WO2025121722A1 - Method, communication device, processing device, and storage medium for transmitting sidelink signal, and method, communication device, processing device, and storage medium for receiving sidelink signal - Google Patents

Abstract

A communication device of the present specification transmits a first SCI format including channel occupancy time (COT) sharing information, which includes time domain information and frequency domain information related to a COT of a cell. The first SCI format may include a first zone identifier and a second zone identifier. The first zone identifier is an identifier of a zone to which the communication device belongs, and the second zone identifier is an identifier of a zone to which a destination of a transport block belongs.

Description

Method for transmitting sidelink signals, communication device, processing device and storage medium, and method for receiving sidelink signals, communication device, processing device and storage medium

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 transmitting a sidelink signal by a communication device in a wireless communication system is provided. The method may include: performing a type 1 channel connection on a cell for transmitting a transport block; and, based on the success of the type 1 channel connection for the cell, transmitting a first sidelink control information (SCI) format including COT sharing information including time domain information regarding a channel occupancy time (COT) for the cell and frequency domain information, and the transport block within the COT determined by the type 1 channel connection, wherein the first SCI format includes a first zone identifier and a second zone identifier, wherein the first zone identifier is an identifier of a zone to which the communication device belongs and the second zone identifier is a zone identifier of a zone to which a destination of the transport block belongs.

In another aspect of the present disclosure, a communication device for transmitting a sidelink signal in a wireless communication system is provided. The communication device comprises: 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 including: performing a type 1 channel connection on a cell for transmitting a transport block; and, based on a success of the type 1 channel connection to the cell, transmitting a first sidelink control information (SCI) format including COT sharing information including time domain information about a channel occupancy time (COT) for the cell and frequency domain information, and the transport block within the COT determined by the type 1 channel connection, wherein the first SCI format includes a first zone identifier and a second zone identifier, the first zone identifier being an identifier of a zone to which the communication device belongs and the second zone identifier being a zone identifier of a zone to which a destination of the transport block belongs.

In another aspect of the present disclosure, a processing device is provided. The processing device comprises: 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 including: performing a type 1 channel connection on a cell for transmitting a transport block; and, based on a success of the type 1 channel connection to the cell, transmitting a first sidelink control information (SCI) format including COT sharing information including time domain information regarding a channel occupancy time (COT) for the cell and frequency domain information, and the transport block within the COT determined by the type 1 channel connection, wherein the first SCI format includes a first zone identifier and a second zone identifier, the first zone identifier being an identifier of a zone to which the communication device belongs and the second zone identifier being a zone identifier of a zone to which a destination of the transport block belongs.

In another aspect of the present disclosure, a computer-readable non-transitory storage medium is provided comprising at least one computer program causing at least one processor to perform operations. The operations may include: performing a type 1 channel connection on a cell for transmitting a transport block; and, based on a success of the type 1 channel connection to the cell, transmitting a first sidelink control information (SCI) format including COT sharing information including time domain information about a channel occupancy time (COT) for the cell and frequency domain information, and the transport block within the COT determined by the type 1 channel connection, wherein the first SCI format includes a first zone identifier and a second zone identifier, wherein the first zone identifier is an identifier of a zone to which the communication device belongs and the second zone identifier is a zone identifier of a zone to which a destination of the transport block belongs.

In another aspect of the present specification, a method for a communication device to receive a sidelink signal in a wireless communication system is provided. The method may include: receiving a first sidelink control information (SCI) format including COT sharing information including time domain information and frequency domain information regarding a channel occupancy time (COT) for a cell, wherein the first SCI format includes a first zone identifier and a second zone identifier, wherein the first zone identifier is an identifier of a zone to which a first communication device transmitting the first SCI format belongs and the second zone identifier is a zone identifier of a zone to which a second communication device, which is a destination of a transport block associated with the first SCI, belongs; and performing sidelink transmission within the COT based on the first zone identifier or the second zone identifier and a third zone identifier of the communication device being the same.

In another aspect of the present disclosure, a communication device for receiving a sidelink signal in a wireless communication system is provided. The communication device comprises: 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 comprising: receiving a first sidelink control information (SCI) format including channel occupancy time (COT) sharing information including time domain information and frequency domain information regarding a cell, the first SCI format including a first zone identifier and a second zone identifier, the first zone identifier being an identifier of a zone to which a first communication device transmitting the first SCI format belongs and the second zone identifier being a zone identifier of a zone to which a second communication device, which is a destination of a transport block associated with the first SCI, belongs; It may include performing sidelink transmission within the COT based on the first zone identifier or the second zone identifier and the third zone identifier of the communication device being the same.

In another aspect of the present disclosure, a processing device is provided. The processing device comprises: at least one processor; and at least one memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations, the operations comprising: receiving a first sidelink control information (SCI) format including COT sharing information including time domain information and frequency domain information regarding channel occupancy time (COT) for a cell, the first SCI format including a first zone identifier and a second zone identifier, the first zone identifier being an identifier of a zone to which a first communication device transmitting the first SCI format belongs and the second zone identifier being a zone identifier of a zone to which a second communication device that is a destination of a transport block associated with the first SCI belongs; performing a sidelink transmission within the COT based on the first zone identifier or the second zone identifier being the same as a third zone identifier of the communication device.

