User equipments, and communication methods

Abstract

A method performed by a user equipment (UE) is described. The method includes receiving a sidelink (SL) resource pool configuration from a base station, the SL resource pool configuration including a first parameter and a second parameter, the first parameter being used to determine a set of PRBs that are used for PSFCH transmission and reception, the second parameter indicating a number of PSFCH occasions for one associated PSSCH transmission; allocating equally N PRBs from the set of PRBs to each PSFCH occasion of the number of PSFCH occasions, wherein, N is an output of the total number of PRBs in the set of PRBs divided by the number of PSFCH occasions, and N PRBs are allocated based on an ascending order of PRB index; allocating, for each N PRBs allocated to each PSFCH occasion, one or more PRBs to each PRB subset based on ascending order of PRB index in an interlace; and performing ordering for the PRB subsets based on ascending order of PRB subset index in an interlace first and ascending order of interlace index second.

Description

[DESCRIPTION][Title of Invention]USER EQUIPMENTS, AND COMMUNICATION METHODS[Technical Field]

[0001] The present disclosure relates to a user equipment, and a communication method.[Background Art]

[0002] At present, as a radio access system and a radio network technology aimed for the fifth generation cellular system, technical investigation and standard development are being conducted, as extended standards of Long Term Evolution (LTE), on LTE-Advanced Pro (LTE-A Pro) and New Radio technology (NR) in The Third Generation Partnership Project (3GPP).

[0003] In the fifth generation cellular system, three services of enhanced Mobile BroadBand (eMBB) to achieve high-speed and large-volume transmission, UltraReliable and Low Latency Communication (URLLC) to achieve low-latency and high- reliability communication, and massive Machine Type Communication (mMTC) to allow connection of a large number of machine type devices such as Internet of Things (loT) have been demanded as assumed scenarios.

[0004] For example, wireless communication devices may communicate with one or more device. For sidelink communication, two communication devices can communicate with each other via PC-5 interface. However, given the existing sidelink communication methods cannot directly applied to unlicensed spectrum, the flexibility and / or the efficiency of the whole side link communication system would be limited. As illustrated by this discussion, systems and methods according to the present invention, supporting sidelink communication over unlicensed spectrum, which may improve the communication flexibility and / or efficiency, would be beneficial.[Brief Description of the Drawings]

[0005] Figure 1 is a block diagram illustrating one configuration of one or more base stations and one or more user equipments (UEs) in which systems and methods for determination of frequency resources for a PSFCH occasion in a resource pool for SL transmissions may be implemented;

[0006] Figure 2 is a diagram illustrating one example 200 of a resource grid;

[0007] Figure 3 is a diagram illustrating one example 300 of common resource block grid, carrier configuration and BWP configuration by a UE 102 and a base station 160;

[0008] Figure 4 is a diagram illustrating one 400 example of CORESET configuration in a BWP by a UE 102 and a base station 160;

[0009] Figure 5 is a diagram illustrating one example 500 of interlaced transmission and reception in a BWP;

[0010] Figure 6 is a diagram illustrating one example 600 of a SL BWP and a resource pool within the SL BWP;

[0011] Figure 7 is a diagram illustrating one example 700 of a resource pool configuration;

[0012] Figure 8 is a diagram illustrating one example 800 of configurations of a SL BWP and SL resource pools;

[0013] Figure 9 is a diagram illustrating one example 900 of sub-channel determination in a resource pool by a UE 102;

[0014] Figure 10 is a diagram illustrating one example 1000 of a resource pool configured with PSFCH resources;

[0015] Figure 11 is a diagram illustrating one implementation of a method 1100 for determination of frequency resources for a PSFCH transmission occasion in a resource pool by a UE 102;

[0016] Figure 12 is a diagram illustrating one implementation of another method 1200 for determination of frequency resources for a PSFCH occasion in a resource pool by a UE 102;

[0017] Figure 13 is a diagram illustrating one implementation of another method 1300 for determination of frequency resources for a PSFCH occasion in a resource pool by a UE 102;

[0018] Figure 14 illustrates various components that may be utilized in a UE;

[0019] Figure 15 illustrates various components that may be utilized in a base station;[Description of Embodiments]

[0020] A user equipment (UE) is described. The UE includes reception unit configured to receive a sidelink (SL) resource pool configuration from a base station, the SL resource pool configuration including a first parameter and a second parameter, the first parameter being used to determine a set of PRBs that are used for PSFCH transmission and reception, the second parameter indicating a number of PSFCH occasions for one associated PSSCH transmission; control circuitry configured to equally allocate N PRBs from the set of PRBs to each PSFCH occasion of the number of PSFCH occasions, wherein, N is an output of the total number of PRBs in the set of PRBs divided by the number of PSFCH occasions, and N PRBs are allocated based on an ascending order of PRB index; and the control circuitry is further configured to, for each N PRBs allocated to each PSFCH occasion, to allocate one or more PRBs to each PRB subset based on ascending order of PRB index in an interlace, and perform ordering for the PRB subsets based on ascending order of PRB subset index in an interlace first and ascending order of interlace index second.

[0021] A communication method performed by a user equipment (UE) is described. The method includes receiving a sidelink (SL) resource pool configuration from a base station, the SL resource pool configuration including a first parameter and a second parameter, the first parameter being used to determine a set of PRBs that are used for PSFCH transmission and reception, the second parameter indicating a number of PSFCH occasions for one associated PSSCH transmission; allocating equally N PRBs from the set of PRBs to each PSFCH occasion of the number of PSFCH occasions, wherein, N is an output of the total number of PRBs in the set of PRBs divided by the number of PSFCH occasions, and N PRBs are allocated based on an ascending order of PRB index; allocating, for each N PRBs allocated to each PSFCH occasion, one or more PRBs to each PRB subset based on ascending order of PRB index in an interlace; and performing ordering for the PRB subsets based on ascending order of PRB subset index in an interlace first and ascending order of interlace index second.

[0022] 3 GPP Long Term Evolution (LTE) is the name given to a project to improve the Universal Mobile Telecommunications System (UMTS) mobile phone or device standard to cope with future requirements. In one aspect, UMTS has been modified to provide support and specification for the Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN). 3GPP NR (New Radio) is the name given to a project to improve the LTE mobile phone or device standard to cope with future requirements. In one aspect, LTE has been modified to provide support and specification (TS 38.331, 38.321, 38.300, 37.340, 38.211, 38.212, 38.213, 38.214, etc.) for the New Radio Access (NR) and Next generation - Radio Access Network (NG-RAN).

[0023] At least some aspects of the systems and methods disclosed herein may be described in relation to the 3GPP LTE, LTE-Advanced (LTE-A), LTE-Advanced Pro, New Radio Access (NR), and other 3G / 4G / 5G standards (e.g., 3GPP Releases 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, and / or 18, and / or Narrow Band-Internet of Things (NB-IoT)). However, the scope of the present disclosure should not be limited in this regard. At least some aspects of the systems and methods disclosed herein may be utilized in other types of wireless communication systems.

[0024] A wireless communication device may be an electronic device used to communicate voice and / or data to a base station, which in turn may communicate with a network of devices (e.g., public switched telephone network (PSTN), the Internet, etc.). In describing systems and methods herein, a wireless communication device may alternatively be referred to as a mobile station, a UE (User Equipment), an access terminal, a subscriber station, a mobile terminal, a remote station, a user terminal, a terminal, a subscriber unit, a mobile device, a relay node, etc. Examples of wireless communication devices include cellular phones, smart phones, personal digital assistants (PDAs), laptop computers, netbooks, e-readers, wireless modems, industrial wireless sensors, video surveillance, wearables, vehicles, roadside units, infrastructure devices, etc. In 3GPP specifications, a wireless communication device is typically referred to as a UE. However, as the scope of the present disclosure should not be limited to the 3GPP standards, the terms “UE” and “wireless communication device” may be used interchangeably herein to mean the more general term “wireless communication device”.

[0025] In 3GPP specifications, a base station is typically referred to as a gNB, a Node B, an eNB, a home enhanced or evolved Node B (HeNB) or some other similar terminology. As the scope of the disclosure should not be limited to 3GPP standards, the terms “base station,”, “gNB”, “Node B,” “eNB,” and “HeNB” may be used interchangeably herein to mean the more general term “base station.” Furthermore, one example of a “base station” is an access point. An access point may be an electronic device that provides access to a network (e.g., Local Area Network (LAN), the Internet, etc.) for wireless communication devices. The term “communication device” may be used to denote both a wireless communication device and / or a base station.

[0026] It should be noted that as used herein, a “cell” may be any communication channel that is specified by standardization or regulatory bodies to be used for International Mobile Telecommunications-Advanced (IMT-Advanced), IMT-2020 (5G) and all of it or a subset of it may be adopted by 3GPP as licensed bands (e.g., frequency bands) to be used for communication between a base station and a UE. It should also be noted that in NR, NG-RAN, E-UTRA and E-UTRAN overall description, as used herein, a “cell” may be defined as “combination of downlink and optionally uplink resources.” The linking between the carrier frequency of the downlink resources and the carrier frequency of the uplink resources may be indicated in the system information transmitted on the downlink resources.

[0027] “Configured cells” are those cells of which the UE is aware and is allowed by a base station to transmit or receive information. “Configured cell(s)” may be serving cell(s). The UE may receive system information and perform the required measurements on configured cells. “Configured cell(s)” for a radio connection may consist of a primary cell and / or no, one, or more secondary cell(s). “Activated cells” are those configured cells on which the UE is transmitting and receiving. That is, activated cells are those cells for which the UE monitors the physical downlink control channel (PDCCH) and in the case of a downlink transmission, those cells for which the UE decodes a physical downlink shared channel (PDSCH). “Deactivated cells” are those configured cells that the UE is not monitoring the transmission PDCCH. It should be noted that a “cell” may be described in terms of differing dimensions. For example, a “cell” may have temporal, spatial (e.g., geographical) and frequency characteristics.

[0028] The base stations may be connected by the NG interface to the 5G - core network (5G-CN). 5G-CN may be called as to NextGen core (NGC), or 5G core (5GC).The base stations may also be connected by the SI interface to the evolved packet core (EPC). For instance, the base stations may be connected to a NextGen (NG) mobility management function by the NG-2 interface and to the NG core User Plane (UP) functions by the NG-3 interface. The NG interface supports a many-to-many relation between NG mobility management functions, NG core UP functions and the base stations. The NG-2 interface is the NG interface for the control plane and the NG-3 interface is the NG interface for the user plane. For instance, for EPC connection, the base stations may be connected to a mobility management entity (MME) by the Sl- MME interface and to the serving gateway (S-GW) by the Sl-U interface. The SI interface supports a many-to-many relation between MMEs, serving gateways and the base stations. The SI -MME interface is the SI interface for the control plane and the Sl-U interface is the S 1 interface for the user plane. The Uu interface is a radio interface between the UE and the base station for the radio protocol.

[0029] The radio protocol architecture may include the user plane and the control plane. The user plane protocol stack may include packet data convergence protocol (PDCP), radio link control (RLC), medium access control (MAC) and physical (PHY) layers. A DRB (Data Radio Bearer) is a radio bearer that carries user data (as opposed to control plane signaling). For example, a DRB may be mapped to the user plane protocol stack. The PDCP, RLC, MAC and PHY sublayers (terminated at the base station 460a on the network) may perform functions (e.g., header compression, ciphering, scheduling, ARQ and HARQ) for the user plane. PDCP entities are located in the PDCP sublayer. RLC entities may be located in the RLC sublayer. MAC entities may be located in the MAC sublayer. The PHY entities may be located in the PHY sublayer.

[0030] The control plane may include a control plane protocol stack. The PDCP sublayer (terminated in base station on the network side) may perform functions (e.g., ciphering and integrity protection) for the control plane. The RLC and MAC sublayers (terminated in base station on the network side) may perform the same functions as for the user plane. The Radio Resource Control (RRC) (terminated in base station on the network side) may perform the following functions. The RRC may perform broadcast functions, paging, RRC connection management, radio bearer (RB) control, mobility functions, UE measurement reporting and control. The Non-Access Stratum (NAS) control protocol (terminated in MME on the network side) may perform, among otherthings, evolved packet system (EPS) bearer management, authentication, evolved packet system connection management (ECM)-IDLE mobility handling, paging origination in ECM-IDLE and security control.

[0031] Signaling Radio Bearers (SRBs) are Radio Bearers (RB) that may be used only for the transmission of RRC and NAS messages. Three SRBs may be defined. SRBO may be used for RRC messages using the common control channel (CCCH) logical channel. SRB1 may be used for RRC messages (which may include a piggybacked NAS message) as well as for NAS messages prior to the establishment of SRB2, all using the dedicated control channel (DCCH) logical channel. SRB2 may be used for RRC messages which include logged measurement information as well as for NAS messages, all using the DCCH logical channel. SRB2 has a lower priority than SRB 1 and may be configured by a network (e.g., base station) after security activation. A broadcast control channel (BCCH) logical channel may be used for broadcasting system information. Some of BCCH logical channel may convey system information which may be sent from the network to the UE via BCH (Broadcast Channel) transport channel. BCH may be sent on a physical broadcast channel (PBCH). Some of BCCH logical channel may convey system information which may be sent from the network to the UE via DL-SCH (Downlink Shared Channel) transport channel. Paging may be provided by using paging control channel (PCCH) logical channel.

[0032] System information may be divided into the MasterlnformationBlock (MIB) and a number of SystemlnformationBlocks (SIBs).

[0033] The UE may receive one or more RRC messages from the base station to obtain RRC configurations or parameters. The RRC layer of the UE may configure RRC layer and / or lower layers (e.g., PHY layer, MAC layer, RLC layer, PDCP layer) of the UE according to the RRC configurations or parameters which may be configured by the RRC messages, broadcasted system information, and so on. The base station may transmit one or more RRC messages to the UE to cause the UE to configure RRC layer and / or lower layers of the UE according to the RRC configurations or parameters which may be configured by the RRC messages, broadcasted system information, and so on.

[0034] The size of various fields in the time domain is expressed in time units Tc=1 / (Δfmax× Nf) where Δfmax=480 ×103Hz and Nf=4096. The constantwhere

[0035] Multiple OFDM numerologies are supported as given by Table 4.2-1 of [TS 38.211] where μ and the cyclic prefix for a bandwidth part are obtained from the higher- layer parameter subcarrierSpacing and cyclicPrefix, respectively.

[0036] The size of various fields in the time domain may be expressed as a number of time units Tc=1 / (15000x2048) seconds. Downlink and uplink transmissions are organized into frames with Tf= (ΔfmaxNf / 100) · Tc= 10ms duration, each consisting of ten subframes of Tsf= (ΔfmaxNf / 1000) · Tc= 1ms duration. The number of consecutive OFDM symbols per subframe is Each frame is divided into two equally-sized half¬frames of five subframes each with half-frame 0 consisting of subframes 0 - 4 and halfframe 1 consisting of subframes 5 - 9.

[0037] For subcarrier spacing (SCS) configuration μ, slots are numberedin increasing order within a subframe andin increasing order within a frame. is the number ofslots per subframe for subcarrier spacing configuration μ. There are consecutiveOFDM symbols in a slot where depends on the cyclic prefix as given by Tables4.3.2-1 and 4.3.2-2 of [TS 38.211], The start of slot in a subframe is aligned in timewith the start of OFDM symbol in the same subframe. Subcarrier spacingrefers to a spacing (or frequency bandwidth) between two consecutive subcarriers in the frequency domain. For example, the subcarrier spacing can be set to 15kHz (i.e., μ=0), 30kHz (i.e. μ=1), 60kHz (i.e. μ=2), 120kHz (i.e. μ=3), or 240kHz (i.e. μ=4). A resource block is defined as a number of consecutive subcarriers (e.g., 12) in the frequency domain. For a carrier with different frequency, the applicable subcarrier may be different. For example, for a carrier in a frequency rang 1, a subcarrier spacing only among a set of {15kHz, 30kHz, 60kHz} is applicable. For a carrier in a frequency rang 2, a subcarrier spacing only among a set of {60kHz, 120kHz, 240kHz} is applicable. The base station may not configure an inapplicable subcarrier spacing for a carrier.

[0038] OFDM symbols in a slot can be classified as 'downlink', 'flexible', or 'uplink'.Signaling of slot formats is described in subclause 11.1 of [TS 38.213].

[0039] In a slot in a downlink frame, the UE may assume that downlink transmissions only occur in 'downlink' or 'flexible' symbols. In a slot in an uplink frame, the UE may only transmit in 'uplink' or 'flexible' symbols.

[0040] Various examples of the systems and methods disclosed herein are now described with reference to the Figures, where like reference numbers may indicate functionally similar elements. The systems and methods as generally described and illustrated in the Figures herein could be arranged and designed in a wide variety of different implementations. Thus, the following more detailed description of several implementations, as represented in the Figures, is not intended to limit scope, as claimed, but is merely representative of the systems and methods.

[0041] Figure 1 is a block diagram illustrating one configuration of one or more base stations 160 (e.g., eNB, gNB) and one or more user equipments (UEs) 102 in which systems and methods for determination of frequency resources for a PSFCH occasion in a resource pool for SL transmissions may be implemented. The one or more UEs 102 may communicate with one or more base stations 160 using one or more antennas 122a-n. For example, a UE 102 transmits electromagnetic signals to the base station 160 and receives electromagnetic signals from the base station 160 using the one or more antennas 122a-n. The base station 160 communicates with the UE 102 using one or more antennas 180a-n. Additionally, one or more UEs 102 may communicate with one or more UEs 102 using one or more antennas 122a-n. For example, aUE 102 transmits electromagnetic signals to another UE(s) 102 and receives electromagnetic signals from another UE(s) 102 using the one or more antennas 122a- n. That is, one or more UEs communicate with each other via sidelink communication.

[0042] The UEs 102 may directly communicate with each other by using the sidelink communication. For illustration, UE(s) 102 capable of sidelink communication include a UE lA, aUE IB and aUE IC. The UE lAmaybe located within the coverage of the base station 160. The UE IB and the UE 1C may be located outside the coverage of the base station 160. The UE 1A and the base station 160 may communicate with each other via downlink and uplink communication. In addition, the UE 1 A and the UE IB may directly communicate with each other via sidelink communication. In addition,the UE 1B and the UE 1C may directly communicate with each other via sidelink communication.

[0043] It should be noted that in some configurations, one or more of the UEs 102 described herein may be implemented in a single device. For example, multiple UEs 102 may be combined into a single device in some implementations. Additionally or alternatively, in some configurations, one or more of the base stations 160 described herein may be implemented in a single device. For example, multiple base stations 160 may be combined into a single device in some implementations. In the context of Figure 1, for instance, a single device may include one or more UEs 102 in accordance with the systems and methods described herein. Additionally or alternatively, one or more base stations 160 in accordance with the systems and methods described herein may be implemented as a single device or multiple devices.

