S-SSBs are mapped repeatedly in the frequency domain. In multiple RB sets corresponding to a time slot, the S-SSB is also repeated in each RB set.

[0131] In addition, according to the current conclusions, each R16 / R17 S-SSB time slot corresponds to K additional S-SSB time slots, and the intervals between these S-SSB time slots need to be obtained through configuration or pre-configuration.

[0132] The above briefly explains the relevant technologies / terms involved in the embodiments of this application, which will not be repeated in the following embodiments.

[0133] It should be understood that the terms "system" and "network" are often used interchangeably in this document. The term "and / or" in this document is merely a description of the association relationship between 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 document generally indicates that the objects associated before and after are in an "or" relationship. It should also be understood that the "indication" mentioned in the embodiments of this 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. It should also be understood that the "correspondence" mentioned in the embodiments of this application can mean that there is a direct or indirect correspondence between the two, or it can mean that there is an association relationship between the two, or it can mean a relationship between indication and indication, configuration and configuration, etc. It should also be understood that the “predefined” or “predefined rules” mentioned in the embodiments of the present application can be implemented by pre-saving corresponding codes, tables or other methods that can be used to indicate relevant information in devices (for example, including terminal devices and network devices), and the present application does not limit its specific implementation method. For example, predefined can refer to what is defined in the protocol. It should also be understood that in the embodiments of the present application, the “protocol” may refer to a standard protocol in the field of communications, such as LTE protocols, NR protocols, and related protocols used in future communication systems, and the present application does not limit this.

[0134] It should also be understood that the embodiments of the present application do not limit the specific form of the terminal. As an example, the terminal in the embodiments of the present application may refer to an access terminal, a user equipment (UE), 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 device, a wireless communication device, a user agent or a user device. The access terminal may be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, an IoT device, a satellite handheld terminal, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device with wireless communication capabilities, a computing device or other processing device connected to a wireless modem, an in-vehicle device, a wearable device, a terminal device in a 5G network or a terminal device in a future evolution network, etc.

[0135] In the current SL unlicensed frequency band technology, when the UE sends S-SSB on a single channel, it needs to perform channel access on the single channel, and the supported channel access methods include Type 1 (Type1) and Type 2A (Type2A) channel access methods; when the UE sends S-SSB on multiple channels, it needs to perform channel access on the multiple channels separately, and the supported multi-channel access methods include Type A (TypeA) and Type B (TypeB) channel access methods.

[0136] During Type A multi-channel access, the UE needs to independently perform Type 1 channel access on the multiple channels. If access is successful on any one or more of the channels, the UE can send S-SSB on the one or more channels. During Type B multi-channel access, the UE can randomly select one channel from the multiple channels for Type 1 channel access and perform Type 2 channel access on the other channels. If Type 1 channel access is successful, the UE can send S-SSB on each channel where access is successful; if Type 1 channel access fails, the multiple channels are considered unavailable.

[0137] In some scenarios, before sending an S-SSB, another UE may share the COT with the current UE. If the current UE sends an S-SSB on a channel included in the COT, the COT resource can be prevented from being preempted by users from other systems. However, neither the Type A nor Type B multi-channel access methods described above can effectively prevent COT resources from being preempted by users from other systems. This is illustrated below using Figures 17 and 18 as examples.

[0138] Figure 17 illustrates an example of channel access using Type A multi-channel access in a scenario where another UE shares its COT with the current UE. As shown in Figure 17, the UE independently uses Type 1 channel access for LBT channel sensing on each channel / RB set. During this process, another UE shares its COT with the current UE, and this COT includes channel #2 (RB set #2) and channel #3 (RB set #3). According to existing mechanisms, the channel sensing duration of Type 1 channel access is very long, far exceeding the 25μs channel sensing duration of Type 2A. Using Type 1 channel access will result in COT loss. Therefore, Type 2 channel access is required within the COT. If the UE still uses Type 1 channel access as planned, it will not be able to use the time-frequency resources within the COT duration. This significantly increases the probability of COT loss, resulting in resource waste. Furthermore, the longer the channel sensing time, the more likely resources are occupied (for example, by UEs from other systems). That is, if other UEs (such as UEs from other systems) use the Type 2A channel access method with a shorter listening time to access channels #2 and #3, there is a high probability that they will preempt the COT resources, forcing the current UE to abandon the existing COT. If the current UE abandons the existing COT and re-initiates COT using the Type 1 channel listening method, the existing COT resources will be wasted.

[0139] Figure 18 shows a schematic diagram of an example of channel access using Type B multi-channel access in a scenario where other UEs share COT with the current UE. As shown in Figure 18, the UE selects one channel from a group of channels / RB sets to use Type 1 channel access, and the other channels use Type 2 channel access. For example, the UE selects channel #2 (RB set #2) to use Type 1 channel access, and channel #0 (RB set #0), channel #1 (RB set #1) and channel #3 (RB set #3) to use Type 2 channel access. Whether the channel using Type 2 channel access can be used to send S-SSB depends on whether Type 1 channel access is successful on channel #2. In other words, the channel access correlation between different channels is very high. If the UE plans to use Type 1 channel access on channel #2 in advance, and COT shared resources appear after the channel listening has started, it is impossible to switch from Type 1 channel access to Type 2 channel access. In this way, if other UEs (such as UEs from different systems) use Type 2A channel access with a shorter listening time to access channel #2 at this time, there is a high probability that the current UE will fail to access channel #2, resulting in the inability to send S-SSB on both channel #2 and channel #3, and thus causing COT loss.

[0140] In the existing mechanism, the purpose of supporting the transmission of S-SSB on multiple channels / RB sets is so that when there are COT shared resources, in addition to being able to send S-SSB on the anchor channel / anchor RB set, the UE can also send S-SSB on the channel / RB set included in the COT, so as to maintain the occupation of the COT resources and prevent the COT resources from being preempted by UEs of different systems, thereby ensuring the resource utilization efficiency of the current sideline system. However, the multi-channel access mechanism of Type A and Type B specified in the existing mechanism does not have an effective way to maintain the occupancy of the COT for scenarios where COT shared resources appear before sending the S-SSB, resulting in a high probability of COT loss (such as COT being preempted by UEs of different systems). This is contrary to the original intention of sending S-SSB on multiple channels / RB sets. Therefore, for scenarios where COT shared resources appear before sending the S-SSB, how to avoid COT loss is an urgent problem that needs to be solved.

[0141] In view of this, the present application provides a channel access method, apparatus, terminal, chip, and storage medium. In this method, a first terminal may perform Type 2 channel access on at least one first channel in a group of channels, and the obtained channel access result may be used to determine whether the at least one first channel can be used to send an S-SSB in a first time slot, wherein the group of channels is a channel planned to be used to send an S-SSB in the first time slot, and the at least one first channel and the first time slot are included in the COT.

[0142] According to the method of the embodiment of the present application, since the channel listening time in the type 2 channel access process is short, type 2 channel access is performed on at least one first channel included in the COT, and based on the result of the channel access, it is determined whether the at least one first channel can be used for S-SSB transmission. This is beneficial to increasing the probability of the first terminal successfully accessing the at least one first channel and sending S-SSB on the at least one first channel, thereby helping to maintain the occupation of COT resources to avoid the loss of COT resources (such as avoiding the COT resources being preempted by users of other systems).

[0143] It should be noted that in the embodiments of the present application, "performing channel access" can also be replaced by "performing LBT" or "performing channel sensing." In some scenarios, "channel (such as the first channel)" in the embodiments of the present application can also be replaced by "RB set (such as the first RB set)."

[0144] To facilitate understanding of the technical solutions of the embodiments of the present application, the technical solutions of the present application are described in detail below through specific embodiments. The above related technologies can be combined arbitrarily with the technical solutions of the embodiments of the present application as optional solutions, and all of them fall within the scope of protection of the embodiments of the present application. The embodiments of the present application include at least part of the following contents.