In another aspect of the present disclosure, a computer-readable non-transitory storage medium is provided comprising at least one computer program causing at least one processor to perform operations. The operations may include: receiving a first sidelink control information (SCI) format including COT sharing information including time domain information and frequency domain information regarding channel occupancy time (COT) for a cell, the first SCI format including a first zone identifier and a second zone identifier, the first zone identifier being an identifier of a zone to which a first communication device transmitting the first SCI format belongs and the second zone identifier being a zone identifier of a zone to which a second communication device that is a destination of a transport block associated with the first SCI belongs; and performing a sidelink transmission within the COT based on the first zone identifier or the second zone identifier being the same as a third zone identifier of the communication device.

In each aspect of this specification, the first SCI format can be transmitted or received over a physical sidelink shared channel (PSSCH).

In each aspect of the present specification, a physical sidelink control channel (PSCCH) carrying a second SCI format for scheduling the PSSCH and the first SCI format may be transmitted or received within the COT.

In each aspect of the present specification, for the method or the operations including receiving the first SCI format, performing the sidelink transmission within the COT based on the first zone identifier or the second zone identifier and the third zone identifier of the communication device being the same may include: performing a type 2 channel connection within the COT; and performing the sidelink transmission within the COT based on the success of the type 2 channel connection.

In each aspect of the present specification, for the method or the operations comprising receiving the first SCI format, performing the sidelink transmission may comprise: transmitting a second SCI format comprising a cast type field set to unicast.

In each aspect of the present specification, for the method or the operations comprising receiving the first SCI format, performing the sidelink transmission within the COT based on the first zone identifier or the second zone identifier being identical to the third zone identifier of the communication device may include: performing the sidelink transmission to the first communication device based on the third zone identifier being identical to the second zone identifier and a source identifier in the first SCI format matching a destination identifier assigned to the communication device.

In each aspect of the present specification, for the method or the operations including receiving the first SCI format, performing the sidelink transmission within the COT based on the first zone identifier or the second zone identifier and the third zone identifier of the communication device being identical may include: performing the sidelink transmission to the target communication device based on the third zone identifier being identical to the second zone identifier and the identifier of a zone to which the target communication device of the sidelink transmission belongs being identical to the first zone identifier.

In each aspect of the present specification, for the method or the operations comprising receiving the first SCI format, performing the sidelink transmission within the COT based on the first zone identifier or the second zone identifier being identical to the third zone identifier of the communication device may include: performing the sidelink transmission to the second communication device based on the third zone identifier being identical to the first zone identifier and a destination identifier within the first SCI format matching a destination identifier assigned to the communication device.

In each aspect of the present specification, for the method or the operations including receiving the first SCI format, performing the sidelink transmission within the COT based on the first zone identifier or the second zone identifier and the third zone identifier of the communication device being identical may include: performing the sidelink transmission to the target communication device based on the third zone identifier being identical to the first zone identifier and the identifier of the zone to which the target communication device of the sidelink transmission belongs being identical to the second identifier.

In each aspect of the present specification, for the method or the operations comprising receiving the first SCI format, performing the sidelink transmission within the COT based on the first zone identifier or the second zone identifier being identical to the third zone identifier of the communication device may include: performing the sidelink transmission to the first communication device based on the third zone identifier being identical to the first zone identifier and a source identifier within the first SCI format matching a destination identifier assigned to the communication device.

In each aspect of the present specification, for the method or the operations comprising receiving the first SCI format, performing the sidelink transmission within the COT based on the first zone identifier or the second zone identifier being identical to the third zone identifier of the communication device may include: performing the sidelink transmission to the second communication device based on the third zone identifier being identical to the second zone identifier and a source identifier in the first SCI format matching a destination identifier assigned to the communication device.

In each aspect of this specification, the first SCI format may include a COT shared availability indication field.

In each aspect of the present specification, the method or the operations comprising receiving the first SCI format may include: comparing the first zone identifier or the second zone identifier with the third zone identifier of the communication device based on the COT shared availability indication field being set to the first value.

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 a block diagram illustrating examples of communication devices capable of performing a method according to the present specification;

Figure 2 illustrates an example of a frame structure available in a 3GPP-based wireless communication system;

Figure 3 illustrates a resource grid of slots;

FIG. 4 illustrates communication links in a wireless communication system;

Figure 5 is a diagram illustrating frequency resources and time resources for sidelink;

Figures 6 and 7 illustrate transmission structures of sidelink physical channels within a slot;

FIG. 8 is a diagram illustrating a channel access mechanism on a shared spectrum according to some implementations;

Figure 9 illustrates the flow of the channel connection process;

Figure 10 illustrates channel occupancy time (COT) sharing between a BS and a UE;

Figures 11 and 12 illustrate UE-to-UE COT sharing that can be used for sidelink communication.

Figure 13 illustrates the relationship between identifiers of a transmitting UE and identifiers of a receiving UE;

Figure 14 illustrates zone identifiers (IDs);

FIG. 15 is a diagram illustrating the concept of UE-to-UE COT sharing according to some implementations of the present specification;

Figures 16 to 21 illustrate location-based COT sharing according to some implementations of the present specification;

FIG. 22 is an example of a process in which a communication device performs sidelink transmission according to some implementations of the present specification;

FIG. 23 is an example of a process by which a communication device performs sidelink reception 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.

