Terminal device and method performed by the terminal device

Abstract

Exemplary embodiments of the present disclosure relate to a method, a terminal device, and a computer-readable medium for communication, the method including: performing, in a first terminal device, a first transmission of a transport block with a second terminal device, the first transmission starting from a first starting position; and performing a second transmission of the transport block with the second terminal device, the second transmission starting from a second starting position determined based on the first starting position.

Description

[Technical Field]

[0001] FIELD Exemplary embodiments of the present disclosure relate generally to the field of communications technologies, and more particularly to methods, apparatus, and media for transport block (TB) multi-transmission. [Background technology]

[0002] Advances in communication technology have made it possible for terminal devices to communicate directly with each other by establishing side links between them and utilizing unlicensed spectrum.

[0003] It is proposed to reuse the channel access mechanism of New Radio Unlicensed (NR-U) for sidelink unlicensed operation. If the existing NR-U channel access framework does not support the required sidelink unlicensed (SL-U) functionality, appropriate recommendations must be made. Regarding the physical channel design framework, changes are required to the NR sidelink physical channel structure and procedures to operate in unlicensed spectrum. Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, embodiments of the present disclosure provide a method, apparatus, and computer storage medium for TB multi-transmission. [Means for solving the problem]

[0005] In a first aspect, a communication method is provided, the method including: performing, in a first terminal device, a first transmission of a transport block with a second terminal device, the first transmission starting from a first starting position; and performing a second transmission of the transport block with the second terminal device, the second transmission starting from a second starting position determined based on the first starting position.

[0006] In a second aspect, a communication method is provided, the method including: determining, in a first terminal device, a start position for transmission of a transport block from a set of candidate positions, the set of candidate positions being determined based on a plurality of demodulation reference signal (DMRS) patterns for the transmission; and performing the transmission from the start position.

[0007] In a third aspect, a communications method is provided, the method including: determining, at a first terminal device, a target DMRS pattern from a group of DMRS patterns, the group of DMRS patterns being determined based on at least one candidate position for transmission of a transport block between the first terminal device and a second terminal device; and performing transmission based on the target DMRS pattern.

[0008] In a fourth aspect, a communication method is provided, the method including: determining, in a first terminal device, resource occupancy information for a plurality of transmission opportunities, where the information regarding resource occupancy for a first transmission opportunity of the plurality of transmission opportunities is determined based on a scaling factor, the scaling factor being associated with a start position of transmission in the first transmission opportunity or being a preset value; and determining channel parameters based on the resource occupancy information.

[0009] In a fifth aspect, there is provided a first terminal device comprising: at least one processor; and at least one memory coupled to the at least one processor and having instructions stored thereon, the instructions, when executed by the at least one processor, causing the first terminal device to perform a method according to the first, second, third or fourth aspect.

[0010] In a sixth aspect, there is provided a computer readable medium having stored thereon instructions which, when executed on at least one processor, cause the at least one processor to implement a method according to the first aspect, the second aspect, the third aspect or the fourth aspect.

[0011] Other features of the present disclosure will become readily apparent from the following description. [Brief explanation of the drawings]

[0012] The above and other objects, features and advantages of the present disclosure will become more apparent from a more detailed description of some exemplary embodiments of the present disclosure in the accompanying drawings.

[0013] [Figure 1] FIG. 1 illustrates an exemplary communication environment in which exemplary embodiments of the present disclosure may be implemented.

[0014] [Figure 2] FIG. 1 illustrates a signaling flow for TB transmission according to some embodiments of the present disclosure.

[0015] [Figure 3] FIG. 10 illustrates a flowchart of a method implemented in a first terminal device according to some exemplary embodiments of the present disclosure.

[0016] [Figure 4A] 1 is a schematic diagram of an exemplary TB transmission according to some embodiments of the present disclosure. [Figure 4B] 1 is a schematic diagram of an exemplary TB transmission according to some embodiments of the present disclosure.

[0017] [Figure 5A] FIG. 2 is a schematic diagram of time domain resource reservation according to some embodiments of the present disclosure. [Figure 5B] FIG. 2 is a schematic diagram of time domain resource reservation according to some embodiments of the present disclosure. [Figure 5C] FIG. 2 is a schematic diagram of time domain resource reservation according to some embodiments of the present disclosure. [Figure 5D] FIG. 2 is a schematic diagram of time domain resource reservation according to some embodiments of the present disclosure.

[0018] [Figure 6] FIG. 1 illustrates a flowchart of a method implemented in a first terminal device according to some exemplary embodiments of the present disclosure.

[0019] [Figure 7] FIG. 2 is a schematic diagram of resource occupancy according to some embodiments of the present disclosure.

[0020] [Figure 8] FIG. 1 illustrates a flowchart of a method implemented in a first terminal device according to some exemplary embodiments of the present disclosure.

[0021] [Figure 9] FIG. 10 is a schematic diagram of resource occupancy according to some other embodiments of the present disclosure.

[0022] [Figure 10] 10 is a schematic diagram of automatic gain control (AGC) and DRMS ​​transmission according to some other embodiments of the present disclosure.

[0023] [Figure 11] FIG. 1 illustrates a flowchart of a method implemented in a first terminal device according to some exemplary embodiments of the present disclosure.

[0024] [Figure 12] FIG. 1 is a schematic diagram of sidelink channel occupancy (CR) measurements according to some embodiments of the present disclosure.

[0025] [Figure 13] FIG. 1 is a schematic diagram of a sidelink channel busy ratio (CBR) measurement according to some embodiments of the present disclosure.

[0026] [Figure 14] FIG. 1 is a simplified block diagram of an apparatus suitable for practicing exemplary embodiments of the present disclosure.

[0027] Throughout the drawings, the same or similar reference numbers represent the same or similar elements. DETAILED DESCRIPTION OF THE INVENTION

[0028] The principles of the present disclosure will be described with reference to several exemplary embodiments. It should be understood that these embodiments are set forth for illustrative purposes only to aid those skilled in the art in understanding and practicing the present disclosure, and are not intended to imply any limitations on the scope of the present disclosure. The embodiments described herein can be embodied in various ways other than those described below.

