WO2025005716A1 - Method, communication device, and storage medium for transmitting wireless channel, and method, communication device, and storage medium for receiving wireless channel - Google Patents

Abstract

In the present specification, second control information of a second physical control channel transmitted within a second resource reserved by a first control information format carried by a first physical control channel may include information on whether a third resource reserved by the first control information format is available for transmission.

Description

Method for transmitting a wireless channel, communication device and storage medium, and method for receiving a wireless channel, communication device and storage medium

This specification relates to wireless communication systems.

Various devices and technologies such as machine-to-machine (M2M) communication, machine type communication (MTC), and smart phones and tablet PCs (Personal Computers) that require high data transmission rates are emerging and becoming widespread. Accordingly, the amount of data required to be processed in cellular networks is increasing very rapidly. In order to satisfy this rapidly increasing demand for data processing, carrier aggregation technology and cognitive radio technology for efficient use of more frequency bands, multi-antenna technology for increasing the data capacity transmitted within a limited frequency, and multi-base station (BS) cooperation technology are being developed.

A wireless communication system supports communication of user equipment (UE) 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 that a base station (BS) must provide services to in a given resource area increases, but also the amount of data and control information that the BS transmits/receives with the UEs it provides services to increases. Since the amount of wireless 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 wireless resources. In other words, as the density of nodes and/or the density of UEs increases, a method for efficiently utilizing high-density nodes or high-density UEs for communication has been required. For example, as a method to solve the burden of the BS due to the rapidly increasing data traffic, direct communication between two or more nearby UEs without going through a network node has been studied using wireless communication technologies. As the need for V2X (vehicle-to-everything), a communication technology that supports wired and wireless communication between vehicles and other vehicles, infrastructure, networks, or pedestrians, arises, a rapid increase in communication between devices is expected.

Considering the rapidly increasing amount and frequency of communication between devices, a method to stably support communication between devices 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 wireless channel by a communication device in a wireless communication system is provided. The method comprises: determining a first resource, a second resource, and a third resource for wireless communication within a resource pool on a cell; generating a first control information format including time information about the second resource and the third resource; transmitting a first physical control channel carrying the first control information format within the first resource and an associated first physical shared channel; and transmitting a second physical control channel carrying the second control information format within the second resource and an associated second physical shared channel, the second control information format including information related to availability of the third resource; and determining whether to perform wireless channel transmission on the third resource based on the information related to availability of the third resource.

In another aspect of the present disclosure, a communication device for transmitting a wireless channel 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 include: determining a first resource, a second resource, and a third resource for wireless communication within a resource pool on a cell; generating a first control information format including time information about the second resource and the third resource; transmitting a first physical control channel carrying the first control information format within the first resource and an associated first physical shared channel; and transmitting a second physical control channel carrying the second control information format within the second resource and an associated second physical shared channel, the second control information format including information related to availability of the third resource; and determining whether to perform wireless channel transmission on the third resource based on the information related to availability of the third resource.

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 include: determining a first resource, a second resource, and a third resource for wireless communication within a resource pool on a cell; generating a first control information format including timing information about the second resource and the third resource; transmitting a first physical control channel and an associated first physical shared channel carrying the first control information format within the first resource; and transmitting a second physical control channel and an associated second physical shared channel carrying the second control information format within the second resource, the second control information format including availability-related information of the third resource; and determining whether to perform wireless channel transmission on the third resource based on the availability-related information of the third resource.

In another aspect of the present specification, a method for a communication device to receive a wireless channel in a wireless communication system is provided. The method comprises: detecting a first physical control channel carrying a first control information format from a first resource in a resource pool on a cell, the first control information format including time information about a second resource and a third resource; receiving an associated first physical shared channel within the first resource in which the first physical control channel is detected; receiving a second physical control channel carrying a second control information format and an associated second physical shared channel within the second resource, the second control information format including information related to availability of the third resource; and determining whether the third resource is valid based on the information related to availability of the third resource.

In another aspect of the present disclosure, a communication device for receiving a wireless channel 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 include: detecting a first physical control channel carrying a first control information format in a first resource within a resource pool on a cell, the first control information format including time information regarding a second resource and a third resource; receiving an associated first physical shared channel within the first resource in which the first physical control channel is detected; receiving a second physical control channel carrying a second control information format and an associated second physical shared channel within the second resource, the second control information format including information regarding availability of the third resource; and determining whether the third resource is available based on the information regarding availability of the third resource.

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 include: detecting a first physical control channel carrying a first control information format in a first resource within a resource pool on a cell, the first control information format including time information about a second resource and a third resource; receiving an associated first physical shared channel within the first resource in which the first physical control channel is detected; receiving a second physical control channel carrying a second control information format and an associated second physical shared channel within the second resource, the second control information format including availability-related information of the third resource; and determining whether the third resource is available based on the availability-related information of the third resource.

In each aspect of the present specification, the communication device transmitting the wireless channel or the operations related thereto may include: performing LBT before a slot including the third resource; and determining availability of the third resource based on a result of the LBT.

In some implementations, the LBT may be performed based on shared spectrum channel access related parameters set for the cell.

In each aspect of the present specification, the communication device transmitting the wireless channel or the operations related thereto may further include: transmitting a third physical control channel carrying a third control information format within the third resource and an associated third physical shared channel, based on availability of the third resource.

In each aspect of the present specification, the availability-related information of the third resource in the second control information format may include time information of the fourth resource that replaces the third resource.

In each aspect of this specification, the time information of the fourth resource may include a slot offset from the third resource to the fourth resource.

In each aspect of the present specification, the communication device transmitting the wireless channel or the operations related thereto may further include transmitting a third physical control channel carrying a third control information format within the fourth resource and an associated third physical shared channel.

In each aspect of the present specification, the communication device transmitting the wireless channel or the operations related thereto may further include: receiving a setting regarding a maximum number N of reserved resources indicated by the control information, wherein N > 2.

