Method executed by user equipment, and user equipment
By executing the method of selecting side-line communication scheduling permission and resource selection process on the user equipment, the problems of low utilization of side-line communication resource and high LBT frequency on the unauthorized spectrum are solved, and efficient resource utilization and low power consumption continuous time slot transmission MCSt is achieved.
Patent Information
- Application Number
- PCT/CN2024/120639
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-09-26
- Filing Date
- 2024-09-24
- Publication Date
- 2025-04-03
AI Technical Summary
When side-link communication is carried out on unauthorized spectrum, the prior art is difficult to effectively improve resource utilization, and in the continuous time slot transmission MCSt scenario, the frequency of LBT is high, resulting in an increase in user equipment power consumption.
A method is proposed for execution by a user equipment, including selecting to generate a selected sideline communication scheduling license and performing a send resource selection or reselection process for the license. In the case where MCSt is transmitted by multiple consecutive time slots, the user equipment may select a candidate multi-time slot resource and determine the number of candidate time slots through a partially perceptual resource allocation method to optimize resource selection.
By optimizing resource selection and allocation, the resource utilization rate of communication on the unauthorized spectrum is improved, and the continuous time slot transmission of MCSt on the unauthorized spectrum is realized, reducing the frequency of LBT and the power consumption of user equipment.
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Figure CN2024120639_03042025_PF_FP_ABST
Abstract
Description
Method performed by user equipment and user equipment Technical Field
[0001] The present invention relates to the technical field of wireless communications, and in particular to a method executed by a user equipment and corresponding user equipment. Background Art
[0002] In traditional cellular networks, all communications must go through the base station. In contrast, D2D (Device-to-Device) communication refers to direct communication between two user devices without forwarding through the base station or core network. At the RAN#63 plenary meeting of the 3rd Generation Partnership Project (3GPP) in March 2014, a research project on implementing proximity-based D2D communication services using LTE devices was approved (see Non-Patent Document 1). LTE Release 12 D2D introduces the following features:
[0003] 1) Discovery between nearby devices in LTE network coverage scenarios;
[0004] 2) Direct broadcast communication between nearby devices (Broadcast function);
[0005] 3) The upper layer supports unicast and multicast communication functions.
[0006] At the 3GPP RAN#66 plenary meeting in December 2014, the enhanced LTE eD2D (enhanced D2D) research project was approved (see Non-Patent Document 2). The main features introduced in LTE Release 13 eD2D include:
[0007] 1) D2D discovery in scenarios with no network coverage and partial network coverage;
[0008] 2) Priority processing mechanism for D2D communication.
[0009] Based on the design of D2D communication mechanisms, the 3GPP RAN#68 plenary meeting in June 2015 approved a feasibility study on V2X based on D2D communication. V2X, standing for Vehicle to Everything, aims to enable information exchange between vehicles and all entities that may affect them. The goal is to reduce accidents, ease traffic congestion, reduce environmental pollution, and provide other information services. V2X application scenarios primarily include four areas:
[0010] 1) V2V, Vehicle to Vehicle, i.e. vehicle-to-vehicle communication;
[0011] 2) V2P, Vehicle to Pedestrian, where a vehicle sends a warning to a pedestrian or non-motor vehicle;
[0012] 3) V2N, Vehicle to Network, which refers to vehicles connecting to mobile networks;
[0013] 4) V2I, Vehicle to Infrastructure, refers to the communication between vehicles and road infrastructure.
[0014] 3GPP divides the research and standardization work of V2X into three phases. The first phase was completed in September 2016, focusing mainly on V2V, based on LTE Release 12 and Release 13 D2D (also known as sidelink communication), that is, proximity communication technology (see non-patent document 3). V2X stage 1 introduced a new D2D communication interface called the PC5 interface. The PC5 interface is mainly used to solve the communication problems of cellular vehicle networks in high-speed (up to 250 km / h) and high-node density environments. Vehicles can exchange information such as location, speed and direction through the PC5 interface, that is, vehicles can communicate directly through the PC5 interface. Compared with the proximity communication between D2D devices, the functions introduced by LTE Release 14 V2X mainly include:
[0015] 1) Higher density DMRS to support high-speed scenarios;
[0016] 2) Introducing sub-channels to enhance resource allocation;
[0017] 3) Introducing user device sensing with semi-persistent scheduling
[0018] mechanism.