The communication system 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, wireless devices may include robots, vehicles, XR (eXtended Reality) devices, hand-held devices, home appliances, IoT (Internet of Things) devices, and AI devices/servers. For example, BS, network 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 can be connected to a network via a BS. AI (Artificial Intelligence) technology can be applied to wireless devices, and wireless devices can be connected to AI servers via a network. Wireless devices can communicate with each other via a BS/network, but can also communicate directly (e.g. sidelink communication) without going through a BS/network.

Wireless communication/connection can be established between a wireless device and a BS, between a BS and a BS, and/or between wireless devices. 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. 1 is a block diagram illustrating examples of communication devices capable of performing a method according to the present specification. Referring to FIG. 1, a first wireless device (100) and a second wireless device (200) can transmit and/or receive wireless signals through various wireless access technologies. Here, {the first wireless device (100), the second wireless device (200)} may be wireless devices included in a communication system.

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

The structure of the frame in Fig. 2 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. 2, 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 _s and T _c have a constant relationship κ = T _s /T _c = 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. 3 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 4 illustrates communication links in a wireless communication system.

Referring to FIG. 4, 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 the 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. 2 and the resource grid structure described in Fig. 3 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 5 is a diagram illustrating frequency resources and time resources for sidelink.

Referring to Fig. 5, 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 6 and 7 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. 6, 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 configured 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 within the subchannel N _sch (i.e., N _PSCCH <= N _sch ). PSCCH carries 1 ^{st -stage} SCI including control information associated with PSSCH and 2 ^nd -stage SCI. For this purpose, for example, SCI format 1-A can be used. The above 1 ^st -stage SCI may indicate frequency resources (e.g., subchannel(s)) of a PSSCH carrying a current (re-)transmission of a transport block (TB), and may indicate resource reservation for retransmission(s) of the TB up to a predetermined number (e.g., 2). The 1 ^st -stage SCI may include a priority of an associated PSSCH, and may include information about a format and a size of a 2 ^nd -stage SCI. The 1 ^st -stage SCI may include information about a modulation and coding scheme (MCS) of a transport block (TB) carried in the associated PSSCH. Although not illustrated in FIG. 6, a DM-RS associated with a PSCCH (hereinafter, referred to as PSCCH DM-RS) may be transmitted within the PSCCH for demodulation of the PSCCH. For example, each PSCCH symbol (i.e., an OFDM symbol including a PSCCH) may include a PSCCH DM-RS. Although not illustrated in FIG. 6, the DM-RS associated with a PSSCH is carried on different symbols within a slot to which the PSSCH is allocated (hereinafter, referred to as a PSSCH slot). Multiple time patterns within a resource pool may be (pre-)configured for the PSSCH DM-RS, 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. 6, 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 carrying the PSCCH or the PSCCH/PSSCH) may be duplicated with the first symbol of the slot for use in automatic gain control (AGC) purposes. Additionally, the symbol after the last symbol with PSSCH can be used as a guard symbol.

In FIG. 6, 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. 7, 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. 6 and 7, 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. 7, 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 8 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 9 illustrates the flow of a channel connection process. In particular, Figure 9 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 (S901), the UE/BS generates a random back-off counter N between 0 and a contention window size (S902). 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 (S903, S904). 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 shared spectrum channel access of NR introduces mini-slot level channel access to increase the number of transmissions and supports back-to-back transmissions during the COT as long as the time gap between two consecutive transmissions is not 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 10 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. 10, 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. 10.

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.

Figures 11 and 12 illustrate UE-to-UE COT sharing that can be used for sidelink communication.

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. Since UE-to-UE sharing is performed by a COT initiating UE with only interference information around itself to perform COT sharing, if COT is shared with an unspecified number of UEs, an unexpected interference problem may occur since the interference environment around each UE may be different from the interference environment around the COT initiating UE. Therefore, in some implementations, as illustrated in FIG. 11, UE-to-UE COT sharing is performed such that a channel occupancy state determined by the COT initiating UE, which is the subject of sensing, is shared only with the UE(s) with which the COT initiating UE intends to communicate.

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.

In some implementations of this specification, SCI formats may be used to transmit COT sharing information. For example, SCI Format 2-A, SCI Format 2-B, or SCI Format 2-C may include the following sidelink transmission information:

> HARQ process number - 4 bits.

> New data indicator - 1 bit

> Redundancy version - 2 bits

> Source ID - 8 bits

> Destination ID - 16 bits

> HARQ feedback enabled/disabled indicator - 1 bit

> Cast type indicator - 2 bits

The above cast type directive can contain values according to the following table.

In some implementations of the present specification, for example, a responding UE for a shared COT may be a receiving UE that is a target of a PSCCH/PSSCH transmission from the COT initiating UE, i) in case of a unicast from the COT initiating UE, when the source and destination IDs included in the SCI of the COT initiating UE match corresponding destination and source IDs associated with the same unicast from the receiving UE, and ii) in case of a groupcast and broadcast, when the destination ID included in the SCI of the COT initiating UE matches a destination ID known to the receiving UE. In some implementations of the present specification, a responding UE for a shared COT may be a UE identified by ID(s) if additional IDs (in addition to the source and destination IDs of the PSCCH/PSSCH transmission) are included in the COT shared information from the COT initiating UE. Hereinafter, the additional ID may be a source ID and/or destination ID additionally included in the SCI format in addition to the source ID and destination ID transmitted in the 2 ^nd -stage SCI format, SCI format 2-A, SCI format 2-B, or SCI format 2-C.