In each aspect of this specification, each of the first, second and third resources may include L _subCH subchannels.

In each aspect of the present specification, the communications device receiving the wireless channel or the operations related thereto may include: if the third resource is available, the operations may include attempting to detect a third physical control channel carrying a third control information format in the third resource, and if the third physical control channel is detected, attempting to decode an associated third physical shared channel.

In each aspect of the present specification, the communications device receiving the wireless channel or the operations related thereto may include: not attempting to detect a physical control channel on the third resource if the third resource is not available. For example, in some implementations, the operations may include: not performing physical control channel monitoring on the lowest subchannel of the third resource if the third resource is not available.

In each aspect of the present specification, the communication device receiving the wireless channel or the operations related thereto may further include: receiving a setting regarding a maximum number N of reserved resources indicated by the control information, wherein N > 2.

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, the technology for communicating between devices in licensed spectrum, which is licensed to a particular network operator and has exclusive or preferential use by that network operator, may also be utilized in shared spectrum.

Some implementations of this specification enable efficient communication between devices over shared spectrum, which is unlicensed spectrum that is not licensed to a specific network operator and can be freely used by multiple network operators.

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

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

FIG. 2 is a block diagram illustrating examples of communication devices capable of performing a method according to the present specification;

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

Figure 4 illustrates a resource grid of slots;

FIG. 5 illustrates communication links in a wireless communication system;

Figure 6 is a diagram illustrating frequency resources and time resources for communication between devices;

Figures 7 and 8 illustrate transmission structures of physical channels for communication between devices within a slot;

Figure 9 illustrates a resource block (RB) interlace;

Figure 10 illustrates interlaced RB-based uplink resource allocation in a shared spectrum;

FIG. 11 and FIG. 12 are diagrams illustrating channel access mechanisms on shared spectrum according to some implementations;

FIGS. 13 and 14 are diagrams illustrating resource allocation for communication between devices according to some implementations;

FIG. 15 illustrates an example of resource reservation for device-to-device communication over a shared spectrum according to some implementations of this specification;

FIG. 16 illustrates another example of resource reservation for device-to-device communication over a shared spectrum according to some implementations of the present specification;

FIG. 17 illustrates another example of resource reservation for device-to-device communication over a shared spectrum according to some implementations of this specification;

FIG. 18 illustrates further examples of resource reservation for device-to-device communication over a shared spectrum according to some implementations of the present specification;

FIG. 19 is an example of a process in which a communication device performs wireless channel transmission according to some implementations of the present specification;

FIG. 20 is an example of a process by which a communication device performs wireless channel 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.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Referring to FIG. 3, uplink and downlink transmissions are organized into frames. Each frame has a duration T _f = (△f _max *N _f /100)*T _c = 10 ms, where T _c = 1/(△f _max *N _f ) is the basic time unit, △f _max = 480*10 ³ Hz, and N _f =4096. For reference, the sampling time T _s = 1/(△f _ref *N _f,ref ), △f _ref = 15*10 ³ Hz, and N _f,ref =2048. T _c and T _s 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. 4 illustrates a resource grid of a slot. A slot contains a plurality of (e.g., N ^slot _symb ) symbols in the time domain. For each numeral (e.g., subcarrier spacing) and carrier, a resource grid of N ^size,u _grid,x * N ^RB sc subcarriers and N subframe,u ^symb OFDM symbols is defined, starting from a common resource block (CRB) N ^start,u _grid indicated by higher layer signaling (e.g., radio resource control (RRC) signaling). Here, N ^size,u _grid,x is the number of resource blocks ( _RBs ) in the resource grid, and the subscript x is _DL for downlink and UL for uplink. N ^RB _sc is the number of subcarriers per RB, and N ^RB _sc is typically 12 in 3GPP-based wireless communication systems. For a given antenna port p , subcarrier spacing configuration u , and transmission direction (DL or UL), there is one resource grid. The carrier bandwidth N ^size,u _grid for subcarrier spacing configuration u is given to the UE by higher-layer parameters (e.g., RRC parameters) from the network. Each element in the resource grid for antenna port p and subcarrier spacing configuration u is called a resource element (RE), and one complex-valued symbol may be mapped to each RE. Each RE in the resource grid is uniquely identified by an index k in the frequency domain and an index l indicating the symbol position relative to a reference point in the time domain. RBs may be classified into common resource blocks (CRBs) and physical resource blocks (PRBs). The CRBs are numbered upwards from 0 in the frequency domain for subcarrier spacing configuration u . The center of subcarrier 0 of CRB 0 for a subcarrier spacing setting u coincides with 'point A', which is a common reference point for resource block grids. The PRBs for the subcarrier spacing setting u are defined in a bandwidth part (BWP) and are numbered from 0 to N ^size,u _BWP,i -1, where i is the number of the bandwidth part. The relationship between the common resource block n ^u _CRB and the physical resource block n _PRB in the bandwidth part i is as follows: n ^u _PRB = n ^u _CRB + N ^start,u _BWP,i , where N ^start,u _BWP,i is the common resource block where the bandwidth part starts relative to CRB 0. A BWP comprises a plurality of contiguous RBs in the frequency domain. For example, a BWP is a subset of contiguous CRBs defined for a given numerology u _i within BWP i on a given carrier. A carrier can contain up to N (e.g., 5) BWPs. A UE can be configured to have one or more BWPs on a given component carrier. Data communication is performed via the activated BWPs, and only a predetermined number (e.g., 1) of BWPs configured for the UE can be activated on the carrier.

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

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

Figure 5 illustrates communication links in a wireless communication system.

Referring to FIG. 5, in a wireless communication system, a UE receives information from a BS through a downlink (DL), and the UE transmits information to the BS through an uplink (UL). As a solution to the burden on the BS due to the rapidly increasing data traffic, a technology (e.g., sidelink (SL) communication) that 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 a sidelink that supports UE-to-UE direct communication using sidelink resource allocation modes, physical layer signals/channels, and physical layer processes.