[0145] FIG19 is a flow chart of a channel access method provided in an embodiment of the present application. As shown in FIG19 , the method may include the following steps:

[0146] S1901, the first terminal performs type 2 channel access on at least one first channel in a group of channels, and the channel access result obtained by performing type 2 channel access on the at least one first channel is used to determine whether the at least one first channel can be used to send S-SSB in the first time slot; wherein, the group of channels is a channel planned to be used to send S-SSB in the first time slot, and the at least one first channel and the first time slot are included in the COT.

[0147] The channel planned to be used to send the S-SSB in the first time slot can also be understood as a predetermined / determined channel to be used to send the S-SSB in the first time slot. That is, for a predetermined set of channels to be used to send the S-SSB in the first time slot, the first terminal can use a Type 2 (such as Type 2A, Type 2B, or Type 2C) channel access method to access the channel on at least one first channel in the set of channels, and the at least one first channel is included in the COT.

[0148] Furthermore, the channel access result obtained by the first terminal when performing type 2 channel access on the at least one first channel can be used to determine whether the at least one first channel can be used to send an S-SSB in the first time slot. For example, for a first channel among the at least one first channels, if the result of the first terminal performing type 2 channel access on the first channel is successful, the first terminal can send an S-SSB on the first channel, and the time slot for sending the S-SSB is the first time slot; if the result of the first terminal performing type 2 channel access on the first channel is unsuccessful, the first terminal cannot send an S-SSB on the first channel in the first time slot.

[0149] In some embodiments, since the S-SSB is repeatedly mapped in the frequency domain within a channel, that is, the S-SSB can be repeated multiple times (repeatedly mapped multiple times) within a channel, sending the S-SSB on a certain channel can also be understood as sending multiple repeated S-SSBs on the channel.

[0150] According to the above technical solution, the first terminal can perform type 2 channel access on at least one first channel, and the obtained channel access result can be used to determine whether the at least one first channel can be used to send an S-SSB in the first time slot. Since the channel listening time in the type 2 channel access process is relatively short, performing type 2 channel access on at least one first channel included in the COT and determining whether the at least one first channel can be used to send an S-SSB based on the result of the channel access is beneficial to increasing the probability of the first terminal successfully accessing the at least one first channel and sending an S-SSB on the at least one first channel, thereby facilitating the maintenance of COT resource occupation to avoid COT resource loss (such as preventing COT resources from being preempted by users of other systems). In addition, if the result of the first terminal performing type 2 channel access on a certain first channel is successful, the first terminal can send S-SSB on the first channel. That is to say, whether each first channel can be used to send S-SSB in the first time slot does not need to depend on whether the channel access result of another channel is successful. In other words, the channel access of each first channel can be performed independently, thereby further increasing the probability of the first terminal successfully accessing the at least one first channel and sending S-SSB on the at least one first channel, thereby improving the transmission / detection effect of S-SSB.

[0151] In some embodiments, before the first moment, for all or part of the at least one first channel, the planned channel access mode may be channel access of type 1. The first moment is the moment when the first terminal obtains the time-frequency information of the COT.

[0152] That is to say, before the first terminal obtains the time-frequency information of the COT, the first terminal may plan / pre-plan to perform type 1 channel access on all or part of the first channel; if the first terminal obtains the time-frequency information of the COT, the first terminal may change to type 2 channel access on all or part of the first channel before the first time slot, or before sending the S-SSB, so as to increase the probability of successful channel access and thereby reduce the probability of COT loss.

[0153] In some embodiments, if at a first moment, the first terminal has started to perform type 1 channel access on the entire or partial first channel, then at the first moment, the first terminal may stop performing type 1 channel access.

[0154] That is, if the first terminal has already started to perform type 1 channel access on all or part of the first channel according to the pre-planned plan when obtaining the time-frequency information of the COT, the first terminal may stop performing type 1 channel access on all or part of the first channel when obtaining the time-frequency information of the COT, and may abandon part / all of the channel listening results obtained during the process of performing type 1 channel access. Furthermore, the first terminal may wait until before the first time slot to perform type 2 channel access on all or part of the first channel to increase the probability of successful channel access, thereby reducing the probability of COT loss.

[0155] In some embodiments, if the first terminal does not start to perform type 1 channel access on the entire or partial first channel at the first moment, the first terminal may not perform the type 1 channel access.

[0156] That is to say, if the first terminal has not performed type 1 channel access on all or part of the first channel as planned in advance when obtaining the time and frequency information of the COT, then when the original (pre-planned) moment of starting to perform type 1 channel access is reached, the first terminal may not need to perform type 1 channel access on all or part of the first channel, but may wait until before the first time slot to perform type 2 channel access on all or part of the first channel, so as to increase the probability of successful channel access and thereby reduce the probability of COT loss.

[0157] It should be noted that, in the embodiment of the present application, starting to execute type 1 channel access can also be understood as starting to implement the channel listening process of type 1 channel access, or can also be understood as starting to execute type 1 channel listening.

[0158] In some embodiments, the time interval between the first moment (the moment when the first terminal obtains the time-frequency information of the COT) and the first time slot is greater than or equal to the duration required to perform channel access of type 2. In some scenarios, the duration required to perform channel access of type 2 can also be understood as the duration required to perform channel sensing using the channel access method of type 2.

[0159] It can be understood that if the time interval between the first moment and the first time slot is greater than or equal to the time required to perform type 2 channel access, it means that when the first terminal obtains the time and frequency information of the COT, the first terminal has sufficient time to perform type 2 channel access before the first time slot. Therefore, in this case, the first terminal may stop the type 1 channel access being performed on all or part of the first channel, or may not perform type 1 channel access on the whole or part of the first channel according to the pre-planned time slot, but may wait until before the first time slot to perform type 2 channel access on the whole or part of the first channel.

[0160] In some embodiments, if the time interval between the first moment and the first time slot is less than the time required to perform type 2 channel access, it means that when the first terminal obtains the time and frequency information of the COT, before the first time slot, the first terminal is not sufficient to implement type 2 channel access. Therefore, in this case, the first terminal can perform type 1 channel access on all or part of the first channel according to the pre-planned plan.

[0161] In some embodiments, the method may further include: the first terminal determining / judging whether the time interval between the first moment and the first time slot is greater than or equal to the duration required to perform type 2 channel access. Based on the determination result, the first terminal may decide whether to perform type 1 channel access on all or part of the first channel as planned.

[0162] In some embodiments, all or part of the first channels are non-anchor channels in the set of channels. That is, the channels on which the first terminal pre-plans to perform type 1 channel access may be non-anchor channels in the set of channels.

[0163] In some embodiments, for the anchor channel in the set of channels, the first terminal may perform channel access using a channel access method of type 2. Since in some scenarios, the device communicating with the first terminal may be a weak-capability device (such as a weak-capability terminal), and the weak-capability device may not be able to receive S-SSB on channels other than the anchor channel, the first terminal can increase the probability of successfully accessing the anchor channel and sending an S-SSB on the anchor channel by performing type 2 channel access on the anchor channel, thereby increasing the probability that the weak-capability device receives the S-SSB sent by the first terminal.

[0164] In some embodiments, the method may further include: performing type 1 channel access on at least one second channel in the group of channels; wherein the COT does not include at least one second channel; and a channel access result obtained by performing type 1 channel access on the at least one second channel is used to determine whether the at least one second channel can be used to send S-SSB in the first time slot.

[0165] That is, for at least one second channel not included in the COT, the first terminal may perform Type 1 channel access on the at least one second channel. For example, before the first moment, the first terminal has planned to perform Type 1 channel access on the at least one second channel. Then, at the pre-planned moment for starting the Type 1 channel access, the first terminal may perform Type 1 channel access on the at least one second channel according to the pre-planned moment.

