KR20250019430A - Method, communidation device and storage medium for transmitting sidelink channel - Google Patents

Abstract

A UE receives first COT sharing information for a cell and second COT sharing information for the cell, each of the first COT sharing information and the second COT sharing information including time information about a channel occupancy duration and frequency information about available frequency resources; and based on the first COT sharing information and the second COT sharing information, a COT duration and frequency resources available to the communication device can be determined.

Description

METHOD, COMMUNIDATION DEVICE AND STORAGE MEDIUM FOR TRANSMITTING SIDELINK CHANNEL

This specification relates to wireless communication systems.

A wireless communication system supports communication of user equipment (UEs) by utilizing available system resources (e.g., bandwidth, transmission power, etc.). With the introduction of new wireless communication technologies, not only the number of UEs to which a base station (BS) must provide services in a given resource area increases, but also the amount of data and control information transmitted/received by the BS to/from the UEs it provides services to also increases. Since the amount of radio resources that the BS can use for communication with the UE(s) is finite, a new method is required for the BS to efficiently receive/transmit uplink/downlink data and/or uplink/downlink control information from/to the UE(s) by utilizing the finite radio resources. In other words, as the density of nodes and/or the density of UEs increases, a method is required for efficiently utilizing a high density of nodes or a high density of UEs for communication. For example, as a solution to the burden on BS due to rapidly increasing data traffic, sidelink (SL) communication has been studied, which supports direct communication between two or more nearby UEs without going through network nodes using wireless communication technology. As the need for V2X (vehicle-to-everything), a communication technology that supports wired/wireless communication between vehicles and other vehicles, infrastructure, networks, or pedestrians, arises, a rapid increase in SL communication is expected.

Considering the rapidly increasing volume and frequency of SL communications, a method to stably support SL communications is required.

The technical problems to be solved by this specification are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art related to this specification from the detailed description below.

In one aspect of the present specification, a method for a communication device to transmit a sidelink channel in a wireless communication system is provided. The method includes: receiving first channel occupancy time (COT) sharing information for a cell and second COT sharing information for the cell, each of the first COT sharing information and the second COT sharing information including time information regarding a channel occupancy duration and frequency information regarding available frequency resources; determining a COT period and frequency resource available to the communication device based on the first COT sharing information and the second COT sharing information; and transmitting the sidelink channel on the determined frequency resource within the determined COT period.

In another aspect of the present disclosure, a communication device for transmitting a sidelink channel in a wireless communication system is provided. The communication device includes: at least one transceiver; at least one processor; and at least one memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations. The operations include: receiving first channel occupancy time (COT) sharing information for a cell and second COT sharing information for the cell, each of the first COT sharing information and the second COT sharing information including time information regarding a channel occupancy duration and frequency information regarding available frequency resources; determining a COT period and frequency resource available to the communication device based on the first COT sharing information and the second COT sharing information; and transmitting the sidelink channel on the determined frequency resource within the determined COT period.

In another aspect of the present disclosure, a computer-readable non-transitory storage medium comprising at least one computer program causing at least one processor to perform operations, the operations comprising: receiving first channel occupancy time (COT) sharing information for a cell and second COT sharing information for the cell, each of the first COT sharing information and the second COT sharing information including time information regarding a channel occupancy duration and frequency information regarding available frequency resources; determining a COT period and frequency resource available to the communication device based on the first COT sharing information and the second COT sharing information; and transmitting the sidelink channel on the determined frequency resource within the determined COT period.

In each aspect of the present specification, determining a COT period and frequency resources available to the communication device based on the first COT sharing information and the second COT sharing information may include: determining an intersection of a first channel occupancy period indicated by the first COT sharing information and a second channel occupancy period indicated by the second COT sharing information as the COT period available to the communication device; and determining an intersection of the first available frequency resources indicated by the first COT sharing information and the second available frequency resources indicated by the second COT sharing information as the frequency resource available to the communication device.

In each aspect of the present specification, the first COT sharing information includes a first channel access priority class (CAPC) value, the second COT sharing information includes a second CAPC value, and determining a COT period and a frequency resource available to the communication device based on the first COT sharing information and the second COT sharing information may include: determining the COT period and the frequency resource available to the communication device based on time information and frequency information included in COT sharing information including a higher CAPC value among the first COT sharing information and the second COT sharing information.

In each aspect of the present specification, the method may include determining the COT period and the frequency resource available to the communication device based on COT sharing information received earlier among the first COT sharing information and the second COT sharing information, based on the first COT sharing information and the second COT sharing information including the same CAPC value.

In each aspect of the present specification, the first COT sharing information and the second COT sharing information may include determining the COT period and the frequency resource available to the communication device based on COT sharing information randomly selected from the first COT sharing information and the second COT sharing information, wherein the first COT sharing information and the second COT sharing information include the same CAPC value and the first COT sharing information and the second COT sharing information are received in the same slot.

In each aspect of the present specification, determining the COT period and frequency resources available to the communication device based on the first COT sharing information and the second COT sharing information may include: determining the COT period and the frequency resources available to the communication device based on COT sharing information that is received earlier among the first COT sharing information and the second COT sharing information.

In each aspect of the present specification, based on receiving the first COT sharing information and the second COT sharing information in the same slot, determining the COT period and the frequency resource available to the communication device based on time information and frequency information included in COT sharing information including a higher CAPC value among the first COT sharing information and the second COT sharing information may be included.

In each aspect of the present specification, the method may include determining the COT period and the frequency resource available to the communication device based on COT sharing information randomly selected from among the first COT sharing information and the second COT sharing information, based on receiving the first COT sharing information and the second COT sharing information in the same slot and including the same CAPC value as the first COT sharing information and the second COT sharing information.

In each aspect of the present specification, determining a COT period and a frequency resource available to the communication device based on the first COT sharing information and the second COT sharing information may include: determining the COT period and the frequency resource available to the communication device based on the first COT sharing information, based on that the sidelink channel is for the first communication device that transmitted the first COT sharing information; and determining the COT period and the frequency resource available to the communication device based on the second COT sharing information, based on that the sidelink channel is for the second communication device that transmitted the second COT sharing information.

In each aspect of this specification, the frequency information may include information about at least one set of available resource blocks.

In each aspect of the present specification, the frequency resource available to the communication device may include a plurality of subchannels, and transmitting the sidelink channel may include transmitting the sidelink channel on at least one of the plurality of subchannels.

The above problem solving methods are only some of the examples of this specification, and various examples reflecting the technical features of this specification can be derived and understood by a person having ordinary knowledge in the relevant technical field based on the detailed description below.

According to some implementation(s) of this specification, wireless communication signals can be transmitted/received efficiently. Accordingly, the overall throughput of the wireless communication system can be increased.

According to some implementations of this specification, sidelink technologies in licensed spectrum, which is licensed to a particular network operator and is used exclusively or preferentially by that network operator, may also be utilized in shared spectrum.

Some implementations of this specification enable sidelink communications to be performed efficiently over shared spectrum, which is unlicensed spectrum that is not licensed to a specific network operator and can be freely used by multiple network operators.

The effects according to this specification are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art related to this specification from the detailed description below.

FIG. 1 is an example of a communication system 1 to which implementations of the present specification can be applied;
FIG. 2 is a block diagram illustrating examples of communication devices capable of performing a method according to the present specification;
Figure 3 illustrates an example of a frame structure available in a 3GPP-based wireless communication system;
Figure 4 illustrates a resource grid of slots;
FIG. 5 illustrates communication links in a wireless communication system;
Figure 6 is a diagram illustrating frequency resources and time resources for sidelink;
Figures 7 and 8 illustrate transmission structures of sidelink physical channels within a slot;
FIG. 9 is a diagram illustrating a channel access mechanism on a shared spectrum according to some implementations;
Figure 10 illustrates the flow of the channel connection process;
Figure 11 illustrates channel occupancy time (COT) sharing between a BS and a UE;
Figure 12 illustrates UE-to-UE COT sharing according to some implementations of this specification;
Figure 13 illustrates a situation where multiple channel occupancy time (COT) initiating UEs transmit COT sharing information.
Figures 14 to 17 are illustrated to illustrate implementations of the present specification for determining time/frequency resources available to a responding UE via COT sharing.
FIG. 18 is an example of a process in which a communication device performs sidelink transmission according to some implementations of the present specification.

Hereinafter, implementations according to this specification will be described in detail with reference to the accompanying drawings. The detailed description set forth below, together with the accompanying drawings, is intended to describe exemplary implementations of this specification and is not intended to represent the only implementation forms in which this specification may be practiced. The detailed description below includes specific details in order to provide a thorough understanding of this specification. However, one of ordinary skill in the art will appreciate that this specification may be practiced without these specific details.

In some cases, in order to avoid ambiguity in the concepts of this specification, well-known structures and devices may be omitted or illustrated in block diagram form focusing on the core functions of each structure and device. In addition, the same components are described using the same drawing reference numerals throughout this specification.

The techniques, devices, and systems described below can be applied to various wireless multiple access systems.

For convenience of explanation, the following description is based on a 3rd Generation Partnership Project (3GPP)-based communication system. However, the technical features of the present specification are not limited thereto. For example, even if the detailed description below is based on a 3rd Generation Partnership Project (3GPP) LTE or 5G technology, some implementations of the present specification are applicable to any other mobile communication system and systems to be introduced in the future (e.g., 6G) except for the specifics of 3GPP LTE/5G.