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

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

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

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

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

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

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

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

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

A PSCCH can be multiplexed with its associated PSSCH on non-overlapping resources within the same slot. Referring to Fig. 7, a PSCCH is transmitted starting from the lowest RB in the subchannel(s) occupied by the associated PSSCH in the frequency domain, and from the second symbol in the slot in the time domain. The number of symbols for the PSCCH is (pre-)configured per resource pool, and can be, for example, 2 or 3 symbols. In some scenarios (e.g., NR V2X), the PSCCH occupies RBs of N _PSCCH in the frequency domain, and the N _PSCCH can be (pre-)configured to the UE(s) per resource pool via higher layer signaling (e.g., RRC signaling). In some scenarios (e.g., NR V2X), N _PSCCH can be 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. 7, 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. 7, 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. 7, the PSSCH may be transmitted from the second symbol in a slot to the second to the last symbol or from the second symbol to the symbol immediately preceding the last symbol in a slot. In some scenarios, 7 to 14 symbols may be (pre-)configured in a slot for sidelink and the PSCCH may be sent in 5 to 12 consecutive symbols. The number of symbols occupied by the PSSCH depends on the number of SL symbols allocated in the slot and whether the PSFCH is sent in that slot. Within the symbols carrying the PSCCH, the PSSCH may be multiplexed in the frequency domain with the PSCCH (if the PSCCH does not occupy the entire L _PSSCH sub-channel(s)). The second symbol in a slot (i.e., the first symbol with the PSCCH or with the PSCCH/PSSCH) may be duplicated with the first symbol of the slot for use for automatic gain control (AGC) purposes. Additionally, the symbol after the last symbol with PSSCH can be used as a guard symbol.

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

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

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

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

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

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

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

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

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

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

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

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.

In a shared spectrum, the size of the time interval and/or the frequency occupied region of the signal/channel transmitted by the UE and/or the power spectral density (PSD) may be required to be above a certain level, respectively, with respect to channel occupancy. For example, a communication device may be required to perform transmission in the shared spectrum with the size of the time interval and/or the frequency occupied region of the signal/channel and/or with the PSD above a certain level. Considering such occupied channel bandwidth (OCB) and power spectral density regulations for the shared spectrum, a set of (equally spaced) non-contiguous RBs in frequency may be defined as a resource unit used for physical channel/signal transmission. Hereinafter, such a set of non-contiguous RBs is called an interlaced RB, an RB interlace, or an interlace.

Figure 9 illustrates a resource block (RB) interlace. Referring to Figure 9, multiple interlaces of RBs can be defined in the frequency domain. An interlace m∈{0, 1, ..., M-1} can be composed of (common) RBs {m, M+m, 2M+m, 3M+m, ...}, where M represents the number of interlaced RBs. That is, each interlace can be composed of multiple non-contiguous RBs. In some implementations, M can be given as follows.

An interlaced RB n ^u _IRB,m ∈{0, 1, ...} within BWP i and interlace m and a CRB n ^u _CRB can be given by: n ^u _CRB = M*n ^u _IRB,m + N ^start,u _BWP,i + ((m - N ^start,u _BWP,i ) mod M).

A communication device (e.g., UE) can transmit a signal/channel using one or more interlaced RBs.

For example, in a 3GPP based system, the resource block assignment information in the DCI carried by the PDCCH informs the UE of a set of up to M interlace indices, and a set of up to N ^BWP _{RB-set, UL contiguous} RB sets (for DCI format 0_0 and for DCI format 0_1 monitored in ^a UE-specific search space). An RB set consists of a plurality of contiguous RBs. DCI format 0_0 and DCI format 0_1 are DCI formats used to schedule the PUSCH. In some implementations, an RB set may correspond to a frequency resource on which a channel access procedure (CAP) is individually performed in a shared spectrum. For operation with shared spectrum channel access, uplink transmission subcarriers are mapped to one or more RB interlaces.

In some scenarios, the UE may determine RB(s) corresponding to the intersection of i) the indicated interlace and ii) the union of the indicated RB set(s) and, if any, the guard bands between the indicated RB set(s) as the frequency resource for PUSCH transmission.

Figure 10 illustrates an interlaced RB-based uplink resource allocation in a shared spectrum. Figure 10(a) illustrates a case where one RB set is indicated through resource allocation information for PUSCH, and Figure 10(b) illustrates a case where contiguous RB sets are indicated through resource allocation information for PUSCH.

Referring to Fig. 10(a), based on the resource allocation (RA) information for PUSCH indicating {interlace #2, RB set #1}, RBs belonging to interlace #2 in RB set #1 can be determined to be PUSCH resources. That is, RBs corresponding to the intersection of {interlace #2, RB set #1} can be determined as PUSCH resources. Referring to Fig. 10(b), based on the resource allocation information for PUSCH indicating {interlace #2, RB set #1/#2}, RBs belonging to interlace #2 in RB sets #1 and #2 can be determined to be PUSCH resources. In this case, a guard band (i.e., GB #1) between RB set #1 and RB set #2 can also be used as a PUSCH transmission resource. That is, in some implementations, RBs corresponding to the intersection of {interlace #2, RB set #1 + RB set #2 + GB #1} can be determined as PUSCH resources. In this case, the guard band (i.e., GB #0) that is not between RB set #1 and RB set #2 even if it is adjacent to RB sets #1 and #2 is not used as a PUSCH transmission resource.

Figures 11 and 12 are diagrams illustrating channel access mechanisms on 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, as illustrated in Fig. 11. LBT parameters, such as channel assessment parameters, can be set to the UE by the BS.