Figure 13 illustrates the relationship between identifiers of a transmitting UE and identifiers of a receiving UE. In Figure 13, L1 represents Layer-1 and L2 represents Layer-2.

Each UE is assigned one or more Layer-2 IDs consisting of source Layer-2 ID(s) and destination Layer-2 ID(s), and the Layer-2 ID is determined according to the V2X communication mode.

A transport block carried by the PSSCH corresponds to a MAC PDU in the MAC layer, and the MAC PDU may include a MAC SDU including SL-SCH data and a MAC subheader for the MAC SDU. The MAC subheader includes an SRC field and a DST field, and carries 16 most significant bits (MSBs) of a source Layer-2 ID set to an identifier provided by a higher layer than the MAC layer in a protocol stack, and the DST field carries 8 MSBs of a destination Layer-2 ID set to the identifier provided by a higher layer than the MAC layer.

When a transmitting (TX) UE performs transmission, the (8-bit) source Layer-1 ID is determined as the 8 LSBs of the source Layer-2, and the (16-bit) destination Layer-1 ID is determined as the 16 LSBs of the destination Layer-2 ID. For example, a TX UE sets the source Layer-1 ID (e.g., source ID of SCI format 2-A) in the sidelink transmission information of a transport block (TB) for a source and destination pair of MAC PDU to be transmitted, to the 8 least significant bits (LSBs) of the source Layer-2 ID of the MAC PDU, and sets the destination Layer-1 ID (e.g., destination ID of SCI format 2-A) to the 16 LSBs of the destination Layer-2 ID of the MAC PDU.

When a receiving (RX) UE receives, the RX UE obtains the source Layer-1 ID and the destination Layer-1 ID from the 2 ^nd -stage SCI format (e.g., SCI format 2-A).

Referring to Fig. 13(a), in the case of unicast, the RX UE checks whether 16 LSBs among the source Layer-2 IDs it has are identical to the destination Layer-1 ID acquired by the RX UE, and whether 8 LSBs among the destination Layer-2 IDs it has are identical to the source Layer-1 ID acquired by the RX UE. If the 16 LSBs of the source Layer-2 ID that the RX UE has are identical to the acquired destination Layer-1 ID and the 8 LSBs of the destination Layer-2 ID that the RX UE has are identical to the source Layer-1 ID acquired by the RX UE, decoding of the received PSSCH can be performed to acquire a transport block. For example, if a transport block is associated with unicast, and a DST field of a MAC PDU subheader decoded by the UE is equal to 8 MSBs and 16 LSBs of one of the source Layer-2 ID(s) of the UE and is equal to a destination ID within the corresponding SCI, and a SRC field of the decoded MAC PDU subheader is equal to 16 MSBs and 8 LSBs of one of the destination Layer-2 ID(s) of the UE and is equal to a source ID within the corresponding SCI, the UE can determine that the UE is a target UE of the transport block.

Referring to Fig. 13(b), in the case of groupcast, the RX UE can check whether 16 LSBs among the destination Layer-2 IDs it has are identical to the destination Layer-1 ID acquired by the RX UE, and if so, can decode the received PSSCH to acquire a transport block. For example, if the transport block is associated with groupcast and the DST field of the MAC PDU subheader decoded by the UE is identical to 8 MSBs of any one of the destination Layer-2 ID(s) of the UE and 16 LSBs are identical to the destination ID in the corresponding SCI, the UE can determine that it is one of the target UEs of the transport block.

Figure 14 illustrates zone identifiers (IDs).

In the existing SL communication, the zone ID of a TX UE can be transmitted via SCI format 2-B, which is a format of 2 ^nd -stage SCI carried by PSSCH. The SCI format 2-B includes a required communication range and a zone ID of the TX UE. The zone ID field in the SCI format 2-B indicates a zone in which the TX UE is located. The zone ID is indicated by, for example, 12 bits, and a given area can be divided into 2 ¹² squared regions of equal size. The required communication range can be expressed by 4 bits using a set of 16 (pre-)configured values selected from a defined set of possible values. The defined set of possible values may include: 20, 50, 80, 100, 120, 150, 180, 200, 220, 270, 300, 350, 370, 400, 420, 450, 500, 600, 700, 1000 m. The UE may determine the ID of the zone in which the TX UE is located (i.e., zone ID) using the following equations if the RRC configuration sl-ZoneConfig is set by the network:

x ₁ = Floor(x/L) mod 64;

y ₁ = Floor (y/L) mod 64;

Zone_ID = y ₁ *64 + x ₁ .

Here, L is the value of sl-ZoneLength , which represents the length of each geographical zone contained in sl-ZoneConfig , x is the geodesic distance (expressed in meters) in longitude between the UE's current position and geographical coordinates (0, 0), and y is the geodesic distance (expressed in meters) in latitude between the UE's current position and geographical coordinates (0, 0).