For terms and technologies used in this specification that are not specifically explained, refer to 3GPP-based standard documents, such as 3GPP TS 23.304, 3GPP TS 23.285, 3GPP TS 23.287, 3GPP TS 24.587, 3GPP TS 36.211, 3GPP TS 36.212, 3GPP TS 36.213, 3GPP TS 36.300, 3GPP TS 36.321, 3GPP 36.322, 3GPP TS 36.323, 3GPP TS and 3GPP TS 36.331, 3GPP TS 37.213, 3GPP TS 38.211, 3GPP TS 38.212, 3GPP TS 38.213, 3GPP TS 38.214, 3GPP TS 38.300, 3GPP TS 38.321, 3GPP TS 38.322, 3GPP TS 38.323, and 3GPP TS 38.331.

In the examples of this specification described below, the expression that a device "assumes" may mean that a subject transmitting a channel transmits the channel in a manner consistent with the "assumption." It may mean that a subject receiving the channel receives or decodes the channel in a form consistent with the "assumption," under the premise that the channel was transmitted in a manner consistent with the "assumption."

In this specification, UE may be fixed or mobile, and includes various devices that communicate with a BS (base station, BS) to transmit and/or receive user data and/or various control information. UE may be called (Terminal Equipment), MS (Mobile Station), MT (Mobile Terminal), UT (User Terminal), etc. In addition, in this specification, BS generally refers to a fixed station that communicates with UE and/or other BS, and exchanges various data and control information with UE and other BS. BS may be called by other terms such as ABS (Advanced Base Station), NB (Node-B), eNB (evolved-NodeB), gNB, BTS (Base Transceiver System), Access Point, and PS (Processing Server). For convenience of explanation, base stations are collectively referred to as BSs regardless of the type or version of communication technology.

In this specification, a node refers to a fixed point that can communicate with a UE and transmit/receive a radio signal. Various types of BSs can be used as nodes regardless of their names. At least one antenna is installed in a node. The antenna may mean a physical antenna, or may mean an antenna port, a virtual antenna, or an antenna group. A node is also called a point.

Meanwhile, 3GPP-based communication systems use the concept of cells to manage radio resources, and cells associated with radio resources are distinguished from cells of geographical areas. The "cell" of a geographical area can be understood as a coverage in which a node can provide a service using a carrier, and the "cell" of radio resources is associated with a bandwidth (BW), which is a frequency range configured by the carrier. Since the downlink coverage, which is a range in which a node can transmit a valid signal, and the uplink coverage, which is a range in which a node can receive a valid signal from a UE, depend on the carrier carrying the signal, the coverage of a node is also associated with the coverage of the "cell" of radio resources used by the node. Therefore, the term "cell" can sometimes be used to mean the coverage of a service by a node, sometimes a radio resource, and sometimes a range in which a signal using the radio resource can reach with a valid intensity.

A "cell" associated with wireless resources can be defined as a combination of downlink resources (DL resources) and uplink resources (UL resources), i.e., a combination of a DL component carrier (CC) and an UL CC. A cell can be configured with only DL resources, or a combination of DL resources and UL resources. When carrier aggregation is supported, the linkage between the carrier frequency of the DL resources (or DL CC) and the carrier frequency of the UL resources (or UL CC) can be indicated by system information. Here, the carrier frequency can be the same as or different from the center frequency of each cell or CC.

In a wireless communication system, a UE receives information from a BS via a downlink (DL), and the UE transmits information to the BS via an uplink (UL). The information transmitted and/or received by the BS and the UE includes data and various control information, and various physical channels exist depending on the type/purpose of the information they transmit and/or receive.

3GPP-based communication standards define downlink physical channels corresponding to resource elements carrying information originating from a higher layer, and downlink physical signals corresponding to resource elements used by the physical layer but not carrying information originating from a higher layer. For example, a physical downlink shared channel (PDSCH), a physical broadcast channel (PBCH), a physical downlink control channel (PDCCH), etc. are defined as downlink physical channels, and a reference signal and a synchronization signal are defined as downlink physical signals. A reference signal (RS), also called a pilot, means a signal with a special waveform defined mutually known to a BS and a UE. For example, a demodulation reference signal (DMRS), a channel state information RS (CSI-RS), etc. are defined as downlink reference signals. 3GPP-based communication standards define uplink physical channels corresponding to resource elements carrying information originating from higher layers, and uplink physical signals corresponding to resource elements used by the physical layer but not carrying information originating from higher layers. For example, physical uplink shared channel (PUSCH), physical uplink control channel (PUCCH), and physical random access channel (PRACH) are defined as uplink physical channels, and demodulation reference signal (DMRS) for uplink control/data signals and sounding reference signal (SRS) used for uplink channel measurement are defined.

In this specification, PDCCH means a set of time-frequency resources (e.g., resource elements (REs)) carrying downlink control information (DCI), and PDSCH means a set of time-frequency resources carrying downlink data. In addition, PUCCH, PUSCH, and PRACH mean sets of time-frequency resources carrying uplink control information (UCI), uplink data, and random access preamble, respectively. Hereinafter, the expression that a UE/BS transmits/receives a PUCCH/PUSCH/PRACH is used to have an equivalent meaning that it transmits/receives UCI/uplink data/random access preamble on or through the PUCCH/PUSCH/PRACH, respectively. Additionally, the expression that BS/UE transmits/receives PBCH/PDCCH/PDSCH is used with the same meaning as transmitting/receiving broadcast information/DCI/downlink data on or through PBCH/PDCCH/PDSCH, respectively.

In this specification, radio resources (e.g., time-frequency resources) scheduled or configured by the BS to the UE for transmission or reception of PUCCH/PUSCH/PDSCH are also referred to as PUCCH/PUSCH/PDSCH resources.

Since a communication device receives a physical channel and/or a physical signal in the form of radio signals on a cell, it cannot selectively receive only radio signals including only a specific physical channel or a specific physical signal through a radio frequency (RF) receiver, or selectively receive only radio signals excluding only a specific physical channel or a physical signal through an RF receiver. In actual operation, the communication device first receives radio signals on a cell through an RF receiver, converts the radio signals, which are RF band signals, into baseband signals, and decodes the physical signals and/or physical channels within the baseband signals using one or more processors. Therefore, in some implementations of the present specification, not receiving a physical signal and/or a physical channel may not actually mean that the communication device does not receive radio signals including the physical signal and/or the physical channel at all, but may mean that it does not attempt to restore the physical signal and/or the physical channel from the radio signals, for example, it does not attempt to decode the physical signal and/or the physical channel.

Figure 1 is an example of a communication system 1 to which implementations of the present specification can be applied.

Referring to Fig. 1, a communication system (1) applied to this specification includes a wireless device, a BS, and a network. Here, the wireless device may mean a device that performs communication using a wireless access technology (e.g., 5G NR (New RAT), LTE (e.g., E-UTRA), WiFi, and 6G to be introduced in the future).

Although not limited thereto, the wireless devices may include a robot (100a), a vehicle (100b-1, 100b-2, 100b-3, 100b-4), an XR (eXtended Reality) device (100c), a hand-held device (100d), a home appliance (100e), an IoT (Internet of Thing) device (100f), and an AI device/server (400). For example, the vehicles may include a ground vehicle equipped with a wireless communication function, an autonomous vehicle, a vehicle capable of performing communication between vehicles, etc. Here, the vehicles may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone) and an Urban Air Mobility (UAM) (e.g., an unmanned aerial vehicle). The XR devices may include an AR (Augmented Reality)/VR (Virtual Reality)/MR (Mixed Reality) device. Portable devices may include smartphones, smart pads, wearable devices (e.g., smart watches, smart glasses), computers (e.g., laptops, etc.). Home appliances may include TVs, refrigerators, washing machines, etc.. IoT devices may include sensors, smart meters, etc. For example, BS and networks may also be implemented as wireless devices, and a specific wireless device may act as a BS/network node to other wireless devices.

Wireless devices (100a to 100f) can be connected to a network through a BS (200). AI (Artificial Intelligence) technology can be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (400) through a network. The wireless devices (100a to 100f) can communicate with each other through the BS (200)/network, but can also communicate directly (e.g. sidelink communication) without going through the BS/network. For example, transportation devices (100b-1, 100b-2, 100b-3, 100b-4) can communicate directly (e.g. V2V (Vehicle to Vehicle)/V2X (Vehicle to everything) communication). Additionally, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

Wireless communication/connection can be established between wireless devices (100a~100f)/BS(200) - BS(200)/wireless devices (100a~100f). Here, the wireless communication/connection can be established through uplink/downlink communication (UL/DL) and sidelink communication (SL) (or, D2D communication) via various wireless access technologies (e.g., 5G NR). Through the wireless communication/connection (UL/DL, SL), the wireless device and the BS/wireless device can transmit/receive wireless signals to/from each other. To this end, at least some of various configuration information setting processes for transmitting/receiving wireless signals, various signal processing processes (e.g., channel encoding/decoding, modulation/demodulation, resource mapping/demapping, etc.), resource allocation processes, etc. can be performed based on various proposals of this specification.

FIG. 2 is a block diagram illustrating examples of communication devices that can perform a method according to the present specification. Referring to FIG. 2, a first wireless device (100) and a second wireless device (200) can transmit and/or receive wireless signals via various wireless access technologies. Here, {the first wireless device (100), the second wireless device (200)} can correspond to {the wireless device (100x), the BS (200)} and/or {the wireless device (100x), the wireless device (100x)} of FIG. 1.