3GPP based systems, e.g., NR, can support dynamic time division duplex (TDD), where uplink-downlink allocation can vary over time depending on traffic conditions. Referring to FIG. 12, to enable dynamic TDD on a shared spectrum, a UE/BS decides when and where to transmit and/or receive based on an indication of a channel occupancy time (COT) structure. A COT includes multiple slots, each slot can include downlink resources, uplink resources, or flexible resources. The COT structure reduces power consumption and channel access delay. In some scenarios (e.g., NR), a typical COT is around 8 ms, and the COT duration can be indicated by the DCI format 2_0. A higher layer parameter co-DurationsPerCellToAddModList can be set by the BS. The following is an example of a part of an information element (IE) SlotFormatIndicator containing co-DurationsPerCellToAddModList . In some scenarios, the IE SlotFormatIndicator is used to configure 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. 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.

When the upper layer parameter co-DurationsPerCellToAddModList is set, the following information can be transmitted via DCI format 2_0 with cyclic redundancy check (CRC) scrambled by SFI-RNTI: COT Duration Indicator 1, COT Duration Indicator 2, ..., COT Duration Indicator N2. For example, if the position of the COT Duration Indicator 1 in the bit fields of DCI format 2_0 is set as a bit field for a serving cell having a serving cell index of 1 by parameters servingCellId and positionInDCI in the CoDurationsPerCell object and the reference subcarrier spacing for the serving cell is set as 15 kHz by subcarrierSpacing , and if the bit field COT Duration Indicator 1 in the DCI format 2_0 transmitted by the BS to the UEs 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.

In some implementations, resource allocation for operations with shared spectrum channel access may be done via a two-level resource indication, e.g., X+Y, where the X-bit may be used to indicate a set of allocated interlace indices. For example, for a contiguous allocation, the X-bit may be used to represent a resource indication value (RIV) indicating a start interlace index m ₀ and a length l , while for a non-contiguous allocation, the X-bit may be used to represent a bitmap consisting of bits each bit corresponding to an interlace. For example, the Y-bit may be used to indicate a set of contiguously allocated RB set(s). For example, the Y-bit may be used to represent a RIV indicating a start RB set index N ^start _RB-set and a length L _RB-set . The value of Y can be determined by Floor{log ₂ (N ^start _RB-set *(N ^start _RB-set +1)/2)}, where N ^start _RB-set is the number of RB sets included in the active BWP.

FIGS. 13 and 14 are diagrams illustrating resource allocation for wireless communication according to some implementations.

Two SL resource allocation modes are considered for selection of subchannels in inter-device communications: Mode 1, where the SL resource allocation is provided by the network, and Mode 2, where the UE determines the SL transmission resources within the resource pool(s). Figures 13 and 14 illustrate, in particular, resource reservation for retransmissions of the same transport block (TB) and for transmissions and retransmissions of the next TB in Mode 2.

In some implementations, SL resource allocation mode 2 allows the UE to autonomously select its SL resources (e.g., one or more subchannels) from a pool of resources, in which case the UE may operate without network coverage, and the pool of resources may be (pre-)configured by the BS when it is in network coverage. In some implementations, SL resource allocation mode 2 may operate in a dynamic or a semi-persistent manner. The SL resource allocation mode 2 uses almost the same process to select resources for the dynamic and the semi-persistent manner, but the dynamic manner selects new resources for each TB and reserves resources only for retransmissions of that TB, whereas the semi-persistent manner selects resources for consecutive SL_Resource_Reselection_Counter TBs.

In the following description, the selected resources that the UE reserves for future transmissions by notifying neighboring UEs using the 1 ^st -step SCI are specifically called reserved resources. The UE can select and reserve resources for transmission of several TBs (and their retransmissions). The UE can select new SL resources when it creates a new TB. To select new SL resources, the UE first defines a selection window in which to find candidate resources for transmitting the TB. Referring to FIG. 13, the selection window includes all resources within the range of slots [n+T ₁ , n+T ₂ ], where n is a resource (re-)selection trigger or slot from which new resources should be selected, T ₁ is a processing time (in slots) required by the UE to identify candidate resources and select new SL resources for transmission, where T ₁ is less than T proc,1 , which is, for example, 3, 5, 9, or 17 slots for subcarrier spacings of 15, 30, 60 _, or 120 kHz, respectively, and the value of T ₂ is a value determined by the UE within the range of T _2min <= T ₂ <= PDB, where PDB is a packet delay budget (in slots) which is a latency deadline by which the TB should be transmitted and is determined by an application transmitting a packet to be transmitted in the TB. T _2min depends on the priority of TB and the subcarrier spacing, for example, the possible values of T _2min can include {1, 5, 10, 20}*2 ^u , where u is the subcarrier spacing setting. Once the selection window is determined, the UE identifies candidate resources within the selection window, and the candidate resources are defined in time by slots and in frequency by contiguous subchannels of L _PSSCHs (i.e., L _subCHs ). Since L _PSSCHs should be selected such that the TB and its associated SCI (including the 1 ^st -stage SCI and the 2 ^nd -stage SCI) fit within the candidate resources, L _PSSCHs depend on the size of the TB and the size of the SCI, and on a modulation and coding scheme (MCS).

If the UE is not transmitting, the UE senses SL resources during a sensing window to identify available candidate resources. The sensing window includes all resources within the range of slots [nT ₀ , nT _proc,0 ], where n is a resource (re-)selection trigger or slot from which new resources have to be selected and T ₀ is an integer defined as the number of slots depending on the subcarrier spacing configuration, for example equal to 1100 ms or 100 ms and determined by the (pre-)configuration of the resource pool. T _proc,0 is the time required to complete the sensing process and can be equal to, for example, 1 slot for a subcarrier spacing of 15 or 30 kHz, or 2 or 4 slots for a subcarrier spacing of 60 or 120 kHz. During the sensing process, the UE decodes 1 ^st -step SCI(s) received from other UE(s) within the sensed SL resources. The 1 ^{st -step SCI may indicate that the other UE has reserved the SL resources for its transport block (TB) and SCI transmission(s) over PSCCH and PSCCH. In particular, the 1 st -step} SCI may indicate SL resources reserved for retransmission of the TB associated with the 1 ^st -step SCI, and resources reserved for initial transmission and retransmissions of the next TB. The UE may store the sensed information (e.g., decoded 1 ^st -step SCI and reference signal received power (RSRP) measurements) and may utilize the sensed information when determining which candidate resources to exclude from the selection window when a new selection is triggered.