[0029] In the following description and claims, unless defined otherwise, all technical and scientific terms used have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0030] As used herein, the term "terminal device" refers to any device with wireless or wired communication capabilities. Examples of terminal devices include user equipment (UE), personal computers, desktops, mobile phones, cellular phones, smartphones, personal digital assistants (PDAs), portable computers, tablets, wearable devices, internet of things (IoT) devices, Ultra-reliable and Low Latency Communication (URLLC) devices, Internet of Everything (IoE) devices, machine type communication (MTC) devices, in-vehicle devices for V2X communications where X represents pedestrian, vehicle, or infrastructure / network, devices for Integrated Access and Backhaul (IAB), spacecraft or air vehicles in a Non-terrestrial network (NTN) including Satellites and High Altitude Platforms (HAPs) including Unmanned Aircraft Systems (UASs), Augmented Reality (AR), Mixed Reality (MR), and other technologies. This includes, but is not limited to, extended reality (XR) devices, which include different types of reality such as real reality (VR), virtual reality (VR), unmanned aerial vehicles (UAVs), commonly known as drones, i.e., aircraft without a human pilot, devices on high speed trains (HST), image capture devices such as digital cameras, sensors, gaming devices, music storage and playback devices, and internet appliances that enable wireless or wired internet access and browsing.The "terminal device" may also have "multicast / broadcast" capabilities and support public safety and mission-critical, V2X applications, transparent IPV4 / IPV6 multicast delivery, IPTV, smart TV, wireless services, over-the-air software delivery, group communication, and IoT applications. It may also incorporate one or more Subscriber Identity Modules (SIMs), known as multi-SIMs. The term "terminal device" may be used interchangeably with UE, mobile station, subscriber station, mobile terminal, user terminal, or wireless device.

[0031] The term "network device" refers to a device capable of providing or hosting a cell or coverage area over which terminal devices can communicate. Examples of network devices include, but are not limited to, a Node B (NodeB or NB), an evolved Node B (eNodeB or eNB), a next generation Node B (gNB), a transmission reception point (TRP), a remote radio unit (RRU), a radio head (RH), a remote radio head (RRH), a low-power node such as an IAB node, a femto node, a pico node, and a reconfigurable intelligent surface (RIS).

[0032] A terminal device or network device may have artificial intelligence (AI) or machine learning capabilities, which typically include models trained from a large amount of collected data for a specific function and can be used to predict some information.

[0033] The terminal device or network device may operate in multiple frequency ranges, such as FR1 (e.g., 450 MHz to 6000 MHz), FR2 (e.g., 24.25 GHz to 52.6 GHz), frequency bands greater than 100 GHz, and terahertz (THz). It can also operate in licensed, unlicensed, and shared spectrum. The terminal device may have multiple connections with network devices in Multi-Radio Dual Connectivity (MR-DC) application scenarios. The terminal device or network device can operate in full duplex, flexible duplex, and cross division duplex modes.

[0034] Embodiments of the present disclosure may be implemented in test equipment, such as a signal generator, a signal analyzer, a spectrum analyzer, a network analyzer, a test terminal equipment, a test network equipment, or a channel emulator. In some embodiments, the terminal equipment may be connected to a first network device and a second network device. One of the first network device and the second network device may be a master node and the other may be a secondary node. The first network device and the second network device may use different radio access technologies (RATs). In some embodiments, the first network device may be a first RAT device and the second network device may be a second RAT device. In some embodiments, the first RAT device is an eNB and the second RAT device is a gNB. Information related to the different RATs may be transmitted to the terminal device from at least one of the first network device and the second network device. In some embodiments, the first information may be transmitted from the first network device to the terminal device, and the second information may be transmitted from the second network device to the terminal device directly or via the first network device. In some embodiments, information regarding the configuration of the terminal device configured by the second network device may be transmitted from the second network device via the first network device, and information regarding the reconfiguration of the terminal device configured by the second network device may be transmitted to the terminal device directly from the second network device or via the first network device.

[0035] In this disclosure, unless the context clearly indicates otherwise, the singular forms "a," "the," and "the" are intended to include the plural. The term "comprises" and variations thereof are interpreted as open-ended terms meaning "including, but not limited to." The term "based on" is interpreted as "based at least in part on." The terms "one embodiment" and "embodiment" are interpreted as "at least one embodiment." The term "another embodiment" is interpreted as "at least one other embodiment." Terms such as "first," "second," etc. may refer to different objects or the same object. The following content may include other definitions, both explicit and implicit.

[0036] In some instances, values, procedures, or devices are referred to as "optimal," "lowest," "highest," "minimum," "maximum," etc. It is understood that such descriptions are intended to indicate choices among multiple functional alternatives used, and that such choices are not necessarily better, smaller, higher, or more preferred than other choices.

[0037] As used herein, the terms "resource," "transmission resource," "uplink resource," or "downlink resource" may refer to any resource for performing communication, such as a time domain resource, a frequency domain resource, a space domain resource, a code domain resource, or any other resource that enables communication. Hereinafter, unless otherwise specified, both frequency domain and time domain resources are used as examples of transmission resources for describing some exemplary embodiments of the present disclosure. It should be noted that the exemplary embodiments of the present disclosure are equally applicable to other resources in other domains.

[0038] As mentioned above, the existing NR-U channel access framework may not support all the necessary SL-U features, so some modifications are necessary. For example, for physical sidelink control channel (PSCCH) / physical sidelink shared channel (PSSCH) transmission, it is proposed that up to two candidate starting symbols be supported within a slot, so a unified design for PSCCH / PSSCH transmission from the first or second starting symbol is needed. Furthermore, it is necessary to consider whether two or more candidate starting symbols are supported for slots using the physical sidelink feedback channel (PSFCH). Furthermore, it is necessary to further consider issues related to, for example, (but not limited to) transport block size (TBS) determination when two or more (re)transmissions of the same TB start from different starting symbols, DMRS symbols affected by the second starting symbol used for AGC, CR, and CBR measurements for transmissions starting from the second starting symbol, deferred operation for sidelink control information (SCI) / PSCCH in the second starting symbol, and insufficient PSSCH symbols from the second starting symbol when a slot includes a PSFCH symbol.

[0039] To solve the above and other potential problems, embodiments of the present disclosure propose a mechanism to support two or more starting positions for TB transmission / retransmission. In the proposed solution, a first transmission of a TB on the sidelink starts from a first starting position, and a second transmission of the same TB starts from a second starting position determined based on the first starting position. In this way, two or more transmissions of a TB from different starting positions can be properly supported.