[0044] The UE 102 and the base station 160 may use one or more channels 119, 121 to communicate with each other. For example, a UE 102 may transmit information or data to the base station 160 using one or more uplink (UL) channels 121 and signals. Examples of uplink channels 121 include a physical uplink control channel (PUCCH) and a physical uplink shared channel (PUSCH), etc. Examples of uplink signals include a demodulation reference signal (DMRS) and a sounding reference signal (SRS), etc. The one or more base stations 160 may also transmit information or data to the one or more UEs 102 using one or more downlink (DL) channels 119 and signals, for instance. Examples of downlink channels 119 include a PDCCH, a PDSCH, etc. A PDCCH can be used to schedule DL transmissions on PDSCH and UL transmissions on PUSCH, where the Downlink Control Information (DCI) on PDCCH includes downlink assignment and uplink scheduling grants. A PDCCH can be also used for scheduling of sidelink transmissions on PSCCH and PSSCH in one cell, where the Downlink Control Information (DCI) on PDCCH includes sidelink scheduling grants. The PDCCH is used for transmitting Downlink Control Information (DCI) in a case of downlink radio communication (radio communication from the base station to the UE). Here, one or more DCIs (may be referred to as DCI formats) are defined for transmission of downlink control information. Information bits are mapped to one or more fields defined in a DCI format. Examples of downlink signals include a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a cell-specific reference signal (CRS), a non-zero power channel state information reference signal(NZP CSI-RS), and a zero-power channel state information reference signal (ZP CSI- RS), etc. Other kinds of channels or signals may be used.

[0045] For the UE(s) 102 capable of sidelink communication, the UEs 102 may use one or more sidelink channels 123 to communicate with each other. For example, a UE 102 may transmit information or data to another UE 102 using one or more sidelink (SL) channels 123 and signals. Examples of sidelink channels 123 include a physical sidelink control channel (PSCCH), a physical sidelink shared channel (PSSCH), a physical sidelink feedback channel (PSFCH), and a physical sidelink broadcast channel (PSBCH). Examples of sidelink signals include a demodulation reference signal (DMRS), a phase-tracking reference signal (PT-RS), a channel-state information reference signal (CSI-RS), a sidelink primary synchronization signal (S-PSS), and a sidelink secondary synchronization signal (S-SSS).

[0046] Each of the one or more UEs 102 may include one or more transceivers 118, one or more demodulators 114, one or more decoders 108, one or more encoders 150, one or more modulators 154, one or more data buffers 104 and one or more UE operations modules 124. For example, one or more reception and / or transmission paths may be implemented in the UE 102. For convenience, only a single transceiver 118, decoder 108, demodulator 114, encoder 150 and modulator 154 are illustrated in the UE 102, though multiple parallel elements (e.g., transceivers 118, decoders 108, demodulators 114, encoders 150 and modulators 154) may be implemented.

[0047] The transceiver 118 may include one or more receivers (reception units) 120 and one or more transmitters (transmission units) 158. The one or more receivers 120 may receive signals (e.g., downlink channels, downlink signals, sidelink channels, sidelink signals) from the base station 160 or from another UE 102 using one or more antennas 122a-n. For example, the receiver 120 may receive and downconvert signals to produce one or more received signals 116. The one or more received signals 116 may be provided to a demodulator 114. The one or more transmitters 158 may transmit signals (e.g., uplink channels, uplink signals, sidelink channels, sidelink signals) to the base station 160 or to another UE 102 using one or more antennas 122a-n. For example, the one or more transmitters 158 may upconvert and transmit one or more modulated signals 156.

[0048] The demodulator 114 may demodulate the one or more received signals 116 to produce one or more demodulated signals 112. The one or more demodulated signals112 may be provided to the decoder 108. The UE 102 may use the decoder 108 to decode signals. The decoder 108 may produce one or more decoded signals 106, 110. For example, a first UE-decoded signal 106 may comprise received payload data, which may be stored in a data buffer 104. A second UE-decoded signal 110 may comprise overhead data and / or control data. For example, the second UE-decoded signal 110 may provide data that may be used by the UE operations module 124 to perform one or more operations.

[0049] As used herein, the term “module” may mean that a particular element or component may be implemented in hardware, software or a combination of hardware and software. However, it should be noted that any element denoted as a “module” herein may alternatively be implemented in hardware. For example, the UE operations module 124 may be implemented in hardware, software or a combination of both.

[0050] In general, the UE operations module 124 may enable the UE 102 to communicate with the one or more base stations 160. For a UE capable of sidelink communication, the UE operations module 124 may enable the UE 102 to communicate with the one or more other UE. The UE operations module 124 may include a UE RRC information configuration module 126. For a UE capable of sidelink communication, the UE operations module 124 may include a UE sidelink (SL) control module (unit) 128. In some implementations, the UE operations module 124 may include physical (PHY) entities, Medium Access Control (MAC) entities, Radio Link Control (RLC) entities, packet data convergence protocol (PDCP) entities, and a Radio Resource Control (RRC) entity. For example, the UE RRC information configuration module 126 may process RRC parameter for random access configurations, initial UL BWP configuration, maximum bandwidth the UE can support, and cell specific PUCCH resource configuration(s).

[0051] For a UE capable of sidelink transmission, the UE RRC information configuration module 126 may process parameters included in the (pre-)configuration(s) related to sidelink communications. The UE RRC information configuration module 126 may include a memory unit to store the (pre-)configuration(s) related to sidelink communications. For example, the UE RRC information configuration module 126 may, based on the parameters, determine a SL BWP, one or more resource pools within the SL BWP in frequency domain and time domain for SL communications. The UE RRC information configuration module 126 may provideinformation related to SL BWP configuration and resource pool configuration to the UE SL control module 128. The UE SL control module 128 may set the SL BWP configuration and the resource pool configuration.

[0052] The UE SL control module 128 may determine the frequency resources, the time resources, the code resources, and / or numerologies for transmission or reception of the PSCCH, the PSSCH, S-SS / PSBCH and / or the PSFCH. The frequency resources for transmission or reception of the PSCCH, the PSSCH and the PSFCH include information related to assigned sub-channel(s) (or interlace(s)) and RB set(s).

[0053] The UE operations module 124 may provide information 148 to the one or more receivers 120. For example, the UE operations module 124 may inform the receiver(s) 120 when or when not to receive transmissions based on the Radio Resource Control (RRC) message (e.g., broadcasted system information, RRC reconfiguration message), MAC control element, SCI (Sidelink Control Information) and / or the DCI (Downlink Control Information). The UE operations module 124 may provide information 148, including the PDCCH monitoring occasions, DCI format size, PSCCH monitoring occasions and SCI format size, to the one or more receivers 120. The UE operation module 124 may inform the receiver(s) 120 when or where to receive / monitor the PDCCH candidate for DCI formats and / or the PSCCH candidate for SCI formats. DCI formats can be used at least for scheduling of SL transmission(s) (PSCCH and / or PSSCH transmission(s)) in one cell and / or for scheduling of PUSCH and / or PDSCH in one cell.

[0054] The UE operations module 124 may provide information 138 to the demodulator 114. For example, the UE operations module 124 may inform the demodulator 114 of a modulation pattern anticipated for transmissions from the base station 160.

[0055] The UE operations module 124 may provide information 136 to the decoder 108. For example, the UE operations module 124 may inform the decoder 108 of an anticipated encoding for transmissions from the base station 160. For example, the UE operations module 124 may inform the decoder 108 of an anticipated PDCCH candidate encoding with which DCI size for transmissions from the base station 160. The UE operations module 124 may inform the decoder 108 of an anticipated PSCCH candidate encoding with which SCI size for transmissions from another UE 102.

[0056] The UE operations module 124 may provide information 142 to the encoder 150. The information 142 may include data to be encoded and / or instructions for encoding. For example, the UE operations module 124 may instruct the encoder 150 to encode transmission data 146 and / or other information 142.

[0057] The encoder 150 may encode transmission data 146 and / or other information 142 provided by the UE operations module 124. For example, encoding the data 146 and / or other information 142 may involve error detection and / or correction coding, mapping data to space, time and / or frequency resources for transmission, multiplexing, etc. The encoder 150 may provide encoded data 152 to the modulator 154.

[0058] The UE operations module 124 may provide information 144 to the modulator 154. For example, the UE operations module 124 may inform the modulator 154 of a modulation type (e.g., constellation mapping) to be used for transmissions to the base station 160. The modulator 154 may modulate the encoded data 152 to provide one or more modulated signals 156 to the one or more transmitters 158.

[0059] The UE operations module 124 may provide information 140 to the one or more transmitters 158. This information 140 may include instructions for the one or more transmitters 158. For example, the UE operations module 124 may instruct the one or more transmitters 158 when to transmit a signal to the base station 160 or another UE 102. The one or more transmitters 158 may upconvert and transmit the modulated signal(s) 156 to one or more base stations 160 or another one or more UEs 102.

[0060] The base station 160 may include one or more transceivers 176, one or more demodulators 172, one or more decoders 166, one or more encoders 109, one or more modulators 113, one or more data buffers 162 and one or more base station operations modules 182. For example, one or more reception and / or transmission paths may be implemented in a base station 160. For convenience, only a single transceiver 176, decoder 166, demodulator 172, encoder 109 and modulator 113 are illustrated in the base station 160, though multiple parallel elements (e.g., transceivers 176, decoders 166, demodulators 172, encoders 109 and modulators 113) may be implemented.

[0061] The transceiver 176 may include one or more receivers (reception units) 178 and one or more transmitters (transmission units) 117. The one or more receivers 178 may receive signals (e.g., uplink channels, uplink signals) from the UE 102 using one or more antennas 180a-n. For example, the receiver 178 may receive and downconvert signals to produce one or more received signals 174. The one or more received signals174 may be provided to a demodulator 172. The one or more transmitters 117 may transmit signals (e.g., downlink channels, downlink signals) to the UE 102 using one or more antennas 180a-n. For example, the one or more transmitters 117 may upconvert and transmit one or more modulated signals 115.

[0062] The demodulator 172 may demodulate the one or more received signals 174 to produce one or more demodulated signals 170. The one or more demodulated signals 170 may be provided to the decoder 166. The base station 160 may use the decoder 166 to decode signals. The decoder 166 may produce one or more decoded signals 164, 168. For example, a first base station-decoded signal 164 may comprise received payload data, which may be stored in a data buffer 162. A second base station-decoded signal 168 may comprise overhead data and / or control data. For example, the second base station-decoded signal 168 may provide data (e.g., PUSCH transmission data) that may be used by the base station operations module 182 to perform one or more operations.

[0063] In general, the base station operations module 182 may enable the base station 160 to communicate with the one or more UEs 102. For a base station capable of sidelink communication, the UE operations module 124 may enable the base station 160 to communicate with the one or more UEs 102 capable of side link communication. The base station operations module 182 may include a base station RRC information configuration module 194. For a base station capable of sidelink communication, the base station operations module 182 may include a base station sidelink (SL) control module 196 (or a base station SL processing module 196). The base station operations module 182 may include PHY entities, MAC entities, RLC entities, PDCP entities, and an RRC entity.

[0064] For a base station capable of sidelink transmission, the base station SL control module 196 may determine, for respective UE, the time and frequency resources for scheduling PSCCH and PSSCH and input the information to the base station RRC information configuration module 194.

[0065] The base station operations module 182 may provide the benefit of performing PDCCH candidate search and monitoring efficiently. The base station operations module 182 may provide information 190 to the one or more receivers 178. For example, the base station operations module 182 may inform the receiver(s) 178 when or when not to receive transmissions based on the RRC message (e.g.,broadcasted system information, RRC reconfiguration message), MAC control element, and / or the DCI (Downlink Control Information).

[0066] The base station operations module 182 may provide information 188 to the demodulator 172. For example, the base station operations module 182 may inform the demodulator 172 of a modulation pattern anticipated for transmissions from the UE(s) 102.

[0067] The base station operations module 182 may provide information 186 to the decoder 166. For example, the base station operations module 182 may inform the decoder 166 of an anticipated encoding for transmissions from the UE(s) 102.

[0068] The base station operations module 182 may provide information 101 to the encoder 109. The information 101 may include data to be encoded and / or instructions for encoding. For example, the base station operations module 182 may instruct the encoder 109 to encode transmission data 105 and / or other information 101.

[0069] In general, the base station operations module 182 may enable the base station 160 to communicate with one or more network nodes (e.g., a NG mobility management function, a NG core UP functions, a mobility management entity (MME), serving gateway (S-GW), gNBs). The base station operations module 182 may also generate a RRC reconfiguration message to be signaled to the UE 102.

[0070] The encoder 109 may encode transmission data 105 and / or other information 101 provided by the base station operations module 182. For example, encoding the data 105 and / or other information 101 may involve error detection and / or correction coding, mapping data to space, time and / or frequency resources for transmission, multiplexing, etc. The encoder 109 may provide encoded data 111 to the modulator 113. The transmission data 105 may include network data to be relayed to the UE 102.

[0071] The base station operations module 182 may provide information 103 to the modulator 113. This information 103 may include instructions for the modulator 113. For example, the base station operations module 182 may inform the modulator 113 of a modulation type (e.g., constellation mapping) to be used for transmissions to the UE(s) 102. The modulator 113 may modulate the encoded data 111 to provide one or more modulated signals 115 to the one or more transmitters 117.

[0072] The base station operations module 182 may provide information 192 to the one or more transmitters 117. This information 192 may include instructions for the oneor more transmitters 117. For example, the base station operations module 182 may instruct the one or more transmitters 117 when to (or when not to) transmit a signal to the UE(s) 102. The base station operations module 182 may provide information 192, including the PDCCH monitoring occasions and DCI format size, to the one or more transmitters 117. The base station operation module 182 may inform the transmitter(s) 117 when or where to transmit the PDCCH candidate for DCI formats with which DCI size. The one or more transmitters 117 may upconvert and transmit the modulated signal(s) 115 to one or more UEs 102.

[0073] It should be noted that one or more of the elements or parts thereof included in the base station(s) 160 and UE(s) 102 may be implemented in hardware. F or example, one or more of these elements or parts thereof may be implemented as a chip, circuitry or hardware components, etc. It should also be noted that one or more of the functions or methods described herein may be implemented in and / or performed using hardware. For example, one or more of the methods described herein may be implemented in and / or realized using a chipset, an application-specific integrated circuit (ASIC), a large-scale integrated circuit (LSI) or integrated circuit, etc.

[0074] A base station may generate a RRC message including the one or more RRC parameters and may transmit the RRC message to a UE. A UE may receive, from a base station, a RRC message including one or more RRC parameters. In the present disclosure, the terms ‘RRC parameter(s)’, ‘RRC information element(s)’, ‘higher layer parameter(s)’ can be used interchangeably. In the present disclosure, higher layer may refer to a layer upper than the physical layer (i.e., Layer 1), for example, MAC layer, RLC layer, PDCP layer, SDAP layer, RRC layer, and / or application layer.

[0075] A RRC parameter may further include one or more RRC parameter(s). In the present disclosure, a RRC message may include system information, a RRC message may include one or more RRC parameters. A RRC message may be sent on a broadcast control channel (BCCH) logical channel, a common control channel (CCCH) logical channel or a dedicated control channel (DCCH) logical channel.

[0076] In the present disclosure, a description “a UE is configured with or is provided a parameter” also implies the description “the UE may receive, from the base station, an RRC message (or information) which includes the parameter”. Likewise, the description “a base station configures the UE with or provides the UE the parameter”also implies the description “the base station may transmit, to the UE, an RRC message (or information) which includes the parameter”.

[0077] Figure 2 is a diagram illustrating one example of a resource grid 200.

[0078] For each numerology (i.e., for each SCS u) and carrier, a resource grid of Ngrid,xsize,μNscRBsubcarriers and Nsymbsubframe’μOFDM symbols is defined, starting at common resource block Ngridstart,μindicated by higher layer signaling. There is one set of resource grids per transmission direction (uplink or downlink) with the subscript x set to DL and UL for downlink and uplink, respectively. There is one resource grid for a given antenna port p, subcarrier spacing configuration μ, and the transmission direction (downlink or uplink). When there is no risk for confusion, the subscript x may be dropped.

[0079] In the Figure 2, the resource gird 200 includes the Ngrid,xsize,μNscRB(202) subcarriers in the frequency domain and includes Nsymbsubframe’μ(204) symbols in the time domain. In the Figure 2, as an example for illustration, the subcarrier spacing configuration μ is set to 0. That is, in the Figure 2, the number of consecutive OFDM symbols Nsymbsubframe’μ(204) per subframe is equal to 14.

[0080] The carrier bandwidth Ngridsize,μ(Ngrid,xsize,μ) for subcarrier spacing configuration μ is given by the higher-layer (RRC) parameter carrier Bandwidth in the SCS-SpecificCarrier IE. The starting position Ngridstart,μfor subcarrier spacing configuration μ is given by the higher-layer parameter offsetToCarrier in the SCS- SpecificCarrier IE. The frequency location of a subcarrier refers to the center frequency of that subcarrier.

[0081] In the Figure 2, for example, a value of offset is provided by the higher-layer parameter offsetToCarrier. That is, k = 12 X offset is the lowest usable subcarrier on this earner.

[0082] Each element in the resource grid for antenna port p and subcarrier spacing configuration μ is called a resource element and is uniquely identified by (k,l)p,μ where k is the index in the frequency domain and l refers to the symbols position in the time domain relative to same reference point. The resource element consists of one subcarrier during one OFDM symbol.

[0083] A resource block is defined as NscRB=12 consecutive subcarriers in the frequency domain. As shown in the Figure 2, a resource block 206 includes 12consecutive subcarriers in the frequency domain. Resource block can be classified as common resource block (CRB) and physical resource block (PRB).

[0084] Common resource blocks are numbered from 0 and upwards in the frequency domain for subcarrier spacing configuration μ. The center of subcarrier 0 of common resource block with index 0 (i.e. CRB0) for subcarrier spacing configuration μ. coincides with point A. The relation between the common resource block number in the frequency domain and resource element (k, l) for subcarrier spacing configuration μ is given by Formula (1) nCRBμ=floor(k / NscRB) where k is defined relative to the point A such that k=0 corresponds to the subcarrier centered around the point A. The function floor(A) hereinafter is floor operation to output a maximum integer not larger than the A.