To select new resources, the above SL resource allocation mode 2 defines the following two-step algorithm.

> Step 1: The UE first excludes candidate resources from the selection window according to certain rules.

> Step 2: After performing all exclusions in Step 1, the UE selects (N candidate) resource(s) from the remaining available candidate resources (not excluded in Step 1).

The UE selects N candidate resources within the same selection window for the initial transmission of a TB and its N-1 blind or potential HARQ retransmissions, wherein the selection of the N candidate resources follows the 2-step algorithm described above. The UE can perform HARQ retransmissions for groupcast or unicast transmissions if the PSFCH is (pre-)configured within the resource pool, otherwise it can perform only blind retransmissions. When a TB is positively acknowledged with HARQ retransmissions, the TX UE drops all subsequent scheduled retransmissions of the TB within the selected resources (including the reserved resources). The value of N may vary depending on the UE implementation. When the UE selects a value of N, the UE considers the limitations of the 1 ^st -step SCI for the selection and reservation of the N candidate resources. For example, a 1 ^st -step SCI can only notify about resource reservations located within a window W (e.g., of 32 slots) starting from the slot in which the 1 ^st -step SCI is transmitted, and can only notify about at most N resources, where the maximum value of N can be (pre-)configured by the higher-layer parameter sl-MaxNumPerReserve to, for example, 2 or 3 for the resource pool. Thus, a 1 ^st -step SCI can notify about a transmission (or retransmission) of a TB occurring in the same slot as the transmission of the 1 ^st -step SCI, and about N - 1 reserved resources for the following N - 1 retransmissions of the TB. For example, the time resource assignment field in a 1 ^st -level SCI (e.g., SCI format 1-A) carries a logical slot offset indication of N = 1 or 2 actual resources if the upper layer parameter sl-MaxNumPerReserve is 2, or of N = 1 or 2 or 3 actual resources if sl-MaxNumPerReserve is 3, in the form of a time resource indicator value (TRIV) determined as follows:

Here, the first resource is within the slot in which SCI format 1-A is transmitted, and t _i means the i-th resource time offset based on the first resource, where 1 <= t ₁ <=31 for N=2; and 1 <= t ₁ <=30, 1 <= t ₂ <=31 for N=3. The time resource allocation field within the SCI format 1-A is 5 bits when the value of the upper layer parameter sl-MaxNumPerReserve is set to 2, and 9 when sl-MaxNumPerReserve is set to 3.

After performing all exclusions in step 1, the UE may first randomly select one of the N resources among the available candidate resources. For example, referring to FIG. 14, a UE that selects a first resource in slot m ₁ randomly selects a second resource such that the 1-th resource time offset t ₁ with respect to the first resource is less than the window W. If N > 2, the UE randomly selects a third resource within the range [m ₁ , m ₁ +(W-1)] or the range [m ₂ , m ₂ +(W-1)]. This process is repeated until all resources for TB retransmissions are reserved by the previous SCI. If the UE can select only a subset of the N resources through this process, the remaining resources can be randomly selected within the selection window even if they do not satisfy the previous 1 ^st -step SCI constraints.

The start subchannel n ^start _subCH,0 of the above first resource is the subchannel on which the lowest RB of the associated PSCCH is transmitted. The number of consecutively allocated subchannels L _subCH >=1 for each of the above N resources, and the start subchannel indices of the resources indicated by the transmitted SCI format 1-A can be determined from a frequency resource allocation field equivalent to a frequency resource indicator value (FRIV), except for the start subchannel index of the resource on which the SCI format 1-A is transmitted in the slot, as follows.

Here, n ^start _subCH,1 means the start subchannel for the second resource, n ^start _subCH,2 means the start subchannel for the third resource, and N ^SL _subchannel is the number of subchannels in the resource pool provided according to the higher layer parameter sl-NumSubchannel (e.g., see L in FIG. 6). The number of subchannels allocated sequentially, L _subCH , is the number of subchannels to be used for PSSCH/PSCCH transmission in the slot (i.e., the number of subchannels available for PSSCH/PSCCH transmission in the slot), and is indicated identically for N = 1, 2, and 3. The frequency resource allocation field in the above SCI format 1-A is Ceil{log ₂ (N ^SL _subchannel *(N ^SL _subchannel +1)/2)}-bits when the value of the upper layer parameter sl-MaxNumPerReserve is set to 2, and Ceil{log ₂ (N ^SL _subchannel *(N ^SL _subchannel +1)*(2*N ^SL _subchannel +1)/6)}-bits when sl-MaxNumPerReserve is set to 3.

The SCI format 1-A for the 1 ^st retransmission performed on the second resource may include an offset for the third resource relative to the second resource.

The above SCI format 1-A can signal a resource reservation period (RRP) when reserving resources semi-persistently for PSSCH. As mentioned above, the semi-persistent one among the scheduling schemes of SL resource allocation mode 2 selects resources for consecutive SL_Resource_Reselection_Counter TBs. The time period between selected resources for transmission of consecutive TBs is defined by a resource reservation interval (RRI), and the allowed RRIs are (pre-)configured via the higher layer parameter sl-ResourceReservePeriodList regarding the set of possible RRPs allowed in the resource pool for mode 2. When the UE selects new SL resources, it selects an RRI from the list, and the SL_Resource_Reselection_Counter is randomly set within the interval depending on the selected RRI. For example, a UE transmitting a PSCCH with SCI format 1-A using SL resource allocation mode 2, if the UE is provided with a higher layer (e.g., RRC) parameter sl-MultiReserveResource , sets the resource reservation period field of the SCI format 1-A to an index among the indices in sl-ResourceReservePeriodList corresponding to a reservation period provided by a higher layer (e.g., MAC). The number of bits of the resource reservation period field in SCI format 1-A is determined by Ceil(log ₂ N _{rsv_period} ), where N _{rsv_period} is the number of entries in the higher layer parameter sl-ResourceReservePeriodList if sl-MultiReserveResource is set, and 0 otherwise.