Each of the first wireless device (100) and the second wireless device (200) includes one or more processors (102, 202) and one or more memories (104, 204), and may additionally include one or more transceivers (106, 206) and/or one or more antennas (108). The processor (102, 202) controls the memories (104, 204) and/or the transceivers (106, 206), and may be configured to implement the functions, procedures, and/or methods described/suggested below. For example, the processor (102, 202) may process information in the memories (104, 204) to generate first information/signal, and then transmit a wireless signal including the first information/signal via the transceivers (106, 206). In addition, the processor (102, 202) may receive a wireless signal including second information/signal through the transceiver (106, 206), and then store information obtained from signal processing of the second information/signal in the memory (104, 204). The memory (104, 204) may be connected to the processor (102, 202) and may store various information related to the operation of the processor (102, 202). For example, the memory (104, 204) may perform some or all of the processes controlled by the processor (102, 202), or store software code including commands for performing the procedures and/or methods described/suggested below. Here, the processor (102, 202) and the memory (104, 204) may be part of a communication modem/circuit/chip designed to implement wireless communication technology. A transceiver (106, 206) may be coupled to a processor (102, 202) and may transmit and/or receive wireless signals via one or more antennas (108, 208). The transceiver (106, 206) may include a transmitter and/or a receiver.

Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, the one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as a physical (PHY) layer, a medium access control (MAC) layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer, a radio resource control (RRC) layer, a service data adaption protocol (SDAP) layer). The one or more processors (102, 202) may generate one or more protocol data units (PDUs) and/or one or more service data units (SDUs) in accordance with the functions, procedures, suggestions and/or methods disclosed in this specification. One or more processors (102, 202) may generate messages, control information, data or information according to the functions, procedures, proposals and/or methods disclosed in this specification. One or more processors (102, 202) may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, proposals and/or methods disclosed in this specification and provide them to one or more transceivers (106, 206). One or more processors (102, 202) may receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the functions, procedures, proposals and/or methods disclosed in this specification.

The one or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. The one or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof, and the firmware or software may be implemented to include modules, procedures, functions, etc. The firmware or software configured to perform the functions, procedures, suggestions, and/or methods disclosed in this specification may be included in the one or more processors (102, 202) or stored in one or more memories (104, 204) and executed by the one or more processors (102, 202). The functions, procedures, suggestions, and/or methods disclosed in this specification may be implemented using firmware or software in the form of code, instructions, and/or sets of instructions.

One or more memories (104, 204) may be coupled to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions and/or commands. The one or more memories (104, 204) may be located internally and/or externally to one or more processors (102, 202). Additionally, the one or more memories (104, 204) may be coupled to one or more processors (102, 202) via various technologies, such as wired or wireless connections.

One or more transceivers (106, 206) may transmit/receive user data, control information, wireless signals/channels, etc., referred to in the methods and/or flowcharts of this specification, to/from one or more other devices. In addition, one or more processors (102, 202) may control one or more transceivers (106, 206) to transmit/receive user data, control information, or wireless signals to/from one or more other devices. In addition, one or more transceivers (106, 206) may be connected to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and/or receive user data, control information, wireless signals/channels, etc., referred to in the functions, procedures, suggestions, methods, and/or flowcharts of this specification, via one or more antennas (108, 208). In this specification, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) may convert received user data, control information, wireless signals/channels, etc. from RF band signals to baseband signals for processing using one or more processors (102, 202). One or more transceivers (106, 206) may convert processed user data, control information, wireless signals/channels, etc. from baseband signals to RF band signals using one or more processors (102, 202). For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and/or a filter.

In this specification, at least one memory (104, 204) can store instructions or programs, which, when executed, cause at least one processor (102, 202) operably connected to the at least one memory to perform operations according to some embodiments or implementations of the present specification.

In this specification, a computer-readable (non-transitory) storage medium can store at least one instruction or a computer program, which when executed by at least one processor causes the at least one processor to perform operations according to some embodiments or implementations of the present specification.

Figure 3 illustrates an example of a frame structure available in a 3GPP-based wireless communication system.

The structure of the frame in Fig. 3 is only an example, and the number of subframes, the number of slots, and the number of symbols in the frame can be variously changed. In some wireless communication systems, OFDM numerologies (e.g., subcarrier spacing (SCS)) may be set differently between multiple cells aggregated to one UE. Accordingly, the (absolute time) duration of time resources (e.g., subframes, slots, or transmission time intervals (TTIs)) composed of the same number of symbols may be set differently between the aggregated cells. Here, the symbol may include an OFDM symbol (or a cyclic prefix - orthogonal frequency division multiplexing (CP-OFDM) symbol), an SC-FDMA symbol (or a discrete Fourier transform-spread-OFDM (DFT-s-OFDM) symbol). In this specification, the terms symbol, OFDM-based symbol, OFDM symbol, CP-OFDM symbol and DFT-s-OFDM symbol are interchangeable.

Referring to FIG. 3, uplink and downlink transmissions are organized into frames. Each frame has a duration T _f = (△f _max *N _f /100)*T _c = 10 ms, where T _c = 1/(△f _max *N _f ) is the basic time unit, △f _max = 480*10 ³ Hz, and N _f =4096. For reference, the sampling time T _s = 1/(△f _ref *N _f,ref ), △f _ref = 15*10 ³ Hz, and N _f,ref =2048. T _c and T _f have a constant relationship κ = T _c /T _f = 64. A frame consists of 10 subframes, and the duration T _sf of a single subframe is 1 ms. Subframes are further divided into slots, and the number of slots in a subframe depends on the subcarrier spacing. Each slot can consist of N ^slot _symb symbols based on a cyclic prefix (CP). For example, in some scenarios, each slot consists of 14 OFDM symbols for the normal CP, and each slot consists of 12 OFDM symbols for the extended CP. The numerology depends on the exponentially scalable subcarrier spacing △f = 2 ^u *15 kHz. The following table shows the number of OFDM symbols per slot ( N ^slot _symb ), the number of slots per frame ( N ^frame,u _slot ), and the number of slots per subframe ( N ^subframe,u _slot ) for the normal CP with the subcarrier spacing △f = 2 ^u *15 kHz.

The following table shows the number of OFDM symbols per slot, the number of slots per frame, and the number of slots per subframe according to the subcarrier spacing △f = 2 ^u *15 kHz for the extended CP.

For a subcarrier spacing setting u, slots are numbered in increasing order within a subframe as n ^u _s ∈ {0, ..., n ^subframe,u _slot - 1} and in increasing order within a frame as n ^u _s,f ∈ {0, ..., n ^frame,u _slot - 1}.

Hereinafter, implementations of the present specification are described by referring to the minimum unit of time for scheduling uplink, downlink, and sidelink transmissions as a slot; however, the minimum unit of time for scheduling may be referred to by a different term depending on the wireless communication system. For example, in an LTE-based system, the minimum unit of time for scheduling transmissions is referred to as a subframe or a transmission time interval (TTI), whereas in an NR-based system, the minimum unit of time for scheduling is referred to as a slot.

Fig. 4 illustrates a resource grid of a slot. A slot contains a plurality of (e.g., N ^slot _symb ) symbols in the time domain. For each numeral (e.g., subcarrier spacing) and carrier, a resource grid of N ^size,u _grid,x * N ^RB sc subcarriers and N subframe,u ^symb OFDM symbols is defined, starting from a common resource block (CRB) N ^start,u _grid indicated by higher layer signaling (e.g., radio resource control (RRC) signaling). Here, N ^size,u _{grid,x is} the number of resource blocks (RBs) in the resource grid, and the subscript x is _DL for downlink and UL for uplink. N ^RB _sc is the number of subcarriers per RB, and N ^RB _sc is typically 12 in 3GPP-based wireless communication systems. For a given antenna port p , subcarrier spacing configuration u , and transmission direction (DL or UL), there is one resource grid. The carrier bandwidth N ^size,u _grid for subcarrier spacing configuration u is given to the UE by higher-layer parameters (e.g., RRC parameters) from the network. Each element in the resource grid for antenna port p and subcarrier spacing configuration u is called a resource element (RE), and one complex-valued symbol may be mapped to each RE. Each RE in the resource grid is uniquely identified by an index k in the frequency domain and an index l indicating the symbol position relative to a reference point in the time domain. RBs may be classified into common resource blocks (CRBs) and physical resource blocks (PRBs). The CRBs are numbered upwards from 0 in the frequency domain for subcarrier spacing configuration u . The center of subcarrier 0 of CRB 0 for a subcarrier spacing setting u coincides with 'point A', which is a common reference point for resource block grids. The PRBs for the subcarrier spacing setting u are defined in a bandwidth part (BWP) and are numbered from 0 to N ^size,u _BWP,i -1, where i is the number of the bandwidth part. The relationship between the common resource block n ^u _CRB and the physical resource block n _PRB in the bandwidth part i is as follows: n ^u _PRB = n ^u _CRB + N ^start,u _BWP,i , where N ^start,u _BWP,i is the common resource block where the bandwidth part starts relative to CRB 0. A BWP comprises a plurality of contiguous RBs in the frequency domain. For example, a BWP is a subset of contiguous CRBs defined for a given numerology u _i within BWP i on a given carrier. A carrier can contain up to N (e.g., 5) BWPs. A UE can be configured to have one or more BWPs on a given component carrier. Data communication is performed via the activated BWPs, and only a predetermined number (e.g., 1) of BWPs configured for the UE can be activated on the carrier.

For each BWP, the UE may be provided with at least one of the following parameters for the serving cell: i) subcarrier spacing, ii) cyclic prefix, iii) CRB N ^start _BWP = O carrier + RB start and the number of contiguous RBs N _{size BWP} = L _RB , and O _carrier provided by the RRC parameter offsetToCarrier for subcarrier spacing, provided by the RRC parameter locationAndBandwidth indicating offset RB _set and ^length L _RB as resource indicator value (RIV) with assumption that N ^start _BWP = 275; an _index within the set of DL BWPs or of UL BWPs; a set of BWP-common parameters and a set of BWP-specific parameters.