[0166] Exemplarily, the channel access result obtained by performing Type 1 channel access on the at least one second channel can be used to determine whether the at least one second channel can be used to send an S-SSB in the first time slot. For example, for a second channel among the at least one second channels, if the result of the first terminal performing Type 1 channel access on the second channel is successful, the first terminal can send an S-SSB on the second channel, and the time slot for sending the S-SSB is the first time slot; if the result of the first terminal performing Type 1 channel access on the second channel is unsuccessful, the first terminal cannot send an S-SSB on the second channel in the first time slot.

[0167] According to the above technical solution, if the result of the first terminal performing type 1 channel access on a second channel is successful, the first terminal can send S-SSB on the second channel. That is to say, whether each second channel can be used to send S-SSB in the first time slot does not need to depend on whether the channel access result of another channel is successful. In other words, the channel access of each second channel can be carried out independently, thereby increasing the probability of the first terminal successfully accessing the at least one second channel and sending S-SSB on the at least one second channel, thereby improving the transmission / detection effect of S-SSB.

[0168] In some embodiments, the at least one second channel is a non-anchor channel in the set of channels. That is, the first terminal may select at least one second channel from the non-anchor channels in the set of channels to perform type 1 channel access.

[0169] In some embodiments, the method may further include: performing type 2 channel access on at least one third channel in the group of channels; wherein the COT does not include the at least one second channel; and the channel access result obtained by performing type 2 channel access on the at least one third channel can be used to determine whether the at least one third channel can be used to send S-SSB in the first time slot.

[0170] That is, for at least one third channel not included in the COT, the first terminal may perform Type 2 channel access on the at least one third channel. For example, before the first moment, the first terminal has planned to perform Type 2 channel access on the at least one third channel. Then, at the pre-planned moment for starting the Type 2 channel access, the first terminal may perform Type 2 channel access on the at least one third channel according to the pre-planned moment.

[0171] Exemplarily, the channel access result obtained by performing Type 2 channel access on the at least one third channel can be used to determine whether the at least one third channel can be used to send an S-SSB in the first time slot. For example, for a third channel among the at least one third channel, if the result of the first terminal performing Type 2 channel access on the third channel is successful, the first terminal can send an S-SSB on the third channel, and the time slot for sending the S-SSB is the first time slot; if the result of the first terminal performing Type 2 channel access on the third channel is unsuccessful, the first terminal cannot send an S-SSB on the third channel in the first time slot.

[0172] According to the above technical solution, if the result of the first terminal performing type 2 channel access on a third channel is successful, the first terminal can send S-SSB on the third channel. That is to say, whether each third channel can be used to send S-SSB in the first time slot does not need to depend on whether the channel access result of another channel is successful. In other words, the channel access of each third channel can be carried out independently, thereby increasing the probability of the first terminal successfully accessing the at least one third channel and sending S-SSB on the at least one third channel, thereby improving the transmission / detection effect of S-SSB.

[0173] In some embodiments, before the first moment (the moment when the first terminal obtains the time-frequency information of the COT), for one of the at least one first channels (for example, recorded as the target first channel), the channel access method planned to be adopted may be type 1 signal access.

[0174] That is, before the first terminal obtains the time-frequency information of the COT, the first terminal may plan / pre-plan to perform type 1 channel access on the target first channel; if the first terminal obtains the time-frequency information of the COT, the first terminal may switch to type 2 channel access on the target first channel before the first time slot. For other first channels in the at least one first channel (other first channels except the target first channel), the first terminal may perform type 2 channel access before the first time slot according to the pre-planned plan. This helps to increase the probability of the first terminal successfully accessing the first channel included in the COT, thereby helping to avoid the loss of the COT resources.

[0175] In some embodiments, if the first terminal has started to perform type 1 channel access on the target first channel at the first moment, the first terminal may stop performing the type 1 channel access at the first moment.

[0176] That is, if the first terminal has already started to perform type 1 channel access on the target first channel according to the pre-planned plan when obtaining the time-frequency information of the COT, the first terminal may stop performing type 1 channel access on the target first channel when obtaining the time-frequency information of the COT, and may abandon some / all channel listening results obtained during the process of performing type 1 channel access. Furthermore, the first terminal may wait until before the first time slot to perform type 2 channel access on the target first channel to increase the probability of successful channel access, thereby reducing the probability of COT loss.

[0177] In some embodiments, if the first terminal does not start to perform type 1 channel access on the target first channel at the first moment, the first terminal may not perform the type 1 channel access.

[0178] That is to say, if the first terminal has not performed type 1 channel access on the target first channel as planned when obtaining the time-frequency information of the COT, then when the original (pre-planned) moment to start performing the type 1 channel access is reached, the first terminal may not need to perform the type 1 channel access on the target first channel, but instead wait until before the first time slot to perform type 2 channel access on the target first channel, so as to increase the probability of successful channel access and thereby reduce the probability of COT loss.

[0179] In some embodiments, the time interval between the first moment (the moment when the first terminal obtains the time-frequency information of the COT) and the first time slot is greater than or equal to the duration required to perform type 2 channel access.

[0180] It can be understood that if the time interval between the first moment and the first time slot is greater than or equal to the time required to perform type 2 channel access, it means that when the first terminal obtains the time and frequency information of the COT, the first terminal has sufficient time to perform type 2 channel access before the first time slot. Therefore, in this case, the first terminal can stop the type 1 channel access being performed on the target first channel, or, instead of performing type 1 channel access on the target first channel according to the pre-planned schedule, it can wait until before the first time slot to perform type 2 channel access on the target first channel.

[0181] In some embodiments, if the time interval between the first moment and the first time slot is less than the time required to perform type 2 channel access, it means that when the first terminal obtains the time and frequency information of the COT, before the first time slot, the first terminal is not sufficient to implement type 2 channel access. Therefore, in this case, the first terminal can perform type 1 channel access on the target first channel according to the pre-planned plan.

[0182] In some embodiments, the method may further include: the first terminal determining / judging whether the time interval between the first moment and the first time slot is greater than or equal to the duration required to perform type 2 channel access. Based on this determination result, the first terminal may decide whether to perform type 1 channel access on the target first channel according to the pre-planned schedule.

[0183] In some embodiments, the target first channel is a non-anchor channel in the set of channels. That is, the first terminal may select a channel (such as the target first channel) from the non-anchor channels in the set of channels to perform type 1 channel access.

[0184] In some embodiments, the channel access result obtained by performing type 2 channel access on the above-mentioned at least one first channel includes: the first channel access result obtained by performing type 2 channel access on the target first channel; when the first channel access result is successful, the channel access result obtained by performing type 2 channel access on the at least one first channel can be used to determine whether the at least one first channel can be used to send S-SSB in the first time slot.

[0185] That is to say, if the result of the first terminal performing type 2 channel access on the target first channel is successful, the first terminal can determine whether the at least one first channel can be used to send S-SSB in the first time slot based on the channel access result obtained by performing type 2 channel access on the at least one first channel.

[0186] In some embodiments, the method may further include: performing type 2 channel access on at least one fourth channel in the group of channels; wherein the COT does not include the at least one fourth channel; when the first channel access result is successful, the channel access result obtained by performing type 2 channel access on the at least one fourth channel can be used to determine whether the at least one fourth channel can be used to send S-SSB in the first time slot.

[0187] That is, for at least one fourth channel not included in the COT, the first terminal may perform Type 2 channel access on the at least one fourth channel. For example, before the first moment, the first terminal has planned to perform Type 2 channel access on the at least one fourth channel. Then, at the pre-planned moment for starting the Type 2 channel access, the first terminal may perform Type 2 channel access on the at least one fourth channel according to the pre-planned moment.