[0085] Point A refers to as a common reference point. Point A coincides with subcarrier 0 (i.e., k=0) of a CRB 0 for all subcarrier spacing. Point A can be obtained from a RRC parameter offsetToPointA or a RRC parameter absoluteFrequencyPointA. The RRC parameter offsetToPointA is used for a PCell downlink and represents the frequency offset between point A and the lowest subcarrier of the lowest resource block, which has the subcarrier spacing provided by a higher-layer parameter subCarrierSpacingCommon and overlaps with the SS / PBCH block used by the UE for initial cell selection, expressed in units of resource blocks assuming 15 kHz subcarrier spacing for frequency range (FR) 1 and 60 kHz subcarrier spacing for frequency range (FR2). FR1 corresponds to a frequency range between 410MHz and 7125MHz. FR2 corresponds to a frequency range between 24250MHz and 52600MHz. The RRC parameter absoluteFrequencyPointA is used for all cased other than the PCell case and represents the frequency-location of point A expressed as in ARFCN. The frequency location of point A can be the lowest subcarrier of the carrier bandwidth ( or the actual carrier). Additionally, point A may be located outside the carrier bandwidth ( or the actual carrier).

[0086] As above mentioned, the information element (IE) SCS-SpecificCarrier provides parameters determining the location and width of the carrier bandwidth or the actual carrier. That is, a carrier (or a carrier bandwidth, or an actual carrier) is determined (identified, or defined) at least by a RRC parameter offsetToCarrier, a RRCparameter subcarrierSpacing, and a RRC parameter carrier Bandwidth in the SCS- SpecificCarrier IE.

[0087] The subcarrierSpacing indicates (or defines) a subcarrier spacing of the carrier. The offsetToCarrier indicates an offset in frequency domain between point A and a lowest usable subcarrier on this carrier in number of resource blocks (e.g. CRBs) using the subcarrier spacing defined for the carrier. The carrier Bandwidth indicates width of this carrier in number of resource blocks (e.g., CRBs or PRBs) using the subcarrier spacing defined for the carrier. A carrier includes at most 275 resource blocks.

[0088] Physical resource blocks for subcarrier spacing configuration μ are defined within a bandwidth part and numbered form 0 to NB WP,isize,μwhere i is the number of the bandwidth part. The relation between the physical resource block nPRBμin bandwidth part (BWP) i and the common resource block nCRBμis given by Formula (2) nCRBμ= nPRBμ+ NB WP,istart,μwhere NB WP,istart,μis the common resource block where bandwidth part i starts relative to common resource block 0 (CRBO). When there is no risk for confusion the index μ may be dropped.

[0089] A BWP is a subset of contiguous common resource block for a given subcarrier spacing configuration μ on a given carrier. To be specific, a BWP can be identified (or defined) at least by a subcarrier spacing μ indicated by the RRC parameter subcarrierSpacing, a cyclic prefix determined by the RRC parameter cyclicPrefix, a frequency domain location, a bandwidth, an BWP index indicated by bwp-Id and so on. The locationAndBandwidth can be used to indicate the frequency domain location and bandwidth of a BWP. The value indicated by the locationAndBandwidth is interpreted as resource indicator value (RIV) corresponding to an offset (a starting resource block) Restart and a length LRBin terms of contiguously resource blocks. The offset RBstartis a number of CRBs between the lowest CRB of the carrier and the lowest CRB of the BWP. The NB WP,istart,μis given as Formula (3) NB WP,istart,μ= Ocarrier+RB The value of Ocarrieris provided by offsetTocarrier for the corresponding subcarrier spacing configuration μ.

[0090] AUE 102 configured to operate in BWPs of a serving cell, is configured by higher layers for the serving cell a set of at most four BWPs in the downlink for reception. At a given time, a single downlink BWP is active. The bases station 160 may not transmit, to the UE 102, PDSCH and / or PDCCH outside the active downlink BWP. A UE 102 configured to operate in BWPs of a serving cell, is configured by higherlayers for the serving cell a set of at most four BWPs for transmission. At a given time, a single uplink BWP is active. The UE 102 may not transmit to the base station 160, PUSCH or PUCCH outside the active BWP. The specific signaling (higher layers signaling) for BWP configurations are described later.

[0091] A UE 102, configured to operate in a SL BWP, is configured or preconfigured by higher layers for the serving cell or by a pre-configuration a SL BWP for sidelink reception and / or transmission. At a given time, a single SL BWP is active. The UE 102 may not transmit, to another UE 102, sidelink channel (PSCCH, PSCCH, and / or PSFCH) outside the active SL BWP.

[0092] Figure 3 is a diagram illustrating one example 300 of common resource block grid, carrier configuration and BWP configuration by a UE 102 and a base station 160.

[0093] Point A 301 is the lowest subcarrier of a CRB0 for all subcarrier spacing configurations. The CRB grid 302 and the CRB grid 312 are corresponding to two different subcarrier spacing configurations. The CRB grid 302 is for subcarrier spacing configuration μ =0 (i.e., the subcarrier spacing with 15kHz). The CRB grid 312 is for subcarrier spacing configuration μ =7 (i.e., the subcarrier spacing with 30kHz).

[0094] One or more carriers are determined by respective SCS-SpecificCarrier lEs, respectively. In the Figure 3, the carrier 304 uses the subcarrier spacing configuration μ=0. And the carrier 314 uses the subcarrier spacing configuration μ=1. The starting position Ngridstart,μof the carrier 304 is given based on the value of an offset 303 (i.e. Ocarrier) indicated by an offsetToCarrier in an SCS-SpecificCarrier IE. As shown in the Figure 3, for example, the offsetToCarrier indicates the value of the offset 303 as Ocarrier=3. That is, the starting position Ngridstart,μof the carrier 304 corresponds to the CRB3 of the CRB grid 302 for subcarrier spacing configuration μ=0. In the meantime, the starting position Ngridstart,μof the carrier 314 is given based on the value of an offset 313 (i.e. Ocamer) indicated by an offsetToCarrier in another SCS-SpecificCarrier IE. For example, the offsetToCarrier indicates the value of the offset 313 as Ocamer =1. That is, the starting position Ngridstart,μof the carrier 314 corresponds to the CRB1 of the CRB grid 312 for subcarrier spacing configuration μ=1. A carrier using different subcarrier spacing configurations can occupy different frequency ranges.

[0095] As above-mentioned, a BWP is for a given subcarrier spacing configuration μ. One or more BWPs can be configured for a same subcarrier spacing configuration μ.For example, in the Figure 3, the BWP 306 is identified at least by the μ=0, a frequency domain location, a bandwidth (LRB), and an BWP index (index A). The first PRB (i.e. PRBO) of a BWP is determined at least by the subcarrier spacing of the BWP, an offset derived by the locationAndBandwidth and an offset indicated by the offsetToCarrier corresponding to the subcarrier spacing of the BWP. An offset 305 (Restart) is derived as 1 by the locationAndBandwidth. According to the Formulas (2) and (3), the PRB0 of BWP 306 corresponds to CRB 4 of the CRB grid 302, and the PRB1 of BWP 306 corresponds to CRB 5 of the CRB grid 302, and so on.

[0096] Additionally, in the Figure 3, the BWP 308 is identified at least by the μ=0, a frequency domain location, a bandwidth (LRB), and an BWP index (index B). For example, an offset 307 (RBstart) is derived as 6 by the locationAndBandwidth. According to the Formulas (2) and (3), the PRBO of BWP 308 corresponds to CRB 9 of the CRB grid 302, and the PRB1 of BWP 308 corresponds to CRB 10 of the CRB grid 302, and so on.

[0097] Additionally, in the Figure 3, the BWP 316 is identified at least by the μ=1, a frequency domain location, a bandwidth (LRB), and an BWP index (index C). For example, an offset 315 (RBstart) is derived as 1 by the locationAndBandwidth. According to the Formulas (2) and (3), the PRBO of BWP 316 corresponds to CRB 2 of the CRB grid 312, and the PRB1 of BWP 316 corresponds to CRB 3 of the CRB grid 312, and so on.

[0098] In the present disclosure, a BWP illustrated in the Figure 3 may refer to a DL BWP, a UL BWP, or a sidelink BWP.

[0099] As shown in the Figure 3, a carrier with the defined subcarrier spacing locate in a corresponding CRB grid with the same subcarrier spacing. A BWP with the defined subcarrier spacing locate in a corresponding CRB grid with the same subcarrier spacing as well.

[0100] A base station may transmit a RRC message including one or more RRC parameters related to BWP configuration to a UE. A UE may receive the RRC message including one or more RRC parameters related to BWP configuration from a base station. For each cell, the base station may configure at least an initial DL BWP, one initial uplink bandwidth parts (initial UL BWP) and one sidelink BWP to the UE. Furthermore, the base station may configure additional UL and DL BWPs to the UE for a cell.

[0101] SSIIBB11, which i iss a cell-specific system information block (SystemlnformationBlock, SIB), may contain information relevant when evaluating if a UE is allowed to access a cell and define the scheduling of other system information. SIB 1 may also contain radio resource configuration information that is common for all UEs, and barring information applied to the unified access control. The RRC parameter ServingCellConfigCommon is used to configure cell specific parameters of a UE's serving cell. The RRC parameter ServingCellConflg is used to configure (add or modify) the UE with a serving cell, which may be the SpCell or an SCell of an MCG or SCG. The RRC parameter ServingCellConfig herein are mostly UE specific but partly also cell specific.

[0102] The base station may configure the UE with a RRC parameter BWP- Downlink and a RRC parameter BWP-Uplink. The RRC parameter BWP-Downlink can be used to configure an additional DL BWP. The RRC parameter BWP-Uplink can be used to configure an additional UL BWP. The base station may transmit the B WP- Downlink and the BWP-Uplink which may be included in RRC parameter ServingCellConfig to the UE.

[0103] The UE may be configured by the based station, at least one initial BWP and up to 4 additional BWP(s). One of the initial BWP and the configured additional BWP(s) may be activated as an active BWP. The UE may monitor DCI format, and / or receive PDSCH in the active DL BWP. The UE may not monitor DCI format, and / or receive PDSCH in a DL BWP other than the active DL BWP. The UE may transmit PUSCH and / or PUCCH in the active UL BWP. The UE may not transmit PUSCH and / or PUCCH in a BWP other than the active UL BWP.

[0104] As above-mentioned, a UE may monitor DCI format in the active DL BWP. To be more specific, a UE may monitor a set of PDCCH candidates in one or more CORESETs on the active DL BWP on each activated serving cell configured with PDCCH monitoring according to corresponding search space set where monitoring implies decoding each PDCCH candidate according to the monitored DCI formats.

[0105] A set of PDCCH candidates for a UE to monitor is defined in terms of PDCCH search space sets. A search space set can be a CSS set or a USS set. AUE may monitor a set of PDCCH candidates in one or more of the search space sets.

[0106] Figure 4 is a diagram illustrating one 400 example of CORESET configuration in a BWP by a UE 102 and a base station 160.

[0107] Figure 4 illustrates that a UE 102 is configured with three CORESETs for receiving PDCCH transmission in two BWPs. In the Figure 4, 401 represent point A. 402 is an offset in frequency domain between point A 401 and a lowest usable subcarrier on the carrier 403 in number of CRBs, and the offset 402 is given by the offsetToCarrier in the SCS-SpecificCarrier IE. The BWP 405 with index A and the carrier 403 are for a same subcarrier spacing configuration μ. The offset 404 between the lowest CRB of the carrier and the lowest CRB of the BWP in number of RBs is given by the locationAndBandwidth included in the BWP configuration for BWP A. The BWP 407 with index B and the carrier 403 are for a same subcarrier spacing configuration μ. The offset 406 between the lowest CRB of the carrier and the lowest CRB of the BWP in number of RBs is given by the locationAndBandwidth included in the BWP configuration for BWP B.

[0108] For the BWP 405, two CORESETs are configured. As above-mentioned, a RRC parameter frequencyDomainResource in respective CORESET configuration indicates the frequency domain resource for respective CORESET. In the frequency domain, a CORESET is defined in multiples of RB groups and each RB group consists of 6 RBs. For example, in the Figure 4, the RRC parameter frequencyDomainResource provides a bit string with a fixed size (e.g., 45 bits) as like ‘11010000...000000’ for CORESET#1. That is, the first RB group, the second RB group, and the fourth RB group belong to the frequency domain resource of the CORESET#1. Additionally, the RRC parameter frequencyDomainResource provides a bit string with a fixed size (e.g., 45 bits) as like ‘00101110...000000’ for CORESET#2. That is, the third RB group, the fifth RB group, the sixth RB group and the seventh RB group belong to the frequency domain resource of the CORESET#2.

[0109] For the BWP 407, one CORESET is configured. As above-mentioned, a RRC parameter frequencyDomainResource in the CORESET configuration indicates the frequency domain resource for the CORESET #3. In the frequency domain, a CORESET is defined in multiples of RB groups and each RB group consists of 6 RBs. For example, in the Figure 4, the RRC parameter frequencyDomainResource provides a bit string with a fixed size (e.g., 45 bits) as like ‘ 11010000...000000’ for CORESET&3. That is, the first RB group, the second RB group, and the fourth RB group belong to the frequency domain resource of the CORESET#3. Although the bit string configured for CORESET#3 is same as that for CORESET#!, the first RB group of the BWP B isdifferent from that of the BWP A in the carrier. Therefore, the frequency domain resource of the CORESET#3 in the carrier is different from that of the CORESET#1 as well.

[0110] For the communication system, spectrum is divided into licensed spectrum and unlicensed spectrum. The NR technologies have been developed in the licensed spectrum and in the unlicensed spectrum. The operation in unlicensed spectrum, used as a complementary solution, can increase the throughput of the overall wireless communication system. However, operation in unlicensed spectrum is subject to regulatory limitations and restrictions. For example, the European Telecommunications Standards Institute (ETSI) has defined regulations for operation over the unlicensed spectrum. For example, the occupied channel bandwidth (OCB), which is defined as a bandwidth containing 99% of the signal power, should be larger than a percentage of the nominal channel bandwidth (NCB). For example, according to the ETSI regulations, the OCB should be between 70% and 100% of the NCB for 5GHz band.

[0111] An unlicensed band (or a carrier, or a subband) would be divided into one or multiple non-overlapping channels of 20MHz bandwidth in the frequency domain. For a (nominal) channel bandwidth of 20MHz, one transmission should occupy a channel bandwidth larger than what the regulation on OCB requires, for example, one transmission should be larger than 80% of the channel bandwidth of 20MHz to meet the OCB requirement. To meet the OCB requirement, the design of interlaced transmission had been introduced where each interlace transmission within a channel bandwidth can occupy a channel bandwidth being larger than what the OCB requires.

[0112] The unlicensed band (unlicensed spectrum) may be or may be not configured with operation with shared spectrum channel access. Likewise, the licensed band (licensed spectrum) may be or may be not configured with operation with shared spectrum channel access. In the present disclosure, the unlicensed band (the unlicensed spectrum) configured with operation with shared spectrum channel access can be termed the unlicensed band A (the unlicensed spectrum A). The unlicensed band (unlicensed spectrum) not configured with operation with shared spectrum channel access can be termed the unlicensed band B (the unlicensed spectrum B). The licensed band (the licensed spectrum) configured with operation with shared spectrum channel access can be termed the licensed band C (the licensed spectrum C). The licensed band(licensed spectrum) not configured with operation with shared spectrum channel access can be termed the licensed band D (the licensed spectrum D).

[0113] Interlaced transmission had been introduced to ensure the compliance with the regulations on OCB and NCB requirements. Specifically, the interlaced transmission is designed such that each interlace can occupy the channel bandwidth where the occupied channel bandwidth can fulfill the requirement of the OCB.

[0114] An interlace includes a set of resource blocks that are spread out across the bandwidth of a carrier in the frequency domain. A number of interlaces M is subject to the value of a SCS. That is, the number of interlaces Mmay be predefined according to a specific SCS. For example, if the SCS is equal to 15kHz, the number of resource block interlaces M is correspondingly equal to 10. If the SCS is equal to 30kHz, the number of resource block interlaces M is correspondingly equal to 5.

[0115] Figure 5 is a diagram illustrating one example 500 of interlaced transmission and reception in a BWP.

[0116] In the Figure 5, each block in the frequency domain refers to a common resource block. In the Figure 5, the subcarrier spacing is configured as 30kHz and the number of resource block interlaces Mare 5. Then the interlaces are indexed from 0 to M-l. That is, an interlace m, where m = 0, 1, ..., M-1, consists of a plurality of common resource blocks with indexes {m, M+m, 2M+m, 3M+m, ... } . For example, in the Figure 5, the interlace m=Q consists of common resource blocks with indexes {0, 5, 10, 15, ...}, the interlace m=1 consists of common resource blocks with indexes {1, 6, 11, 16, ...}, and so on.

[0117] In the frequency domain, a BWP 501 is determined as illustrated in Figure 3. An interlaced resource block in the BWP is denoted as where the isindexed from 0, 1, ..., in the BWP. The relation between the interlace resource block an(^ interlace m and the common resource block is given byTheis the common resourceblock where the BWP starts relative to common resource block 0 (i.e., a common resource block with index 0). In the Figure 5, the BWP 501 starts in a CRB with index 4 relative to the CRB with index 0.

[0118] At least for NR-U operation in, for example, 5 GHz spectrum, a BWP may have a bandwidth of multiple of 20MHz. A sub-band may comprise 20MHz or amultiple of 20MHz bandwidth. A sub-band may also be referred to as a sub-channel, or a channel access bandwidth (e.g., a channel of 20MHz). Then a BWP may include one or more sub-bands in the frequency domain. A sub-band consists of multiple nonoverlapping RBs. The number of resource blocks within a sub-band may depend on the SCS of the BWP. For example, the sub-band size for SCS=15kHz may be equal to 108 for a 40MHz BWP, and the sub-band size for SCS=30kHz may be equal to 53 for a 40MHz BWP. That is, a sub-band is an RB set of non-overlapping and contiguous (common) resource blocks. And a sub-band can be defined by a starting common RB and an ending common RB in the frequency domain. Hereinafter, an RB set is used to refer to a sub-band. In other words, an RB set consists of non-overlapping resource blocks and can be defined by a starting common RB and an ending common RB.

[0119] As in the Figure 5, the BWP 501 includes two RB sets, i.e., a RB set 502 and a RB set 503. The RB sets within a BWP can be indexed from 0 in an increase order along with the frequency. According to higher layer (RRC) configurations, there may be a gap 504 between two consecutive RB sets. The gap in unit of resource block can be indicated by the higher layer configurations. Additionally or alternatively, there may be no gap between two RB sets. In other words, there may be a separation of zero, one, or more RBs between two contiguous RB sets within the BWP in the frequency domain.