Virtual resource blocks (VRBs) are defined within a bandwidth part and numbered from 0 to N ^size,u _BWP,i -1, where i is the number of the bandwidth part. A UE may assume that VRBs are mapped to PRBs according to a mapping scheme indicated to the UE (e.g., non-interleaved or interleaved mapping). If no mapping scheme is indicated, the UE assumes non-interleaved mapping. In the case of non-interleaved VRB-to-PRB mapping, VRB n may be mapped to PRB n. In the case of interleaved VRB-to-PRB mapping, VRBs may be distributed and mapped to PRBs according to predefined rules.

Figure 5 illustrates communication links in a wireless communication system.

Referring to FIG. 5, in a wireless communication system, a UE receives information from a BS through a downlink (DL), and the UE transmits information to the BS through an uplink (UL). As a solution to the burden on the BS due to rapidly increasing data traffic, sidelink (SL) communication, which supports direct communication between two or more nearby UEs without going through a network node using wireless communication technology, has been studied. UEs within or outside the coverage of a BS can send data to another UE without going through the network through the sidelink, which supports UE-to-UE direct communication by using sidelink resource allocation modes, physical layer signals/channels, and physical layer processes.

Transmissions in SL use OFDM waveform with CP. The frame structure described in Fig. 3 and the resource grid structure described in Fig. 4 can be applied to SL. In some scenarios, for example in NR V2X, only certain slots can be (pre-)configured to accommodate SL transmissions, and the available sidelink resources can consist of (common) RBs in sidelink (time resources) and SL BWP (frequency resources). A subset of the available SL resources can be (pre-)configured to be used by several UEs for SL transmissions. This subset of the available SL resources is called a resource pool.

Figure 6 is a diagram illustrating frequency resources and time resources for sidelink.

Referring to Fig. 6, a resource pool is composed of (pre-configured) i) contiguous PRBs and ii) contiguous or non-contiguous slots for SL transmissions. The concept of BWP can also be applied to sidelink. A UE can be configured with a BWP having a numerology and a resource grid for SL transmissions. Hereinafter, a BWP configured for SL transmissions is referred to as an SL BWP. The SL BWP can occupy a contiguous portion of bandwidth within a carrier. SL transmissions and receptions can be performed within the SL BWP. A resource pool can be defined within the SL BWP, and a single numerology is used within the resource pool. A resource pool can be shared by several UEs for SL transmissions, and can be used for all transmission types (e.g., unicast, groupcast, and broadcast). A UE may be configured with one or more sidelink resource pools via higher layer signaling (e.g., RRC signaling). The UE may transmit on the sidelink using its own transmission resource pool(s), while receiving data on the resource pools used for sidelink transmissions by other UE(s).

In the frequency domain, the resource pool is divided into a (pre-)configured number L of consecutive subchannels, where a subchannel consists of a group of consecutive RBs within a slot. The number of RBs in a subchannel, N _{sch ,} corresponds to the subchannel size and is (pre-)configured for the resource pool. L and N _sch can be provided to the UE via higher layer signaling (e.g., RRC signaling). The first RB of the first subchannel in the SL BWP is (pre-)configured via RRC signaling. For example, the lowest RB index of the subchannel with the lowest index within the resource pool can be provided to the UE(s) based on the lowest RB index of the SL BWP. In NR V2X, the subchannel size N _sch can be equal to 10, 12, 15, 20, 25, 50, 70 or 100 RBs. In sidelink, a subchannel represents the smallest unit for sidelink data transmission or reception. Sidelink transmission can be performed using one or more subchannels.

In the time domain, slots, which are part of a resource pool, are (pre-)configured and occur periodically (e.g., 10240 ms). In each slot of the resource pool, among the N ^slot _symb symbols per slot, only a subset of the consecutive symbols are (pre-)configured for sidelink. The subset of sidelink symbols per slot is indicated by the start symbol and the number of consecutive symbols, which are (pre-)configured per resource pool.

3GPP-based communication standards define sidelink physical channels corresponding to resource elements carrying information originating from higher layers, and sidelink physical signals corresponding to resource elements used by the physical layer but not carrying information originating from higher layers. For example, a physical sidelink shared channel (PSSCH), a physical sidelink control channel (PSCCH), a physical sidelink broadcast channel (PSBCH), a physical sidelink feedback channel (PSFCH), etc. can be used as sidelink physical channels. In this specification, the PSCCH carries sidelink control information (SCI) in the sidelink. For example, the SCI is used to indicate resources and other transmission parameters used by the UE for the PSSCH, and a PSCCH transmission is associated with a demodulation reference signal (DM-RS). The PSSCH can carry data payload in the sidelink and additional control information. Data can be organized into TB(s), and each TB can be associated with an SCI. For example, the PSSCH is used to carry transport block (TB)(s), control information for hybrid automatic repeat request (HARQ) processes and CSI feedback trigger. In some scenarios, at least 6 OFDM symbols in a slot are used for PSSCH transmission, and the PSSCH is associated with a DM-RS. The PSBCH carries information to support synchronization in the sidelink, and in some scenarios the PSBCH may be sent within a sidelink synchronization signal block (S-SSB). The PSFCH carries HARQ feedback on the sidelink from a UE intended to be the recipient of the PSSCH to the UE that performed the PSSCH transmission. Hereinafter, a UE performing a sidelink transmission is referred to as a TX UE, and the intended recipient(s) of the sidelink transmission is referred to as RX UE(s).

In some scenarios, the SCI is transmitted in two stages. For example, in NR V2X, the 1 ^st -stage SCI may be carried on the PSCCH and the 2 ^nd -stage SCI may be carried on the corresponding PSSCH. Splitting the SCI into the 1 ^st -stage SCI and the 2 ^nd -stage SCI allows other UEs than the RX UEs of the sidelink transmission to decode only the 1 ^st -stage SCI for channel sensing purposes, i.e., to determine resources reserved by other transmissions. Meanwhile, the 2 ^nd -stage SCI provides additional control information required for the RX UE(s) of the sidelink transmission.

The number of symbols used for sidelink transmission within a slot may vary depending on the physical channels carried within the slot.

Figures 7 and 8 illustrate the transmission structure of sidelink physical channels within a slot.

A PSCCH can be multiplexed with its associated PSSCH on non-overlapping resources within the same slot. Referring to Fig. 7, a PSCCH is transmitted starting from the lowest RB in the subchannel(s) occupied by the associated PSSCH in the frequency domain, and from the second symbol in the slot in the time domain. The number of symbols for the PSCCH is (pre-)configured per resource pool, and can be, for example, 2 or 3 symbols. In some scenarios (e.g., NR V2X), the PSCCH occupies RBs of N _PSCCH in the frequency domain, and the N _PSCCH can be (pre-)configured to the UE(s) per resource pool via higher layer signaling (e.g., RRC signaling). In some scenarios (e.g., NR V2X), N _PSCCH can be set to be equal to 10, 12, 15, 20 or 25 RBs per resource pool. In some scenarios (e.g., NR V2X), N _PSCCH is contained within one subchannel, and the number of RBs for PSCCH, N _PSCCH , can be constrained by the number of RBs in the subchannel, N _sch (i.e., N _PSCCH N _sch ). The PSCCH carries a 1 ^st -stage SCI including control information associated with the PSSCH and the 2 ^nd -stage SCI. For this purpose, for example, SCI format 1-A may be used. The 1 ^st -stage SCI may indicate frequency resources (e.g., subchannel(s)) of the PSSCH carrying the current (re-)transmission of a transport block (TB) and may indicate resource reservation for retransmission(s) of the TB up to a predefined number (e.g., 2). The 1 ^st -stage SCI may include a priority of the associated PSSCH and may include information about a format and a size of the 2 ^nd -stage SCI. The 1 ^st -stage SCI may include information about a modulation and coding scheme (MCS) of the transport block (TB) carried on the associated PSSCH. Although not illustrated in FIG. 7, for demodulation of the PSCCH, a DM-RS associated with the PSCCH (hereinafter, PSCCH DM-RS) may be transmitted within the PSCCH. For example, each PSCCH symbol (i.e., an OFDM symbol including the PSCCH) may include a PSCCH DM-RS. Although not illustrated in FIG. 7, the DM-RS associated with the PSSCH is carried on different symbols within a slot to which the PSSCH is allocated (hereinafter, PSSCH slot). Multiple time patterns may be (pre-)configured for the PSSCH DM-RS within a resource pool, and the 1 ^st -step SCI may include information about which time pattern is used for the associated PSSCH.

The PSSCH carries a data payload consisting of a 2 ^nd -stage SCI and TB(s). The 2 ^nd -stage SCI may carry information used for decoding the PSSCH and information to support HARQ feedback and CSI reporting. The 2 ^nd -stage SCI may include a layer 1 source ID representing an identifier (within the physical layer) of a TX UE and a layer 1 destination ID representing identifier(s) of intended recipient(s) (RX UE(s)) of the corresponding TB. The 2 ^nd -stage SCI may carry a 1-bit new data indicator (NDI) used to specify whether a TB sent on the PSSCH corresponds to transmission of new data or a retransmission. After decoding the 1 ^st -stage SCI in the PSCCH, the RX UE has the information required to decode the 2 ^nd -stage SCI. The 2 ^nd -stage SCI can be decoded using the PSSCH DM-RS. Before being mapped to the PSSCH, the 2 ^nd -stage SCI and the TB are respectively channel coded and multiplexed according to a predefined process. Depending on the number of layers supported in the PSSCH (i.e., the number of data streams), the multiplexed 2 ^nd -stage SCI and TB are mapped to one or two layers and precoded before being mapped to the L _PSSCH subchannel(s) of the PSSCH. A PSSCH occupies N _PSSCH = L _PSSCH * N _sch RBs starting from the lowest RB in the subchannel carrying the corresponding PSCCH, where N _PSSCH is the number of RBs occupied by the PSSCH, L _PSSCH is the number of subchannels for the PSSCH, and N _sch is the number of RBs per subchannel.