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.

For SL transmission on shared spectrum, TX UE needs to perform LBT for channel access. UEs can occupy channels for the time indicated by COT duration. Considering the aforementioned SL communication and shared spectrum channel access, the question is how to support resource reservation for SL communication on shared spectrum. For example, if reserved resources cannot be used due to LBT failure, i) blind retransmission handling, and/or ii) resource reservation handling are issues.

In some implementations of this specification, taking into account the SL communication and shared spectrum channel access described above, the following may be considered for resource reservation of SL communication on shared spectrum.

> COT duration T _COT is indicated by the SCI format.

> As previously explained, a resource reservation period (RRP) instruction may be used.

> As explained previously, time domain resource assignment (TDRA) instructions may be used.

> As explained above, frequency domain resource assignment (FDRA) instructions based on X+Y can be used.

Figure 15 illustrates an example of resource reservation for device-to-device communication over a shared spectrum according to some implementations of this specification.

In some implementations of this specification, for blind retransmission handling, it may be specified that resource reservation for retransmission is not allowed outside the COT duration. Referring to Fig. 15, TRIV may be indicated in the range [0, T _COT ]. The RX UE is not expected to receive a TRIV value where t _max > T _COT . Here, t _max may be the largest value among the reserved resource slots indicated by TRIV. For example, if slots 0, 2 and 4 are indicated by TRIV, t _max = 4. Referring to Fig. 15, in some implementations, the TX UE does not perform SL transmission in the resource reserved in slot 15 among the reserved resources, and the RX UE does not expect SL reception in the resource reserved in slot 15. The TDRA field size may be determined by:

> Alt 1-1. In some implementations, the TDRA field size may be fixed (e.g., 5 bits) regardless of T _COT .

> Alt 1-2. Alternatively, in some implementations, the TDRA field size may vary depending on the indicated T _COT , for example, the RX UE may assume Ceil(log ₂ (T _COT ))-bits for the TDRA field size. If the TDRA field size depends on T _COT , the TDRA field size may be reduced compared to the TDRA field size determined by assuming the maximum value that can be given as T _COT , and the bit(s) corresponding to the difference may be used for other purposes. Alternatively, since the size of the SCI format is reduced, the SCI format may be transmitted at a lower code rate, and thus the SCI format whose TDRA field size depends on T _COT may be transmitted with higher reliability than the SCI format which does not.

Figure 16 illustrates another example of resource reservation for wireless communications (e.g., device-to-device communications) over a shared spectrum according to some implementations of the present specification. In the example of Figure 16, two COT durations (e.g., T _COT #1 and T _COT #2) are indicated at different times by a UE initiating the same COT.

Unlike the example in Fig. 15, in some implementations of the specification, for blind retransmission handling, resource reservation for retransmission may be stipulated to be allowed outside the _COT duration. TRIV may be indicated within the range [0, 31] of a window W (e.g., of 32 slots) starting from the slot in which the 1 ^st -stage SCI is transmitted, regardless of T COT . Referring to Fig. 16, resources reserved for t _k >T _COT #1 may or may not be valid depending on the LBT results.

> Alt 2-1. In some implementations of this specification, the TX UE and/or the RX UE may determine resource validity for a resource (hereinafter, reserved resource #15) reserved outside a first COT duration T _COT #1 based on a subsequent COT duration T _COT #2. For example, if the TX UE/RX UE transmits/receives a second COT duration T _COT #2 and the reserved resource #15 is within the second COT duration, the reserved resource #15 may be determined to be valid. Otherwise, the TX UE/RX UE may determine the reserved resource #15 is not valid.

Figure 17 illustrates another example of resource reservation for wireless communication on a shared spectrum according to some implementations of the present specification. In the example of Figure 17, two COT durations (e.g., T _COT #1 and T _COT #2) are indicated at different times by a UE initiating the same COT.

As in the example of Figure 16, in some implementations of this specification, for blind retransmission handling, it may be stipulated that resource reservation for retransmission is allowed outside the COT duration.

> Alt 2-2. Automatic time shift for reserved resources

In some implementations, unlike the example of FIG. 16, the example of FIG. 17 may perform automatic time transition for a resource reserved outside the COT duration. Referring to FIG. 17, the TX UE and/or the RX UE may transition the originally reserved resource #12 at t _k by t _k ' = t k + △t, if the TX UE/RX UE transmits/receives a second COT duration T _COT #2 with respect to the resource (hereinafter, reserved resource #12) reserved outside t _k of the first COT duration T _COT #1 and the reserved resource #12 is not within _the second COT duration. Alternatively, referring to FIG. 17, the TX UE and/or the RX UE may transition a resource (hereinafter, reserved resource #12) reserved outside t _k of the first COT duration T _COT #1 by t _k ' = t _k + △t, and determine that the transitioned reserved resource is valid for SL transmission/reception if t _k ' is within the COT duration during which LBT is successful. In some implementations of the present specification, t _k ' may be determined by:

>> Alt 2-2-1. t _k ' may be the first slot of the second COT duration.

>> Alt 2-2-1. t _k ' can be (pre-)configured. For example, t _k ' can be a value preset by the BS, or a value preset by a parameter embedded in the UE. In this case, if t _k ' is not within the second COT duration, the reserved resource is dropped.