[0019] The second phase of the V2X research project falls within the scope of LTE Release 15 (see Non-Patent Document 4). The main features introduced include high-order 64QAM modulation, V2X carrier aggregation, short TTI transmission, and feasibility studies of transmit diversity.
[0020] At the 3GPP RAN#80 plenary meeting in June 2018, the corresponding third phase V2X feasibility study topic based on 5G NR network technology (see non-patent document 5) was approved.
[0021] The 5G NR V2X project supports a resource allocation mode 2 based on user equipment sensing, also known as transmission mode 2. In resource allocation mode 2 based on user equipment sensing, the physical layer of the user equipment senses the transmission resources in the resource pool. This means that the user equipment determines whether to exclude resources in the candidate resource set that overlap with the resources indicated by the SCI received from other user equipment. The resources in the candidate resource set that are not excluded are reported to the upper layer, which randomly selects resources for PSSCH / PSCCH transmission from the reported resource set.
[0022] At the 3GPP RAN#95e plenary meeting in March 2022, a standardization research topic on the evolution of NR sidelink communications (NR SL evo) based on the already standardized NR was approved (see Non-Patent Document 6). The research objectives of NR SL evo include the following:
[0023] 1) Research and standardize NR sidelink communications in unlicensed spectrum, referred to as SL-U. SL-U includes both resource allocation methods 1 and 2 for NR sidelink communications. This research project specifically includes:
[0024] a. In SL-U, the channel access technology and operations of the NR air interface in unlicensed spectrum (NR unlicensed, referred to as NR-U) are reused. The channel access technology of NR-U refers to the Listen Before Talk (LBT) technology, which means that before transmitting, the user equipment needs to listen to the channel resources used for transmission. If the channel is idle, the transmission is carried out; otherwise, the transmission is abandoned.
[0025] b. Study the design framework of the physical channel in sideline communication: that is, make necessary modifications to the structure of the physical channel in the existing NR sideline communication to enable SL-U.
[0026] At the 3GPP RAN1#110 meeting in August 2022, the following conclusions were reached regarding SL-U (see Non-Patent Document 7):
[0027] 1) Sideline communication in unlicensed spectrum supports transmission in multiple consecutive time slots (MCSt). MCSt indicates that a sideline communication user equipment transmits in consecutive time slots. The transmission resources of one MCSt can be used to transmit one transport block (TB) or multiple different transport blocks (TB).
[0028] The scheme disclosed herein includes a method for a sideline communication user equipment to perform resource selection (or resource reselection) when multiple consecutive time slots MCSt are transmitted in SL-U, and a method for the user equipment to determine the number of candidate time slots for partial sensing resource allocation in the case of MCSt.
[0029] Prior art literature
[0030] Non-patent literature
[0031] Non-Patent Literature 1: RP-140518, Work Item Proposal on LTE Device to Device Proximity Services
[0032] Non-Patent Document 2: RP-142311, Work Item Proposal for Enhanced LTE Device to Device Proximity Services
[0033] Non-Patent Document 3: RP-152293, New WI proposal: Support for V2V services based on LTE sidelink
[0034] Non-Patent Document 4: RP-170798, New WID on 3GPP V2X Phase 2
[0035] Non-Patent Document 5: RP-181480, New SID Proposal: Study on NR V2X
[0036] Non-Patent Literature 6: RP-220300, WID revision: NR sidelink evolution
[0037] Non-Patent Document 7: RAN1#110 Chairman's notes, section 9.4.1.1
[0038] Summary of the Invention
[0039] In order to solve at least part of the above problems, the present invention provides a method and user equipment executed by a user equipment, which can improve the resource utilization of side communication on the unlicensed spectrum, and can realize continuous time slot transmission MCSt on the unlicensed spectrum, reduce the frequency of LBT, and reduce the power consumption of the user equipment.
[0040] According to the present invention, a method performed by a user equipment is proposed, comprising the following steps: selecting and generating a selected sideline communication scheduling grant; and performing a transmission resource selection or reselection process for the selected sideline communication scheduling grant.
[0041] Preferably, the selected sidelink communication scheduling permission corresponds to the transmission of one or more MAC protocol data units (PDUs).