Referring to FIG. 7, the PSSCH may be transmitted from the second symbol in a slot to the second to the last symbol or from the second symbol to the symbol immediately preceding the last symbol in a slot. In some scenarios, 7 to 14 symbols may be (pre-)configured in a slot for sidelink and the PSCCH may be sent in 5 to 12 consecutive symbols. The number of symbols occupied by the PSSCH depends on the number of SL symbols allocated in the slot and whether the PSFCH is sent in that slot. Within the symbols carrying the PSCCH, the PSSCH may be multiplexed in the frequency domain with the PSCCH (if the PSCCH does not occupy the entire L _PSSCH sub-channel(s)). The second symbol in a slot (i.e., the first symbol with the PSCCH or with the PSCCH/PSSCH) may be duplicated with the first symbol of the slot for use for automatic gain control (AGC) purposes. Additionally, the symbol after the last symbol with PSSCH can be used as a guard symbol.

In FIG. 7, a sidelink transmission structure is illustrated in which PSCCH occupies 3 symbols in the time domain and 14 symbols within a slot of 14 symbols are used for PSCCH/PSSCH transmission. However, PSCCH may occupy 2 symbols, or some leading symbols within a slot may be used for PSCCH/PSSCH transmission and the remaining symbols may be used for PSFCH or for additional guard symbols.

Referring to FIG. 8, in some scenarios (e.g., NR V2X), for a resource pool with L subchannels, there are L possible PSCCH locations in a slot, starting from the second SL symbol in the slot and from the lowest RB in each subchannel. In other words, for a resource pool with L subchannels, there can be L PSCCH candidate resources in each slot. Therefore, in some scenarios, to receive a 1 ^st -stage SCI, the UE needs to check (or monitor) the L possible PSCCH locations in each slot in the resource pool.

Referring to FIGS. 7 and 8, in some scenarios (e.g., NR V2X), the UE is provided with a number of symbols for PSCCH, N _sym,PSCCH , and a number of RBs for PSCCH, N _PSCCH , via higher layer signaling (e.g., RRC signaling), for a resource pool, and the PSCCH is transmitted on N _PSCCH RBs starting from the lowest RB of the lowest subchannel of the associated PSSCH within the N _sym,PSCCH symbols starting from the second symbol available for SL transmissions in a slot.

A UE may be configured with one or more sidelink resource pools via higher layer signaling (e.g., RRC signaling). The sidelink resource pools may be used for transmitting a PSSCH or for receiving a PSSCH. In some scenarios, a PSSCH is transmitted in the same slot as an associated PSCCH. In some scenarios, a minimum resource allocation unit for a PSSCH in the time domain is a slot. A PSSCH transmitted in consecutive symbols within a slot is not transmitted in symbols that are not configured for sidelink. An index of a first symbol among consecutive symbols that can be used for sidelink and the number of consecutive symbols that can be used for sidelink may be provided to the UE(s) via higher layer signaling (e.g., RRC signaling). The UE does not transmit a PSSCH in the last symbol configured for sidelink, which may be used as a guard symbol. In some scenarios, a minimum resource allocation unit for a PSSCH in the frequency domain is a subchannel.

Referring to FIG. 8, when a PSCCH is transmitted/received in a PSCCH resource candidate of a slot within a resource pool, a PSSCH associated with the PSCCH is transmitted/received within consecutive symbols within the slot in the time domain, and is transmitted/received on L _PSSCH subchannels having the subchannel on which the PSCCH is transmitted/received as the lowest subchannel in the frequency domain. When a PSSCH occupies a plurality of subchannels, the PSCCH resource candidate(s) of the remaining subchannel(s) other than the lowest subchannel among the plurality of subchannels are used for transmission of the PSSCH. The PSCCH resource candidate(s) of the subchannel(s) that are not used for PSSCH transmission in a slot within the resource pool are also not used for PSCCH transmission. The RX UE attempts to detect a PSCCH from the PSCCH resource candidates, and if it detects a PSCCH in a slot, it considers the lowest RB on which the PSCCH is detected as the lowest RB of the PSSCH based on the SCI carried by the PSCCH, and can receive the PSSCH on N _PSSCH = L _PSSCH * N _sch RBs starting from the lowest RB.

As the need for vehicle-to-everything (V2X), a communication technology that supports wired/wireless communication between vehicles and other vehicles, infrastructure, networks, or pedestrians, arises, a rapid increase in SL communication is expected. In order to stably support SL communication, it may be considered to support SL communication not only in a licensed spectrum that is licensed to a specific network operator and can be used exclusively or preferentially by the network operator, but also in a shared spectrum, which is an unlicensed spectrum that is not licensed to a specific network operator and can be freely used by multiple network operators. However, in order to support SL communication in a shared spectrum, a method for coexisting communication in the shared spectrum and SL communication is required. Hereinafter, technologies applied to uplink communication and/or downlink communication between UE and BS in a shared spectrum among 3GPP-based communication technologies are described.

Unless otherwise stated, the following definitions apply to terms relating to shared spectrum in this specification:

- Channel: Consists of consecutive RBs on which a channel access process is performed in a shared spectrum, and may refer to a carrier or a part of a carrier.

- Channel access procedure (CAP): This refers to the process of evaluating channel availability based on sensing to determine whether other communication devices(s) are using the channel before signal transmission. When a BS or UE senses a channel during a sensing slot period, and the detected power is less than an energy detection threshold for at least a certain period of time within the sensing slot period, the sensing slot period is considered as an idle or free state, otherwise the sensing slot period is considered as a busy state. CAP may be referred to as LBT (Listen-Before-Talk).

- Channel occupancy: refers to the corresponding transmission(s) on the channel(s) by the BS/UE after the execution of CAP.

- Channel occupancy time (COT): refers to the total time that the BS/UE and any BS/UE(s) sharing the channel occupancy can perform transmission(s) on the channel after the BS/UE performs CAP. COT can be shared for transmissions between the BS and corresponding UE(s).

In some scenarios, when a carrier with SCS configuration u in a shared spectrum is configured with IntraCellGuardBandsPerSCS , the UE is provided with N _RB-set - 1 intra-cell guard bands on the carrier, each intra-cell guard band defined by a start RB GB ^start,u _s and a size G ^size,u _s in terms of the number of RBs, where GB ^start,u _s and GB ^size,u _s are determined by higher layer parameters provided to the UE from the BS, s∈{0,1,…, N _RB-set - 2}. The intra-cell guard bands separate N _{RB-set RB sets, each RB set defined by a start RB (RB start,u s ) and an end RB (RB end,u s ). The UE is provided with N RB-set} - 1 intra-cell guard bands on the carrier, each of which is defined by a start RB (RB ^start,u _s ) and an end RB (RB ^end,u _s ). , N _RB-set - 1}, the start RB index RB ^start,u _s and the end RB index RB ^end,u _s can be determined by the following mathematical formulas, respectively.

An RB set with index s consists of RB ^size,u _s resource blocks, where RB ^size,u _s = RB ^end,u _s - RB ^start,u _s + 1. If the UE is not configured with IntraCellGuardBandsPerSCS for u, the UE determines the RB indices and the corresponding RB set(s) for the intra-cell guard band(s) according to the nominal intra-cell guard band and RB pattern corresponding to u and the carrier size N ^size,u _grid . If the nominal intra-cell guard band and RB set pattern does not include any intra-cell guard bands, the number of RB sets for the carrier N _RB-set = 1.

When a UE is provided with the number of RBs = 0 for all intra-cell guard band(s) on a carrier with SCS configuration u, the UE is instructed that no intra-cell guard bands are configured for the cell and expects N _RB-set > 1.

Since the shared spectrum is not dedicated to a specific network operator, the BS and UE may apply Listen-Before-Talk (LBT) before performing transmission on a cell established with shared spectrum channel access. When LBT is applied, the transmitter listens/senses the channel to determine whether the channel is free or busy, and performs transmission only if the channel is deemed free. In other words, for shared spectrum, a communication device must determine whether the channel is occupied by other communication device(s) before transmitting a signal.

Figure 9 is a diagram illustrating a channel access mechanism on a shared spectrum according to some implementations.

In 3GPP based systems, channel access in downlink and uplink relies on LBT. The UE and BS must first sense the communication channel to detect that there is no communication prior to transmission. If the communication channel is an unlicensed band with a wide bandwidth, the channel sensing process relies on detecting energy levels on multiple subbands of the communication channel. LBT parameters, such as channel assessment parameters, can be set to the UE by the BS.

In some implementations, the channel access mechanism for a cell configured with shared spectrum channel access, i.e., the LBT mechanism, can be broadly divided into a Type 1 channel access process and a Type 2 channel access process.

Figure 10 illustrates the flow of a channel connection process. In particular, Figure 10 illustrates the flow of a type 1 channel connection process.