The UE-to-UE COT sharing described in FIG. 11 or FIG. 12 is very limited and inefficient because COT sharing with other UEs than the responding UE is not allowed. For example, referring to FIG. 11, even if a UE (e.g., UE_A in FIG. 11) is located close to a responding UE for a COT initiating UE, the COT of the COT initiating UE cannot be shared with UE_A if the UE_A is not the responding UE. Hereinafter, some implementations of the present specification are described to solve these problems.

FIG. 15 is a diagram illustrating the concept of UE-to-UE COT sharing according to some implementations of the present specification.

In some implementations of the present specification described below, UE-to-UE COT sharing can be performed based on UE location information. For example, in some implementations of the present specification, referring to FIG. 15, a COT initiated by a COT initiating UE is shared not only with a responding UE to the COT initiating UE, but also with other UEs (e.g., UE_A in FIG. 15) in the vicinity of the responding UE. In some implementations of the present specification described below, UE-to-UE sharing based on UE location information can allow more UEs to share the COT. In the description below, it is assumed that:

> COT sharing information (COT-SI) includes CAPC used to initiate COT, source and destination Layer-1 IDs, time domain information of the shared COT (e.g., COT duration), and frequency domain information of the shared COT (e.g., available RB set(s)).

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

> The indicated COT may be shared by the responding UE if the CAPC value(s) of the SL transmission(s) of the responding UE are less than or equal to the CAPC value indicated in the SCI format containing the COT-SI (or in the case where the SCI format containing the COT-SI is carried by the PSSCH, the SCI format scheduling the PSSCH).

In some implementations of this specification, the COT-SI includes the zone ID of the COT initiating UE and the zone ID of the responding UE. Hereinafter, the zone ID of the transmitting UE (TX UE) performing the SL transmission is expressed as ZoneID_TX, and the zone ID of the receiving UE (RX UE) of the SL transmission is expressed as ZoneID_RX. The zone ID(s) are included in the 1 ^st -step SCI format and/or the 2 ^nd -step SCI format. UEs according to some implementations of this specification can perform a location-based COT sharing procedure using the zone ID(s) included in the COT-SI. For example, referring to FIG. 15, UE_A can decode the SCI format including the COT-SI and identify ZoneID_TX and ZoneID_RX in the COT-SI. The UE_A may compare the ZoneID_A of the UE_A with ZoneID_RX and/or ZoneID_TX in the COT-SI. If ZoneID_A is equal to ZoneID_TX or ZoneID_RX, the COT indicated by the COT-SI may be potentially shared with the UE_A.

Figures 16 to 21 illustrate location-based COT sharing according to some implementations of the present specification. In the examples of Figures 16 to 21, ZoneID_A is the zone ID of UE_A, ZoneID_B is the zone ID of UE_B, and UE_A is a UE that is not a responding UE of the COT initiating UE but shares the COT of the COT initiating UE.

* Case 1. Unicast with COT initiating UE: Referring to FIG. 16, if ZoneID_A is identical to ZoneID_RX in COT-SI and source ID included in SCI format of COT initiating UE matches corresponding destination ID of UE_A, then COT indicated by COT-SI can be shared with UE_A belonging to the same zone as responding UE of COT initiating UE for unicast with COT initiating UE. For example, in case 1, UE_A can transmit a transport block within COT to COT initiating UE together with SCI format including Cast Type field set to unicast, or COT initiating UE can transmit a transport block within COT to UE_A together with SCI format including Cast Type field set to unicast.

* Case 2. Unicast with a UE other than the COT initiating UE: Referring to FIG. 17, if ZoneID_A is identical to ZoneID_RX in COT-SI and ZondID_B is identical to ZoneID_TX in the COT-SI, the COT indicated by the COT-SI can be shared with UE_A belonging to the same zone as a responding UE of the COT initiating UE for unicast with UE_B belonging to the same zone as the COT initiating UE. The UE_A and the UE_B can listen to the COT-SI transmitted by the COT initiating UE and compare it with their own zone IDs, and use the COT for unicast communication between the UE_A and the UE_B. For example, in case 2, the UE_A may transmit a transport block to the UE_B within the COT together with an SCI format including a cast type field set to unicast, or the UE_B may transmit a transport block to the UE_A within the COT together with an SCI format including a cast type field set to unicast.

* Case 3. Unicast with Responding UE: Referring to FIG. 18, if ZoneID_A is identical to ZoneID_TX in COT-SI and a destination ID included in the SCI format of the COT initiating UE matches the corresponding destination ID of UE_A, the COT indicated by the COT-SI can be shared with UE_A belonging to the same zone as the COT initiating UE for unicast with the responding UE of the COT initiating UE. For example, in case 3, the UE_A may transmit a transport block within the COT to the responding UE of the COT initiating UE together with an SCI format including a cast type field set to unicast, or the responding UE may transmit a transport block within the COT to the UE_A together with an SCI format including a cast type field set to unicast.

* Case 4. Unicast with other UE than responding UE: Referring to FIG. 19, if ZoneID_A is identical to ZoneID_TX in COT-SI and ZoneID_B is identical to ZoneID_RX in COT-SI, the COT indicated by the COT-SI can be shared with UE_A belonging to the same zone as the COT initiating UE for unicast with UE_B belonging to the same zone as the responding UE. The UE_A and the UE_B can listen to the COT-SI transmitted by the COT initiating UE and compare it with their own zone IDs, and use the COT for unicast communication between the UE_A and the UE_B. For example, in case 4, the UE_A may transmit a transport block to the UE_B within the COT together with an SCI format including a cast type field set to unicast, or the UE_B may transmit a transport block to the UE_A within the COT together with an SCI format including a cast type field set to unicast.