[0120] In the Figure 5, in the frequency domain, a interlace whose RBs have a lowest CRB index within the first RB set is the interlace m = 4, while the interlace whose RBs have a lowest CRB index within the second RB set is the m = 0.

[0121] In order to ensure a fair co-existence with another NR-U node and / or another radio access technology (RAT) node such as wireless LAN node, the base station 160 and / or the UE 102 may have to perform Listen Before Talk (LBT) procedure before their transmissions. LBT procedure is also referred to as Channel Access procedure. The base station 160 and / or the UE 102 may perform the channel access procedure to determine if there is the presence of other transmission in a channel before their transmission. There may be several types of Channel Access (CA) procedures. For example, Cat-1 LBT is a channel access procedure without channel sensing. Cat-2 LBT is a channel access procedure with one shot channel sensing. Cat-2 LBT may also be referred to as Type-2 channel access procedure. Cat-1 and Cat-2 LBTs may be allowed only inside COT. Cat- 3 LBT is a channel access procedure with random backoff with a fixed contention window (CW) size. Cat-4 LBT is a channel access procedure withrandom backoff with an adaptive CW size. Cat-4 LBT may also be referred to as Type- 1 channel access procedure.

[0122] In a BWP, before a gNB and / or a UE attempt to transmit a signal, the gNB and / or the UE may first perform channel sensing in each RB set to check whether a channel (or one or more RB sets within the BWP allocated for transmission) is available or not for transmission. If the channel or the allocated RB set(s) is sensed to be considered to be idle (i.e., the channel is available for transmission or the gNB and / or the UE gets a channel access successfully), the gNB and / or the UE may transmit on the channel or on the allocated RB set(s). On the other hand, if the channel or the allocated RB set(s) is sensed to be considered to be busy (i.e., the channel is not available or the gNB and / or the UE does not get a channel access successfully), the gNB and / or the UE may not transmit on the channel or on the allocated RB set(s).

[0123] Vehicle-to-everything (V2X) communication technologies have been developed by 3 GPP for the automotive industry. V2X refers to a communication technology through which a vehicle exchanges information with another vehicle, a pedestrian, an object having an infrastructure, and so on. The V2X is divided into 4 types, such as vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle -to- network (V2N), and vehicle-to-pedestrian (V2P). Therefore, the V2X communication is different from the communication between the UEs and gNBs. The V2X communication enables the communication between the UEs, which is also called as sidelink. That is, sidelink communication supports UE-to-UE direct communication via a PC5 interface. In other words, sidelink communication is directly performed or communicated between one transmitting UE and one or more receiving UEs.

[0124] Sidelink communication consists of unicast, groupcast and broadcast. The unicast may refer to a communication between two UEs, i.e., one transmitting UE and one receiving UE. The groupcast and / or the broadcast may refer to a communication between one transmitting UE and multiple receiving UEs.

[0125] Currently NR Sidelink communication supports two sidelink resource allocation modes, mode 1 and mode 2. The difference between the sidelink resource allocation mode 1 and the sidelink resource allocation mode 2 lies in which determine the resource to be used for the sidelink communication.

[0126] In mode 1, the sidelink resource allocation is provided or determined by the base station and / or the network. That is, for mode 1, the base station may manage theresource allocation for the UEs. For example, a base station may allocate the resources for sidelink communication to an in-coverage UE. In sidelink resource allocation mode 1, dynamic grant, configured grant type 1 and configured grant type 2 are supported for PSSCH and PSCCH transmission. In sidelink resource allocation mode 1, for sidelink dynamic grant, the PSSCH transmission is scheduled by a DCI format 3_0. For sidelink configured grant type 1, the configured grant is provided (activated) or released (deactivated) by RRC signaling. For sidelink configured grant type 2, the configured grant is provided or released by PDCCH with the DCI format 3_0.

[0127] In mode 2, the sidelink resource allocation is determined by a TX UE itself. The UE may decide the sidelink transmission resources in a resource pool. The UE may carry out the resource allocation without involvement of the base station. These UEs may autonomously determine to select resources for sidelink communication based on a sensing-based procedure.

[0128] In mode 1, the DCI format 3_0 is used by the base station for scheduling of NR PSCCH and NR PSSCH in one cell. The base station may determine the scheduling information of NR PSCCH and NR PSSCH and provide the scheduling information to an in-coverage UE. The scheduling information may at least include a Resource pool index field, a time gap field, a HARQ process number field, a new data indicator field, a Lowest index of the subchannel allocation to the initial transmission field, SCI format 1 -A fields, and so on. The Resource pool index field is used to indicate an index of a resource pool for which the sidelink transmission is scheduled and the SCI format 1-A fields here refer to the frequency resource assignment field and the time resource assignment field. That is, in mode 1, the base station may determine the time and frequency resource assignment for scheduling of sidelink transmission and then generate the corresponding fields of the scheduling information in the DCI format 3_0. A TX UE (an in-coverage UE) that received the DCI format 3_0 may transmit the PSCCH with SCI format 1-A and the PSSCH in the resource assigned by the base station based on the scheduling information in the DCI fonnat 3_0. Moreover, the SCI format 1-A transmitted by the TX UE includes the frequency resource assignment field and the time resource assignment field which are as same as those included in the DCI fonnat 3_0. A RX UE (an out-coverage UE and / or an in-coverage UE) that received the PSCCH with the SCI fonnat 1-A can receive the PSSCH in the resource assigned by the base station.

[0129] In mode 2, a TX UE may autonomously determine to select resources for sidelink communication and generate the fields in SCI format 1-Ato notify an RX UE of the time and frequency resource assignment. The RX UE that received the PSCCH with the SCI format 1-A can receive the PSSCH in the resource assigned by the TX UE.

[0130] Sidelink communication supports physical channels such as Physical Sidelink Control Channel (PSCCH), Physical Sidelink Shared Channel (PSSCH), Physical Sidelink Feedback Channel (PSFCH), and Physical Sidelink Broadcast Channel (PSBCH).

[0131] The PSCCH is used for transmitting / receiving sidelink control information (e.g., the 1st-stage SCI). For example, the PSCCH indicates resource and other transmission parameters used by a UE for PSSCH reception. PSCCH transmission is associated with a DM-RS. For PSCCH, QPSK is supported.

[0132] The PSSCH is used for transmitting / receiving sidelink control information (e.g., the 2nd-stage SCI), transport block(s) of data, and channel state information (CSI). The sidelink control information herein may include information, for example, for HARQ for HARQ procedures and CSI feedback triggers, etc. At least 6 OFDM symbols within a slot are used for PSSCH transmission. PSSCH transmission is associated with a DM-RS and may be associated with a PT-RS. For PSSCH, QPSK, 16QAM, 64QAM and 256QAM are supported.

[0133] Each PSSCH transmission is associated with an PSCCH transmission. A PSCCH transmission carries the 1ststage of the SCI where the 1ststage of the SCI may schedule one or more resources for one or more PSSCH transmissions. That is, the one or more PSSCH transmissions are associated with the PSCCH transmission. In other words, the PSCCH transmission (or the 1ststage of the SCI) may be associated with one or more PSSCH transmissions.

[0134] PSFCH is used for carrying HARQ feedback over the sidelink from a UE which is an intended recipient of a PSSCH transmission to the UE which performed the PSSCH transmission. PSFCH sequence is transmitted in one PRB repeated over two OFDM symbols near the end of the sidelink resource in a slot.

[0135] The PSBCH is used for transmitting broadcast information. PSBCH occupies 9 and 7 symbols for normal and extended CP cases respectively, including the associated DM-RS.

[0136] Sidelink communication supports physical signals such as demodulation reference signal (DM-RS), phase-tracking reference signal (PT-RS), channel-state information reference signal (CSI-RS), sidelink synchronization signals.

[0137] The DMRS(s) are associated with PSCCH, PSSCH and / or PSBCH. A transmitting UE may transmit the DMRS within the associated sidelink physical channel. A receiving UE may use the DMRS to estimate and / or decode the associated sidelink physical channel.

[0138] The PT-RS is used to mitigate the effect of phase noise. A transmitting UE may transmit the PT-RS within the PSSCH transmission. The receiving UE may receive the PT-RS and use the PT-RS to mitigate the effect of phase noise.

[0139] The CSI-RS is used for measuring channel state information. A transmitting UE may transmit sidelink CSI-RS within a unicast PSSCH transmission. A receiving UE may measure the channel state information by using the CSI-RS and transmit a CSI report based on the measurement to the transmitting UE.

[0140] The Sidelink synchronization signal consists of sidelink primary and sidelink secondary synchronization signals (S-PSS, S-SSS), each occupying 2 symbols and 127 subcarriers. The sidelink synchronization signals are transmitted together with the PSBCH in a slot. Specifically, reception occasions of a PSBCH, S-PSS, and S-SSS are in consecutive symbols in a slot and form a S-SS / PSBCH block. For a SL-BWP, the S-SS / PSBCH block has a same SCS as the PSCCH, the PSSCH, and / or the PSFCH.

[0141] In various implementations of the present disclosure, a UE may be provided NR sidelink communication (pre-)configuration(s). For simplicity, (pre-)configuration(s) hereinafter refer to the NR sidelink communication (pre-)configuration(s). (Pre-)configuration(s) in the present disclosure may include configuration(s) received by system information (e.g., SIB 12) from a base station, configuration(s) received by dedicated RRC signaling (e.g., RRC configuration / parameters / message) from a base station, and / or configuration(s) preconfigured in the UE (i.e., pre-configuration). Regarding the pre-configuration, a memory unit of the UE may store the pre-configuration in advance.

[0142] In various examples or implementations of the present disclosure, (pre-)configuration(s) may include configuration(s) of one or more sidelink BWPs for sidelink communication. That is, a UE may receive the configuration(s) of the one or more BWPs included in system information, in dedicated RRC signaling, and / or in apre-configuration. In the present disclosure, a UE may be provided by the (pre-)configuration(s) a BWP for sidelink transmissions.

[0143] In various examples or implementations of the present disclosure, a SL BWP configuration may include configuration(s) of one or more resource pools for sidelink communication. That is, the configuration(s) of the one or more resource pools (the configuration(s) related to the one or more resource pools) may be received in system information, received in dedicated RRC signaling, and / or preconfigured in a preconfiguration. According to the configuration(s), a resource pool may be indicated to be used either for sidelink communication reception or for sidelink communication transmission. Additionally or alternatively, a resource pool may be indicated to be used for both sidelink communication reception and sidelink communication transmission. Each resource pool is associated with either the sidelink resource allocation Mode 1 or the sidelink resource allocation Mode 2.

[0144] Figure 6 is a diagram illustrating one example 600 of a SL BWP and a resource pool within the SL BWP.

[0145] A UE 102 is provided by a parameter SL-BWP-Config a BWP (a SL BWP) for sidelink transmission with numerology and resource grid. The determination of a SL BWP 601 is similar as how to determine a BWP specified in the Figure 3.

[0146] In the Figure 6, each block in the time domain represents a slot. One resource pool is configured within the SL BWP 601. The resource pool can be for transmission of PSSCH, PSCCH and / or PSFCH, and / or for reception of PSSCH, PSCCH and / or PSFCH. The first RB of the resource pool relative to the first RB of SL BWP, 602, may be indicated by a parameter included in the (pre-)configurations.

[0147] Not all the slots within the SL BWP may be assigned to a resource pool within the SL BWP. That is, not all the slots may belong to a resource pool. A slot assigned to a resource pool (or a slot belongs to a resource pool) can be also referred to a slot available for the resource pool. On the contrary, a slot not assigned to a resource pool (or a slot does not belong to a resource pool) can be also referred to a slot unavailable for the resource pool. Therefore, a resource pool may consist of a plurality (set) of non-contiguous slots in the time domain. In a SL BWP, different resource pools may be assigned with different sets of slots. The UE may determine the set of slots assigned to a resource pool according to the (pre-)configurations. A transmitting UE may transmit one or more physical SL channels or one or more SL signals in one ormore resource pools within a SL BWP, while a receiving UE may receive one or more physical SL channels or one or more SL signals in one or more resource pools within a SL BWP.

[0148] In the Figure 6, slot#0 refers to a first slot of a radio frame corresponding to SFN 0 of the serving cell or DFN 0. As illustrated in the Figure 6, a set of slots with indexes #4, #5, #7 and #10 belong to the resource pool. The slots in the set for a resource pool are re-indexed such that the logical slot indexes are successive from 0 to T’max-1 where the T’maxis the number of the slot in the set. For example, in the Figure 6, the four slots in the set can be re-indexed as slots with logical slot indexes 0, 1, 2, and 3. The slots available for a resource pool may be provided or indicated by a parameter sl- TimeResource and may occur with a periodicity of 10240 ms.

[0149] Sidelink control information is split into two stages, i.e., 1st-stage SCI and 2nd-stage SCI. Specifically, SCI carries onPSCCH is the 1st-stage SCI, which transports sidelink scheduling information. That is, the 1st- stage SCI is sent on PSCCH. The SCI carries on PSSCH is the 2nd-stage SCI, which transports sidelink scheduling information, and / or inter-UE coordination related information. That is, the 2nd- stage SCI is send on PSSCH.

[0150] The fields of the Postage SCI formats (e.g., the SCI format 1-A) are mapped to the information bits of the 1st- stage SCI. The SCI format 1-A is used for the scheduling of PSSCH and 2nd- stage SCI on PSSCH.

[0151] The SCI format 1-A may include the following fields, e.g., Priority, Frequency resource assignment, Time resource assignment, Resource reservation period, DMRS pattern, 2nd-stage SCI format, Beta_offset indicator, Number of DMRS port, Modulation and coding scheme, Additional MCS table indicator, PSFCH overhead indication, Reserved, Conflict information receiver flag. As above-mentioned, in Mode 1 , the UE may obtain the time resource assignment field and the frequency resource assignment field from DCI format 3_0 and include them in SCI format 1-A. In mode 2, the UE may determine the resource allocation for sidelink transmission and generate the time resource assignment field and the frequency resource assignment field in SCI format 1-A.

[0152] The fields defined in each of the 2nd- stage SCI formats (e.g., the SCI format 2-A, SCI format 2-B, SCI format 2-C) are mapped to the information bits of the 2nd- stage SCI. The SCI format 2-A is used for the decoding of PSSCH, with HARQoperation when HARQ-ACK information includes ACK or NACK, when HARQ-ACK information includes only NACK, or when there is no feedback of HARQ-ACK information. The SCI format 2-B is used for the decoding of PSSCH, with HARQ operation when HARQ-ACK information includes only NACK, or when there is no feedback of HARQ-ACK information. The SCI format 2-C is used for the decoding of PSSCH and providing inter-UE coordination information or requesting inter-UE coordination information.

[0153] In NR Releases 16 / 17, sidelink communication was developed to operate in licensed spectrum. In NR Release 18, to further support commercial use cases with increased sidelink data rate, sidelink communication over unlicensed spectrum is under discussion. As above-mentioned, operation over unlicensed spectrum should fulfill different regulatory limitations and restrictions, e.g., OCB / NCB requirements. Interlaced transmission should be introduced for sidelink communication over unlicensed spectrum such that the regulatory requirement can be fulfilled. Hereinafter, unlicensed spectrum refers to the above-mentioned unlicensed spectrum A, i.e., the shared spectrum.

[0154] For the sidelink transmissions over unlicensed spectrum, whether the OCB requirement is needed to be complied with is depending on region regulation. Therefore, for an unlicensed spectrum where OCB requirement is not required, the existing transmission scheme (in other words, contiguous RB -based transmission scheme) for sidelink physical channel and signals, which is specified in 3 GPP NR Releases 16 and 17, can be reused for sidelink communication over the unlicensed spectrum. On the other hand, for an unlicensed spectrum where OCB requirement is required, the interlaced transmission (interlace RB-based transmission) scheme can be applied to sidelink communication over the unlicensed spectrum.

[0155] In some embodiments of the present disclosure, for operation with shared spectrum channel access, to achieve a flexible and efficient design, a parameter A (i.e., a higher layer parameter A) is introduced to indicate which scheme of the contiguous RB-based transmission scheme and the interlace RB-based transmission scheme is applied for a SL BWP. Specifically, the parameter A indicates a SL BWP is (pre-)configured with contiguous RB-based transmission or interlace RB-based transmission. The transmission here may refer to SL transmission such as PSCCH / PSSCH transmission.

[0156] For operation with shared spectrum channel access, the UE 102 and / or the bases station 160 may determine, based on the parameter A, whether interlace RB-based transmission or contiguous RB-based transmission is used for SL transmission in the SL BWP. On the other hand, for operation without shared spectrum channel access, the parameter A is not present in the SL BWP configuration. The UE 102 and / or the base station 160 may determine that contiguous RB-based transmission is used for SL transmission (e.g., PSSCH / PSCCH transmission) in the resource pool.

[0157] To be specific, in a case that a SL BWP configuration includes the parameter A and the parameter A is set to “a first value”, the UE 102 may determine that the SL BWP is configured with interlace RB-based transmission, that is, the UE 102 may determine interlace RB-based transmission is used for the PSCCH / PSSCH transmission in the SL BWP provided by the SL BWP configuration, and / or, may determine OCB requirement is required for the SL BWP provided by the SL BWP configuration.

[0158] In a case that a SL BWP configuration include the parameter A and the parameter A is set to “a second value”, the UE 102 may determine that the SL BWP is configured with contiguous RB-based transmission, that is, the UE 102 may determine contiguous RB-based transmission is used for the PSCCH / PSSCH transmission in the SL BWP provided by the SL BWP configuration, and / or, may determine OCB requirement is not required for the SL BWP provided by the SL BWP configuration.

[0159] In some embodiments, the parameter A may be a common parameter to a plurality of SL resource pools which are configured within a SL BWP. That is, a SL BWP configuration may include the parameter A such that the parameter A is a common indication of which scheme is applied to all the resource pools which are configured in the SL BWP provided by the SL BWP configuration. Specifically, in a case that the SL BWP configuration includes the parameter A and the parameter A is set to “a first value”, the interlaced RB-based transmission scheme is applied to all the resource pools configured in the SL BWP. That is, the UE 102 may determine to use interlaced RB- based transmission for sidelink transmission / reception in all the resource pools configured in the SL BWP. In a case that the SL BWP configuration includes the parameter A and the parameter A is set to “a second value”, the contiguous RB-based transmission is applied to all the resource pools configured in the SL BWP. That is, the UE 102 may determine to not use interlaced transmission scheme and to use thecontiguous RB-based transmission scheme for sidelink transmission / reception in all the resource pools configured in the SL BWP.