FIG. 18 illustrates further examples of resource reservation for wireless communications over shared spectrum according to some implementations of the present specification.

In some implementations of this specification, blind retransmission can be handled based on dynamic indication. Since the PSCCH carrying SCI format 1-A is transmitted whenever the PSSCH is transmitted, the TX UE can utilize SCI format 1-A to provide dynamic indication to the RX UE(s). For example, the following can be considered.

> Alt 3-1. Dynamic indication of availability of reserved resources may be provided. For example, referring to Fig. 18(a), SCI format 1-A transmitted with an initial transmission at time t ₀ (e.g., slot t ₀ ) may include information about t ₁ and t 2 (e.g., resource time offsets) to indicate a reserved second resource at time t ₁ (e.g., slot t ₁ ) and a reserved third resource at time t ₂ (e.g., slot t _{2 )} (for the transport block of the initial transmission). The SCI format 1-A transmitted with the 1 ^st retransmission on the reserved resource at time t ₁ may include information about the time t _{2 of the third resource (e.g., resource time offset) with respect to the time t 1} ^at _which the 1 st retransmission was performed and an availability indication for the 2 ^nd retransmission. Depending on the availability indication, the 2 ^nd retransmission may or may not be valid.

> Alt 3-2. Dynamic instructions for updated TRIV can be provided. For example, the following methods can be considered:

>> Alt 3-2-1. Referring to Fig. 18(b), the SCI format 1-A transmitted with the 1 ^st retransmission may indicate a new t ₂ ' value (e.g., resource time offset from t ₁ ). In this case, the latest t ₂ ' may override the previous value. That is, the UE may determine the slot for the 2 ^nd retransmission as t ₂ '.

>> Alt 3-2-2. Referring to Fig. 18(c), the SCI format 1-A transmitted with the 1 ^st retransmission may indicate a slot offset △t from the previous t ₂ . The UE may determine the slot for the 2 ^nd retransmission as t ₂ '= t ₂ + △t by considering both the t ₂ value indicated by the SCI format 1-A transmitted with the initial transmission and the above △t value.

Although the implementations of this specification have been described above using sidelink communication as an example, the implementations of this specification can be applied to communication between devices regardless of their name.

FIG. 19 is an example of a process in which a communication device performs wireless channel transmission according to some implementations of the present specification.

A communication device (hereinafter, TX UE) can receive (from a BS or another communication device) configuration(s) for wireless channel communication via higher layer signaling (e.g., RRC signaling). The TX UE can be the first wireless device of FIG. 2 or the second wireless device of FIG. 2. The configuration(s) can include the configuration(s) described above with respect to wireless channel communication (e.g., BWP configuration for communication between devices, the number of subchannels L , the number of RBs per subchannel N _sub , and/or the number of RBs for wireless shared channel N _PSSCH or L _subCH , etc.), and/or interlace related configuration. The configuration(s) can include a configuration regarding a maximum number N of wireless shared channel/wireless control channel resources that can be indicated by control information.

A TX UE may perform operations according to some implementations of the present disclosure in connection with wireless channel 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: determining a first resource, a second resource, and a third resource for wireless communication within a resource pool on a cell (S1901); generating a first control information format including time information about the second resource and the third resource; transmitting a first physical control channel carrying the first control information format and an associated first physical shared channel within the first resource (S1903); and transmitting a second physical control channel carrying the second control information format and an associated second physical shared channel within the second resource (S1905). The second control information format may include information related to availability of the third resource. The operations may include: determining whether to perform wireless channel transmission on the third resource based on the information related to availability of the third resource.

In some implementations, the operations may include: performing an LBT prior to a slot including the third resource; and determining availability of the third resource based on a result of the LBT. For example, the operations may include: determining that the third resource is available based on the success of the LBT, and setting availability-related information in the second control information format. As another example, the operations may include: determining that the third resource is unavailable based on the failure of the LBT, and setting availability-related information in the second control information format.

In some implementations, the LBT may be performed based on shared spectrum channel access related parameters set for the cell.

In some implementations, the operations may further include: transmitting a third physical control channel carrying a third control information format within the third resource and an associated third physical shared channel, based on the availability of the third resource.

In some implementations, the availability related information of the third resource in the second control information format may include time information of the fourth resource that replaces the third resource.

In some implementations, the timing information of the fourth resource may include a slot offset from the third resource to the fourth resource.

In some implementations, the operations may further comprise transmitting a third physical control channel carrying a third control information format within the fourth resource and an associated third physical shared channel.

In some implementations, the operations may further include receiving a setting regarding a maximum number N of reserved resources indicated by the control information, wherein N > 2.

In some implementations, each of the first, second and third resources may include L _subCH subchannels.

An RX UE may perform operations according to some implementations of the present disclosure in connection with receiving a wireless channel. 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: detecting (S2001) a first physical control channel carrying a first control information format in a first resource within a resource pool on a cell. The first control information format may include time information regarding a second resource and a third resource. The operations may include determining the first resource, the second resource, and the third resource based on the first control information format. The operations may include: receiving an associated first physical shared channel within the first resource in which the first physical control channel is detected; receiving a second physical control channel H carrying a second control information format within the second resource and an associated second physical shared channel (S2003). In some implementations, the second control information format may include information related to availability of the third resource. In some implementations, the operations may include: determining whether the third resource is valid based on the information related to availability of the third resource.

In some implementations, the operations may include: if the third resource is available, attempting to detect a third physical control channel carrying a third control information format in the third resource, and if the third physical control channel is detected, attempting to decode an associated third physical shared channel.

In some implementations, the actions may include: if the third resource is invalid, not attempting to detect a physical control channel on the third resource. For example, in some implementations, the actions may include: if the third resource is invalid, not performing physical control channel monitoring on the lowest subchannel of the third resource.

In some implementations, the availability related information of the third resource in the second control information format may include time information of the fourth resource that replaces the third resource.