[0040] The embodiments of the present disclosure also propose several mechanisms to solve problems related to DMRS transmission, resource occupation, etc. The principles and embodiments of the present disclosure are described in detail below with reference to the drawings.

[0041] 1 is a schematic diagram of an exemplary communication environment 100 in which exemplary embodiments of the present disclosure may be implemented. In the communication environment 100, multiple communication devices, including a first terminal device 110 and a second terminal device 120, may communicate with each other.

[0042] In the example of FIG. 1, the first terminal device 110 may be a UE, and the second terminal device 120 may be another UE that is communicating or will communicate with the first terminal device 110 via a sidelink.

[0043] 1 are shown for illustrative purposes only and are not intended to limit the present disclosure. Communication environment 100 may include any suitable number of devices configured to implement the exemplary embodiments of the present disclosure. While illustrated as UEs, it should be noted that first terminal device 110 or second terminal device 120 may be a terminal device other than a UE.

[0044] For purposes of explanation, some exemplary embodiments are described below with first terminal device 110 operating as a UE and second terminal device 120 operating as another UE. In some exemplary embodiments, operations described in conjunction with first terminal device 110 may be implemented in second terminal device 120, and operations described in conjunction with second terminal device 120 may be implemented in first terminal device 110.

[0045] In some exemplary embodiments, first terminal 110 and second terminal 120 communicate with each other over a sidelink (SL). Either first terminal 110 or second terminal 120 can function as a transmit (TX) device (or transmitter). When first terminal 110 is a TX device or transmitter, second terminal 120 operates as a receive (RX) device (or receiver). Similarly, when second terminal 120 is a TX device or transmitter, first terminal 110 operates as an RX device or receiver.

[0046] Communications in communication environment 100 may conform to any suitable standard, including, but not limited to, Global System for Mobile Communications (GSM), Long Term Evolution (LTE), LTE-Evolution, LTE-Advanced (LTE-A), New Radio (NR), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), GSM EDGE Radio Access Network (GERAN), Machine Type Communication (MTC), etc. Embodiments of the present disclosure may be performed in accordance with any currently known or future-developed generation of communication protocols. Examples of communication protocols include, but are not limited to, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G) communication protocols, 5.5G, 5G-Advanced networks, or sixth generation (6G) networks.

[0047] 2, which illustrates a signaling flow 200 for TB transmission in accordance with some embodiments of the present disclosure. For purposes of discussion, signaling flow 200 will be discussed with reference to FIG. 1, for example, with first terminal device 110 and second terminal device 120.

[0048] In the embodiment of FIG. 2, the first terminal device 110 transmits a first transmission of a TB starting from a first starting position to the second terminal device 120 (205). The first transmission may be an initial transmission of the TB or a retransmission of the TB. The second terminal device 120 receives the first transmission from the first terminal device 110 (210). The second terminal device 120 may provide feedback (e.g., ACK / NACK) to the first terminal device 110 indicating whether the TB was successfully received.

[0049] If the NACK feedback is received, the first terminal device 110 recognizes that the TB was not received successfully and may decide to perform a retransmission of the TB. As shown in Figure 2, the first terminal device 110 transmits a second transmission of the TB at a second starting position to the second terminal device 120 (215), and the second terminal device 120 receives the second transmission in response (220).

[0050] The second starting position is determined based on the first starting position. In some embodiments, there may be a set of candidate starting positions. For example, the set of candidates may include, but is not limited to, a first candidate position and a second candidate position, where the first candidate position precedes the second candidate position. For example, the first candidate position may be symbol 0 of a slot, and the second candidate position may be symbol 7 of the slot.

[0051] In some cases, if the first transmission is an initial transmission of a transport block, the second transmission may be a retransmission of the transport block. Alternatively, if the first transmission is a retransmission of a transport block, the second transmission may be a further retransmission of the transport block.

[0052] 3 illustrates a flowchart of a method 300 implemented in a first terminal device according to some exemplary embodiments of the present disclosure. For purposes of discussion, the method 300 will be described from the perspective of the first terminal device 110 of FIG.

[0053] In block 310, first terminal device 110 performs a first transmission of a transport block with second terminal device 120. The first transmission starts from a first starting position.

[0054] In block 320, the first terminal device 110 performs a second transmission of the transport block with the second terminal device, the second transmission starting from a second starting position determined based on the first starting position.

[0055] It should be understood that first terminal device 110 may be a transmitter or a receiver in sidelink communication with second terminal device 120. For example, if first terminal device 110 is a transmitter in sidelink communication, first terminal device 110 transmits a first transmission to second terminal device 120 in block 310 and transmits a second transmission to second terminal device 120 in block 320. Otherwise, if first terminal device 110 is a receiver, first terminal device 110 receives a first transmission from second terminal device 120 in block 310 and receives a second transmission from second terminal device 120 in block 310.

[0056] The size of the TB (hereinafter also referred to as "TBS") may be determined in various ways. In some exemplary embodiments, the TBS may be determined based on the length of time from the second candidate location to the end of the transmission opportunity. For example, the transmission opportunity may be a PSSCH duration, a slot, or other time period.

[0057] In some embodiments, the transmission opportunity may be a slot that includes multiple symbols. In such cases, the starting position may be a symbol within the slot, also referred to as the "starting symbol" in some embodiments of the present disclosure.

[0058] In the case of multiple transmissions of a TB, if the first transmission of the TB starts from the second start symbol in slot n, the subsequent second transmission of the TB can use either the first (first) start symbol or the second start symbol in slot m. In these embodiments, both the first start symbol and the second start symbol are candidate start positions. In this case, the first transmission may be an initial transmission or a retransmission of the TB, and the second transmission may be a retransmission of the TB. The number of symbols for calculating the TBS for the first and second transmissions may be equal to the symbol length from the second start symbol to the end of the PSSCH duration. This advantageously maintains consistent TBS for multiple transmissions of the same TB.

[0059] Alternatively, in some exemplary embodiments, the TBS may be determined based on the length of time from the first candidate location to the end of the transmission opportunity, excluding the second candidate location. The first starting location may be the first candidate location before the second candidate location.