[0160] Additionally or alternatively, in some embodiments, the parameter may be a dedicated parameter specific to a resource pool. That is, a resource pool configuration may include the parameter A such that the parameter A is a specific indication of which scheme is applied for a resource pool provided by the resource pool configuration. Specifically, in a case that the resource pool configuration includes the parameter A and the parameter A is set to “a first value”, the interlaced transmission scheme is applied to a resource pool configured by the resource pool configuration. That is, the UE 102 may determine to use interlaced RB-based transmission for sidelink transmission / reception in the resource pool. In a case that the resource pool configuration includes the parameter A and the parameter A is set to “a second value”, the contiguous RB-based transmission scheme is applied to the resource pool configured by the resource pool configuration. That is, the UE 102 may determine to not use interlaced transmission scheme and determine to use the contiguous RB-based transmission scheme for sidelink transmission / reception in the resource pool.

[0161] For convenience of illustration, hereinafter, the first case can be referred to as the case that the SL BWP or the SL resource pool is configured with contiguous RB- based transmission, while the second case can be referred to as the case that the SL BWP or the SL resource pool is configured with interlace RB-based transmission.

[0162] In the present disclosure, for a carrier with a SCS u, a number of intra-cell guard bands may be configured on the carrier with the SCS u. Each intra-cell guard band is defined by a start common resource block and a size in number of common resource blocks. For each intra-cell guard band, the start common resource block and the size in number of common resource blocks are provided by parameters, for example, parameters startCRB and nrofCRBs, respectively. The size of a guard band can be configured as 0 RB or non-zero RBs. For a carrier, if information of the intra-cell guard bands is not configured by parameters, the intra-cell guard bands may be predefined or predetermined for the carrier with a SCS u.

[0163] The intra-cell guard bands separate RB sets in the carrier with the SCS u. The number of intra-cell guard bands on a carrier with a SCS can be denoted as NRB-set-1. That is, the UE is provided with NRB-set-1 intra-cell guard bands on a carrier. The NRB-set-1 intra-cell guard bands separate NRB-setRB sets in a carrier. That is, the numberof RB set for the carrier is NRB-set. Each RB set is defined by a start common resource block and an end common resource block in the frequency domain. The UE may determine a start common resource block and an end common resource block for an RB set based on the information of the intra-cell guard bands. Then an RB set consists of a plurality of contiguous common resource blocks in the frequency domain. For a carrier with different SCSs, an RB set may include different numbers of common resource blocks. For example, in a case that subcarrier spacing equals to 15KHz, the number of resource blocks within an RB set may be configured to be between 100 and 110. In a case that subcarrier spacing equals to 30kHz, the number of resource blocks within an RB set may be configured to be between 50 and 55. However, as an exception, for a resource pool, at most one RB set may be configured to contain 56 resource blocks. Specifically, a single RB set is defined by a starting common RB and an ending common RB in the frequency domain.

[0164] A UE may be configured with one or more SL BWP on the carrier with the SCS u. In the frequency domain, a SL BWP may be configured to include one or more RB sets on the carrier. The number of the one or more RB sets within a SL BWP are based on the configured bandwidth of the SL BWP. The one or more RB sets within a SL BWP can be denoted as NRB-setBWPwhere NRB-setBWPcan be less than or equal to ARB- set. The one or more RB sets within a SL BWP are indexed from 0 to NRB-setBWP-1 in the order of increasing frequency of the SL BWP and starting at the lowest frequency.

[0165] Likewise, the UE may be configured with one or more SL resource pools within a SL BWP on the carrier with the SCS u. In the frequency domain, a SL resource pool may be configured to include one or more RB sets within the SL BWP on the carrier. The number of RB sets included in a SL resource pool are based on the configured bandwidth of the resource pool. The RB sets included in a SL resource pool can be denoted as NRB-setRPwhere NRB-setRPcan be less than or equal to NRB-setBWP. The RB sets included in a resource pool are indexed from 0 to NRB-setRP-1 in the order of increasing frequency of the resource pool and starting at the lowest frequency.

[0166] In the present disclosure, a SL BWP and / or a resource pool may be divided into one or more RB sets, where each of the one or more RB sets does not overlap with each other in the frequency domain. That is, the one or more RB sets do not have overlapping RBs in the frequency domain. The one or more RB sets within the resource pool are indexed from 0 in the order of increasing frequency of the one or more RB sets.

[0167] Additionally or alternatively, a guard band including zero, one or multiple RBs may separate two consecutive (or adjacent) RB sets amongst the one or more RB sets within a resource pool or a SL BWP. In other words, in the frequency domain, a SL BWP or a SL resource pool may include one or more RB sets and zero, one or more guard bands wherein one guard band is located between two adjacent RB sets.

[0168] In the present disclosure, in a resource pool, the sub-channel is a resource allocation granularity in frequency domain for SL transmission. Therefore, how to make the SL transmissions meet OCB and PSD requirement depends on how to design the sub-channel structure. In other words, how to determine sub-channels in a resource pool depends on whether the resource pool is configured with contiguous RB-based transmission or interlace RB-based transmission.

[0169] In the first case, the UE 102 may determine that a sub-channel consists of multiple contiguous PRBs in frequency domain, while in the second case, the UE 102 may determine that a sub-channel includes PRBs of one or more interlaces contained in an RB set. In the first case, the determination of sub-channel in a resource pool is specified in the Figure 7. The determination of sub-channels for the first case is similar as the existing design of sub-channel specified in NR Releases 16 and 17 where a subchannel consists of contiguous PRBs in the frequency domain. In the second case, a sub-channel may be associated with one or more interlaces. That is, a sub-channel may include PRBs of one or more interlaces contained in an RB set in the frequency domain where the PRBs of one or more interlaces are not contiguous in the frequency domain. An RB set of a resource pool consists of one or more sub-channels in the frequency domain. A resource pool consists of one or more sub-channels in the frequency domain.

[0170] Figure 7 is a diagram illustrating one example 700 of a resource pool configuration in time and frequency domain. In the Figure 7, the resource pool is configured with the contiguous RB-based transmission indicated by the parameter A, that is, the first case. A PSSCH transmission / reception is performed in one or more contiguously allocated sub-channels in the frequency domain where each sub-channel consists of multiple contiguous RBs in the frequency domain. The SCS of the resource pool may be 15kHz, 30kHz or 60kHz.

[0171] As illustrated in the Figure 7, a resource pool within a SL BWP can be divided into one or multiple contiguous sub-channels in the frequency domain. That is, a resource pool within a SL BWP consists of NsubchannelSLcontiguous sub-channels in thefrequency domain. The number of NsubchannelSLis indicated by a parameter sl- NumSubchannel included in the configuration of the resource pool. Each sub-channel includes a number of contiguous RBs in the frequency domain. The number of contiguous RBs is indicated by a parameter sl-SubchannelSize included in the configuration of the resource pool. For convenience of illustration, the number of contiguous RBs indicated by the parameter sl-SubchannelSize can be denoted as Ksub.

[0172] In the Figure 7, each block in the frequency domain represents a sub-channel of the resource pool 701 . For example, in the Figure 7, the parameter sl-NumSubchannel indicates that NsubchannelSLis 4. That is, the resource pool 701 consists of 4 contiguous sub-channels in the frequency domain. The first RB of the first sub-channel of the resource pool 701 in the SL BWP may be indicated by a parameter sl-StartRB- Subchannel. The first sub-channel of a resource pool refers to a sub-channel with the lowest subchannel index in the resource pool. In the Figure 7, the subchannel #0 is the first sub-channel of the resource pool 701, that is, the sub-channel with the lowest subchannel index 0. As shown in the Figure 7, the subchannel #0 includes Ksubcontiguous PRBs starting from the PRB indicated by the parameter sl-StartRB- Subchanneb, the subchannel #1 includes Ksubcontiguous PRBs starting from a PRB adjacent to the last RB of the subchannel #0; the subchannel #2 includes Ksubcontiguous PRBs starting from a PRB adjacent to the last RB of the subchannel # 1 ; subchannel #3 includes Ksubcontiguous PRBs starting from a PRB adjacent to the last RB of the subchannel #2.

[0173] In the Figure 7, in a case that the resource pool 701 includes one RB set, a sub-channel includes or consists of RBs in the RB set. In a case that the resource pool 701 includes multiple RB sets and one or more guard bands, for sub-channels in the resource pool 701, some sub-channels may consist of RBs in one RB set, some subchannels may consist of RBs in two RB sets and RBs in one guard band, and / or some sub-channels may consist of RBs in one RB set and RBs in one guard band,.

[0174] In the second case, for a resource pool that is configured with interlace RB- based transmission, each RB of the resource pool is mapped to an RB of an interlace m. Furthermore, each RB within a resource pool is mapped to an interlace. In other words, in the present disclosure, a resource pool may consist of a plurality of interlaces. In the frequency domain, a resource pool is divided into a number of interlaces M where eachinterlace consists of non-contiguous (common) resource blocks. As above-mentioned, the value of M is determined per SCS.

[0175] Figure 8 is a diagram illustrating one example 800 of configurations of a SL BWP and SL resource pools.

[0176] As in the Figure 8, a CRB grid is used to represent the common resource blocks in a carrier with a SCS. That is, a CRB index is used to represent a CRB in the carrier. The CRBs in the carrier are indexed from 0 in an order of increasing frequencies and starting from point A. Here, as an example in the Figure 8, the carrier 801 uses the subcarrier spacing configuration μ=1, i.e., the SCS = 30kHz. The starting position Ngridstart,μof the carrier 801 is given based on the value of an offset 802 (i.e. Ocarrier) indicated by a parameter (e.g., the above-mentioned offsetToCarrier). That is, the carrier 801 starts from the CRB with index 2, i.e., the Ngridstart,μ= 2, and includes a plurality of contiguous CRBs with index from 2 to 107. That is, the carrier bandwidth Ngridsize,μof the carrier 801 in number of RBs is 106.

[0177] Each CRB on the carrier is mapped to an interlace m where the mapping between CRBs and interlaces are performed cyclically from 0 to M-1 in an order of increasing frequencies of CRBs. As in the Figure 8, CRBs on the carrier are mapped to an interlace cyclically from 0 to 4 in the order of increasing frequencies of the CRBs and starting from the lowest frequency of a CRB.

[0178] As illustrated in the Figure 8, a number of intra-cell guard band is equal to 1, i.e., NRB-set-1=1. As above-mentioned, the intra-cell guard band 803 can be defined by a start CRB and a size in number of CRBs provided by a parameter startCRB and a parameter nrofCRBs, respectively. Specifically, the parameter startCRB indicates an RB offset relative to the starting CRB of the carrier 801. A CRB index of a starting CRB of an intra-cell guard band is given by its corresponding parameter startCRB and the Ngridstart,μof the carrier 801. In the Figure 8, the parameter startCRB indicates an RB offset as 50. The starting CRB of the intra-cell guard band 803 is determined by the summation of the RB offset and the Ngridstart,μ, i.e., the starting CRB of the intra-cell guard band 803 is the CRB with index 52. And the intra-cell guard band 803 includes 6 CRBs that is provided by the parameter nrofCRBs.

[0179] Then the intra-cell guard band 803 separates two RB sets 804 and 805 in the carrier 801, i.e., NRB-set=2. Within the carrier, the RB sets are indexed from 0 to NRB-set-1 in an order of increasing frequencies. The RB set 804 can be indexed with 0, i.e., theRB set 804 refers to the RB set 0 within the carrier 801. Likewise, the RB set 805 can be indexed with 1, i.e., the RB set 805 refers to the RB set 1 within the carrier 801.

[0180] The starting position (the starting CRB) of the RB set 804 is the starting position Ngridstart,μof the carrier 801. The ending CRB of the RB set 804 is determined based on the starting position Ngridstart,μof the carrier 801 and the RB offset provided by the parameter startCRB for the intra-cell guard band 803. Additionally, the starting CRB of the RB set 805 is determined based on the starting position Ngridstart,μof the carrier 801, the RB offset provided by the parameter startCRB for the intra-cell guard band 803, and the size of the intra-cell guard band 803 by the parameter nrofCRBs. The ending CRB of the RB set 805 is determined based on the starting position Ngridstart,μof the carrier 801 and the size Ngridsize,μof the carrier 801.

[0181] In the present disclosure, a SL BWP can be configured to include one, more or all RB sets within the carrier. In the Figure 8, a SL BWP 806 is configured to include all RB sets within the carrier 801. That is, the number of RB sets within the SL BWP806 is same as that within the carrier 801. Likewise, the RB sets within a SL BWP are numbered in increasing order from 0.

[0182] A PRB grid is used to represent the physical resource blocks in a SL BWP. That is, a PRB index is used to represent a PRB in the SL BWP. The PRBs in the BWP are indexed from 0 in an order of increasing frequencies. A PRB in a SL BWP corresponds to a CRB in a carrier. Likewise, a PRB in a BWP corresponds to an RB of an interlace m in a carrier. As illustrated in the Figure 8, the PRB with index 0 corresponds to the CRB with index 2, the PRB with index 1 corresponds to the CRB with index 3, and so on. Likewise, the PRB with index 0 corresponds to an RB of interlace m=2. The PRB with index 1 corresponds to an RB of interlace m=3.

[0183] In various examples or various implementations of the present disclosure, one or more SL resource pools can be configured within a SL BWP on the carrier with the SCS u. A SL resource pools can be configured to include one or more RB sets of a SL BWP in the frequency domain.

[0184] As illustrated in Figure 8, two SL resource pools, i.e., a SL resource pool807 and a SL resource pool 808 are configured in the SL BWP 806. The SL resource pool 807 is configured to include the RB set 804, the RB set 805, and the guard band 803 in the frequency domain. The SL resource pool 808 is configured to include the RB set 805 in the frequency domain. That is, different SL resource pools can be configuredwith different number of RB sets within a SL BWP, which are depending on configured bandwidths of the resource pools. The RB sets included in a SL resource pool can be denoted as NRB-setRPwhere NRB-setRPcan be less than or equal to NRB-setBWP. The RB sets included in a resource pool are indexed from 0 to NRB-setR P-1 in the order of increasing frequency of the resource pool and starting at the lowest frequency. The resource pool807 includes NRB-setRP=2 RB sets and the resource pool 808 includes NRB-setRP=1 RB set.

[0185] In the Figure 8, the resource pool 807 starts in a RPB with index 0 relative to the starting PRB of the SL BWP (i.e., PRB with index 0), while the resource pool808 starts in a RPB with index 56 relative to the starting PRB of the SL BWP (i.e., PRB with index 0). A SL BWP and / or a resource pool is configured not to include parts of an RB set. In the present disclosure, a SL BWP and / or a resource pool may be configured to start on an RB with a lowest CRB index within a first RB set and to end an RB with a largest CRB index within a second RB set. The first RB set and the second RB set can refer to a same RB set or different RB sets within the carrier. In other words, a starting RB of a SL BWP and / or a SL resource pool is a starting RB of an RB set. Likewise, an ending (last) RB of a SL BWP and / or a SL resource pool is an ending RB of an RB set.

[0186] Hereinafter, mapping (determination) between sub-channel(s) and interlace(s) is illustrated for a resource pool where interlaced transmission scheme is configured. In the second case, a sub-channel is defined and indexed within 1 RB set within a resource pool. That is, the mapping between sub-channel and interlace(s) is performed in each RB set within a resource pool. In the present disclosure, the number of one or more interlaces to be included in a sub-channel may be provided by a parameter. That is, a parameter can be introduced to indicate the number of above- mentioned one or more interlaces to the UE 102. For example, a parameter B is introduced to indicate K interlace(s) wherein 1 sub-channel includes the K interlaces within 1 RB set. That is, K interlaces within 1 RB set are formed to a sub-channel. A sub-channel may consist of K interlaces within 1 RB set. The value of K can be equal to 1 or larger than 1. For example, in case of SCS=15kHz (i.e., M=10), the value of K indicated by the parameter B may be 1, 2, 5, or 10. In case of SCS=30kHz (i.e., M=5), the value of K indicated by the parameter B may be 1 or 5.

[0187] Additionally or alternatively, the SL resource pool configuration may not include the parameter B. The UE 102 may determine the value of A as a default value or a predefined value. For example, in a case that the SL resource pool configuration may not include the parameter B, the UE 102 may determine K=1. That is, if a SL resource pool configuration aims to set K as the default value, the SL resource pool configuration is not necessary to always include the parameter B so that signaling overhead of the parameter B can be reduced.

[0188] To determine or identify each sub-channel in an RB set, besides determining the number of interlaces to be included in a sub-channel, the UE 102 also needs to determine a starting interlace index for each sub -channel or at least for a first subchannel in the RB set. The first sub-channel in an RB set means a sub-channel with the lowest sub-channel index (i.e., index 0) in the RB set. In other words, within an RB set, the sub-channel is indexed starting from index 0. The sub-channel within index #0 in an RB set can be referred to as the first sub-channel in the RB set.

[0189] In some embodiments, the UE 102 may determine that the starting interlace index for the first sub-channel in each RB set is the interlace index 0. That is, the subchannel with index 0 includes K interlaces starting from a starting interlace index 0. For each RB set in a resource pool, 1 sub-channel is defined within 1 RB set, and is incrementally indexed in increasing order of interlace indexes starting from interlace index 0. Within an RB set, the starting interlace index for a sub-channel with index i is an interlace index successively following the interlace index of the last interlace included in the sub-channel with index z'-l. Specifically, the UE 102 may determine that a sub-channel with an index i includes K interlace(s) with interlace index(es) calculated as (i*K + j) where i = 0, 1, ..., {numSubchannel-1), and j=0, 1, ..., K-1. The value of numSubchannel may be explicitly indicated by a parameter. Additionally or alternatively, the value of numSubchannel may be given as {MIK). The Mis 10 in a case that a subcarrier spacing (SCS) of the SL BWP is 15kHz and 5 in a case that the SCS is 30kHz. Here, the value of numSubchannel is the number of sub-channels included in each RB set in the resource pool. For convenience of illustration, AsubChannelRBsetis used to denote the number of sub-channels for each RB set. AsubChannelRBsetmay be provided by a parameter or AsubChannelRBset= (M / K).

[0190] As long as the UE 102 determines which interlace(s) among M interlaces to be included in a sub-channel, the UE 102 is able to determine which resources blocksto be included in the sub-channel. In other words, mapping between sub-channel and interlace(s) also means mapping between sub-channel in an RB set and resource blocks in one or more interlaces contained within the RB set. For an RB set, a sub-channel includes resource blocks in respective determined K interlace(s) contained within the RB set. That is, for an RB set, resource blocks in K interlace(s) contained within the RB set are mapped or grouped to 1 sub-channel in the RB set. Specifically, for a subchannel with an index i in an RB set where i = 0, 1, ..., (NsubChanneRBset-1), the subchannel with index i includes resource blocks in K interlace(s) with interlace index(es) calculated as (i*K + j) contained within the RB set. Herein, j=0, 1, ..., K-1. In other words, the UE may determine resource blocks of a sub-channel in an RB set as an intersection of the RBs of the determined K interlaces and the RB set.