In some implementations, the timing information of the fourth resource may include a slot offset from the third resource to the fourth resource.

In some implementations, the operations may further include receiving a setting regarding a maximum number N of reserved resources indicated by the control information, wherein N > 2.

In some implementations, each of the first, second and third resources may include L _subCH subchannels.

In some implementations, based on the shared spectrum channel access related parameters set for the cell, the second control information format may further include information related to the availability of the third resource.

According to some implementations, radio channel retransmission can be performed even if radio resource(s) are reserved outside the COT duration on a cell of the shared spectrum. Or, according to some implementations of the present specification, radio resources for retransmission can be reliably reserved on a cell of the shared spectrum. According to some implementations of the present specification, the risk that a TX UE and a RX UE interpret radio resources used for radio channel transmissions by the TX UE differently can be reduced.

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

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

Claims (19)

In a wireless communication system, when a communication device transmits a wireless channel, Determine the first resource, the second resource and the third resource for wireless communication within the resource pool on the cell; Generating a first control information format including time information regarding the second resource and the third resource; Transmitting a first physical control channel and an associated first physical shared channel carrying the first control information format within the first resource; and A second physical control channel carrying a second control information format within said second resource and transmitting an associated second physical shared channel, said second control information format including information related to the availability of said third resource; and Based on the availability information of the third resource, determining whether to perform wireless channel transmission on the third resource; Method of transmitting wireless channels. In the first paragraph, Further comprising transmitting a third physical control channel carrying a third control information format within the third resource and an associated third physical shared channel based on the availability of the third resource. Method of transmitting wireless channels. In the first paragraph, The availability related information of the third resource in the second control information format includes time information of the fourth resource that will replace the third resource. Method of transmitting wireless channels. In the third paragraph, The time information of the fourth resource includes a slot offset from the third resource to the fourth resource. Method of transmitting wireless channels. In the third paragraph, Further comprising transmitting a third physical control channel carrying a third control information format within said fourth resource and an associated third physical shared channel, Method of transmitting wireless channels. In the first paragraph, Further comprising receiving a setting regarding the maximum number N of reserved resources indicated by the control information, wherein N > 2, Method of transmitting wireless channels. In the first paragraph, Each of the first, second and third resources includes L _subCH subchannels, Method of transmitting wireless channels. In the first paragraph, Further comprising performing LBT (listen-before-talk) before performing transmission on the cell based on the cell being set to shared spectrum channel access. Method of transmitting wireless channels. In a wireless communication system, when a communication device transmits a wireless channel, 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: Determine the first resource, the second resource and the third resource for wireless communication within the resource pool on the cell; Generating a first control information format including time information regarding the second resource and the third resource; Transmitting a first physical control channel and an associated first physical shared channel carrying the first control information format within the first resource; and A second physical control channel carrying a second control information format within said second resource and transmitting an associated second physical shared channel, said second control information format including information related to the availability of said third resource; and Based on the availability information of the third resource, determining whether to perform wireless channel transmission on the third resource; Communication device. A computer-readable non-transitory storage medium comprising at least one computer program that causes at least one processor to perform operations, the operations comprising: Determine the first resource, the second resource and the third resource for wireless communication within the resource pool on the cell; Generating a first control information format including time information regarding the second resource and the third resource; Transmitting a first physical control channel and an associated first physical shared channel carrying the first control information format within the first resource; and A second physical control channel carrying a second control information format within said second resource and transmitting an associated second physical shared channel, said second control information format including information related to the availability of said third resource; and Based on the availability information of the third resource, determining whether to perform wireless channel transmission on the third resource; Storage medium. In a wireless communication system, when a communication device receives a wireless channel, A first physical control channel carrying a first control information format is detected from a first resource in a resource pool on a cell, the first control information format including time information about a second resource and a third resource; Receive an associated first physical shared channel within the first resource in which the first physical control channel is detected; Receiving a second physical control channel and an associated second physical shared channel carrying a second control information format within said second resource, said second control information format including information related to the availability of said third resource; and Based on the information related to the availability of the third resource, determining whether the third resource is valid; How to receive wireless channels. In Article 11, The availability related information of the third resource in the second control information format includes time information of the fourth resource that will replace the third resource. How to receive wireless channels. In Article 12, The time information of the fourth resource includes a slot offset from the third resource to the fourth resource. How to receive wireless channels. In Article 12, Further comprising receiving a third physical control channel carrying a third control information format within said fourth resource and an associated third physical shared channel, How to receive wireless channels. In Article 11, Further comprising receiving a setting regarding the maximum number N of reserved resources indicated by the control information, wherein N > 2, How to receive wireless channels. In Article 11, Each of the first, second and third resources includes L _subCH subchannels, How to receive wireless channels. In Article 16, Based on the above cell being set to shared spectrum channel access, the second control information format includes information related to the availability of the third resource. How to receive wireless channels. In a wireless communication system, when a communication device receives a wireless channel, 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: A first physical control channel carrying a first control information format is detected from a first resource in a resource pool on a cell, the first control information format including time information about a second resource and a third resource; Receive an associated first physical shared channel within the first resource in which the first physical control channel is detected; Receiving a second physical control channel H carrying a second control information format within said second resource and an associated second physical shared channel, said second control information format including information related to the availability of said third resource; and Based on the information related to the availability of the third resource, determining whether the third resource is valid; Communication device. A computer-readable non-transitory storage medium comprising at least one computer program that causes at least one processor to perform operations, the operations comprising: Detecting a first physical control channel carrying a first control information format from a first resource in a resource pool on a cell, the first control information format including time information about a second resource and a third resource; Receive an associated first physical shared channel within the first resource in which the first physical control channel is detected; Receiving a second physical control channel and an associated second physical shared channel carrying a second control information format within said second resource, said second control information format including information related to the availability of said third resource; and Based on the information related to the availability of the third resource, determining whether the third resource is valid; Storage medium.

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