* Case 5. Unicast with COT initiating UE: Referring to FIG. 20, if ZoneID_A is identical to ZoneID_TX in COT-SI and source ID included in SCI format of COT initiating UE matches corresponding destination ID of UE_A, then COT indicated by COT-SI can be shared with UE_A belonging to the same zone as COT initiating UE for unicast with COT initiating UE. For example, in case 5, UE_A can transmit a transport block within COT to COT initiating UE together with SCI format including Cast Type field set to unicast, or COT initiating UE can transmit a transport block within COT to UE_A together with SCI format including Cast Type field set to unicast.

* Case 6. Unicast with Responding UE: Referring to FIG. 21, if ZoneID_A is identical to ZoneID_RX in COT-SI and a destination ID included in the SCI format of the COT initiating UE matches the corresponding destination ID of UE_A, the COT indicated by the COT-SI can be shared with UE_A belonging to the same zone as the responding UE for unicast with the responding UE of the COT initiating UE. For example, in case 6, the UE_A may transmit a transport block together with an SCI format including a cast type field set to unicast to the responding UE of the UCOT initiating UE within the COT, or the responding UE may transmit a transport block together with an SCI format including a cast type field set to unicast to the UE_A within the COT.

In some implementations of this specification, a COT sharing availability indication (COT-AI) may be included in the COT-SI. For example, if the COT-AI is indicated with a first value (e.g., '1'), sharing of the COT initiated by the COT initiating UE with UE_A as mentioned in Cases 1 to 6 above may be allowed, otherwise it may be not allowed.

Location-based COT sharing according to some implementations of this specification may also be applied to additional ID(s) if the SCI format including the COT-SI includes additional ID(s). For example, a UE identified by a destination ID and/or a source ID indicated by an additional ID may determine whether to share a COT identified by an SCI format including the additional ID according to some implementations of this specification as described above.

A COT initiating UE may perform Type 1 LBT (i.e., Type 1 channel access) on behalf of other UEs and transmit COT-SI including ZoneID_TX and ZoneID_RX according to some implementations of the present specification described above. A UE receiving the COT-SI may compare its own zone ID with ZoneID_TX and ZoneID_RX included in the COT-SI to determine whether it can perform transmission using resources within the COT indicated by the COT-SI.

According to some implementations of the present specification, other UEs than the target RX UE transmitting the PSCCH/PSSCH of the TX UE may also perform SL transmission and/or SL reception on the COT initiated by the TX UE based on the COT-SI. In other words, according to some implementations of the present specification, a COT initiating UE may grant COT sharing opportunities to more UEs.

In the case of conventional communication on a shared spectrum, all UEs that receive a DCI format (e.g., DCI format 2_0) including COT sharing information transmitted by a BS can share the COT. Since UE-to-UE COT sharing is in which a COT initiating UE determines COT sharing based only on the channel conditions around itself, sharing COT with an unspecified number of UEs may cause unexpected problems because the interference environment of each UE may be different from the interference environment of the COT initiating UE. According to some implementations of the present specification, additional COT sharing may be allowed only to UEs that belong to the same zone as the COT initiating UE or the corresponding responding UE and have similar channel environment or interference environment based on ZoneID_TX and ZoneID_RX.

FIG. 22 is an example of a process by which a communication device performs sidelink transmission according to some implementations of the present specification.

A TX UE may perform operations according to some implementations of the present disclosure in connection with SL transmission. The TX UE 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 TX UE 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 TX UE, the processing device, the computer-readable (non-transitory) storage medium, and/or the computer program product, the operations may include: performing a type 1 channel connection on a cell for transmitting a transport block (S2201); and, based on the success of the type 1 channel connection to the cell, transmitting a first SCI format including COT sharing information including time domain information and frequency domain information regarding a COT for the cell and the transport block within the COT determined by the type 1 channel connection (S2203). The first SCI format includes a first zone identifier and a second zone identifier, wherein the first zone identifier is an identifier of a zone to which the communication device belongs and the second zone identifier is a zone identifier of a zone to which a destination of the transport block belongs.

In some implementations, the transport block and the first SCI format may be transmitted over the PSSCH.

In some implementations, the operations may include: transmitting, within the COT, a PSCCH carrying a second SCI format for scheduling the PSSCH and the first SCI format.

FIG. 23 is an example of a process by which a communication device performs sidelink reception according to some implementations of the present specification.

An RX UE may perform operations according to some implementations of the present disclosure in connection with SL reception. The RX UE 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 RX UE 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 RX UE, the processing device, the computer-readable (non-transitory) storage medium, and/or the computer program product, the operations may include: receiving a first SCI format including COT sharing information including time domain information and frequency domain information regarding a COT for a cell (S2301), wherein the first SCI format includes a first zone identifier and a second zone identifier, wherein the first zone identifier is an identifier of a zone to which a first communication device transmitting the first SCI format belongs and the second zone identifier is a zone identifier of a zone to which a second communication device, which is a destination of a transport block associated with the first SCI format, belongs; and performing sidelink transmission within the COT based on the first zone identifier or the second zone identifier and a third zone identifier of the communication device being the same (S2303).