[0191] In some embodiments, for an interlace with index, the number of resource blocks in the interlace contained within an RB set may be same as or different from that of resource blocks in the interlace contained within another RB set. Likewise, for an RB set, the number of resource blocks in an interlace contained within the RB set may be same as or different from that of resource blocks in another interlace contained within the RB set. Therefore, within an RB set, although a sub-channel includes same number of interlaces within the same RB set, the number of resource blocks included in a sub-channel may be same as or different from that of resource blocks included in another sub-channel. Likewise, for a sub-channel with a same index z in different RB sets, the number of resource blocks included in the sub-channel with index z in an RB set may be same as or different from that of resource blocks included in the sub-channel with index i in another sub-channel RB set.

[0192] Figure 9 is a diagram illustrating one example 900 of sub-channel determination in a resource pool by a UE 102. In the example 900, K is equal to 1, that is, one sub-channel includes 1 interlace within 1 RB set. To be specific, 1 sub-channel consists of resource blocks of K=1 interlace within 1 RB set. A SL resource pool 901 in the Figure 9 is as same as the SL resource pool 807 that is specified in the Figure 8. That is, the above description for the resource pool 807 in the Figure 8 can be applied to that for the SL resource pool 901. The SCS of the resource pool is 30kHz and, as above-mentioned, the number of interlaces M is 5 for 30KHz SCS.

[0193] As in the Figure 9, the resource pool 901 is configured to include an RB set 902, an guard band 903, and, an RB set 904 in the frequency domain. The UE 102 maydetermine sub-channels for each RB set in the resource pool 901. The RB set 902 includes NsubChannelRBset= (MIK) =5 sub-chaimels. The sub-channels within in the RB set 902 are indexed from 0 to 4. Within the RB set 902, the sub-channel with index 0 includes the interlace with index m = 0, the sub-channel with index 1 includes the interlace with index m = 1, sub-channel with index 2 includes the interlace with index m = 2, sub-channel with index 3 includes the interlace with index m = 3, and, subchannel with index 4 includes the interlace with index m = 4. In other words, within the RB set 902, the sub-channel with index 0 includes resource blocks in the interlace with index m = 0 contained in the RB set 902, the sub-channel with index 1 includes resource blocks in the interlace with index m = 1 contained in the RB set 902 and so on.

[0194] Likewise, the RB set 904 includes NsubChannelRBset= (MIK) =5 sub-channels. The sub-channels within in the RB set 904 are indexed from 0 to 4 as well. Within the RB set 904, the sub-channel with index 0 includes the interlace with index m = 0, the sub-channel with index 1 includes the interlace with index m = 1, sub-channel with index 2 includes the interlace with index m = 2, sub-channel with index 3 includes the interlace with index m = 3, and, sub-channel with index 4 includes the interlace with index m = 4. In other words, within the RB set 904, the sub-channel with index 0 includes resource blocks in the interlace with index m = 0 contained in the RB set 904, the sub-channel with index 1 includes resource blocks in the interlace with index m = 1 contained in the RB set 904 and so on.

[0195] As in the Figure 9, a sub-channel is defined within each RB set and does not include resource block in guard band 903. And the total number of sub-channels in the resource pool 901, which can be denoted as NsubchannelSL, is 10. That is, in the second case, the total number of sub-channels included in a resource pool (i.e., NsubchannelSL) is calculated or determined by the UE 102 based on the parameter B (i.e., the value of K), the value of M, and the number of RB set(s) contained in the resource pool. Specifically, the value of NsubchannelSLmay be determined or calculated as {MIK) * NRB-setRPwhere NRB-setRPis the number of RB set(s) contained in the resource pool. On the other hand, as above-mentioned in the Figure 7, in the first case, the total number of sub-channels included in aresource pool (i.e., NsubchannelSL) is indicated or determined by the parameter sl-NumSubchannel.

[0196] In the frequency domain, the frequency domain resource allocation granularity is one sub-channel for a PSSCH transmission. That is, for PSSCHtransmission, the frequency domain unit is a sub-channel. A PSSCH transmission may be performed in one or more contiguous sub-channels in the frequency domain.

[0197] Regardless of whether the resource pool is configured with contiguous RB- based transmission or interlace RB-based transmission, in the time domain, the UE may be configured with a set of slots assigned to a resource pool for SL transmission. For example, as illustrated in the Figure 7, each block in the time domain represents a slot in the set of slots assigned to the resource pool 701. The slot indexes in the Figure 7 refer to the logical slot indexes. The OFDM symbols within a slot assigned for sidelink transmission are provided by parameters included in the (pre-)configuration. To be specific, SL transmissions can start from a first symbol indicated by a parameter sl- StartSymbol and be within a number of consecutive symbols indicated by a parameter sl-LengthSymbols . As in the Figure 7, the duration 702 starts at the third OFDM symbol which is indicated by the parameter sl-StartSymbol and consists of 11 consecutive OFDM symbols which is indicated by the parameter sl-LengthSymbols . For a slot indicated for transmission of S-SS / PSBCH blocks, the first symbol and the number of consecutive symbols is predetermined.

[0198] In NR Releases 16 / 17, a PSFCH transmission is performed in one PRB in the frequency domain. For operation with shared spectrum channel access, whether to use interlace RB-based PSFCH transmission depends on whether OCB requirement is required in a SL BWP. A parameter (e.g., a parameter C) in the SL BWP configuration can be used to indicate whether the SL BWP is configured with interlace RB-based PSFCH transmission or not. The UE 102 may determine whether interlace RB-based PSFCH transmission is applied or not based on the parameter. In the present disclosure, for a resource pool which includes multiple RB sets and one or more guard bands, one PSFCH transmission / reception is performed by the UE 102 within an RB set of a resource pool. The UE 102 does not use resource blocks in a guard band for the PSFCH transmission / reception.

[0199] In some embodiments, the parameter C can be the above-mentioned parameter A. In other words, the above-mentioned parameter A may be used to indicate whether interlace RB-based transmission is used for both PSCCH / PSSCH transmission and PSFCH transmission. In a case that a SLBWP configuration includes the parameter A and the parameter A is set to “a first value”, the UE 102 may determine that the SL BWP is configured with interlace RB-based transmission, that is, the UE 102 maydetermine interlace RB-based transmission is used for the PSCCH / PSSCH transmission and the PSFCH transmission in the SL BWP. In a case that a SL BWP configuration include the parameter A and the parameter A is set to “a second value”, the UE 102 may determine that the SL BWP is configured with contiguous RB-based transmission, that is, the UE 102 may determine contiguous RB-based transmission is used for the PSCCH / PSSCH transmission and one RB is used for the PSFCH transmission.

[0200] In some embodiments, the parameter C may be a separate parameter from the above-mentioned parameter A. The parameter C is different from the parameter A. In a case that a SL BWP configuration includes the parameter C or in a case that a SL BWP configuration includes the parameter C and the parameter C is set to “a first value”, the UE 102 may determine interlace RB-based transmission is used for the PSFCH transmission in the SL BWP. In a case that a SL BWP configuration does not include the parameter C or in a case that a SL BWP configuration include the parameter C and the parameter C is set to “a second value”, the UE 102 may determine that one RB is used for the PSFCH transmission.

[0201] For one RB-based PSFCH transmission / reception in a resource pool, the UE 102 may perform a PSFCH transmission / reception with HARQ-ACK information in a PRB of the resource pool.

[0202] For interlace RB-based PSFCH transmission / reception in a resource pool, there are two types, i.e., type 1 and type 2. Type 1 is a PSFCH transmission / reception type where a PSFCH transmission / reception with HARQ-ACK information occupies all PRBs of an interlace within an RB set of the resource pool. Type 2 is a PSFCH transmission / reception type where a PSFCH transmission / reception with HARQ-ACK information occupies a set of PRBs in a first interlace and PRBs (i.e., a PRBsubset) in a second interlace within an RB set of the resource pool. The resource pool configuration may include a parameter to indicate which type is configured for PSFCH transmission / reception in the resource pool. In a case that type 2 is configured, the resource pool configuration may further include a parameter to indicate the interlace index of the first interlace and include a parameter to indicate the value of

[0203] For a sidelink transmission over the unlicensed spectrum, the UE 102 may apply LBT procedure before performing a SL transmission. When LBT procedure is applied, the UE 102 senses the channel to determine whether the channel is free or busy.Specifically, Physical layer may perform an LBT procedure before a SL transmission. In a case that the channel is sensed free, the UE 102 (i.e., the Layer 1 of the UE 102) may perform the SL transmission. On the other hand, in a case that the channel is sensed busy, the UE 102 (i.e., the Layer 1 of the UE 102) may not perform the SL transmission.

[0204] Hereinafter, for purposes of illustration, a TX UE refers to a UE which transmits a PSSCH in a resource pool. A RX UE refers to a UE which receives the PSSCH in a resource pool. In response to the reception of the PSSCH, the RX UE may transmit, to the TX UE, a PSFCH transmission with HARQ-ACK information in a PSFCH resource of the resource pool. The HARQ-ACK information corresponding to one HARQ-ACK information bit may include ACK or NACK, or only NACK. The TX UE may receive the PSFCH transmission from the RX UE in corresponding PSFCH resource of the resource pool. For convenience of illustration, “PSFCH occasion” hereinafter may refer to either “PSFCH transmission occasion” or “PSFCH reception occasion”. Form RX UE perspective, “PSFCH occasion” hereinafter may refer to “PSFCH transmission occasion”, while, from TX UE perspective, “PSFCH occasion” hereinafter may refer to “PSFCH reception occasion”.

[0205] Given that LBT failure would prevent UE from transmitting PSFCH, for a resource pool, it is beneficial to configure multiple PSFCH occasions for an associated PSCCH / PSSCH transmission in time domain such that opportunities of PSFCH transmissions or receptions can be increased. However, when the multiple PSFCH occasions are configured for a resource pool, how to determine PSFCH resources for a PSFCH occasion has not been specified. The present implementations of the present disclosure provide new methods and solutions on how to determine PSFCH resources for a PSFCH occasion in a resource pool when the resource pool is configured with multiple PSFCH occasions, which would provide a more efficient and flexible sidelink communication system.

[0206] In various embodiments of the present disclosure, determination of a PSFCH occasion may include determination of time resources for the PSFCH occasion and / or the determination of frequency resources for the PSFCH occasion.

[0207] For a RX UE, determination of a PSFCH transmission occasion may include the determination of time resources for the PSFCH transmission occasion and / or the determination of frequency resources for the PSFCH transmission occasion. Likewise, for a TX UE, determination of a PSFCH reception occasion may include thedetermination of time resources for the PSFCH reception occasion and / or the determination of frequency resources for the PSFCH reception occasion.

[0208] Figure 10 is a diagram illustrating one example 1000 of a resource pool configured with PSFCH resources. Here, interlace RB-based transmission is configured for PSSCH transmission and PSFCH transmission in the resource pool. The resource pool may include one or multiple RB sets in the frequency domain. In the Figure 10, 1001 represents an RB set of the resource pool.

[0209] In the time domain, PSFCH resources may be (pre-)configured periodically with a period in the unit of slots within the resource pool wherein the value ofis indicated by a parameter D (e.g., a parameter sl-PSFCH-Period ) which isincluded in the resource pool configuration. For example, the value of may beindicated as 0, 1, 2 or 4. In a case the value of is indicated to be 0, the UE 102may determine there is no resource for PSFCH and the PSFCH transmissions (i.e., the HARQ feedbacks for PSSCH transmissions) in the resource pool are disabled. In a case the value of is indicated to be not 0, the UE 102 may determine resources forPSFCH are periodically configured every slot(s) within the resource pool.

[0210] Specifically, the UE 102 may determine, in the resource pool, whether a slot includes the PSFCH resources according to the slot index k and the value ofIn a case that k mod the SL UE 102 may determine that the slot with theslot index k includes PSFCH resources. Otherwise, the SL UE 102 may determine the slot with the slot index k does not include PSFCH resources. As in the Figure 10, the value of is indicated as 4, the slots with indexes k=0, 4, 8, 12 includes thePSFCH resources. A slot including the PSFCH resources can be also called as PSFCH slot. The slots with indexes k=0, 4, 8, 12 are the PSFCH slots.

[0211] If a RX UE receives a PSSCH in a resource pool, the RX UE may transmit PSFCH with HARQ-ACK information in a PSFCH transmission occasion in the resource pool. The PSFCH transmission occasion locates in a first slot that includes PSFCH resources and is at least a number of slots of the resource pool after the PSSCH reception. The number of slots is provided by a parameter included in the SL resource pool configuration. The minimum time gap between PSFCH and the associated PSSCH is in the unit of slots. The number of slots provides a minimum time gap between PSFCH and the associated PSSCH in the unit of slots. The minimum time gap is usedto accommodate the processing time of the RX UE, for example, including the PSCCH / PSSCH processing / decoding time and the generation time of HARQ feedback.

[0212] As above-mention, in various embodiments, the resource pool can be configured with multiple PSFCH occasions provided by a parameter (e.g., parameter E). That is, SL resource pool configuration may include the parameter E to indicate a number of PSFCH occasions for PSFCH transmission and PSFCH reception. The number of PSFCH occasions can be denoted asFor a PSSCH reception, there arePSFCH occasions associated with the PSSCH reception. The RX UE may attempt to transmit the PSFCH over a number of first slots that include PSFCHresources and are at least a number of slots after a last slot of the PSSCH reception.

[0213] For example, in the Figure 10, the parameter E indicates the value of N occasion is 2 in the resource pool and the number of slots is configured to 2. Then for a PSSCH reception in the resource pool, one PSSCH reception may be associated with 2 PSFCH transmission occasions. The RX UE may attempt to transmit the PSFCH over a number of first slots that include PSFCH resources and are at least anumber of slots after a last slot of the PSSCH reception.

[0214] When the RX UE receives the PSSCH 1005 in the slot with index 1 in the resource pool, the RX UE may determine that the first slots (time locationof the PSFCH transmission occasion) is the slot with index 4 and the slot with index 8. Specifically, the first PSFCH transmission occasion associated with the PSSCH reception 1005 is in the slot with index 4, while the second PSFCH transmission occasion associated with the PSSCH reception 1005 is in the slot with index 8.

[0215] Likewise, when the RX UE receives the PSSCH 1006 in the slot with index 3 in the resource pool, the RX UE may determine that the first slots (timelocation of the PSFCH transmission occasion) is the slot with index 8 and the slot with index 12. Specifically, the first PSFCH transmission occasion associated with the PSSCH reception 1006 is in the slot with index 8, while the second PSFCH transmission occasion associated with the PSSCH reception 1006 is in the slot with index 12.

[0216] In response to a PSSCH reception, the RX UE may attempt to transmit PSFCH in the first PSFCH transmission occasion associated with the PSSCH reception. If the RX UE fails to transmit PSFCH in the first PSFCH transmission occasion due to, for example, LBT failure, the RX UE may attempt to transmit PSFCH in the secondPSFCH transmission occasion associated with the PSSCH reception. If the RX UE transmitted PSFCH in the first PSFCH transmission occasion, the RX UE may not attempt to transmit PSFCH in the second PSFCH transmission occasion.

[0217] In other words, the RX UE may determine time resources of one or multiple PSFCH transmission occasions associated with a PSSCH reception in the resource pool at least based on one, more or all of the (i) the time location of the PSSCH reception, (ii) the number of slots (i.e., time gap configured by the SL parameter), (iii) the value of (iv) the value of

[0218] To be more specific, the time resource of a PSFCH transmission occasion may occupies two OFDM symbols in the time domain. As above-mentioned, a parameter sl-StartSymbol indicates a starting symbol used for sidelink in a slot. A parameter sl-LengthSymbols indicates a number of consecutive symbols used for side link in a slot. For example, in Figure 10, the parameter sl-StartSymbol indicates that a starting symbol used for sidelink in a slot is the third symbol 1002 in a slot. And the parameter sl-LengthSymbols indicates the number of consecutive symbols 1003 used for sidelink in a slot is 12. That is, the 1003 consists of 12 consecutive OFDM symbols in a slot. The symbol 1002 is the first symbol of the consecutive symbols 1003. As in the Figure 10, symbols within 1003 in a slot are configured for sidelink. On the other hand, symbols outside 1003 in a slot (i.e., the first two symbols of a slot) are not configured for sidelink. The UE may not transmit the PSSCH in symbols which are not configured for sidelink in a slot. The UE may transmit the PSSCH in symbols which are configured for sidelink in a slot.

[0219] In a slot where PSFCH resources are not configured, the UE may transmit the PSSCH in the consecutive symbols 1003 except the first symbol and the last symbol of 1003 where the first symbol of 1003 (i.e., the symbol 1002) is used as an automatic gain control (AGC) symbol and the last symbol of 1003 (i.e., the symbol 1005) is used as a guard symbol. An AGC symbol is used to adjust the strength of the received signal in order to reduce the quantization error or the clipping of the received signal at the analog to digital converter. A guard symbol is used for timing adjustment and for switch between transmission and reception by a UE.

[0220] However, in a slot where PSFCH resources are configured, a portion of the consecutive symbols 1003 may be used for PSFCH. Specifically, a second-to-lastsymbol in the 1003 is used for PSFCH transmission and therefore can be called as PSFCH symbol. The OFDM symbol prior to the PSFCH symbol is used as an AGC symbol. The signal transmitted in the PSFCH symbol would be duplicated in the AGC symbol. In other words, the AGC symbol is a duplicated symbol of the PSFCH symbol. A symbol 1004 prior to the AGC symbol is used as a guard symbol between the PSSCH transmission and the PSFCH transmission. As shown in the Figure 10, PSSCH and PSFCH may be multiplexed in the time domain in the slot where PSFCH resources are configured.

[0221] As in the Figure 10, the second PSFCH occasion associated with the PSSCH 1005 and the first PSFCH occasion associated with the PSSCH 1006 locate in a same slot, i.e., the slot with index 8. It is necessary to separate frequency resources for different PSFCH occasions such that the frequency resource collision can be avoided.

[0222] As above-mentioned, when a resource pool is configured withPSFCH occasions, there are PSFCH occasions associated with one PSSCH indifferent slots in the time domain. For a same PSFCH slot, there are partitionsof frequency resources where each partition is associated with a PSFCH occasion located in the PSFCH slot. For example, in the Figure 10, PSFCH resources indicated for PSFCH transmission and reception are partitioned into parts. Forexample, the part 1007 is used for the first PFSCH occasion, while the part 1008 is used for the second PSFCH occasion. Hereinafter, determination of frequency resources for a PSFCH occasion is described.