[0188] Exemplarily, when the first channel access result is successful, the channel access result obtained by performing type 2 channel access on the at least one fourth channel can be used to determine whether the at least one fourth channel can be used to send an S-SSB in the first time slot. For example, when the first channel access result is successful, for a fourth channel among the at least one fourth channels, if the result of the first terminal performing type 2 channel access on the fourth channel is successful, the first terminal can send an S-SSB on the fourth channel, and the time slot for sending the S-SSB is the first time slot; if the result of the first terminal performing type 2 channel access on the fourth channel is unsuccessful, the first terminal cannot send an S-SSB on the fourth channel in the first time slot.

[0189] In some embodiments, if the first channel access result is a failure, the group of channels is not used to send an S-SSB in the first time slot. That is, whether the at least one first channel and / or the at least one fourth channel can be used to send an S-SSB in the first time slot depends on whether the first channel access result is a success. For example, if the first channel access result is a success, the at least one first channel and / or the at least one fourth channel can be used to send an S-SSB in the first time slot; if the first channel access result is a failure, none of the group of channels can be used to send an S-SSB in the first time slot.

[0190] In some embodiments, the method may further include: performing type 2 channel access on at least one fourth channel in the group of channels; wherein the COT does not include the at least one fourth channel; and the channel access result obtained by performing type 2 channel access on the at least one fourth channel can be used to determine whether the at least one fourth channel can be used to send S-SSB in the first time slot.

[0191] That is, for at least one fourth channel not included in the COT, the first terminal may perform Type 2 channel access on the at least one fourth channel. For example, before the first moment, the first terminal has planned to perform Type 2 channel access on the at least one fourth channel. Then, at the pre-planned moment for starting the Type 2 channel access, the first terminal may perform Type 2 channel access on the at least one fourth channel according to the pre-planned moment.

[0192] Exemplarily, the channel access result obtained by performing Type 2 channel access on the at least one fourth channel can be used to determine whether the at least one fourth channel can be used to send an S-SSB in the first time slot. For example, for a fourth channel among the at least one fourth channel, if the result of the first terminal performing Type 2 channel access on the fourth channel is successful, the first terminal can send an S-SSB on the fourth channel, and the time slot for sending the S-SSB is the first time slot; if the result of the first terminal performing Type 2 channel access on the fourth channel is unsuccessful, the first terminal cannot send an S-SSB on the fourth channel in the first time slot.

[0193] According to the above technical solution, if the result of the first terminal performing type 2 channel access on a fourth channel is successful, the first terminal can send S-SSB on the fourth channel. That is to say, whether each fourth channel can be used to send S-SSB in the first time slot does not need to depend on whether the first channel access result is successful. In other words, the channel access of each fourth channel can be performed independently, thereby increasing the probability of the first terminal successfully accessing the at least one fourth channel and sending S-SSB on the at least one fourth channel, thereby improving the transmission / detection effect of S-SSB.

[0194] In some embodiments, the method may further include: the first terminal receiving first information from the second terminal, the first information being used to share the COT with the first terminal, the first information including time-frequency information of the COT, and the COT being initiated by the second terminal.

[0195] That is to say, the second terminal can share the COT initiated by the second terminal with the first terminal by sending the first information to the first terminal, and the time-frequency information of the COT can be carried in the first information. Accordingly, the first terminal can obtain the time-frequency information of the COT by receiving the first information. Based on the time-frequency information of the COT, the first terminal can know which channels and time slots are included in the COT. For example, in this embodiment, the first terminal can know that at least one first channel and a first time slot are included in the COT based on the time-frequency information of the COT, so that the first terminal can perform type 2 channel access on the at least one first channel to increase the probability of the first terminal successfully accessing the at least one first channel and sending S-SSB on the at least one first channel, thereby avoiding the loss of COT resources.

[0196] In some embodiments, the first moment (the moment when the first terminal obtains the time-frequency information of the COT) may also be understood as the moment when the first terminal receives the first information from the second terminal.

[0197] The above introduces the channel access method provided by the embodiment of the present application. To facilitate understanding of the embodiment of the present application, the following introduces possible implementation schemes of the channel access method applicable to the embodiment of the present application with examples.

[0198] Option 1

[0199] Assume that a set of channels (or RB sets) planned by the UE (an example of the first terminal) for transmitting S-SSB in time slot n (corresponding to the first time slot in the aforementioned embodiment) includes C channels, channel C i is any one of the C channels. i , UE can use any of the channel access methods Type1, Type2 (2A, 2B or 2C) to access the channel (channel listening). i If the access is successful, you can i Send S-SSB on.

[0200] In solution 1, when UE is in channel C i In the case of Type 1 channel access, when the UE obtains the COT information (COT time-frequency information), if the COT contains channel C i If the time slot n of the S-SSB is about to be sent, the UE can send the S-SSB on the channel C before the time slot n. i Up-converted to Type 2 (2A, 2B, or 2C) channel access mode.

[0201] The above-mentioned Type 1 channel access may include the following two situations:

[0202] Case #1: Type 1 channel access is planned, but channel sensing has not yet been implemented;

[0203] Case #2: The channel sensing process for Type 1 channel access has already started.

[0204] For the above case #1, that is, the UE plans to use channel C i In this case, when the UE is scheduled to start Type 1 channel access, it no longer performs Type 1 channel access, but waits until time slot n before performing Type 2 channel access.

[0205] For the above situation #2, that is, the UE has started to i In this case, the UE may switch to a Type 2 (2A, 2B, or 2C) channel access method.

[0206] For example, UE is in channel Ci During the implementation of Type 1 channel access, if COT information is obtained at time t1 (corresponding to the first time in the aforementioned embodiment), the UE may stop Type 1 channel access / channel sensing at time t1 and start Type 2 (2A, 2B, or 2C) channel access / channel sensing at time t2 before time slot n. The UE may ignore the Type 1 channel sensing results (partial / full channel sensing results) that have already been obtained.

[0207] In some scenarios, for the above situation #2, if the time interval (remaining time length) between time t1 (the time when the UE obtains the COT information) and time slot n is not sufficient to perform the Type2 (2A, 2B or 2C) channel access process, the UE can continue and complete the currently being implemented Type1 channel access process, and use the Type1 channel listening result (if successful) to access the channel.

[0208] For ease of understanding, FIG20 shows an example of Solution 1. In FIG20 , it is assumed that the multi-channel access method that the UE plans to adopt is Type A multi-channel access. The process shown in FIG20 may include the following steps S201 to S204:

[0209] In S201, the UE plans / decides that the frequency domain resources for transmitting an S-SSB in time slot n (S-SSB time slot n) include RB set #0, RB set #1, RB set #2, and RB set #3. The UE may also determine the number of repeated S-SSBs to be transmitted on each RB set, as well as the interval between adjacent S-SSBs within an RB set. RB set #0 is the anchor RB set, and RB set #1, RB set #2, and RB set #3 are non-anchor RB sets.

[0210] S202, UE performs Type 1 channel access / LBT.

[0211] In this step, the UE can perform channel access using the multi-channel access method of Type A. That is, the UE can independently use the Type 1 channel access method to perform channel access / LBT on RB set #0, RB set #1, RB set #2, and RB set #3.

[0212] S203: The UE changes to using the Type 2 channel access mode to perform channel sensing on the RB set included in the COT.

[0213] For example, the UE obtains COT information at time t1. Based on this COT information, the UE can determine that RB Set #2 and RB Set #3 are included in the COT. Furthermore, the UE can switch to Type 2 channel access for channel sensing on RB Set #2 and RB Set #3. For example, the UE can stop Type 1 channel access at time t1 and start Type 2 channel access at time t2, before time slot n.

[0214] S204, UE sends S-SSB in time slot n.

[0215] For any RB set from RB set #0 to RB set #3, if the UE successfully accesses the channel of that RB set, it can send an S-SSB on that RB set, and the timeslot in which the S-SSB is sent is timeslot n. For example, if the UE successfully accesses the channel of RB set #0, it can send an S-SSB on RB set #0; for another example, if the UE successfully accesses the channel of RB set #2, it can send an S-SSB on RB set #2.