[0060] In some exemplary embodiments, in a multiple transmission of a TB, if the first transmission of the TB starts with the first starting symbol in slot n, the subsequent second transmission of the same TB may use the first starting symbol in slot m. In this case, slot n and slot m may be in the same channel occupation time (COT). Also, the first transmission may be an initial transmission or a retransmission of the TB, and the second transmission may be a retransmission of the TB. The number of symbols for calculating the TBS for the first and second transmissions may be equal to the symbol length from the first starting symbol to the end of the PSSCH duration by removing the second starting symbol. This advantageously avoids different symbol lengths for multiple transmissions of the same TB.

[0061] As a further alternative, in some exemplary embodiments, the TBS may be determined based on a predetermined length of time, e.g., the number of symbols for calculating the TBS for the first and second transmissions may be equal to a predefined value, e.g., M.

[0062] The predetermined length of time may be predefined, for example, by a rule, or may be a preset value that may be received from a higher layer, for example, via RRC signaling. In some alternative embodiments, the predetermined length of time may be determined by the first terminal device 110 and indicated to the second terminal device 120, for example, via SCI signaling.

[0063] Alternatively, the predetermined length of time may be an average value. The average value may represent an average of a first length of time from the first candidate location to the end of the transmission opportunity (e.g., by removing the second starting symbol) and a second length of time from the second candidate location to the end of the transmission opportunity. As an example, the average value may be an average of a first symbol length from the first starting symbol (e.g., symbol 0) to the last symbol of the slot and a second symbol length from the second starting symbol (e.g., symbol 7) to the last symbol of the slot.

[0064] In some exemplary embodiments, the difference between the first and second candidate positions is within a predefined range, e.g., a predefined time range [Min, Max]. "Min" may indicate a minimum length of time between the first and second candidate positions, and "Max" may indicate a maximum length of time between the first and second candidate positions. In such a case, the first terminal device 110 may expect the numerical value of the difference between the first and second starting symbols to be within the range [Min, Max]; otherwise, the second starting symbol may be disabled by the terminal device 110.

[0065] In the above case, if the difference is greater than a predefined Min, there may be enough time to perform channel access for the second start symbol if the first one fails, and to decouple the channel conditions of the first and second start symbols. If the difference is smaller than Max, a reasonable code rate can be achieved for both the first and second transmissions of the same TB.

[0066] In some exemplary embodiments, if the length of time of the second transmission is less than the length of time of the first transmission, the second transmission is punctured.

[0067] 4A-4B show schematic diagrams of exemplary TB transmissions according to some embodiments of the present disclosure. In the embodiment of FIG. 4A, for a TB multi-transmission, it is assumed that the first TB transmission starts from a first candidate position 401, e.g., a first starting symbol, and the second TB transmission starts from a second candidate position 402, e.g., a second starting symbol. If the symbol length of the second transmission is shorter than the symbol length of the preceding first transmission, the remaining data may be punctured for the second transmission. In such a case, the second transmission is a punctured transmission that is part of the intended transmission.

[0068] Alternatively, in some exemplary embodiments, if the duration of the second transmission is greater than the duration of the first transmission, the second transmission is rate matched, for example, based on its intended transmission.

[0069] 4B illustrates such a situation where, for multiple transmissions of TB, it is assumed that the first transmission of TB starts from the second candidate position 402, e.g., the second starting symbol, and the second transmission of TB starts from the first candidate position 401, e.g., the first starting symbol. Because the symbol length of the second transmission is greater than the symbol length of the preceding first transmission, the remaining resources may be rate-matched for the second transmission.

[0070] For two or more starting position mechanisms, it may also be necessary to discuss reservation and sensing operations for the SCI / PSCCH at a second position, e.g., a second starting symbol. In some exemplary embodiments, if the first starting position is a second candidate position and the first transmission includes a reservation indication, the reservation indication may indicate a subsequent reservation resource for a third transmission starting from the first candidate position that is earlier than the second candidate position.

[0071] For the second starting symbol, the interpretation of the time-domain resource reservation in the SCI (SCI monitoring / decoding and encoding) may match the reservation from the first starting symbol. That is, the time-domain resource reservation may always start from the first starting symbol to the end of the slot (i.e., the entire slot). Figures 5A-5D show schematic diagrams of time-domain resource reservation according to some embodiments of the present disclosure. Specifically, Figures 5A-5B show two scenarios that are supported according to embodiments of the present disclosure, and Figures 5C-5D show two additional scenarios that are not supported according to embodiments of the present disclosure.

[0072] In some situations, if a slot includes a PSFCH symbol, there may not be enough PSSCH symbols from the second starting symbol. To address this issue, in some embodiments, in a resource pool, the second starting symbol may be configured / applied only to slots where a PSFCH symbol is not configured. Alternatively, if the number of available PSSCH symbols is less than seven, the second starting symbol may be disabled by first terminal device 110 or second terminal device 120. In some exemplary embodiments, if the first starting position is a second candidate position following the first candidate position, the first transmission does not have feedback from second device 120.

[0073] As described above, the first starting position and the second starting position may have a set of candidates including a first candidate position and a second candidate position, and the first candidate position may precede the second candidate position. In some exemplary embodiments, a transmission starting from the second candidate position uses a second set of redundancy versions (RVs) that differs from the first set of RVs used by a transmission starting from the first candidate position. That is, there may be different sets of redundancy versions corresponding to the first and second candidate positions. For example, a set of RVs, e.g., {RV0, RV1, RV2, and RV3}, may be used only by a transmission starting from the first candidate position, and RVs that may be used by a different transmission starting from the second candidate position should be a different set of RVs, e.g., {RV0′, RV1′, RV2′, RV3′}.

[0074] In some cases, the DMRS symbols may be affected by the second start symbol used for AGC. In this regard, embodiments of the present disclosure propose various solutions, such as, but not limited to, defining a second start position to avoid undesired effects, avoiding the use of some legacy DMRS patterns, and repeating AGC using DMRS RE.

[0075] 6 shows a flowchart of a communication method 600 implemented in a first terminal device according to some embodiments of the present disclosure. For purposes of discussion, the method 600 will be described from the perspective of the first terminal device 110 of FIG.