Type 1 channel access procedure is a counter-based random back-off channel access mechanism. A UE/BS that wants to perform transmission performs LBT to sense an idle channel on a cell of a shared spectrum. If the UE/BS senses that the channel is idle for a defer time T _d (S1001), the UE/BS generates a random back-off counter N between 0 and a contention window size (S1002). The contention window size is adjusted based on HARQ-ACK and a priority access class. If the counter is 0 and the UE/BS has not performed transmission, the UE/BS performs an additional short LBT for an additional slot duration T _sl and an additional slot duration T _d before the transmission (S1003, S1004). The duration of the above additional short LBT is 43 μs, 52 μs and 88 μs depending on the channel access priority class (CAPC) levels. For example, T _d = T _f + m _p *T _sl , where m _p is determined based on the channel access priority class (CAPC). T _f can be, for example, 16 μs and T _sl can be 9 μs. The following table illustrates m _p according to CAPC p and the minimum contention window CW _min,p , the maximum contention window CW _max,p and the maximum channel occupancy time T _mcot,p .

NR's shared spectrum channel access introduces mini-slot level channel access to increase the number of transmissions and supports back-to-back transmissions during COT as long as the time gap between two consecutive transmissions is no longer than 16 μs.

NR's shared spectrum channel access (hereinafter, NR-U) supports COT sharing. Different devices (e.g., UE/BS to UE, BS) can use the medium/channel alternately, provided that there are activity gaps between transmissions. For example, when a UE/BS initiates a COT through a Type 1 channel access procedure, resources within the COT can be used for transmissions by the UE/BS, as well as shared for transmissions by BS/UE(s). NR-U supports Type 2 LBT for COT sharing. When resources in a COT initiated through a Type 1 channel access process performed on a device are shared by another device, the other device may use a Type-2A channel access, a Type-2B channel access, or a Type-2C channel access, and there are specific gap limitations between two adjacent transmissions for these channel access types, and a Type-2 channel transmission can be classified into a Type-2A channel access, a Type-2B channel access, and a Type-2C channel access according to the specific gap limitations. In the case of a Type-2A channel access, a UE/BS performs channel sensing for a period of 25 μs before starting a transmission, and performs the transmission after the channel sensing succeeds. In the case of a Type-2B channel access, a UE/BS performs channel sensing for a period of 16 μs before starting a transmission, and performs the transmission after the channel sensing succeeds, wherein a gap between a start position of the transmission and an end position of a previous transmission is 16 μs. For Type-2C channel access, the UE may perform transmission immediately without channel sensing after a kind of gap, wherein the gap between the start position of said transmission and the end position of the previous transmission may be less than or equal to 16 μs.

Type 2 LBT, i.e., the gap for Type 2 channel access, can be controlled by the BS via the LBT type indication (i.e., channel access type indication) and CAPC indication in the DCI. For example, for a UL transmission burst of a UE occurring within a COT shared by the BS, if the start time position of the UL transmission and the end time position of a previous DL transmission burst are less than or equal to 16 μs, the BS can perform Type-2C channel access to the UE before the UL transmission burst.

To enable dynamic TDD on shared spectrum, UE/BS decides when and where to transmit and/or receive based on the indication of channel occupancy time (COT) structure. COT contains multiple slots, each slot can contain downlink resources, uplink resources, or flexible resources. COT structure reduces power consumption and channel access delay. In some scenarios (e.g., NR), COT is typically about 8 ms, and COT duration and available RB sets within the COT duration can be indicated by DCI format 2_0. Higher layer parameter availableRB-SetsToAddModList and higher layer parameter co-DurationsPerCellToAddModList can be set by BS. The following is an example of part of an information element (IE) SlotFormatIndicator containing availableRB-SetsToAddModList and co-DurationsPerCellToAddModList . In some scenarios, the IE SlotFormatIndicator is used to set monitoring of the group-common-PDCCH for slot format indicators (SFIs).

In the above table, sfi-RNTI is a parameter used to set the RNTI used for SFI on a given cell, dci-PayloadSize is a parameter used to set the total length of the DCI payload scrambled with SFI-RNTI , slotFormatCombToAddModList is a list of SlotFormatCombinations for the serving cells of the UE, where each SlotFormatCombination is a parameter used to set slot formats that occur in consecutive slots in time domain order as listed in the corresponding SlotFormatCombination, and slotFormatCombToReleaseList is a list of SlotFormatCombinations to be released.

availableRB-SetsToAddModList is a list of AvailableRB - SetsPerCell object(s), each of which contains a parameter servingCellId indicating the ID of the cell to which the setting is applicable, and a parameter positionInDCI indicating the (start) position of the bits in the DCI payload indicating the availability of RB sets of the serving cell. For the serving cell, the UE is provided with the position of the available RB set indicator in DCI format 2_0 via the parameter positionInDCI . The positions of the available RB set indicators in DCI format 2_0 are:

i) 1 bit if no intra-cell guard bands are configured for the serving cell, a value of '1' at that position indicates that the serving cell is available for receptions and a value of '0' at that position indicates that the serving cell is not available for receptions, and the serving cell remains available or unavailable for reception until the end of the remaining channel occupancy period.

ii) a bitmap of N _RB-set bits having a one-to-one mapping with RB sets of the serving cell when it is indicated that intra-cell guard band(s) are set for the serving cell, where N _RB-set is the number of RB sets in the serving cell, a value of '1' in the bitmap indicates that the corresponding RB set is available for receptions and a value of '0' in the bitmap indicates that the corresponding RB set is not available for receptions, and the RB set remains available or unavailable for reception until the end of the remaining channel occupancy period.

co-DurationsPerCellToAddModList is a list of CO-DurationsPerCell object(s), each CO-DurationsPerCell object contains a parameter servingCellId indicating the ID of the cell to which the configuration is applicable, a parameter positionInDCI indicating the position in the DCI of a bit field indicating the channel occupancy duration for the UE's serving cells, a parameter subcarrierSpacing indicating a reference subcarrier spacing for the list of channel occupancy durations, and a co-DurationList indicating the list of channel occupancy durations in symbol units.

In some implementations, referring to FIG. 9, the available RB sets and COT period for COT sharing may be notified to the UE(s) via DCI format 2_0 with a cyclic redundancy check (CRC) scrambled by the SFI-RNTI.

Figure 11 illustrates COT sharing between BS and UE.

When the upper layer parameter availableRB-SetsToAddModList is set, the following information can be transmitted via DCI format 2_0: Available RB Set Indicator 1, Available RB Set Indicator 2, ..., Available RB Set Indicator N1.

When the upper layer parameter co-DurationsPerCellToAddModList is set, the following information can be transmitted via the DCI format 2_0: COT Duration Indicator 1, COT Duration Indicator 2, ..., COT Duration Indicator N2.

For example, referring to FIG. 11, if the position of the COT duration indicator 1 among the bit fields in the DCI format 2_0 is set as a bit field for a serving cell having a serving cell index of 1 by the parameters servingCellId and positionInDCI in the CoDurationsPerCell object and the reference subcarrier spacing for the serving cell is set as 15 kHz by the subcarrierSpacing , and if the bit field COT duration indicator 1 in the DCI format 2_0 transmitted to the UEs by the BS includes a bit value indicating 280, the UE(s) detecting the DCI format 2_0 can assume that a COT of 280 OFDM symbols based on the 15 kHz subcarrier spacing is initiated by the BS for the serving cell. If the position of the Available RB Set Indicator 1 among the bit fields in the DCI format 2_0 is set by AvailableRB-SetsPerCell to include a bitmap for a serving cell having a serving cell index of 1, and the serving cell includes four RB sets, and the Available RB Set Indicator 1 includes a bitmap of '1010', RB sets on the serving cell can be shared by the BS and the UE during the COT period as illustrated in FIG. 11.

As mentioned above, for stable support of SL communication, supporting SL communication on shared spectrum can be considered. SL BWP and SL resource pool discussed in sidelink of 3GPP-based system and RB set discussed in shared spectrum transmission of 3GPP-based system can be considered to be reused for SL transmission on shared spectrum. Hereinafter, shared spectrum where SL transmission is supported is referred to as SL-U. Hereinafter, implementations of this specification for coexisting UL/DL transmission and SL transmission on shared spectrum are described.

In some implementations of the present specification, one or more SL BWPs may be (pre-)configured within a carrier on a shared spectrum. In some implementations of the present specification, a SL BWP may be (pre-)configured to include one or more SL resource pools. In some implementations of the present specification, at least one resource pool may be (pre-)configured to include an integer number of RB sets, where an RB set may correspond to about 20 MHz. In some implementations of the present specification, if a resource pool includes two adjacent RB sets, the RB(s) within the intra-cell guard band of the two adjacent RB sets may be defined as belonging to the resource pool. In some implementations of the present specification, interlaced RB based transmission may be configured for PSCCH/PSSCH transmission for the SL BWP. If the UE is not configured to use interlaced-RB based PSCCH/PSSCH transmission for SL BWP, or if contiguous-RB based transmission is configured, the UE may perform PSCCH/PSSCH transmission using contiguous-RB based transmission.

In SL-U, LBT is required to be performed for SL transmission. Type-1 SL channel access procedure is applicable to other SL transmissions, including PSCCH/PSSCH transmission(s), and S-SSB and PSFCH transmissions. Type-2A/2B/2C SL channel access procedure is applicable to the following cases:

> Type-2A is applicable if the gap is at least 25 μs.

> Type-2B is applicable if the gap is at least 16 μs??.

> Type-2C is applicable for gaps less than or equal to 16 μs, and the transmission period is at most 584 μs.

Figure 12 illustrates UE-to-UE COT sharing according to some implementations of this specification.