[0216] It should be understood that the "RB set" in the solution shown in FIG20 can also be replaced by "channel".

[0217] FIG21 shows another example of Solution 1. In FIG21 , it is assumed that the multi-channel access method that the UE plans to adopt is Type A multi-channel access. The process shown in FIG21 may include the following steps S211 to S214:

[0218] S211: The UE plans / decides that the frequency domain resources for transmitting the S-SSB in time slot n (S-SSB time slot n) include RB set #0, RB set #1, RB set #2, and RB set #3. The UE may also determine the number of repeated S-SSBs to be transmitted on each RB set, the interval between adjacent S-SSBs within an RB set, etc. RB set #0 is the anchor RB set, and RB set #1, RB set #2, and RB set #3 are non-anchor RB sets.

[0219] S212: The UE performs Type 1 channel access / LBT on part or all of the RB sets.

[0220] In one possible case (referred to as case #11), the time when the UE obtains the COT information is t 11 That is, UE is at t 11 At this moment, it can be known based on the COT information that RB set #2 and RB set #3 are included in the COT. As shown in Figure 21, t 11 The time is before the scheduled start time of Type 1 channel access, that is, at t 11At the time of the scheduled start of Type 1 channel access, the UE has not yet started Type 1 channel access. In this case, when the scheduled start of Type 1 channel access is reached, the UE will no longer perform Type 1 channel access on RB set #2 and RB set #3. The UE can still perform Type 1 channel access on RB set #0 and RB set #1 as planned.

[0221] In another possible case (referred to as case #12), the time when the UE obtains the COT information is t 12 Time or t 13 That is, UE is at t 12 Time or t 13 At this moment, it can be known based on the COT information that RB set #2 and RB set #3 are included in the COT. As shown in Figure 21, t 12 time and t 13 The time is after the time when the UE plans to start performing Type 1 channel access, that is, at the time when the UE plans to start performing Type 1 channel access, the UE has not yet obtained the time and frequency information of COT. In this case, the UE can perform Type 1 channel access as planned on RB set #0 to RB set #3.

[0222] S213: The UE performs Type 2 channel access / LBT on RB set #2 and RB set #3.

[0223] For the above case #11, the UE may wait until time t2 before time slot n and start performing Type 2 channel access on RB set #2 and RB set #3.

[0224] For the above case #12, assume that the time when the UE obtains the COT information is t 12 As shown in Figure 21, at t 12 At time t, the UE has started to perform Type 1 channel access / channel listening. 12 At time t2 before time slot n, the UE may stop Type 1 channel access / channel sensing on RB set #2 and RB set #3 and may abandon some / all Type 1 channel sensing results already obtained. At time t2 before time slot n, the UE may start Type 2 channel access on RB set #2 and RB set #3.

[0225] For the above case #12, assume that the time when the UE obtains the COT information is t 13 As shown in Figure 21, t 13The time interval between the moment and time slot n is not enough to perform the Type2 channel access process. That is to say, at this time, regardless of whether the UE continues to perform Type1 channel listening, there is not enough time to perform the Type2 channel access process before time slot n. Therefore, in this case, the UE can execute according to the Type1 channel access method that has been performed.

[0226] S214, UE sends S-SSB in time slot n.

[0227] For any RB set from RB set #0 to RB set #3, if the UE successfully accesses the channel of that RB set, it can send an S-SSB on that RB set, and the timeslot in which the S-SSB is sent is timeslot n. For example, if the UE successfully accesses the channel of RB set #0, it can send an S-SSB on RB set #0; for another example, if the UE successfully accesses the channel of RB set #2, it can send an S-SSB on RB set #2.

[0228] It should be understood that the "RB set" in the solution shown in FIG21 can also be replaced by "channel".

[0229] Option 2

[0230] Assume that a set of channels (or RB sets) planned by the UE for sending S-SSB in time slot n (corresponding to the first time slot in the aforementioned embodiment) includes C channels.

[0231] In solution 2, the UE can select any channel C from the non-anchor channels. i Type 1 channel access is used (that is, one RB set is randomly selected from the non-anchor RB set and the Type 1 channel access is used). Type 2 channel access is used for other channels (RB sets).

[0232] At UE in channel C i In the case of Type 1 channel access, when the UE obtains the COT information (COT time-frequency information), if the COT contains channel C i If the time slot n of the S-SSB is about to be sent, the UE can send the S-SSB on the channel C before the time slot n. i Up-converted to Type 2 (2A, 2B, or 2C) channel access mode.

[0233] The above-mentioned Type 1 channel access may include the following two situations:

[0234] Case #3: Type 1 channel access is planned, but channel sensing has not yet been implemented;

[0235] Case #4: The channel sensing process for Type 1 channel access has begun.

[0236] For the above situation #3, that is, the UE plans to use channel C i In this case, when the UE is scheduled to start Type 1 channel access, it no longer performs Type 1 channel access, but waits until time slot n before performing Type 2 channel access.

[0237] For the above situation #4, that is, the UE has started to i In this case, the UE may switch to a Type 2 (2A, 2B, or 2C) channel access method.

[0238] For example, UE is in channel C i During the implementation of Type 1 channel access, if COT information is obtained at time t1 (corresponding to the first time in the aforementioned embodiment), the UE may stop Type 1 channel access / channel sensing at time t1 and start Type 2 (2A, 2B, or 2C) channel access / channel sensing at time t2 before time slot n. The UE may ignore the Type 1 channel sensing results (partial / full channel sensing results) that have already been obtained.

[0239] In some scenarios, for the above situation #4, if the time interval (remaining time length) between time t1 (the time when the UE obtains the COT information) and time slot n is not sufficient to perform the Type2 (2A, 2B or 2C) channel access process, the UE can continue and complete the currently being implemented Type1 channel access process, and use the Type1 channel listening result (if successful) to access the channel.

[0240] In some embodiments, for the above case #3 and / or case #4, if the UE successfully accesses a channel on a certain channel, it can send an S-SSB on the channel, and the time slot for sending the S-SSB is time slot n. In other words, the channel access of each channel can be performed independently without relying on the channel C. i Whether the channel access is successful.

[0241] In some embodiments, for the above case #3 and / or case #4, other channels are only available on channel C. i Only when the channel access is successful can the access channel and S-SSB be sent according to the respective channel access results. In other words, whether other channels can be used to send S-SSB in time slot n depends on the channel C. i Whether the channel access is successful, if in channel C i If channel access fails, all C channels cannot be used for S-SSB transmission.

[0242] For ease of understanding, FIG22 shows an example of Solution 2. In FIG22 , it is assumed that the multi-channel access method that the UE plans to adopt is Type B multi-channel access. The process shown in FIG22 may include the following steps S221 to S224:

[0243] S221: The UE plans / decides that the frequency domain resources for transmitting the S-SSB in time slot n (S-SSB time slot n) include RB set #0, RB set #1, RB set #2, and RB set #3. The UE may also determine the number of repeated S-SSBs to be transmitted on each RB set, the interval between adjacent S-SSBs within an RB set, etc. RB set #0 is the anchor RB set, and RB set #1, RB set #2, and RB set #3 are non-anchor RB sets.

[0244] S222, the UE performs Type 1 channel access / LBT on RB set #2.

[0245] In this embodiment, the UE may, for example, plan to use the channel access mode of Type 1 on RB set #2 and use the channel access mode of Type 2 on other RB sets.

[0246] In one possible case (referred to as case #21), the time when the UE obtains the COT information is t 11 That is, UE is at t 11 At this moment, it can be known based on the COT information that RB set #2 and RB set #3 are included in the COT. As shown in Figure 22, t 11 The time is before the scheduled start time of Type 1 channel access, that is, at t 11 At this moment, the UE has not started to perform Type 1 channel access on RB set #2 as planned. In this case, when the scheduled start time of Type 1 channel access is reached, the UE no longer performs Type 1 channel access on RB set #2.