[0076] In block 610, first terminal device 110 determines a starting location for transmission of a transport block from a set of candidate locations, where the set of candidate locations is determined based on a plurality of DMRS patterns for the transmission.

[0077] Table 1 shows several DMRS patterns. Specifically, Table 1 defines PSSCH DMRS time-domain positions. As shown in Table 1, DMRS patterns may include, for example, "3, 10," "1, 6, 11," "1, 4, 7, 10," "4, 10," "1, 5, 9," etc. [Table 1]

[0078] FIG. 7 illustrates a schematic diagram of resource occupancy 700 according to some embodiments of the present disclosure. As shown in FIG. 7, the first row lists symbol indices 0 through 13 within a slot. In embodiments of the present disclosure, a slot may include 14 symbols, i.e., symbol 0, symbol 1, ..., symbol 13. In FIG. 7, rows "a," "b," "c," "d," "e," and "f" each represent an exemplary slot. Each slot includes 14 symbols, some of which are occupied by DMRS transmissions, as indicated by "R." Specifically, row "a" corresponds to DMRS pattern "3, 10," row "b" corresponds to DMRS pattern "1, 6, 11," row "c" corresponds to DMRS pattern "1, 4, 7, 10," and row "d" corresponds to DMRS pattern "4, 10." It should be understood that the above exemplary rows and their corresponding DMRS patterns are illustrated for illustrative purposes and are not intended to be limiting. Other DMRS patterns are also applicable to embodiments of the present disclosure.

[0079] The symbols occupied by a DMRS transmission are determined according to the DMRS pattern defined in Table 1 and are labeled "R" in Figure 7. It can be seen that column 710 corresponding to symbol 2 and column 720 corresponding to symbol 5 are not occupied by a DMRS transmission at all. Therefore, in these embodiments, symbol 2 or symbol 5 can be used as candidate locations for the start location of a transmission.

[0080] Along these lines, the set of candidate positions may include a position corresponding to symbol 2 and / or a position corresponding to symbol 5. For example, in 610, first terminal device 110 may determine the start position of the transport block as, for example, a position corresponding to symbol 2. Alternatively, first terminal device 110 may determine the start position as a position corresponding to symbol 5.

[0081] In block 620, the first terminal device 110 performs a transmission from the starting position.

[0082] In this way, the DMRS for the PSSCH transmission from the first starting symbol is not affected by the AGC in the second starting symbol. In this way, all defined DMRS patterns can be fully reused.

[0083] 8 illustrates a flowchart of a communication method 800 implemented in a first terminal device according to some embodiments of the present disclosure. For purposes of discussion, the method 800 will be described from the perspective of the first terminal device 110 of FIG.

[0084] In block 810, first terminal device 110 determines a target DMRS pattern from a group of DMRS patterns. The group of DMRS patterns is determined based on at least one candidate location for transmission of a transport block between the first terminal device and the second terminal device. In block 820, first terminal device 110 performs transmission based on the target DMRS pattern.

[0085] In some exemplary embodiments, the group of DMRS patterns may be determined by removing at least one DMRS pattern from a plurality of DMRS patterns, each of which may have a DMRS transmission in at least one candidate location.

[0086] 9 shows a schematic diagram of resource occupation 900 according to some other embodiments of the present disclosure. Specifically, rows "a" through "f" respectively show DMRS patterns. For purposes of discussion, the DMRS pattern corresponding to row "a" is also referred to hereinafter as "DMRS pattern a."

[0087] In some embodiments, the UE / resource pool / bandwidth portion (BWP) may be configured or pre-configured, for example, by signaling from higher layers (e.g., RRC signaling), to have any suitable second starting symbol. If the second starting symbol is symbol 1, the terminal device 110 is not expected to use DMRS patterns b and c for the two-symbol PSCCH and DMRS patterns e and f for the three-symbol PSCCH. DMRS pattern a may be used for the two-symbol PSCCH, and pattern d may be used for the three-symbol PSCCH.

[0088] If the second starting symbol is symbol 3, then terminal device 110 is not expected to use pattern a for the 2-symbol PSCCH, DMRS patterns b and c may be used for the 2-symbol PSCCH, and DMRS patterns d, e, and f may be used for the 3-symbol PSCCH.

[0089] If the second starting symbol is symbol 4, terminal device 110 is not expected to use DMRS pattern c for the two-symbol PSCCH, and patterns d and f for the three-symbol PSCCH. DMRS patterns a and b may be used for the two-symbol PSCCH, and DMRS pattern e may be used for the three-symbol PSCCH.

[0090] If the second starting symbol is symbol 6, terminal device 110 is not expected to use DMRS pattern b for the two-symbol PSCCH and DMRS pattern e for the three-symbol PSCCH. DMRS patterns a and c may be used for the two-symbol PSCCH, and DMRS patterns d and f may be used for the three-symbol PSCCH.

[0091] If the second starting symbol is symbol 7, terminal device 110 is not expected to use DMRS pattern c for a two-symbol PSCCH and DMRS pattern f for a three-symbol PSCCH. DMRS patterns a and b may be used for the two-symbol PSCCH, and DMRS patterns d and e may be used for the three-symbol PSCCH.

[0092] In some exemplary embodiments, one of the at least one candidate position may be configured for automatic gain control (AGC) and DMRS transmission, and repetition from the next symbol for AGC does not affect the DMRS transmission.

[0093] 10 shows a schematic diagram of AGC and DMRS transmission according to some other embodiments of the present disclosure. As shown in FIG. 10, if a second (second) starting symbol is used for AGC and configured to have DMRS, the repetition from the next symbol to this second starting symbol should not affect the DMRS resource elements (REs).

[0094] In some situations, some channel parameters such as sidelink channel occupancy (CR), sidelink channel busy ratio (CBR), etc. may need to be measured for slots where transmission starts from the second starting symbol. To solve this, embodiments of the present disclosure propose adding a scaling factor to adjust the number of counted subchannels for slots where transmission starts from the second starting symbol. Details of the embodiments will be described later.

[0095] 11 shows a flowchart of a communication method 1100 implemented in a first terminal device according to some embodiments of the present disclosure. For purposes of discussion, the method 1100 will be described from the perspective of the first terminal device 110 of FIG.