Referring to FIG. 12, UE-to-UE COT sharing may be supported in sidelink. For S-SSB/PSFCH/PSSCH/PSCCH transmission(s), a responding UE may utilize a COT shared by a COT initiating UE (using Type 1 channel access) within the RB set(s) corresponding to the shared COT. In this specification, a COT initiating UE is a UE performing a Type 1 channel access procedure, and a responding UE may mean a UE receiving a PSCCH/PSSCH from a COT initiating UE, and sharing the COT initiated by the COT initiating UE with the COT initiating UE. SL transmission(s) from the responding UE within the shared COT may be performed if the CAPC value(s) of the SL transmission(s) have a CAPC value less than or equal to a CAPC value indicated in an SCI format including the corresponding COT sharing indication.

Figure 13 illustrates a situation where multiple channel occupancy time (COT) initiating UEs transmit COT sharing information.

In the case of conventional communication on a shared spectrum, COT sharing is initiated by a BS, and all UEs that receive a DCI format (e.g., DCI format 2_0) including COT sharing information transmitted by the BS can share the COT. In the case of conventional communication on a shared spectrum, only one BS initiates COT sharing, whereas in the case of SL transmission, multiple UEs can each initiate COT sharing. In the case of a COT shared by a BS, it is unlikely that a UE will receive multiple different COT-SIs, but in the case of SL transmission, it is not unlikely that a UE will receive different COT-SIs. A method for determining available channel occupancy periods and available frequency resources in a situation where a UE receives multiple COT-SIs is required. As illustrated in FIG. 13, a responding UE can receive COT sharing information (COT-SI) from each of multiple COT initiating UEs. Since the channel conditions experienced or sensed by the multiple COT initiating UEs may be different, the available time and/or frequency resources indicated by the COT-SIs from the multiple COT initiating UEs may be different. When a responding UE receives multiple COT-SIs, the question arises as to how to determine the time/frequency resources available to the UE. In some implementations of the present specification, the cell in which the COT-SI is transmitted and the cell in which the COT period and the available frequency resource(s) (e.g., the available RB set(s)) are indicated by the COT-SI may be the same or different.

Figures 14 to 17 are illustrated to illustrate implementations of the present specification for determining time/frequency resources available to a responding UE via COT sharing. In the following description, the following is assumed with respect to COT sharing:

> COT-SI is assumed to contain CAPC used to initiate COT, source and destination Layer-1 IDs, time domain information of the shared COT (e.g., COT start point, COT duration, last COT slot index, etc.), and frequency domain information of the shared COT (e.g., available RB set(s)).

> COT-SI can be included in the 1 ^st -stage SCI format and/or the 2 ^nd -stage SCI format.

> In some implementations, the time interval for applying the contents of the COT-SI may be determined as a slot corresponding to the COT period indicated by the COT-SI, starting from the slot in which the SCI format including the COT-SI is received.

> The above indicated COT can be shared by the responding UE if the CAPC value(s) of the SL transmission(s) of the responding UE have CAPC values less than or equal to the CAPC value indicated in the SCI format containing the COT sharing indication.

When multiple COT-SIs are received, the following may be considered to determine the available COT period and available RB set(s) at the responding UE:

* Alt 1. Intersection of time/frequency resources.

The responding UE can determine the intersection of the time/frequency resources indicated by multiple COT-SIs as the COT period and RB set available to it. In this case, multiple UEs sharing a COT share one time/frequency resource.

Referring to FIG. 14, when a UE receives COT-SI#1 and COT-SI#2, the UE may determine that the RB set(s) indicated as '1' from both COT-SI#1 and COT-SI#2 are available for transmission on the corresponding cell.

If a UE receives COT-SI#1 indicating COT period #1 and COT-SI#2 indicating COT period #2 in the same slot, the UE may determine the available COT period to be min(COT period #1, COT period #2). For example, if a start of a COT time interval is defined as the start of a slot having an SCI format including COT-SI, and the UE receives COT-SI#1 indicating COT period #1 and COT-SI# indicating COT period #2 in the same slot, the UE may determine a shorter COT period between COT period #1 and COT period #2 to be the available COT period. Alternatively, if the UE receives COT-SI#1 indicating COT period #1 and COT-SI#2 indicating COT period #2 in different slots, the UE may determine the available COT period to be min(last COT slot #1, last COT slot #2). For example, if the COT-SI#1 received by the UE in slot 1 indicates 8 slots as a COT period, it can be determined that the COT sharing interval indicated by COT-SI#1 corresponds to slot 1 to slot 8, and if the COT-SI#1 received in slot 2 indicates 8 slots as a COT period, it can be determined that the COT sharing interval indicated by COT-SI#1 corresponds to slot 2 to slot 9. In this case, the last slot of the COT sharing interval indicated by COT-SI#1 is slot 8, and the last slot corresponding to the COT sharing interval indicated by COT-SI#2 is slot 9, so the UE can determine slot 8 corresponding to the smaller value of the two as the COT period.

According to Alt 1, a UE that has received multiple COT-SIs can determine that COT sharing is not allowed if there is no intersection between the time/frequency resources indicated by the multiple COT-SIs.

Since the COT period and RB set(s) included in the COT-SI are determined through a type 1 channel access procedure by measuring the amount of interference around the UE transmitting the COT-SI, they may be inappropriate time/frequency resources to be shared from the perspective of the UE receiving the COT-SI or the UE transmitting another COT-SI. According to Alt 1, since the intersection of the time/frequency resources indicated by the COT-SIs is determined as the time/frequency resources available to the UE receiving the COT-SIs, the impact on the transmission(s) by other UE(s) on the cell can be minimized.

* Alt 2. Based on COT-SI and CAPC

When multiple COT-SIs are received, the COT-SI with the smallest CAPC (i.e., highest priority) is assumed. Referring to FIG. 15, if a UE receives COT-SI#1 with CAPC = 3 and OT-SI#2 with CAPC = 4, the UE may determine that the RB set(s) indicated as '1' by the COT-SI#1 are available for transmission on the corresponding cell within the COT period indicated by the COT-SI#1 with the smaller CAPC value (higher priority). The UE may also receive multiple COT-SIs with the same CAPC value. In this case, in some implementations, the COT period and the available RB set(s) may be determined based on the earliest received COT-SI. In general, all UEs communicating in the same resource pool receive/transmit SCI formats according to the same PSCCH configuration. Therefore, the start/end time of the SL channel carrying the COT-SI can be all the same, and the time of receiving/transmitting the COT-SI can be determined based on the slot. In some implementations, if multiple COT-SIs with the same CAPC value are received in the same slot, the UE can randomly select a COT-SI among the multiple COT-SIs with the same CAPC value and the same received slot, and determine the COT period and the available RB set(s) based on the selected COT-SI. In this case, the UE performs COT sharing only with the COT initiating UE that transmitted the COT-SI determined by the above procedure (corresponding to UE#1 in the example of FIG. 15), and COT sharing is not allowed for the other UEs (corresponding to UE#2 in the example of FIG. 15).

As a variation of Alt 2, it is also possible to specify that if a responding UE receives multiple COT-SIs from multiple COT initiating UEs, it assumes the COT-SI with the lowest CAPC.

* Alt 3. Based on the timing at which COT-SI is received

Referring to FIG. 16, when multiple COT-SIs are received, the earliest received COT-SI is assumed. In some implementations, it may be specified that if the time slots in which the COT-SIs are received are the same, the COT-SI with the highest CAPC is assumed. Alternatively, in some implementations, it may be specified that if the time slots in which the COT-SIs are received are the same, the COT-SI with the lowest CAPC is assumed.

In some implementations, if the CAPC values of multiple COT-SIs are the same and the multiple COT-SIs are received in the same slot, the UE may randomly select a COT-SI among the multiple COT-SIs and determine the COT period and the available RB set(s) based on the selected COT-SI. The UE performs COT sharing only with the COT initiating UE that transmitted the COT-SI determined by the above procedure (corresponding to UE#2 in the example of FIG. 16), and COT sharing is not allowed for other UEs (corresponding to UE#1 in the example of FIG. 16).

* Alt 4. Independent COT sharing

A UE can independently consider all received COT-SIs. A responding UE can assume multiple COT shares. For example, referring to FIG. 17, a UE that receives COT-SI#1 from UE#1 and COT-S1#2 from UE#2 can assume COT-SI#1 when communicating with UE#1 and assume COT-S1#2 when communicating with UE#2.

If the responding UE performs SL transmission on the available frequency resources within the COT period indicated by the COT-SI, the COT initiating UE that transmitted the COT-SI can determine that the COT is shared with the responding UE. However, if the COT initiating UE fails to receive an SL channel from another UE within the COT that it intended to share with other UE(s), it cannot determine whether the reception of the SL channel is failed due to a bad channel condition or due to a failure in COT sharing. If the HARQ feedback is disabled, it is difficult for the COT initiating UE to know whether the COT sharing is successful or not, since there is no HARQ feedback for the SL transmission sent by the COT initiating UE. Considering these issues, in some implementations of the present specification, the responding UE may determine the indicated COT according to one of Alt 1 to Alt 4 and inform the corresponding COT initiating UE whether the COT can be shared or not. For example, if the responding UE can share a COT with the COT initiating UE#1, the responding UE may transmit an indication of COT sharing to the COT initiating UE#1. In some implementations, this feedback regarding COT sharing may be transmitted using PSFCH within the shared COT.

In some implementations of this specification described above, implementations of this specification have been described for the case where frequency information for COT sharing provides a set(s) of RBs for which it is available, but it is also possible for other units of frequency resource(s), for example, subchannel(s), to be provided via COT-SI.