In some implementations, performing the sidelink transmission within the COT based on the first zone identifier or the second zone identifier being the same as the third zone identifier of the communication device may include: performing a type 2 channel connection within the COT; and performing the sidelink transmission within the COT based on the success of the type 2 channel connection.

In some implementations, performing the sidelink transmission may include transmitting a second SCI format including a cast type field set to unicast.

In some implementations, performing the sidelink transmission within the COT based on the third zone identifier of the communication device being identical to the first zone identifier or the second zone identifier may include performing the sidelink transmission to the first communication device based on the third zone identifier being identical to the second zone identifier and a source identifier within the first SCI format matching a destination identifier assigned to the communication device (see FIG. 16 ).

In some implementations, performing the sidelink transmission within the COT based on the third zone identifier of the communication device being identical to the first zone identifier or the second zone identifier may include: performing the sidelink transmission to the target communication device based on the third zone identifier being identical to the second zone identifier and an identifier of a zone to which the target communication device of the sidelink transmission belongs being identical to the first zone identifier (see FIG. 17 ).

In some implementations, performing the sidelink transmission within the COT based on the third zone identifier of the communication device being identical to the first zone identifier or the second zone identifier may include performing the sidelink transmission to the second communication device based on the third zone identifier being identical to the first zone identifier and a destination identifier within the first SCI format matching a destination identifier assigned to the communication device (see FIG. 18 ).

In some implementations, performing the sidelink transmission within the COT based on the third zone identifier of the communication device being identical to the first zone identifier or the second zone identifier may include: performing the sidelink transmission to the target communication device based on the third zone identifier being identical to the first zone identifier and an identifier of a zone to which the target communication device of the sidelink transmission belongs being identical to the second identifier (see FIG. 19 ).

In some implementations, performing the sidelink transmission within the COT based on the third zone identifier of the communication device being identical to the first zone identifier or the second zone identifier may include: performing the sidelink transmission to the first communication device based on the third zone identifier being identical to the first zone identifier and a source identifier within the first SCI format matching a destination identifier assigned to the communication device (see FIG. 20 ).

In some implementations, performing the sidelink transmission within the COT based on the third zone identifier of the communication device being identical to the first zone identifier or the second zone identifier may include: performing the sidelink transmission to the second communication device based on the third zone identifier being identical to the second zone identifier and a source identifier in the first SCI format matching a destination identifier assigned to the communication device (see FIG. 21 ).

In some implementations, the first SCI format may include a COT Shared Availability Indication field. In some implementations, the operations may include: comparing the first zone identifier or the second zone identifier with the third zone identifier of the communication device based on the COT Shared Availability Indication field being set to a first value.

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, in BSs or UEs, or in other equipment.

Claims (19)