[0096] In block 1110, the first terminal device 110 determines resource occupancy information for a plurality of transmission opportunities. The resource occupancy information for a first transmission opportunity of the plurality of transmission opportunities is determined based on a scaling factor. The scaling factor may be associated with a start position of transmission in the first transmission opportunity or may be a preset value.

[0097] In some embodiments, the resource occupancy information may include information regarding occupancy of sub-channels.

[0098] In block 1120, first terminal device 110 determines channel parameters based on the resource occupancy information.

[0099] In some exemplary embodiments, the channel parameters may include a sidelink channel occupancy ratio (CR), a sidelink channel busy ratio (CBR), and the like.

[0100] 12 shows a schematic diagram of a sidelink channel occupancy (CR) measurement according to some embodiments of the present disclosure. In the embodiment discussed with respect to FIG. 12, for the CR measurement, a scaling factor may be applied to the number of subchannels for transmission starting from the second starting symbol.

[0101] In this case, the Sidelink Channel Occupancy Ratio (SL CR) evaluated in slot n can be defined as the total number of subchannels used for its transmission in slot [na,n-1] and allowed in slot [n,n+b] divided by the total number of configured subchannels in the transmission pool over [na,n+b].

[0102] For a transmission starting from the second (second) starting symbol, a scaling factor f_CR may be applied to determine the number of subchannels for CR evaluation. In some embodiments, the scaling factor f_CR may be determined by: f_CR = Symbol length from the second start symbol to the end of PSSCH / Symbol length from the first start symbol to the end of PSSCH

[0103] Alternatively, the scaling factor may be a set or preset value.

[0104] As shown in FIG. 12, the total number of subchannels is calculated as follows: f_CR*[number of subchannels in slot na]+[number of subchannels in slot n]+[number of subchannels in slot n+b]

[0105] 13 shows a schematic diagram of a sidelink channel busy ratio (CBR) measurement according to some embodiments of the present disclosure. In the embodiment discussed with respect to FIG. 12, for the CBR measurement, a scaling factor may be applied to the number of subchannels for transmission starting from the second starting symbol.

[0106] The SL Channel Busy Ratio (SL CBR) measured in slot n may be defined as the fraction of subchannels in the resource pool whose SL RSSI measured by the UE exceeds a (pre-)configured threshold sensed over the CBR measurement window [na,n-1], where a is either 100 or 100·2 according to the higher layer parameter sl-TimeWindowSizeCBR. μ slots. If the UE is configured by higher layers to perform partial sensing (including when SL DRX is configured), the SL RSSI is measured in slots where the UE performs partial sensing and where the UE performs PSCCH / PSSCH reception within the CBR measurement window. The SL CBR calculation is restricted to the slots where the SL RSSI is measured. If the number of SL RSSI measurement slots within the CBR measurement window is below a (pre)configured threshold, the (pre)configured SL CBR value is used.

[0107] For transmissions starting from the second starting symbol, a scaling factor f_CBR may be applied to determine the number of subchannels. In some embodiments, the scaling factor f_CBR may be determined by: f_CBR = symbol length from the second start symbol to the end of the PSSCH duration / symbol length from the first start symbol to the end of the PSSCH duration

[0108] Alternatively, the scaling factor f_CBR may be a set or pre-set value.

[0109] For example, as shown in Fig. 13, when the SL RSSI measured by the UE exceeds a (pre-set) threshold in slot na, the SL CBR may be determined based on f_CBR * [number of subchannels in slot na]. Specifically, the resource occupancy information of slot na is determined to be f_CBR * [number of subchannels in slot na].

[0110] Figure 14 is a schematic block diagram of an apparatus 1400 suitable for implementing embodiments of the present disclosure. The apparatus 1400 can be considered another exemplary implementation of any of the apparatuses shown in Figure 1. Thus, the apparatus 1400 can be implemented in, or at least as part of, the first terminal device 110 or the second terminal device 120.

[0111] As shown, the apparatus 1400 comprises a processor 1410, a memory 1420 coupled to the processor 1410, a suitable transmitter (TX) / receiver (RX) 1440 coupled to the processor 1410, and a communication interface coupled to the TX / RX 1440. The memory 1410 stores at least a portion of a program 1430. The TX / RX 1440 is for bidirectional communication. The TX / RX 1440 has at least one antenna to facilitate communication, although in practice the access nodes referred to in this disclosure may have multiple antennas. The communication interface may represent any interface required for communication with other network elements, such as, for example, an X2 / Xn interface for bidirectional communication between eNBs / gNBs, an S1 / NG interface for communication between a Mobility Management Entity (MME) / Access and Mobility Management Function (AMF) / SGW / UPF and an eNB / gNB, an Un interface for communication between an eNB / gNB and a relay node (RN), or a Uu interface for communication between an eNB / gNB and a terminal device.

[0112] The program 1430 is assumed to include program instructions that, when executed by the associated processor 1410, cause the device 1400 to operate in accordance with embodiments of the present disclosure, as described herein with reference to Figures 1-13. Embodiments of the present disclosure may be implemented by computer software executable by the processor 1410 of the device 1400, by hardware, or by a combination of software and hardware. The processor 1410 may be configured to implement various embodiments of the present disclosure. Furthermore, the combination of the processor 1410 and the memory 1420 may form a processing means 1450 suitable for implementing various embodiments of the present disclosure.

[0113] Memory 1420 may be of any type suitable for a local technology network and may be implemented using any suitable data storage technology, such as, by way of non-limiting example, non-transitory computer-readable storage media, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. While only one memory 1420 is shown in device 1400, device 1400 may have multiple physically distinct memory modules. Processor 1410 may be of any type suitable for a local technology network and may include, by way of non-limiting example, one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. Device 1400 may have multiple processors, such as application-specific integrated circuit chips that are time-slaved to a clock that synchronizes the main processor.

[0114] In some embodiments, the first terminal device comprises circuitry configured to: perform, at the first terminal device, a first transmission of a transport block with a second terminal device, the first transmission starting from a first starting position; and perform a second transmission of the transport block with the second terminal device, the second transmission starting from a second starting position determined based on the first starting position. According to embodiments of the present disclosure, the circuitry may be configured to perform method 300 performed by the first terminal device as described above.