[0247] In another possible case (referred to as case #22), the time when the UE obtains the COT information is t 12 Time or t 13 That is, UE is at t 12 Time or t 13 At this moment, it can be known based on the COT information that RB set #2 and RB set #3 are included in the COT. As shown in Figure 22, t 12 time and t 13The time is after the time when the UE plans to start executing Type1 channel access, that is, at the time when the UE plans to start executing Type1 channel access, the UE has not yet obtained the time and frequency information of COT. In this case, the UE can execute Type1 channel access as planned on RB set #2.

[0248] S223, the UE performs Type 2 channel access / LBT.

[0249] For the above case #21, the UE may wait until time t2 before time slot n and start performing Type 2 channel access on RB set #0 to RB set #3.

[0250] For the above case #22, assume that the time when the UE obtains the COT information is t 12 As shown in Figure 22, at t 12 At time t, the UE has started to perform Type 1 channel access / channel sensing on RB set #2. Then, at t 12 At time t2 before time slot n, the UE may start performing Type 2 channel access on RB sets #0 to #3.

[0251] For the above case #22, assume that the time when the UE obtains the COT information is t 13 As shown in Figure 22, t 13 The time interval between time instant and time slot n is insufficient for Type 2 channel access. Therefore, in this case, the UE can continue Type 1 channel access on RB set #2. The UE can start Type 2 channel access on RB set #0, RB set #1, and RB set #3 as planned at time t2.

[0252] S224, UE sends S-SSB in time slot n.

[0253] In some embodiments, for Case #21 and / or Case #22 above, if the UE successfully accesses a channel on a certain RB set, it can send an S-SSB on that channel, with the timeslot for sending the S-SSB being timeslot n. In other words, channel access for each RB set can be performed independently, without relying on whether channel access for RB set #2 is successful.

[0254] In some embodiments, for the above-mentioned case #21 and / or case #22, other RB sets can determine whether they can access the channel and send S-SSBs based on their respective channel access results only if RB set #2 successfully accesses the channel. In other words, whether other RB sets can be used to send S-SSBs in time slot n depends on whether RB set #2 successfully accesses the channel. If RB set #2 fails to access the channel, RB sets #0 to RB sets 3 cannot be used to send S-SSBs.

[0255] It should be understood that the "RB set" in the solution shown in FIG22 can also be replaced by "channel".

[0256] According to the channel access method provided in the embodiment of the present application, when the UE adopts a multi-channel access mechanism, in the case of an existing channel access type plan, if the UE obtains the COT time-frequency information, it can decide whether to switch to a new channel access type (for example, switch from Type 1 channel access to Type 2 channel access) based on the time of obtaining the COT time-frequency information and the remaining time before sending the S-SSB. If there is a correlation between the channels originally planned for multi-channel access, then after switching to the new channel access type, the correlation may automatically disappear, or the correlation may still exist. This method increases the probability of channel access by switching the channel access type, while maintaining the existing COT resources to avoid preemption by users of different systems, thereby ensuring the reliability of the sidelink resources in the unlicensed frequency band.

[0257] The preferred embodiments of the present application are described in detail above in conjunction with the accompanying drawings. However, the present application is not limited to the specific details in the above embodiments. Within the technical concept of the present application, the technical solution of the present application can be subjected to a variety of simple modifications, and these simple modifications all fall within the scope of protection of the present application. For example, the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present application will no longer describe the various possible combinations separately. For another example, the various different embodiments of the present application can also be arbitrarily combined, as long as they do not violate the idea of ​​the present application, they should also be regarded as the contents disclosed in the present application. For another example, under the premise of no conflict, the various embodiments and / or the technical features in each embodiment described in the present application can be arbitrarily combined with the prior art, and the technical solution obtained after the combination should also fall within the scope of protection of the present application.

[0258] It should also be understood that in the various method embodiments of the present application, the sequence numbers of the above-mentioned processes do not imply a precedence in 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. In addition, in the embodiments of the present application, the terms "downlink," "uplink," and "sidelink" are used to indicate the transmission direction of signals or data, where "downlink" is used to indicate the first direction of transmission of signals or data from a site to a user equipment in a cell, "uplink" is used to indicate the second direction of transmission of signals or data from a user equipment in a cell to a site, and "sidelink" is used to indicate the third direction of transmission of signals or data from user equipment 1 to user equipment 2. For example, "downlink signal" indicates that the transmission direction of the signal is the first direction. In addition, in the embodiments of the present application, the term "and / or" is merely a description of the association relationship between associated objects, indicating that three relationships can exist. Specifically, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0259] Based on the aforementioned embodiments, the embodiments of the present application provide corresponding channel access devices.

[0260] FIG23 is a schematic diagram of the structure of a channel access device provided in an embodiment of the present application, which is applied to a first terminal. As shown in FIG23 , a channel access device 2300 (hereinafter referred to as device 2300 ) includes:

[0261] The processing unit 2301 is configured to perform type 2 channel access on at least one first channel in a group of channels, and the channel access result obtained by performing type 2 channel access on the at least one first channel is used to determine whether the at least one first channel can be used to send a side link synchronization signal block S-SSB in the first time slot; wherein, a group of channels are channels planned to be used to send S-SSB in the first time slot, and the at least one first channel and the first time slot are included in the channel occupancy time COT.

[0262] In some embodiments, the processing unit 2301 is further configured to: if at a first moment, type 1 channel access has been started on all or part of the first channels in at least one first channel, then at a first moment, stop executing type 1 channel access; the first moment is the moment of obtaining the time-frequency information of the COT.

[0263] In some embodiments, the processing unit 2301 is further configured to: if type 1 channel access is not started on all or part of the at least one first channel at the first moment, then type 1 channel access is not performed; the first moment is the moment of obtaining the time-frequency information of the COT.

[0264] In some embodiments, before the first moment, for all or part of the first channel, the channel access method planned to be adopted is type 1 channel access.

[0265] In some embodiments, all or part of the first channel is a non-anchor channel in a group of channels.

[0266] In some embodiments, the processing unit 2301 is further configured to perform type 1 channel access on at least one second channel in a group of channels; wherein the COT does not include at least one second channel; and the channel access result obtained by performing type 1 channel access on at least one second channel is used to determine whether the at least one second channel can be used to send S-SSB in the first time slot.

[0267] In some embodiments, the at least one second channel is a non-anchor channel in the set of channels.

[0268] In some embodiments, the processing unit 2301 is further configured to perform type 2 channel access on at least one third channel in a group of channels; wherein the COT does not include at least one second channel; and the channel access result obtained by performing type 2 channel access on at least one third channel is used to determine whether the at least one third channel can be used to send S-SSB in the first time slot.

[0269] In some embodiments, the processing unit 2301 is further configured to: if type 1 channel access has been started on the target first channel at a first moment, then stop executing type 1 channel access at a first moment; wherein the target first channel is one of the at least one first channels, and the first moment is the moment of obtaining the time-frequency information of the COT.

[0270] In some embodiments, the processing unit 2301 is further configured to: if type 1 channel access is not started on the target first channel at the first moment, then type 1 channel access is not performed; wherein the target first channel is one of the at least one first channels, and the first moment is the moment of obtaining the time-frequency information of the COT.

[0271] In some embodiments, before the first moment, for the target first channel, the channel access method planned to be adopted is type 1 signal access.

[0272] In some embodiments, the target first channel is a non-anchor channel in a group of channels.

[0273] In some embodiments, the channel access result obtained by performing type 2 channel access on at least one first channel includes: a first channel access result obtained by performing type 2 channel access on a target first channel; when the first channel access result is successful, the channel access result obtained by performing type 2 channel access on at least one first channel is used to determine whether the at least one first channel can be used to send S-SSB in the first time slot.