The UE may transmit the PSSCH on L _PSSCH subchannels having the subchannel on which the PSCCH is transmitted as the lowest subchannel within the available frequency resources within the COT period determined according to some implementations of the present specification as described above.

For conventional communications on a shared spectrum, the UE determines the COT-shareable time and frequency resource(s) based on one COT-SI transmitted by the BS. According to some implementations of this specification, for sidelink communications on a shared spectrum, the UE may receive multiple COT-SIs, and determine the COT-shareable time and frequency resource(s) based on the received multiple COT-SIs.

FIG. 18 is an example of a process in which a communication device performs sidelink transmission according to some implementations of the present specification.

A communications device may perform operations according to some implementations of the present disclosure in connection with SL transmission. The communications device may include at least one transceiver; at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations according to some implementations of the present disclosure. A processing device for the communications device may include at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations according to some implementations of the present disclosure. A computer-readable (non-transitory) storage medium may store at least one computer program comprising instructions that, when executed by the at least one processor, cause the at least one processor to perform operations according to some implementations of the present disclosure. A computer program or computer program product may be recorded on at least one computer-readable (non-transitory) storage medium and may contain instructions that, when executed, cause (at least one processor) to perform operations according to some implementations of the present specification.

In the above communication device, the processing device, the computer-readable (non-transitory) storage medium, and/or the computer program product, the operations may include: receiving first channel occupancy time (COT) sharing information for a cell and second COT sharing information for the cell (S1801), wherein the first COT sharing information and the second COT sharing information each include time information about a channel occupancy duration and frequency information about available frequency resources; determining a COT period and frequency resource available to the communication device based on the first COT sharing information and the second COT sharing information (S1803); and transmitting the sidelink channel on the determined frequency resource within the determined COT period (S1805).

In some implementations, determining a COT period and frequency resource available to the communication device based on the first COT sharing information and the second COT sharing information may include: determining an intersection of a first channel occupancy period indicated by the first COT sharing information and a second channel occupancy period indicated by the second COT sharing information as the COT period available to the communication device; determining an intersection of the first available frequency resources indicated by the first COT sharing information and the second available frequency resources indicated by the second COT sharing information as the frequency resource available to the communication device.

In some implementations, the first COT sharing information may include a first channel access priority class (CAPC) value, and the second COT sharing information may include a second CAPC value. Determining a COT period and a frequency resource available to the communication device based on the first COT sharing information and the second COT sharing information may include: determining the COT period and the frequency resource available to the communication device based on time information and frequency information included in COT sharing information including a higher CAPC value among the first COT sharing information and the second COT sharing information. In some implementations, determining the COT period and the frequency resource available to the communication device based on COT sharing information received earlier among the first COT sharing information and the second COT sharing information, based on the first COT sharing information and the second COT sharing information including the same CAPC value.

In some implementations, determining a COT period and a frequency resource available to the communication device based on the first COT sharing information and the second COT sharing information may include: determining the COT period and the frequency resource available to the communication device based on COT sharing information received earlier among the first COT sharing information and the second COT sharing information. In some implementations, determining the COT period and the frequency resource available to the communication device based on time information and frequency information included in COT sharing information including a higher CAPC value among the first COT sharing information and the second COT sharing information, based on receiving the first COT sharing information and the second COT sharing information in a same slot may include determining the COT period and the frequency resource available to the communication device based on time information and frequency information included in COT sharing information.

In some implementations, determining the COT period and frequency resource available to the communication device based on the first COT sharing information and the second COT sharing information may include: receiving the first COT sharing information and the second COT sharing information in a same slot and determining the COT period and the frequency resource available to the communication device based on COT sharing information randomly selected from the first COT sharing information and the second COT sharing information, based on the first COT sharing information and the second COT sharing information including a same CAPC value.

In some implementations, determining a COT period and a frequency resource available to the communication device based on the first COT sharing information and the second COT sharing information may include: determining the COT period and the frequency resource available to the communication device based on the first COT sharing information, based on that the sidelink channel is for the first communication device that transmitted the first COT sharing information; and determining the COT period and the frequency resource available to the communication device based on the second COT sharing information, based on that the sidelink channel is for the second communication device that transmitted the second COT sharing information.

In some implementations, the frequency information may include information about at least one set of available resource blocks.

In some implementations, the frequency resource available to the communication device may include a plurality of subchannels. Transmitting the sidelink channel may include transmitting the sidelink channel on at least one of the plurality of subchannels.

As described above, the examples of the present disclosure are provided to enable a person skilled in the art to implement and practice the present disclosure. While the examples of the present disclosure have been described above with reference to the examples of the present disclosure, those skilled in the art will appreciate that various modifications and variations may be made to the examples of the present disclosure. Accordingly, the present disclosure is not intended to be limited to the examples set forth herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Implementations of this specification can be used in wireless communication systems, BSs, user equipment, or other equipment.

Claims (13)

When a communication device transmits a sidelink channel in a wireless communication system,
Receive first channel occupancy time (COT) sharing information for a cell and second COT sharing information for the cell, each of the first COT sharing information and the second COT sharing information including time information regarding a channel occupancy duration and frequency information regarding available frequency resources;
Based on the first COT sharing information and the second COT sharing information, determining the COT period and frequency resources available to the communication device; and
Including transmitting the sidelink channel on the determined frequency resource within the determined COT period,
Sidelink channel transmission method. In the first paragraph,
Based on the above first COT sharing information and the above second COT sharing information, determining the COT period and frequency resources available to the communication device:
Determining the intersection of the first channel occupancy period indicated by the first COT shared information and the second channel occupancy period indicated by the second COT shared information as the COT period available to the communication device;
Including determining an intersection of the first available frequency resources indicated by the first COT shared information and the second available frequency resources indicated by the second COT shared information as the frequency resources available to the communication device.
Sidelink channel transmission method. In the first paragraph,
The first COT shared information includes a first channel access priority class (CAPC) value, and the second COT shared information includes a second CAPC value.
Based on the above first COT sharing information and the above second COT sharing information, determining the COT period and frequency resources available to the communication device:
Including determining the COT period and the frequency resource available to the communication device based on time information and frequency information included in the COT sharing information including a higher CAPC value among the first COT sharing information and the second COT sharing information.
Sidelink channel transmission method. In the third paragraph,
Based on the first COT sharing information and the second COT sharing information including the same CAPC value, determining the COT period and the frequency resource available to the communication device based on the COT sharing information received earlier among the first COT sharing information and the second COT sharing information.
Sidelink channel transmission method. In paragraph 4,
Including determining the COT period and the frequency resource available to the communication device based on COT sharing information randomly selected from the first COT sharing information and the second COT sharing information, based on the first COT sharing information and the second COT sharing information including the same CAPC value and receiving the first COT sharing information and the second COT sharing information in the same slot.
Sidelink channel transmission method. In the first paragraph,
Based on the above first COT sharing information and the above second COT sharing information, determining the COT period and frequency resources available to the communication device:
Including determining the COT period and the frequency resource available to the communication device based on the COT sharing information received earlier among the first COT sharing information and the second COT sharing information.
Sidelink channel transmission method. In Article 6,
Based on receiving the first COT sharing information and the second COT sharing information in the same slot, determining the COT period and the frequency resource available to the communication device based on time information and frequency information included in the COT sharing information including a higher CAPC value among the first COT sharing information and the second COT sharing information.
Sidelink channel transmission method. In Article 7,
Including determining the COT period and the frequency resource available to the communication device based on COT sharing information randomly selected from the first COT sharing information and the second COT sharing information, based on receiving the first COT sharing information and the second COT sharing information in the same slot and including the same CAPC value as the first COT sharing information and the second COT sharing information.
Sidelink channel transmission method. In the first paragraph,
Based on the above first COT sharing information and the above second COT sharing information, determining the COT period and frequency resources available to the communication device:
Based on the fact that the sidelink channel is intended for the first communication device that transmitted the first COT sharing information, determining the COT period and the frequency resource available to the communication device based on the first COT sharing information; and
Based on the fact that the sidelink channel is for the second communication device that transmitted the second COT sharing information, determining the COT period and the frequency resource available to the communication device based on the second COT sharing information,
Sidelink channel transmission method. In the first paragraph,
The above frequency information includes information about at least one set of available resource blocks.
Sidelink channel transmission method. In the first paragraph,
The frequency resources available to the above communication device include a plurality of subchannels,
Transmitting the sidelink channel comprises transmitting the sidelink channel on at least one of the plurality of subchannels.
Sidelink channel transmission method. When a communication device transmits a sidelink channel in a wireless communication system,
At least one transceiver;
at least one processor; and
At least one memory operably connected to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform operations, said operations comprising:
Receive first channel occupancy time (COT) sharing information for a cell and second COT sharing information for the cell, each of the first COT sharing information and the second COT sharing information including time information regarding a channel occupancy duration and frequency information regarding available frequency resources;
Based on the first COT sharing information and the second COT sharing information, determining the COT period and frequency resources available to the communication device; and
Including transmitting the sidelink channel on the determined frequency resource within the determined COT period,
Communication device. A computer-readable non-transitory storage medium comprising at least one computer program that causes at least one processor to perform operations, the operations comprising:
Receive first channel occupancy time (COT) sharing information for a cell and second COT sharing information for the cell, each of the first COT sharing information and the second COT sharing information including time information regarding a channel occupancy duration and frequency information regarding available frequency resources;
Based on the first COT sharing information and the second COT sharing information, determining the COT period and frequency resources available to the communication device; and
Including transmitting the sidelink channel on the determined frequency resource within the determined COT period,
Storage medium.

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