[0115] In some embodiments, a first terminal device includes circuitry configured to: determine, at the first terminal device, a starting position for transmission of a transport block from a set of candidate positions, the set of candidate positions being determined based on a plurality of demodulation reference signal (DMRS) patterns for the transmission; and perform the transmission from the starting position. According to embodiments of the present disclosure, the circuitry may be configured to perform method 600 performed by the first terminal device as described above.

[0116] In some embodiments, a first terminal device includes circuitry configured to: determine, at the first terminal device, a target demodulation reference signal (DMRS) pattern from a group of DMRS patterns, the group of DMRS patterns being determined based on at least one candidate position for transmission of a transport block between the first terminal device and a second terminal device; and perform transmission based on the target DMRS pattern. According to embodiments of the present disclosure, the circuitry may be configured to perform method 800 performed by the first terminal device as described above.

[0117] In some embodiments, the first terminal device includes circuitry configured to: determine, at the first terminal device, resource occupancy information for a plurality of transmission opportunities, where the information regarding resource occupancy for a first transmission opportunity of the plurality of transmission opportunities is determined based on a scaling factor, the scaling factor being associated with a start position of transmission in the first transmission opportunity or a preset value; and determine channel parameters based on the resource occupancy information. According to embodiments of the present disclosure, the circuitry may be configured to perform method 1100 performed by the first terminal device as described above.

[0118] The term "circuitry" as used in this disclosure may refer to a hardware circuit and / or a combination of a hardware circuit and software. For example, a circuit may be a combination of analog and / or digital hardware circuitry and software / firmware. As another example, a circuit may be any portion of a hardware processor with software, where the hardware processor includes digital signal processor(s), software, and memory(s) that work together to cause a device, such as a terminal device or network device, to perform various functions. As yet another example, a circuit may be a hardware circuit and / or processor, such as a microprocessor or portion of a microprocessor, that requires software / firmware to operate, but the software may not be present when not necessary for operation. As used in this disclosure, the term circuitry also includes simply a hardware circuit or processor(s) or portion of a hardware circuit or processor(s) and its (or their) associated software and / or firmware implementation.

[0119] In summary, embodiments of the present disclosure provide the following aspects:

[0120] In a first aspect, a communication method is proposed, the method including: performing, in a first terminal device, a first transmission of a transport block with a second terminal device, the first transmission starting from a first start position; and performing a second transmission of the transport block with the second terminal device, the second transmission starting from a second start position determined based on the first start position.

[0121] In some embodiments, the first starting position is the first candidate position and the second starting position is the first candidate position, or the first starting position is the second candidate position and the second starting position is the first candidate position or the second candidate position, and the first candidate position precedes the second candidate position.

[0122] In some embodiments, the first transmission is an initial transmission of the transport block and the second transmission is a retransmission of the transport block, or the first transmission is a retransmission of the transport block and the second transmission is a further retransmission of the transport block.

[0123] In some embodiments, the method further includes determining a size of the transport block based on a length of time from the second candidate location to an end of the transmission opportunity.

[0124] In some embodiments, the method further includes determining a size of the transport block based on a length of time from a first candidate location to an end of the transmission opportunity excluding a second candidate location, wherein the first starting location is the first candidate location before the second candidate location.

[0125] In some embodiments, the method further includes determining a size of the transport block based on a predetermined length of time, the predetermined length of time being an average or a preset value, the average representing an average of a first length of time from the first candidate location to the end of the transmission opportunity and a second length of time from the second candidate location to the end of the transmission opportunity.

[0126] In some embodiments, the difference between the first and second candidate locations is within a predefined range.

[0127] In some embodiments, if the length of time of the second transmission is less than the length of time of the first transmission, the second transmission is a punctured transmission.

[0128] In some embodiments, if the duration of the second transmission is greater than the duration of the first transmission, the second transmission is a rate match transmission.

[0129] In some embodiments, if the first starting location is a second candidate location and the first transmission includes a hold indication, the hold indication indicates a subsequent hold resource for a third transmission starting from the first candidate location, and the first candidate location is before the second candidate location.

[0130] In some embodiments, if the first starting location is the second candidate location, the first transmission has no feedback from the second device and the first candidate location precedes the second candidate location.

[0131] In some embodiments, the first starting location and the second starting location have a set of candidates including a first candidate location and a second candidate location, the first candidate location precedes the second candidate location, and the transmission starting from the second candidate location uses a second set of redundancy versions that is different from the first set of redundancy versions used by the transmission starting from the first candidate location.

[0132] In a second aspect, a communication method is proposed, the method including: determining, in a first terminal device, a start position for transmission of a transport block from a set of candidate positions, the set of candidate positions being determined based on a plurality of demodulation reference signal (DMRS) patterns for the transmission; and performing the transmission from the start position.

[0133] In some embodiments, the set of candidate positions includes candidate positions that indicate symbols within a slot, where the symbol index is 2 or 5.

[0134] In a third aspect, a communication method is proposed, the method including: determining, in a first terminal device, a target demodulation reference signal (DMRS) pattern from a group of DMRS patterns, the group of DMRS patterns being determined based on at least one candidate position for transmission of a transport block between the first terminal device and a second terminal device; and performing transmission based on the target DMRS pattern.

[0135] In some embodiments, the group of DMRS patterns is determined by removing at least one DMRS pattern from the plurality of DMRS patterns, each of the at least one DMRS pattern having a DMRS transmission in at least one candidate location.

[0136] In some embodiments, one of the at least one candidate location is configured for automatic gain control (AGC) and DMRS transmission, and repetition from the next symbol for AGC does not affect the DMRS transmission.

[0137] In a fourth aspect, a communication method is proposed, the method including: determining, in a first terminal device, resource occupancy information of a plurality of transmission opportunities, where the information on resource occupancy of a first transmission opportunity of the plurality of transmission opportunities is determined based on a scaling factor, the scaling factor being associated with a start position of transmission in the first transmission opportunity or a preset value; and determining channel parameters based on the resource occupancy information.

[0138] In some embodiments, the channel parameters include at least one of a sidelink channel occupancy ratio (CR) or a sidelink channel busy ratio (CBR).

[0139] In a fifth aspect, a first terminal device is proposed, the first terminal device comprising: at least one processor; and at least one memory, coupled to the at least one processor, storing instructions that, when executed by the at least one processor, cause the device to perform the method implemented by the first terminal device.