[0274] In some embodiments, the processing unit 2301 is further configured to perform type 2 channel access on at least one fourth channel in a group of channels; wherein the COT does not include at least one fourth channel; and when the first channel access result is successful, the channel access result obtained by performing type 2 channel access on at least one fourth channel is used to determine whether the at least one fourth channel can be used to send S-SSB in the first time slot.

[0275] In some embodiments, if the first channel access result is failure, a group of channels are not used to send S-SSB in the first time slot.

[0276] In some embodiments, the processing unit 2301 is further configured to perform type 2 channel access on at least one fourth channel in a group of channels; wherein the COT does not include at least one fourth channel; and the channel access result obtained by performing type 2 channel access on at least one fourth channel is used to determine whether the at least one fourth channel can be used to send S-SSB in the first time slot.

[0277] In some embodiments, the time interval between the first moment and the first time slot is greater than or equal to the time required to perform type 2 channel access.

[0278] In some embodiments, the processing unit 2301 is further configured to determine whether the time interval between the first moment and the first time slot is greater than or equal to the duration required to perform type 2 channel access.

[0279] In some embodiments, the apparatus 2300 further includes: a communication unit configured to receive first information from the second terminal, the first information being used to share the COT with the apparatus 2300, the first information including time-frequency information of the COT, and the COT being initiated by the second terminal.

[0280] Those skilled in the art should understand that the relevant description of the above-mentioned channel access device in the embodiment of the present application can be understood with reference to the relevant description of the channel access method in the embodiment of the present application.

[0281] Figure 24 is a schematic structural diagram of a communication device 2400 provided in an embodiment of the present application. The communication device 2400 shown in Figure 24 includes a processor 2410, which can call and run a computer program from a memory to implement the method in the embodiment of the present application.

[0282] Optionally, as shown in FIG24 , the communication device 2400 may further include a memory 2420. The processor 2410 may call and execute a computer program from the memory 2420 to implement the method in the embodiment of the present application.

[0283] The memory 2420 may be a separate device independent of the processor 2410 , or may be integrated into the processor 2410 .

[0284] Optionally, as shown in FIG24 , the communication device 2400 may further include a transceiver 2430 , and the processor 2410 may control the transceiver 2430 to communicate with other devices, specifically, to send information or data to other devices, or to receive information or data sent by other devices.

[0285] The transceiver 2430 may include a transmitter and a receiver. The transceiver 2430 may further include an antenna, and the number of antennas may be one or more.

[0286] The communication device 2400 can specifically be a terminal (such as the first terminal) in an embodiment of the present application, and the communication device 2400 can implement the corresponding processes implemented by the terminal (such as the first terminal) in each method of the embodiment of the present application. For the sake of brevity, they will not be repeated here.

[0287] Figure 25 is a schematic structural diagram of a chip according to an embodiment of the present application. The chip 2500 shown in Figure 25 includes a processor 2510, which can call and run a computer program from a memory to implement the method according to the embodiment of the present application.

[0288] Optionally, as shown in FIG25 , the chip 2500 may further include a memory 2520. The processor 2510 may call and execute a computer program from the memory 2520 to implement the method in the embodiment of the present application.

[0289] The memory 2520 may be a separate device independent of the processor 2510 or may be integrated into the processor 2510 .

[0290] Optionally, the chip 2500 may further include an input interface 2530. The processor 2510 may control the input interface 2530 to communicate with other devices or chips, and specifically, may obtain information or data sent by other devices or chips.

[0291] Optionally, the chip 2500 may further include an output interface 2540. The processor 2510 may control the output interface 2540 to communicate with other devices or chips, and specifically, may output information or data to other devices or chips.

[0292] The chip can be applied to the terminal (such as the first terminal) in the embodiment of the present application, and the chip can implement the corresponding processes implemented by the terminal (such as the first terminal) in each method of the embodiment of the present application. For the sake of brevity, they will not be repeated here.

[0293] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0294] It should be understood that the processor of the embodiments of the present application may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method embodiment can be completed by hardware integrated logic circuits in the processor or software instructions. The above processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. The various methods, steps, and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in the embodiments of the present application can be directly embodied as being executed by a hardware decoding processor, or can be executed by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium mature in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, etc. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.

[0295] It is understood that the memory in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct RAM bus random access memory (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0296] It should be understood that the above-mentioned memories are exemplary but not restrictive. For example, the memories in the embodiments of the present application may also be static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct RAM RAM (DR RAM), etc. In other words, the memories in the embodiments of the present application are intended to include, but are not limited to, these and any other suitable types of memories.

[0297] The present application also provides a computer-readable storage medium for storing a computer program. This computer-readable storage medium can be applied to a terminal (e.g., the first terminal) in the present application, and the computer program causes a computer to execute the corresponding processes implemented by the terminal (e.g., the first terminal) in each method of the present application. For the sake of brevity, these are not further described here.

[0298] The present application also provides a computer program product including computer program instructions. This computer program product can be applied to a terminal (e.g., the first terminal) in the present application, and the computer program instructions cause a computer to execute the corresponding processes implemented by the terminal (e.g., the first terminal) in the various methods of the present application. For the sake of brevity, these instructions are not further described here.

[0299] The present application also provides a computer program. This computer program can be applied to a terminal (such as the first terminal) in the present application. When the computer program is executed on a computer, it causes the computer to execute the corresponding processes implemented by the terminal (such as the first terminal) in each method of the present application. For the sake of brevity, these are not further described here.

[0300] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0301] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0302] In the several embodiments provided in this 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 merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, 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.

[0303] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0304] 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.

[0305] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0306] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A channel access method, applied to a first terminal, the method comprising: Performing type 2 channel access on at least one first channel in a set of channels, and the channel access result obtained by performing type 2 channel access on the at least one first channel is used to determine whether the at least one first channel is available for transmitting a side link synchronization signal block S-SSB in a first time slot; Wherein, the set of channels are channels planned for transmitting S-SSB in the first time slot, and the at least one first channel and the first time slot are included in a channel occupancy time COT.

2. The method according to claim 1, wherein, The method further comprises: If, at a first moment, type 1 channel access has been started on all or part of the first channels in the at least one first channel, then at the first moment, stop performing the type 1 channel access; the first moment is the moment of obtaining the time-frequency information of the COT.

3. The method according to claim 1, wherein The method further comprises: If, at a first moment, type 1 channel access has not been started on all or part of the first channels in the at least one first channel, then do not perform the type 1 channel access; the first moment is the moment of obtaining the time-frequency information of the COT.

4. The method according to claim 2 or 3, wherein, Before the first moment, for all or part of the first channels, the planned channel access method is type 1 channel access.

5. The method according to any one of claims 2 to 4, wherein, All or part of the first channels are non-anchor channels in the set of channels.

6. The method according to any one of claims 1 to 5, wherein, The method further comprises: Performing type 1 channel access on at least one second channel in the set of channels; Wherein, the COT does not include the at least one second channel; The channel access result obtained by performing type 1 channel access on the at least one second channel is used to determine whether the at least one second channel is available for transmitting S-SSB in the first time slot.

7. The method according to claim 6, wherein, The at least one second channel is a non-anchor channel in the set of channels.

8. The method according to any one of claims 1 to 7, wherein The method further comprises: Performing type 2 channel access on at least one third channel in the set of channels; Wherein, the COT does not include the at least one second channel; The channel access result obtained by performing type 2 channel access on the at least one third channel is used to determine whether the at least one third channel is available for transmitting S-SSB in the first time slot.

9. The method according to claim 1, wherein The method further comprises: If, at a first moment, type 1 channel access has been started on a target first channel, then at the first moment, stop performing the type 1 channel access; Wherein, the target first channel is one of the at least one first channel, and the first moment is the moment of obtaining the time-frequency information of the COT.