[0223] Therefore, in the present disclosure, a PSFCH transmission occasion is defined or identified by time resources and frequency resources. A PSSCH transmission (i.e., one or multiple sub-channel in a slot) may have associated PSFCHoccasions in different PSFCH slots. A PSFCH slot may also have PSFCHoccasions where different PSFCH occasions have same time resources but separate frequency resources.

[0224] In various embodiments, the SL resource pool may include a parameter (e.g., a parameter F) to indicate frequency resources for PSFCH transmission and reception. The parameter F may provide a bitmap where leftmost of the bitmap refers to the lowest RB index in the resource pool, and so on. The size of bitmap is same as the number of PRBs included in the resource pool. Each bit in the bitmap corresponding to a PRB inthe resource pool. Each bit in the bitmap has a one-to-one mapping to each PRB in the resource pool. Value 0 in the bitmap indicates that the corresponding PRB is not used for PSFCH transmission and reception while value 1 indicates that the corresponding PRB is used for PSFCH transmission and reception. Therefore, the UE may determine, based on the parameter F, a set of PRBs in the resource pool for PSFCH transmission with HARQ-ACK information.

[0225] In other words, the parameter F may be used to determine a set of PRBs that are used for PSFCH transmission and reception in the resource pool. As above- mentioned, a resource pool may include multiple RB sets in the frequency domain. However, one PSFCH transmission should be confined within one RB set in the frequency domain to avoid increasing the risk of potential LBT failure. Therefore, the UE may determine frequency resources for PSFCH transmission and reception in each RB set in the resource pool.

[0226] The UE is provided by the parameter F, a set of PRBs in theresource pool for PSFCH transmission with HARQ-ACK information. For an RB set in the resource pool, the UE may determine a subset of PRBs for PSFCH transmission and reception in the RB set based on the parameter F and frequency location of the RB set. For each PRB in the subset, the value of its corresponding bit in the bitmap is set to 1 and each PRB in the subset are within the RB set in the frequency domain. In other words, the UE may determine a set of PRBs from the PRBs withinan RB set with index k (RB set k) where the PRBs are within the RB set k inthe frequency domain. The value of PRBs is a multiple of

[0227] Additionally or alternatively, for determining frequency resources of PSFCH transmission and reception in an RB set k, the UE may use corresponding bits in the bitmap wherein PRBs corresponding to bits are within the RB set k. A PR B whose corresponding bit in the bitmap indicates value 1 may be included in thePRBs while a PRB whose corresponding bit in the bitmap indicates value 0 may not be included in the PRBs.

[0228] In various embodiments, if a resource pool includes multiple RB sets, the parameter F can be used to determine a set of PRBs for each of the multiple RB setswhere the set of PRBs are used for PSFCH transmission and reception in its corresponding RB set.

[0229] Figure 11 is a diagram illustrating one implementation of a method 1100 for determination of frequency resources for a PSFCH occasion in a resource pool by a UE 102. According to an embodiment of the present disclosure, the method 1100 is provided for determining PSFCH resources for a PSFCH occasion. In the embodiment, interlace RB-based transmission is configured to PSSCH transmission and PSFCH transmission in the resource pool. In the embodiment, the PSFCH transmission / reception type is configured to Type 2 in the resource pool. The method may include one, more or all of (I) determining PSFCH resources (e.g., a set A of PRBs) for each RB set in the resource pool, (II) determining PSFCH resources (e.g., a set B of PRBs) for each PSFCH transmission occasion within an RB set k, and (III) determining PRB subsets for each PSFCH transmission occasion and performing ordering for the determined PRB subsets.

[0230] In the Figure 11, 1101 represents an RB set of a resource pool, which refers to the RB set 804 of the resource pool 807. In other words, in the Figure 11 , the resource pool is the resource pool 807 illustrated in the Figure 8, which include two RB sets in the frequency domain and one guard band. The illustration in Figure 8 relating to the RB set 804 and the resource pool 807 can be applied to the Figure 11.

[0231] As above-mentioned, the UE is provided a bitmap by the parameter F. The bitmap includes a number of bits wherein the number of the bits in the bitmap is same as the number of RBs included in the resource pool. For example, the bitmap for the resource pool 807 may include 106 bits where each bit corresponds to a PRB of the resource pool 807. The UE may determine, based on the parameter F, a set ofPRBs in the resource pool for PSFCH transmission with HARQ-ACK information. ThePRBs are those RBs whose corresponding bits in the bitmap are set to value 1. The PRBs include PRBs in the RB set 804 and / or PRBs in the RB set 805. Thebits corresponding to RBs in the guard band 803 may be set to value 0 and may not be set to value 1.

[0232] In a possible implementation, the implementation of determining PSFCH resource (e.g., a set of PRBs) for each RB set in the resource pool is that the UE may determine PSFCH resource (e.g., a set of PRBs) for an RB set based on the parameterF and / or the frequency location of the RB set. Each bit in the bitmap provided by the parameter F has a one-to-one mapping to each PRB in the resource pool. Likewise, for an RB set of the resource pool, there are bits in the bitmap corresponding to RBs in the RB set of the resource pool. The UE may determine a set of PRBs for an RB set included in the resource pool where the set of PRBs are used for PSFCH transmission and reception in the RB set. For an RB set with index k in the resource pool, the UE may determine, based on the parameter F, a set ofPRBs from the PRBswithin the RB set k where the PRBs are within the RB set k in the frequencydomain. Here, the set of PRBs are used for PSFCH transmission andreception in the RB set k.

[0233] As in the Figure 11, 1102 represents a portion of the bitmap, which includes 50 bits wherein each bit corresponds to an RB in the RB set 1101. For the RB set k (the RB set 1101), the UE may determine, based on the bitmap, the set of PRBs1103 where the set of PRBs 1103 includes PRBs with indexes 2, 3, 4, 5, 6, 7,8, 9, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 22, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 45, 46, 47, 48, 49. The total number of PRB in the set ofPRBs is equal to 40. As above-mentioned, the total number of PRBs in the set ofPRBs is a muitiple ofthe Figure11, theis 5,is 2,is 2, and is 2.

[0234] After determining the set of PRBs for an RB set k, the UE needsto further determine to divide the set of PRBs into subset of PRBsfor the PSFCH occasions in the RB set k. That is, the UE may determinePSFCH resources (e.g., a set of PRBs) for each PSFCH transmission occasion within the RB set k. For a n-th PSFCH transmission occasion within RB set k, where 1 ≤ n ≤the UE 102 may determine to allocate PRBs to the n-th PSFCHtransmission occasion within RB set k. The is the output of the total numberof PRBs in the set ofPRBs divided by the number of PSFCH occasions In other words, the UE 1 02 mavdetermine the number of PRBs, to be allocated in each PSFCH occasion inan RB set based on the number of PRBs indicated for PSFCH transmission / reception within the RB set,and the number of PSFCH occasions,

[0235] In addition, the PRBs are selected from the set of PRBsbased on the PRB index. That is, the UE may determine to allocate RBs fromthe set of PRBs to each PSFCH occasion in an RB set k based on PRB index.To be specific, the UE may determine to allocate PRBs from the set ofPRBs to each PSFCH occasion in an ascending order of PRBs index. Forexample, for a n-th PSFCH transmission occasion within RB set k, where 1 ≤ n ≤ the UE 102 may allocates PRBsfrom the set of PRBs to the n-th PSFCH (transmission) occasion. The first(n=1) PSFCH occasion includes first PRBs, the second PSFCH occasionincludes second PRBs, and so on. Here, [A, B] PRBs from the set ofPRBs means multiple PRBs staring from a PRB in the A-th location in the set of PRBs and ending to a PRB in the B-th location in the set ofPRBs. The locations of PRBs in the set of PRBs are ordered according to anascending order of the PRB index.

[0236] As in the Figure 11, the UE may determine to allocate PRBs from the set of PRBs 1103 to each PSFCH occasion based on ascending order of PRB index. For the n=1 PSFCH occasion 1104, the UE may allocate PRBs with indexes 2,3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 22, 27 to the PSFCH occasion 1104. That is, for the n=1 PSFCH occasion 1104, the PRBs are selectedfrom the set of PRBs by starting from the PRB with the lowest PRB index inthe set of PRBs and by an ascending order of PRB index. For the n=2 PSFCHoccasion 1106, the UE allocated PRBs with indexes 28, 29, 30, 31, 32,33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 45, 46, 47, 48, 49 to the PSFCH occasion 1106. The PRBs allocated to the set of PRBs are also selected byan ascending order of PRB index.

[0237] After allocating PRBs from the setof PRBs to the n-th PSFCH occasion, the UE may further determine anumber of PRB subsets for the n-th PSFCH occasion. Each PRB subset includesPRBS in a same interlace. For example, the UE may determine to allocatePRBS from the allocated PRBs to each PRB subset based onascending order of PRB index in an interlace. As above-mentioned, the value ofPRBs is provided by a parameter when type 2 is configured for the PSFCH transmission in the resource pool. To be specific, for the n-th PSFCH occasion, the UE may determine a number of PRBs for each interlace from the allocated [(n — 1) • PBBs and then may determine a number of PRB subsetsfor each interlace.

[0238] For example, in the Figure 11, for illustration, the value of PRBs isprovided as 2. That is, each PRB set includes 2 PRBs in a same interlace. In the PSFCH occasion 1104 (i.e., the first PSFCH occasion), the UE may determine a number of PRBs for each interlace m and then may determine zero, one or multiple PRB subsets for each interlace m. For an interlace m, the UE may determine PRBs fromthe allocated PRBs. For example, in the Figure 11, the UE may determinePRBs for interlace m=0,PRBs for interlace m=1,=4 PRBs for interlace m=2, PRBs for interlace m=3, andPRBs for interlace m=4. In other words, there are two PRB subsets in interlace m=0, two PRB subsets in interlace m=1, two PRB subsets in interlace m=2, 1 PRB subsets in interlace m=3, 3 PRB subsets in interlace m=4. For an interlace, the PRB subset is indexed in ascending order of PRB index in the interlace. For example, in the interlace m=0, the PRB subset with index 0 includes PRBs with indexes 3 and 8, while the PRB subset with index 1 includes PRBs with indexes 13 and 18. Likewise, in the interlace m=1, the PRB subset with index 0 includes PRBs with indexes 4 and 9, while the PRB subset with index 1 includes PRBs with indexes 14 and 19. The PRB subsets among the interlaces for the n-th PSFCH occasion can be denoted as PRB subsets.

[0239] After determining zero, one or multiple PRB subsets in each interlace m, the UE may determine to perform ordering for the PRB subsets in the n-th PSFCH occasion based on ascending order of PRB subset index in an interlace first and ascending order of interlace index second. That is, the UE may determine the PRB subsets byordering the PRB subsets first in an ascending order of PRB subset index within aninterlace and second in ascending order of interlace index. As illustrated in the Figure 11 , the number of PRB subsets among interlaces is The UE may performordering 1105 for the PRB subsets in the n-th PSFCH occasion 1104 based on ascending order of PRB subset index in an interlace first and ascending order of interlace index second such that, after performing ordering, the first PRB subset corresponds to PRB subset with index 0 in the interlace m=0, the second PRB subset corresponds to PRB subset with index 1 in the interlace m=0, the third PRB subset corresponds to PRB subset with index 0 in the interlace m=1, the fourth PRB subset corresponds to PRB subset with index 2 in the interlace m=1, the fifth PRB subset corresponds to PRB subset with index 0 in the interlace m=2, the sixth PRB subset corresponds to PRB subset with index 1 in the interlace m=2, the seventh PRB subset corresponds to PRB subset with index 0 in the interlace m=3, the eighth PRB subset corresponds to PRB subset with index 0 in the interlace m=4, the ninth PRB subset corresponds to PRB subset with index 1 in the interlace m=4, the tenth PRB subset corresponds to PRB subset with index 2 in the interlace m=4. Likewise, the UE may perform ordering for the PRB subsets in the n-th PSFCH occasion 1106 based on ascending order of PRB subset index in an interlace first and ascending order of interlace index.

[0240] After performing ordering for the PRB subsets in the n-th PSFCH occasion, the ordered PRB subsets are sequentially allocated to each combination of sub-channel and slot based on an ascending order of slot index first and an ascending order of subchannel index.

[0241] According to the method 1100, PSFCH resources can be efficiently allocated to each PSFCH occasion in each RB set such that PSFCH resource collision among PSFCH occasions in each RB set can be avoided. Furthermore, for each PSFCH occasion, each combination of sub-channel and slot may be allocated with specific one or more PRB subsets such that PRB subset for different combination of sub-channel and slot can be avoided. Therefore, an efficient SL transmission system can be provided.

[0242] Figure 12 is a diagram illustrating one implementation of a method 1200 for determination of frequency resources for a PSFCH occasion in a resource pool by a UE 102. According to an embodiment of the present disclosure, the method 1200 is provided for determining PSFCH resources for a PSFCH occasion. In the embodiment, interlace RB-based transmission is configured to PSSCH transmission and PSFCHtransmission in the resource pool. In the embodiment, the PSFCH transmission / reception type is configured to Type 2 in the resource pool. The method 1200 may include one, more or all of (I) determining PSFCH resources (e.g., a set A of PRBs) for each RB set in the resource pool, (II) determining PSFCH resources (e.g., a set B of PRBs) for each PSFCH transmission occasion within an RB set k, and (III) determining PRB subsets for each PSFCH transmission occasion and performing ordering for the determined PRB subsets.

[0243] Descriptions for 1101, 1102, and 1103 can be equally applied to 1201, 1202, and 1203 in the Figure 12, respectively. Likewise, the determination of PSFCH resources for each RB set illustrated in the method 1100 can be also applied to the determination of PSFCH resources for each RB set in the method 1200. The applicable description are omitted here for conciseness. That is, in the method 1200, the UE may determine the set of PRBs for an RB set k by using the same implementationillustrated in the method 1100.

[0244] After determining the set of PRBs for an RB set k, the UE needsto further determine to divide the set of PRBs into subset of PRBsfor the PSFCH occasions in the RB set k. That is, the UE may determinePSFCH resources (e.g., a set of PRBs) for each PSFCH transmission occasion within the RB set k. For a n-th PSFCH transmission occasion within RB set k, where 1 ≤ n ≤ the UE 102 may determine to allocate PRBs to the n-th PSFCHtransmission occasion within RB set k. The is the output of the total numberof PRBs in the set of PRBs divided by the number of PSFCH occasionsIn other words, the UE 102 may determine the number of PRBs, to be allocated in each PSFCH occasion inan RB set based on the number of PRBs indicated for PSFCH transmission / reception within the RB set, and the number of PSFCH occasions,

[0245] In addition, the PRBs are selected from the set of PRBsfirst in an ascending order of PRB index within an interlace and second in an ascending order of interlace index. To be specific, the UE may determine to allocatePRBs from the set of PRBs to each PSFCH occasion first in an ascendingorder of PRB index within an interlace and second in an ascending order of interlace index. For example, as in the Figure 12, the UE may determine to allocate PRBs from the set of PRBs 1203 to each PSFCH occasion in an ascending order of PRB index within an interlace and second in an ascending order of interlace index. By doing so, for the n=1 PSFCH occasion 1204, the UE may allocate PRBs withindexes 3, 8, 13, 18, 28, 33, 38, 48, 4, 9, 14, 19, 29, 34, 39, 49, 5, 10, 15, 20 to the PSFCH occasion 1204. That is, for the n=\ PSFCH occasion 1104, thePRBs are selected from the set of PRBs in an ascending order of PRB indexwithin an interlace and second in an ascending order of interlace index. For the n=2 PSFCH occasion 1206, the UE allocated PRBs with indexes 30, 35, 40,45, 6, 11, 31, 36, 41, 46, 2, 7, 12, 17, 22, 27, 32, 37, 42, 47 to the PSFCH occasion 1206. The PRBs allocated to the set of PRBs are also selected inan ascending order of PRB index within an interlace and second in an ascending order of interlace index.

[0246] After allocating PRBs from the set of PRBs to the n-thPSFCH occasion, the UE may further determine a number of PRB subsets for the n-th PSFCH occasion. Each PRB subset includesPRBs in a same interlace. For example, the UE may determine to allocate PRBs from the allocatedPRBs to each PRB subset based on an ascending order of PRB index in an interlace. As above-mentioned, the value ofPRBs is provided by a parameter when type 2 is configured for the PSFCH transmission in the resource pool. To be specific, for the n-th PSFCH occasion, the UE may determine a number of PRBs for each interlace from the allocated PRBs and then may determine a number of PRB subsets foreach interlace.

[0247] For example, in the Figure 12, for illustration, the value of PRBs isprovided as 2. That is, each PRB set includes 2 PRBs in a same interlace. In the PSFCH occasion 1204 (i.e., the first PSFCH occasion), the UE may determine a number of PRBs for each interlace m and then may determine zero, one or multiple PRB subsets for each interlace m. For an interlace m, the UE may determine PRBs fromthe allocated PRBs. For example, in the Figure 12, the UE may determinePRBs for interlace m=0,PRBs for interlace m=1,=4 PRBs for interlace m=2, PRBs for interlace m=3, andPRBs for interlace m=4. In other words, there are four PRB subsets in interlace m=0, four PRB subsets in interlace m=1, two PRB subsets in interlace m=2, zero PRB subsets in interlace m=3, zero PRB subsets in interlace m=4. For an interlace, the PRB subset is indexed in ascending order of PRB index in the interlace. For example, in the interlace m=Q, the PRB subset with index 0 includes PRBs with indexes 3 and 8, the PRB subset with index 1 includes PRBs with indexes 13 and 18, the PRB subset with index 2 includes PRBs with indexes 28 and 33, and the PRB subset with index 3 includes PRBs with indexes 38 and 48.

[0248] Likewise, in the interlace m=1, the PRB subset with index 0 includes PRBs with indexes 4 and 9, the PRB subset with index 1 includes PRBs with indexes 14 and 19, the PRB subset with index 2 includes PRBs with indexes 29 and 34, and the PRB subset with index 3 includes PRBs with indexes 39 and 49. Likewise, in the interlace m=2, the PRB subset with index 0 includes PRBs with indexes 5 and 10, the PRB subset with index 1 includes PRBs with indexes 15 and 20. The PRB subsets among the interlaces for the n-th PSFCH occasion can be denoted as PRB subsets.