[0140] In a sixth aspect, a computer-readable medium having stored thereon instructions that, when executed on at least one processor, cause the at least one processor to perform the above method implemented by the first terminal device described above.

[0141] In a seventh aspect, there is provided a computer program comprising instructions that, when executed on at least one processor, cause the at least one processor to perform the above method implemented by the first terminal device.

[0142] In general, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic, or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described using block diagrams, flowcharts, or some other pictorial representations, it should be understood that the blocks, devices, systems, techniques, or methods described in this disclosure may be implemented in, by way of non-limiting example, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller, or other computing device, or some combination thereof.

[0143] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions (e.g., computer-executable instructions included in program modules) that execute on a device by a target real or virtual processor to perform the processes or methods described above with reference to FIGS. 1-13. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split among program modules as desired in various embodiments. The machine-executable instructions for the program modules may be executed in local or distributed devices. In a distributed device, the program modules may be located in both local and remote storage media.

[0144] Program code for implementing the methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus, so that when executed by the processor or controller, the program code performs the functions / acts specified in the flowcharts and / or block diagrams. The program code may be executed entirely on a machine, partially on a machine, as a stand-alone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0145] The program code may be embodied in a machine-readable medium, which may be any tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. The machine-readable medium includes, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination thereof. More specific examples of machine-readable storage media include an electrical connection having one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0146] Furthermore, although operations are described in a particular order, this should not be understood as requiring such operations to be performed in the particular order shown, or sequentially, or that all of the operations shown be performed, to achieve desirable results. In certain situations, multitasking and parallel processing may be advantageous. Similarly, while several specific implementation details are included in the above description, these should not be construed as limiting the scope of the disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination.

[0147] Although the present disclosure has been described in language specific to structural features and / or methodological operations, it is to be understood that the present disclosure, which is limited to the appended claims, is not necessarily limited to the specific features or operations described above. Rather, the specific features and operations described above are disclosed as example forms of implementing the claims.

Claims

1. performing, at a first terminal device, a first transmission of a transport block with a second terminal device, the first transmission starting from a first start position; performing a second transmission of a transport block with the second terminal device, the second transmission starting from a second start position determined based on the first start position; A communication method including:

2. the first starting location is a first candidate location and the second starting location is the first candidate location; or the first start position is a second candidate position, and the second start position is either the first candidate position or the second candidate position; the first candidate location is located before the second candidate location; The method of claim 1.

3. the first transmission is an initial transmission of a transport block and the second transmission is a retransmission of a transport block; or The method of claim 1 , wherein the first transmission is a retransmission of a transport block and the second transmission is a further retransmission of a transport block.

4. determining a size of the transport block based on a time length from the second candidate location to an end of the transmission opportunity; The method of any one of claims 1 to 3, further comprising:

5. determining a size of the transport block based on a time length from the first candidate location to an end of the transmission opportunity excluding the second candidate location, wherein the first start location is a first candidate location that precedes the second candidate location. The method according to any one of claims 1 to 3.

6. determining a size of the transport block based on a predetermined length of time; the predetermined time length is an average value or a preset value, and the average value indicates an average of a first time length from the first candidate location to the end of the transmission opportunity and a second time length from the second candidate location to the end of the transmission opportunity. The method according to any one of claims 1 to 3.

7. The method of claim 6 , wherein the difference between the first candidate location and the second candidate location is within a predefined range.

8. 2. The method of claim 1, wherein if the duration of the second transmission is less than the duration of the first transmission, the second transmission is a punctured transmission.

9. The method of claim 1 , wherein if a duration of the second transmission is greater than a duration of the first transmission, the second transmission is a rate-matched transmission.

10. if the first starting location is a second candidate location and the first transmission includes a hold indication, the hold indication indicates a subsequent hold resource for a third transmission starting from the first candidate location; The method of claim 1 , wherein the first candidate location precedes the second candidate location.

11. 2. The method of claim 1, wherein if the first starting location is a second candidate location, the first transmission has no feedback from the second device, and the first candidate location precedes the second candidate location.

12. the first starting position and the second starting position have a candidate set including a first candidate position and a second candidate position, the first candidate position being before the second candidate position; 2. The method of claim 1, wherein transmissions starting from the second candidate location use a second set of redundancy versions that differ from a first set of redundancy versions used by transmissions starting from the first candidate location.

13. determining, in a first terminal device, a start position for transmission of a transport block from a set of candidate positions, the set of candidate positions being determined based on a plurality of demodulation reference signal (DMRS) patterns for the transmission; performing the transmission from the starting location; A communication method including:

14. The method of claim 13 , wherein the set of candidate positions includes candidate positions that indicate symbols within a slot, the index of the symbols being 2 or 5.

15. determining, in a first terminal device, a target demodulation reference signal (DMRS) pattern from a group of DMRS patterns, the group of DMRS patterns being determined based on at least one candidate position for transmission of a transport block between the first terminal device and a second terminal device; performing the transmission based on the target DMRS pattern; and A communication method including:

16. 16. The method of claim 15, wherein the group of DMRS patterns is determined by removing at least one DMRS pattern from a plurality of DMRS patterns, each of the at least one DMRS pattern having a DMRS transmission at the at least one candidate location.

17. 16. The method of claim 15, wherein one of the at least one candidate location is configured for automatic gain control (AGC) and DMRS transmission, and repetition from a next symbol for the AGC does not affect the DMRS transmission.

18. determining, in a first terminal device, resource occupancy information of a plurality of transmission opportunities, wherein the resource occupancy information of a first transmission opportunity among the plurality of transmission opportunities is determined based on a scaling factor, the scaling factor being associated with a start position of transmission in the first transmission opportunity or being a preset value; determining channel parameters based on the resource occupancy information; A communication method including:

19. 20. The method of claim 18, wherein the channel parameters include at least one of a sidelink channel occupancy ratio (CR) and a sidelink channel busy ratio (CBR).

20. at least one processor; at least one memory coupled to the at least one processor and having instructions stored therein; The instructions, when executed by the at least one processor, cause the first terminal device to perform a method according to any one of claims 1 to 12, or any one of claims 13 to 14, or any one of claims 15 to 17, or any one of claims 18 to 19. A first terminal device.

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