10. The method according to claim 1, wherein The method further comprises: If, at a first moment, type 1 channel access has not been started on the target first channel, then do not perform the type 1 channel access; Wherein, the target first channel is one of the at least one first channel, and the first moment is the moment when the time-frequency information of the COT is obtained.

11. The method according to claim 9 or 10, wherein Before the first moment, for the target first channel, the planned channel access mode is type 1 channel access.

12. The method according to any one of claims 9 to 11, wherein The target first channel is one of the non-anchor channels in the group of channels.

13. The method according to any one of claims 9 to 12, wherein The channel access result obtained by performing type 2 channel access on the at least one first channel includes: the first channel access result obtained by performing type 2 channel access on the target first channel; When the first channel access result is successful, the channel access result obtained by performing type 2 channel access on the at least one first channel is used to determine whether the at least one first channel can be used to send S-SSB in the first time slot.

14. The method according to claim 13, wherein, The method further includes: Performing type 2 channel access on at least one fourth channel in the group of channels; Wherein, the COT does not include the at least one fourth channel; When the first channel access result is successful, the channel access result obtained by performing type 2 channel access on the at least one fourth channel is used to determine whether the at least one fourth channel can be used to send S-SSB in the first time slot.

15. The method according to claim 13 or 14, wherein When the first channel access result is a failure, the group of channels is not used to send S-SSB in the first time slot.

16. The method according to any one of claims 9 to 12, wherein The method further includes: Performing type 2 channel access on at least one fourth channel in the group of channels; Wherein, the COT does not include the at least one fourth channel; The channel access result obtained by performing type 2 channel access on the at least one fourth channel is used to determine whether the at least one fourth channel can be used to send S-SSB in the first time slot.

17. The method according to any one of claims 2 to 5, 9 to 16, wherein The time interval between the first moment and the first time slot is greater than or equal to the duration required for performing type 2 channel access.

18. The method according to any one of claims 2 to 5, 9 to 17, wherein, The method further includes: Determining whether the time interval between the first moment and the first time slot is greater than or equal to the duration required for performing type 2 channel access.

19. The method according to any one of claims 1 to 18, wherein, The method further includes: Receiving first information from a second terminal, the first information being used to share the COT with the first terminal, the first information including the time-frequency information of the COT, and the COT being initiated by the second terminal.

20. A channel access device, the device includes: A processing unit, configured to perform type 2 channel access on at least one first channel in a set of channels, and a channel access result obtained by performing type 2 channel access on the at least one first channel is used to determine whether the at least one first channel is available for transmitting a sidelink synchronization signal block S-SSB in a first time slot; Wherein, the set of channels are channels planned to transmit S-SSB in the first time slot, and the at least one first channel and the first time slot are included in a channel occupancy time COT.

21. The apparatus according to claim 20, wherein, The processing unit is further configured to: if at a first moment, type 1 channel access has been started on all or part of the first channels in the at least one first channel, then at the first moment, stop performing the type 1 channel access; the first moment is the moment when the time-frequency information of the COT is obtained.

22. The apparatus according to claim 20, wherein, The processing unit is further configured to: if at a first moment, type 1 channel access has not been started on all or part of the first channels in the at least one first channel, then do not perform the type 1 channel access; the first moment is the moment when the time-frequency information of the COT is obtained.

23. The apparatus according to claim 21 or 22, wherein, Before the first moment, for all or part of the first channels, the planned channel access method is type 1 channel access.

24. The apparatus according to any one of claims 21 to 23, wherein, All or part of the first channels are non-anchor channels in the set of channels.

25. The apparatus according to any one of claims 20 to 24, wherein, The processing unit is further configured to perform type 1 channel access on at least one second channel in the set of channels; Wherein, the COT does not include the at least one second channel; A channel access result obtained by performing type 1 channel access on the at least one second channel is used to determine whether the at least one second channel is available for transmitting S-SSB in the first time slot.

26. The apparatus according to claim 25, wherein, The at least one second channel is a non-anchor channel in the set of channels.

27. The apparatus according to any one of claims 20 to 26, wherein, The processing unit is further configured to perform type 2 channel access on at least one third channel in the set of channels; Wherein, the COT does not include the at least one second channel; A channel access result obtained by performing type 2 channel access on the at least one third channel is used to determine whether the at least one third channel is available for transmitting S-SSB in the first time slot.

28. The apparatus according to claim 20, wherein, The processing unit is further configured to: if at a first moment, type 1 channel access has been started on a target first channel, then At the first moment, stop performing the type 1 channel access; Wherein, the target first channel is one of the at least one first channel, and the first moment is the moment when the time-frequency information of the COT is obtained.

29. The apparatus according to claim 20, wherein, The processing unit is further configured to: if the type 1 channel access has not started on the target first channel at the first moment, then do not perform the type 1 channel access; Wherein, the target first channel is one of the at least one first channel, and the first moment is the moment when the time-frequency information of the COT is obtained.

30. The apparatus according to claim 28 or 29, wherein, Before the first moment, for the target first channel, the planned channel access method is type 1 channel access.

31. The apparatus according to any one of claims 28 to 30, wherein, The target first channel is one of the non-anchor channels in the group of channels.

32. The apparatus according to any one of claims 28 to 31, wherein, The channel access result obtained by performing type 2 channel access on the at least one first channel includes: the first channel access result obtained by performing type 2 channel access on the target first channel; In the case where the first channel access result is successful, the channel access result obtained by performing type 2 channel access on the at least one first channel is used to determine whether the at least one first channel can be used to send S-SSB in the first time slot.

33. The apparatus according to claim 32, wherein, The processing unit is further configured to perform type 2 channel access on at least one fourth channel in the group of channels; Wherein, the COT does not include the at least one fourth channel; In the case where the first channel access result is successful, the channel access result obtained by performing type 2 channel access on the at least one fourth channel is used to determine whether the at least one fourth channel can be used to send S-SSB in the first time slot.

34. The apparatus according to claim 32 or 33, wherein, In the case where the first channel access result is a failure, the group of channels is not used to send S-SSB in the first time slot.

35. The apparatus according to any one of claims 28 to 31, wherein, The processing unit is further configured to perform type 2 channel access on at least one fourth channel in the group of channels; Wherein, the COT does not include the at least one fourth channel; The channel access result obtained by performing type 2 channel access on the at least one fourth channel is used to determine whether the at least one fourth channel can be used to send S-SSB in the first time slot.

36. The apparatus according to any one of claims 21 to 24, 28 to 35, wherein, The time interval between the first moment and the first time slot is greater than or equal to the duration required for performing type 2 channel access.

37. The apparatus according to any one of claims 21 to 24, 28 to 36, wherein, The processing unit is further configured to determine whether the time interval between the first moment and the first time slot is greater than or equal to the duration required for performing channel access of type 2.

38. The device according to any one of claims 20 to 37, wherein, The apparatus further comprises: a communication unit, configured to receive first information from a second terminal, the first information being for sharing the COT with the first terminal, the first information including time-frequency information of the COT, and the COT being initiated by the second terminal.

39. A terminal, comprising: a processor and a memory, the memory being used for storing a computer program, and the processor being used for calling and running the computer program stored in the memory to execute the method according to any one of claims 1 to 19.

40. A chip, comprising: a processor, configured to call and run a computer program from a memory, so that a device installed with the chip executes the method according to any one of claims 1 to 19.

41. A computer-readable storage medium, configured to store a computer program, the computer program causing a computer to execute the method according to any one of claims 1 to 19.

42. A computer program product, comprising computer program instructions, the computer program instructions causing a computer to execute the method according to any one of claims 1 to 19.

43. A computer program, the computer program causing a computer to execute the method according to any one of claims 1 to 19.

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