[0249] After determining zero, one or multiple PRB subsets in each interlace m, the UE may determine to perform ordering for the PRB subsets in the n-th PSFCH occasion based on ascending order of PRB subset index in an interlace first and ascending order of interlace index second. That is, the UE may determine the PRB subsets byordering the PRB subsets first in an ascending order of PRB subset index within an interlace and second in ascending order of interlace index. As illustrated in the Figure 12, the number of PRB subsets among interlaces is The UE may performordering 1205 for the PRB subsets in the 77-th PSFCH occasion 1204 based on ascending order of PRB subset index in an interlace first and ascending order of interlace index second such that, after performing ordering, the first PRB subset corresponds to PRB subset with index 0 in the interlace m=0, the second PRB subset corresponds to PRB subset with index 1 in the interlace m=0, the third PRB subset corresponds to PRB subset with index 2 in the interlace m=0, the fourth PRB subset corresponds to PRB subset with index 3 in the interlace m=0, the fifth PRB subset corresponds to PRB subset with index 0 in the interlace m=1, the sixth PRB subsetcorresponds to PRB subset with index 1 in the interlace m=1, the seventh PRB subset corresponds to PRB subset with index 2 in the interlace m=1, the eighth PRB subset corresponds to PRB subset with index 3 in the interlace m=1, the ninth PRB subset corresponds to PRB subset with index 0 in the interlace m=2, the tenth PRB subset corresponds to PRB subset with index 1 in the interlace m=2. Likewise, the UE may perform ordering for the PRB subsets in the n-th PSFCH occasion 1206 based on ascending order of PRB subset index in an interlace first and ascending order of interlace index.

[0250] After performing ordering for the PRB subsets in the »-th PSFCH occasion, the ordered PRB subsets are sequentially allocated to each combination of sub-channel and slot based on an ascending order of slot index first and an ascending order of subchannel index.

[0251] According to the method 1200, PSFCH resources can be efficiently allocated to each PSFCH occasion in each RB set such that PSFCH resource collision among PSFCH occasions in each RB set can be avoided. Furthermore, for each PSFCH occasion, each combination of sub-channel and slot may be allocated with specific one or more PRB subsets such that PRB subset for different combination of sub-channel and slot can be avoided. Therefore, an efficient SL transmission system can be provided.

[0252] Figure 13 is a diagram illustrating one implementation of another method 1300 for determination of frequency resources for a PSFCH occasion in a resource pool by a UE 102. According to an embodiment of the present disclosure, the method 1300 is provided for determining PSFCH resources for a PSFCH occasion. In the embodiment, interlace RB-based transmission is configured to PSSCH transmission and PSFCH transmission in the resource pool. In the embodiment, the PSFCH transmission / reception type is configured to Type 2 in the resource pool. The method 1300 may include one, more or all of (I) determining PSFCH resources (e.g., a set A of PRBs) for each RB set in the resource pool, (II) determining PRB subsets within an RB set k and performing ordering for the determined PRB subsets, and / or (III) determining / allocating PRB subsets to each PSFCH transmission occasion within an RB set k.

[0253] Descriptions for 1101, 1102, and 1103 can be equally applied to 1301, 1302, and 1303 in the Figure 13, respectively. Likewise, the determination of PSFCH resources for each RB set illustrated in the method 1100 can be also applied to thedetermination of PSFCH resources for each RB set in the method 1300. The applicable description are omitted here for conciseness. That is, in the method 1300, the UE may determine the set of PRBs for an RB set k by using the same implementationillustrated in the method 1100.

[0254] After determining the set of PRBs for an RB set k, the UE needsto further determine PRB subsets for the RB set k. Each PRB subset includesPRBs in a same interlace. For example, the UE may determine to allocate PRBsfrom the allocated PRBs to each PRB subset based on an ascending order ofPRB index in an interlace. As above-mentioned, the value of PRBs is providedby a parameter when type 2 is configured for the PSFCH transmission in the resource pool. For example, in the Figure 12, for illustration, the value of PRBs isprovided as 2. That is, each PRB set includes 2 PRBs in a same interlace.

[0255] The UE may determine to reorder PRB locations in the set ofPRBs for the RB set k first in an ascending order of PRB index in an interlace and second in an ascending order of interlace index. In the Figure 13, the set ofPRBs 1303 is reordered as the set of PRBs 1304.

[0256] After reordering the set of PRBs 1304, the UE may determine tosequentially allocate everyPRBs to each PRB subset in an ascending order of PRB locations in the set of PRBs 1304. In other words, the UE maydetermine to sequentially allocate every PRBs to each PRB subset first in anascending order of PRB index in an interlace and second in ascending order of interlace index from the set of PRBs 1303. By doing so, PRB subsets 1305 aredetermined where the first PRB subset includes first 2 PRBs in the set of set of PRBs 1304 (i.e., 2 PRBs with index 3 and 8), the second PRB subset includessecond 2 PRBs in the set of set of PRBs 1304 (i.e., 2 PRBs with index 13and 18), the third PRB subset includes third 2 PRBs in the set of set of PRBs1304 (i.e., 2 PRBs with index 28 and 33), and so on.

[0257] In a possible implementation, a specific implementation of determine PRB subset from the set of PRBs 1303 is that, for the RB set k, the UE maydetermine a number of PRBs for each interlace from the PRBs and then maydetermine a number of PRB subsets for each interlace. For example, in the Figure 13, the UE may determine a number of PRBs for each interlace m according to the set ofPRBs 1303 and then may determine zero, one or multiple PRB subsets for each interlace m. For an interlace m, the UE may determinePRBs from the allocatedPRBs. For example, in the Figure 13, the UE may determinePRBs for interlace m=0, PRBs for interlace m=1,=8 PRBs for interlace m=2, PRBs for interlace m=3, andPRBs for interlace m=4. In other words, for the RB set k, there are four PRB subsets in interlace m=0, four PRB subsets in interlace m=1, four PRB subsets in interlace m=2, three PRB subsets in interlace m=3, five PRB subsets in interlace m=4. For an interlace, the PRB subset is indexed in ascending order of PRB index in the interlace. For example, in the interlace m=0, the PRB subset with index 0 includes PRBs with indexes 3 and 8, the PRB subset with index 1 includes PRBs with indexes 13 and 18, the PRB subset with index 2 includes PRBs with indexes 28 and 33, and the PRB subset with index 3 includes PRBs with indexes 38 and 48. In the interlace m=1, the PRB subset with index 0 includes PRBs with indexes 4 and 9, the PRB subset with index 1 includes PRBs with indexes 14 and 19, the PRB subset with index 2 includes PRBs with indexes 29 and 34, and the PRB subset with index 3 includes PRBs with indexes 39 and 49. In the interlace m=2, the PRB subset with index 0 includes PRBs with indexes 5 and 10, the PRB subset with index 1 includes PRBs with indexes 15 and 20, the PRB subset with index 2 includes PRBs with indexes 30 and 35, and the PRB subset with index 3 includes PRBs with indexes 40 and 45. In the interlace m=3, the PRB subset with index 0 includes PRBs with indexes 6 and 11, the PRB subset with index 1 includes PRBs with indexes 31 and 36, the PRB subset with index 2 includes PRBs with indexes 41 and 46. In the interlace m=4, the PRB subset with index 0 includes PRBs with indexes 2 and 7, the PRB subset with index 1 includes PRBs with indexes 12 and 17, the PRB subset with index 2 includes PRBs with indexes 22 and 27, the PRB subset with index 3 includes PRBs with indexes 32 and 37, and the PRB subset with index 4 includes PRBs with indexes 42 and 47.

[0258] The PRB subsets among the interlaces for the RB set k can be denoted asPRB subsets. After determining zero, one or multiple PRB subsets in each interlace m, the UE may determine to perform ordering for the PRB subsets in the RBset k based on ascending order of PRB subset index in an interlace first and ascending order of interlace index second. That is, the UE may determine the PRBsubsets by ordering the PRB subsets first in an ascending order of PRB subset index within an interlace and second in ascending order of interlace index.

[0259] As illustrated in the Figure 13, the number of PRB subsets among interlaces is The UE may perform ordering 1305 for the PRB subsets in the RB setk based on ascending order of PRB subset index in an interlace first and ascending order of interlace index second such that, after performing ordering, the first PRB subset includes PRBs with index 3 and 8 ( i.e., PRB subset with index 0 in the interlace m=0), the second PRB subset includes PRBs with index 13 and 18 (i.e., PRB subset with index 1 in the interlace m=0), the third PRB subset includes PRBs with index 28 and 33 (i.e., PRB subset with index 2 in the interlace m=0), the fourth PRB subset includes PRBs with index 38 and 48 (i.e., PRB subset with index 3 in the interlace m=0), the fifth PRB subset includes PRBs with index 4 and 9 (i.e., PRB subset with index 0 in the interlace m=1), and so on.

[0260] After performing ordering for the PRB subsets in the RB set k, the UE may determine to allocate PRB subsets to each PSFCH transmission occasion within the RB set k.

[0261] For a n-th PSFCH transmission occasion within RB set k, where 1 ≤ n ≤the UE 102 may determine to allocate PRB subsets to the n-thPSFCH transmission occasion within RB set k. The is the output of thedivided by the number of PSFCH occasionsThe UE may determine to allocatePRB subsets from the set of PRB subsets to each PSFCH occasion in an RB set k in an ascendingorder of PRB subset index in the set of PRB. For example, for a n-th PSFCHtransmission occasion within RB set k, where 1 ≤ n ≤the UE 102 may allocatesPRBsubsets from the set ofPRB subsets to the n-th PSFCH (transmission) occasion. The first (n=1) PSFCH occasion includes first PRBs, the second PSFCH occasion includes secondPRBs, and so on. As in the Figure 13, the first PSFCH occasion 1306 isallocated with PRB subsets with indexes from 1 to 10, while the second PSFCH occasion 1307 is allocated with PRB subsets with indexes from 11 to 20.

[0262] After allocating PRB subsets to the n-th PSFCH occasion, the allocated PRB subsets are sequentially allocated to each combination of sub-channel and slot based on an ascending order of slot index first and an ascending order of sub-channel index.

[0263] According to the method 1300, PSFCH resources can be efficiently allocated to each PSFCH occasion in each RB set such that PSFCH resource collision among PSFCH occasions in each RB set can be avoided. Furthermore, for each PSFCH occasion, each combination of sub-channel and slot may be allocated with specific one or more PRB subsets such that PRB subset for different combination of sub-channel and slot can be avoided. Therefore, an efficient SL transmission system can be provided.

[0264] In an embodiment of the present disclosure, a UE may use different methods to divide the set of PRBs into each PSFCH occasion based on which type ofPSFCH transmission / reception is configured to the resource pool. The set ofPRBs is above-mentioned PRBs indicated for PSFCH transmission and reception in the RB set k. The determination of PRBs described above in other embodimentscan be also applied to the embodiment. As above-mentioned, the UE 102 may receive a parameter to indicate which type of the type 1 and type 2 is used for PSFCH transmission and reception in the resource pool. Additionally, the UE 102 may receive the above-mentioned parameter E to indicate a number of PSFCH occasions for PSFCH transmission and PSFCH reception.

[0265] In the embodiment, in a case that the type 1 is configured in the resource pool by the parameter, the PRBs in the set of PRBs are divided into eachPSFCH occasion based on interlace index. Specifically, the UE may determine a set of interlaces within the RB-set k based on the above-mentioned parameter Fand / or the set of PRBs. The UE may determine an interlace to be included inthe set of interlaces if one or multiple RBs of the interlaces are the PRBs inthe set of PRBs. The UE may determine an interlace to not be included in theset of interlaces if the set of PRBs does not include any PRB ofthe interlace in the RB set k. The UE may determine to equally allocate one or multiple interlaces in the set of interlaces to each PSFCH occasion in an ascendingorder of interlace index. For example, for a n-th candidate PSFCH transmission occasion within RB-set k, 1 ≤ n ≤the UE may determine to allocate interlaces from the interlaces tothe n-th candidate PSFCH transmission occasion, whereThen the PRBs of the allocated interlaces to the PSFCH occasion are used for PSFCH transmission and reception in the PSFCH occasion. Given interlaces may have different PRBs, different PSFCH occasion may have same or different PRBs.

[0266] In a case that the type 2 is configured in the resource pool by the parameter, the PRBs in the set of PRBs are divided into each PSFCH occasion based onan ascending order of PRB index. That is, the UE may determine to equally allocate PRBs in the set ofPRBs to each PSFCH occasion first in an ascending order of PRB index. For example, for a n-th candidate PSFCH transmission occasion within RB-set k, where 1 ≤ n ≤the UE may determine to allocatePRBs fromPRBs to the n -th candidate PSFCH transmission occasion where

[0267] Figure 14 illustrates various components that may be utilized in a UE 1402. The UE 1402 (UE 102) described in connection with Figure 14 may be implemented in accordance with the UE 102 described in connection with Figure 1. The UE 1402 includes a processor 1481 that controls operation of the UE 1402. The processor 1481 may also be referred to as a central processing unit (CPU). Memory 1487, which may include read-only memory (ROM), random access memory (RAM), a combination of the two or any type of device that may store information, provides instructions 1483a and data 1485a to the processor 1481. A portion of the memory 1487 may also include non-volatile random access memory (NVRAM). Instructions 1483b and data 1485b may also reside in the processor 1481. Instructions 1483b and / or data 1485b loaded into the processor 1481 may also include instructions 1483a and / or data 1485a from memory 1487 that were loaded for execution or processing by the processor 1481. The instructions 1483b may be executed by the processor 1481 to implement one or more of the methods described above.

[0268] The UE 1402 may also include a housing that contains one or more transmitters 1458 and one or more receivers 1420 to allow transmission and receptionof data. The transmitter(s) 1458 and receiver(s) 1420 may be combined into one or more transceivers 1418. One or more antennas 1422a-n are attached to the housing and electrically coupled to the transceiver 1418.

[0269] The various components of the UE 1402 are coupled together by a bus system 1489, which may include a power bus, a control signal bus and a status signal bus, in addition to a data bus. However, for the sake of clarity, the various buses are illustrated in Figure 14 as the bus system 1489. The UE 1402 may also include a digital signal processor (DSP) 1491 for use in processing signals. The UE 1402 may also include a communications interface 1493 that provides user access to the functions of the UE 1402. The UE 1402 illustrated in Figure 14 is a functional block diagram rather than a listing of specific components.

[0270] Figure 15 illustrates various components that may be utilized in a base station 1560. The base station 1560 described in connection with Figure 15 may be implemented in accordance with the base station 160 described in connection with Figure 1. The base station 1560 includes a processor 1581 that controls operation of the base station 1560. The processor 1581 may also be referred to as a central processing unit (CPU). Memory 1587, which may include read-only memory (ROM), random access memory (RAM), a combination of the two or any type of device that may store information, provides instructions 1583a and data 1585a to the processor 1581. A portion of the memory 1587 may also include non-volatile random access memory (NVRAM). Instructions 1583b and data 1585b may also reside in the processor 1581. Instructions 1583b and / or data 1585b loaded into the processor 1581 may also include instructions 1583a and / or data 1585a from memory 1587 that were loaded for execution or processing by the processor 1581. The instructions 1583b may be executed by the processor 1581 to implement one or more of the methods 300 described above.

[0271] The base station 1560 may also include a housing that contains one or more transmitters 1517 and one or more receivers 1578 to allow transmission and reception of data. The transmitter(s) 1517 and receiver(s) 1578 maybe combined into one or more transceivers 1576. One or more antennas 1580a-n are attached to the housing and electrically coupled to the transceiver 1576.

[0272] The various components of the base station 1560 are coupled together by a bus system 1589, which may include a power bus, a control signal bus and a status signal bus, in addition to a data bus. However, for the sake of clarity, the various busesare illustrated in Figure 15 as the bus system 1589. The base station 1560 may also include a digital signal processor (DSP) 1591 for use in processing signals. The base station 1560 may also include a communications interface 1593 that provides user access to the functions of the base station 1560. The base station 1560 illustrated inFigure 15 is a functional block diagram rather than a listing of specific components.

[0273] The term “computer-readable medium” refers to any available medium that can be accessed by a computer or a processor. The term “computer-readable medium,” as used herein, may denote a computer- and / or processor-readable medium that is non- transitory and tangible. By way of example, and not limitation, a computer-readable or processor-readable medium may comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer or processor. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray® disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers.

[0274] It should be noted that one or more of the methods described herein may be implemented in and / or performed using hardware. For example, one or more of the methods described herein may be implemented in and / or realized using circuitry, a chipset, an application-specific integrated circuit (ASIC), a large-scale integrated circuit (LSI) or integrated circuit, etc.

[0275] Each of the methods disclosed herein comprises one or more steps or actions for achieving the described method. The method steps and / or actions may be interchanged with one another and / or combined into a single step without departing from the scope of the claims. In other words, unless a specific order of steps or actions is required for proper operation of the method that is being described, the order and / or use of specific steps and / or actions may be modified without departing from the scope of the claims.

[0276] It is to be understood that the claims are not limited to the precise configuration and components illustrated above. Various modifications, changes and variations may be made in the arrangement, operation and details of the systems, methods and apparatus described herein without departing from the scope of the claims.

Claims

[CLAIMS]1. A user equipment (UE), comprising: reception circuitry configured to receive a sidelink (SL) resource pool configuration from a base station, the SL resource pool configuration including a first parameter and a second parameter, the first parameter being used to determine a set of PRBs that are used for PSFCH transmission and reception, the second parameter indicating a number of PSFCH occasions for one associated PSSCH transmission; control circuitry configured to equally allocate N PRBs from the set of PRBs to each PSFCH occasion of the number of PSFCH occasions, wherein, N is an output of the total number of PRBs in the set of PRBs divided by the number of PSFCH occasions, and N PRBs are allocated based on an ascending order of PRB index; and the control circuitry is further configured to, for each N PRBs allocated to each PSFCH occasion, to allocate one or more PRBs to each PRB subset based on ascending order of PRB index in an interlace, and perform ordering for the PRB subsets based on ascending order of PRB subset index in an interlace first and ascending order of interlace index second.

2. A communication method performed by a user equipment (UE), comprising: receiving a sidelink (SL) resource pool configuration from a base station, the SL resource pool configuration including a first parameter and a second parameter, the first parameter being used to determine a set of PRBs that are used for PSFCH transmission and reception, the second parameter indicating a number of PSFCH occasions for one associated PSSCH transmission; allocating equally N PRBs from the set of PRBs to each PSFCH occasion of the number of PSFCH occasions, wherein, N is an output of the total number of PRBs in the set of PRBs divided by the number of PSFCHoccasions, and N PRBs are allocated based on an ascending order of PRB index; allocating, for each N PRBs allocated to each PSFCH occasion, one or more PRBs to each PRB subset based on ascending order of PRB index in an interlace; and performing ordering for the PRB subsets based on ascending order of PRB subset index in an interlace first and ascending order of interlace index second.

Images