When a communication device transmits a sidelink signal in a wireless communication system, Performing a type 1 channel connection on the cell for transmission of transport blocks; and Based on the success of the type 1 channel access to the cell, a first sidelink control information (SCI) format including COT sharing information including time domain information and frequency domain information about channel occupancy time (COT) for the cell and transmitting the transport block within the COT determined by the type 1 channel access, The first SCI format includes a first zone identifier and a second zone identifier, wherein the first zone identifier is an identifier of a zone to which the communication device belongs, and the second zone identifier is a zone identifier of a zone to which the destination of the transport block belongs. Sidelink signal transmission method. In the first paragraph, The above transport block and the first SCI format are transmitted through a physical sidelink shared channel (PSSCH). Sidelink signal transmission method. In the second paragraph, Including transmitting a physical sidelink control channel (PSCCH) carrying a second SCI format for scheduling the PSSCH and the first SCI format within the COT. Sidelink signal 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: Performing a type 1 channel connection on the cell for transmission of transport blocks; and Based on the success of the type 1 channel access to the cell, a first sidelink control information (SCI) format including COT sharing information including time domain information and frequency domain information about channel occupancy time (COT) for the cell and transmitting the transport block within the COT determined by the type 1 channel access, The first SCI format includes a first zone identifier and a second zone identifier, wherein the first zone identifier is an identifier of a zone to which the communication device belongs, and the second zone identifier is a zone identifier of a zone to which the destination of the transport block belongs. Communication device. In a processing device for a communication device, 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: Performing a type 1 channel connection on the cell for transmission of transport blocks; and Based on the success of the type 1 channel access to the cell, a first sidelink control information (SCI) format including COT sharing information including time domain information and frequency domain information about channel occupancy time (COT) for the cell and transmitting the transport block within the COT determined by the type 1 channel access, The first SCI format includes a first zone identifier and a second zone identifier, wherein the first zone identifier is an identifier of a zone to which the communication device belongs, and the second zone identifier is a zone identifier of a zone to which the destination of the transport block belongs. Processing 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: Performing a type 1 channel connection on the cell for transmission of transport blocks; and Based on the success of the type 1 channel access to the cell, a first sidelink control information (SCI) format including COT sharing information including time domain information and frequency domain information about channel occupancy time (COT) for the cell and transmitting the transport block within the COT determined by the type 1 channel access, The first SCI format includes a first zone identifier and a second zone identifier, wherein the first zone identifier is an identifier of a zone to which the communication device belongs, and the second zone identifier is a zone identifier of a zone to which the destination of the transport block belongs. Storage medium. When a communication device receives a sidelink signal in a wireless communication system, Receive a first sidelink control information (SCI) format including COT sharing information including time domain information about channel occupancy time (COT) for a cell and frequency domain information; The first SCI format includes a first zone identifier and a second zone identifier, wherein the first zone identifier is an identifier of a zone to which a first communication device transmitting the first SCI format belongs, and the second zone identifier is a zone identifier of a zone to which a second communication device which is a destination of a transport block related to the first SCI belongs; Including performing sidelink transmission within the COT based on the first zone identifier or the second zone identifier and the third zone identifier of the communication device being the same. How to receive sidelink signals. In Article 7, Performing the sidelink transmission within the COT based on the first zone identifier or the second zone identifier and the third zone identifier of the communication device being the same: Performing type 2 channel connection within the above COT; and Based on the success of the above type 2 channel connection, performing the sidelink transmission within the COT, How to receive sidelink signals. In Article 7, Performing the above sidelink transmission: Including transmitting a second SCI format including a cast type field set to unicast, How to receive sidelink signals. In Article 7, Performing the sidelink transmission within the COT based on the first zone identifier or the second zone identifier and the third zone identifier of the communication device being the same: Including performing the sidelink transmission to the first communication device based on the third zone identifier being identical to the second zone identifier and the source identifier in the first SCI format matching the destination identifier assigned to the communication device. How to receive sidelink signals. In Article 7, Performing the sidelink transmission within the COT based on the first zone identifier or the second zone identifier and the third zone identifier of the communication device being the same: Including performing the sidelink transmission to the target communication device based on the third zone identifier being identical to the second zone identifier and the identifier of the zone to which the target communication device of the sidelink transmission belongs being identical to the first zone identifier. How to receive sidelink signals. In Article 7, Performing the sidelink transmission within the COT based on the first zone identifier or the second zone identifier and the third zone identifier of the communication device being the same: Including performing the sidelink transmission to the second communication device based on the third zone identifier being identical to the first zone identifier and the destination identifier in the first SCI format matching the destination identifier assigned to the communication device. How to receive sidelink signals. In Article 7, Performing the sidelink transmission within the COT based on the first zone identifier or the second zone identifier and the third zone identifier of the communication device being the same: Including performing the sidelink transmission to the target communication device based on the third zone identifier being identical to the first zone identifier and the identifier of the zone to which the target communication device of the sidelink transmission belongs being identical to the second identifier. How to receive sidelink signals. In Article 7, Performing the sidelink transmission within the COT based on the first zone identifier or the second zone identifier and the third zone identifier of the communication device being the same: Including performing the sidelink transmission to the first communication device based on the third zone identifier being identical to the first zone identifier and the source identifier in the first SCI format matching the destination identifier assigned to the communication device. How to receive sidelink signals. In Article 7, Performing the sidelink transmission within the COT based on the first zone identifier or the second zone identifier and the third zone identifier of the communication device being the same: Including performing the sidelink transmission to the second communication device based on the third zone identifier being identical to the second zone identifier and the source identifier in the first SCI format matching the destination identifier assigned to the communication device. How to receive sidelink signals. In Article 7, The above first SCI format includes a COT shared availability indication field, Comprising comparing the first zone identifier or the second zone identifier with the third zone identifier of the communication device based on the COT shared availability indication field being set to the first value. How to receive sidelink signals. When a communication device receives a sidelink signal 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 a first sidelink control information (SCI) format including COT sharing information including time domain information about channel occupancy time (COT) for a cell and frequency domain information; The first SCI format includes a first zone identifier and a second zone identifier, wherein the first zone identifier is an identifier of a zone to which a first communication device transmitting the first SCI format belongs, and the second zone identifier is a zone identifier of a zone to which a second communication device which is a destination of a transport block related to the first SCI belongs; Including performing sidelink transmission within the COT based on the first zone identifier or the second zone identifier and the third zone identifier of the communication device being the same. Communication device. In a processing device for a communication device, 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 a first sidelink control information (SCI) format including COT sharing information including time domain information about channel occupancy time (COT) for a cell and frequency domain information; The first SCI format includes a first zone identifier and a second zone identifier, wherein the first zone identifier is an identifier of a zone to which a first communication device transmitting the first SCI format belongs, and the second zone identifier is a zone identifier of a zone to which a second communication device which is a destination of a transport block related to the first SCI belongs; Including performing sidelink transmission within the COT based on the first zone identifier or the second zone identifier and the third zone identifier of the communication device being the same. Processing 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 a first sidelink control information (SCI) format including COT sharing information including time domain information about channel occupancy time (COT) for a cell and frequency domain information; The first SCI format includes a first zone identifier and a second zone identifier, wherein the first zone identifier is an identifier of a zone to which a first communication device transmitting the first SCI format belongs, and the second zone identifier is a zone identifier of a zone to which a second communication device which is a destination of a transport block related to the first SCI belongs; Including performing sidelink transmission within the COT based on the first zone identifier or the second zone identifier and the third zone identifier of the communication device being the same. Storage medium.

Images