[0042] Preferably, the step of performing a transmission resource selection or reselection process comprises selecting a number of consecutive time slots for a plurality of consecutive time slot transmissions.
[0043] Preferably, the step of performing a transmission resource selection or reselection procedure comprises selecting a number of HARQ retransmissions.
[0044] Preferably, the step of performing the transmission resource selection or reselection process includes: if one or more HARQ retransmissions are selected, and / or the number of selected HARQ retransmissions is greater than the number of consecutive time slots, then selecting available resources from the candidate resources indicated by the physical layer for the HARQ retransmission.
[0045] In addition, according to the present invention, a method performed by a user equipment is proposed, comprising the following steps: determining, for resource allocation mode 2, on an unlicensed spectrum, a resource subset for PSSCH / PSCCH transmission; determining candidate time slots in a partially perceived resource allocation mode; and performing a candidate resource exclusion process.
[0046] Preferably, the step of determining a resource subset for PSSCH / PSCCH transmission comprises: applying candidate multi-slot resources when the number of consecutive time slots of the multiple consecutive time slot transmission is greater than one.
[0047] Preferably, the step of determining candidate time slots comprises: for periodic transmission, selecting a first number of candidate time slots; for aperiodic transmission, selecting a second number of candidate time slots.
[0048] Preferably, both the first number and the second number are not less than the number of consecutive time slots.
[0049] In addition, according to the present invention, a user equipment is proposed, comprising: a processor; and a memory storing instructions, wherein the instructions execute the above method when executed by the processor.
[0050] Effects of the Invention
[0051] In SL-U, the solution of the present invention describes that in the case of continuous time slot transmission MCSt, when the sum of the number of initial transmissions and HARQ retransmissions selected by the MAC layer is greater than the number of continuous time slots indicated to the physical layer, the user equipment selects time-frequency resources for the remaining transmission opportunities on the premise that a candidate multi-slot resource has been selected; otherwise, the user equipment does not proceed to the next resource selection (or reselection) process on the premise that a candidate multi-slot resource has been selected. This solution effectively ensures that the number of resources selected by the MAC layer of the user equipment for a transmission block TB is consistent with the number of HARQ retransmissions selected by the MAC layer, thereby improving the resource utilization of sidelink communications on the unlicensed spectrum. At the same time, the solution of the present invention also describes that in the case of MCSt, the number of candidate time slots selected by the physical layer for the partial perception resource allocation method should be no less than the number of continuous time slots indicated by the MAC layer for MCSt. This solution ensures the validity of the candidate multi-slot resources within the resource selection window, realizes continuous time slot transmission MCSt on the unlicensed spectrum, reduces the frequency of LBT, and reduces the power consumption of the user equipment. BRIEF DESCRIPTION OF THE DRAWINGS
[0052] The above and other features of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0053] FIG1 is a schematic diagram illustrating a basic process of a method executed by a user equipment in a first embodiment of the present invention.
[0054] FIG2 is a schematic diagram illustrating a basic process of a method executed by a user equipment in a second embodiment of the present invention.
[0055] FIG3 is a block diagram illustrating a user equipment according to an embodiment of the present invention. DETAILED DESCRIPTION
[0056] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the present invention is not limited to the specific embodiments described below. In addition, for the sake of simplicity, detailed descriptions of known technologies that are not directly related to the present invention are omitted to prevent confusion in understanding the present invention.
[0057] The following describes multiple embodiments of the present invention using a 5G mobile communication system and its subsequent evolutionary versions as example application environments. However, it should be noted that the present invention is not limited to the following embodiments, but is applicable to many other wireless communication systems, such as communication systems after 5G and 4G mobile communication systems before 5G.
[0058] The following describes some of the terms involved in the present invention. Unless otherwise specified, the terms used in the present invention are defined herein. The terms given in the present invention may be named differently in LTE, LTE-Advanced, LTE-Advanced Pro, NR, and later communication systems. However, the present invention adopts unified terminology. When applied to a specific system, the terms can be replaced with the terms used in the corresponding system.
[0059] 3GPP: 3rd Generation Partnership Project
[0060] LTE: Long Term Evolution
[0061] NR: New Radio, New Wireless, New Air Interface
[0062] PDCCH: Physical Downlink Control Channel, physical downlink control channel
[0063] DCI: Downlink Control Information, downlink control information
[0064] PDSCH: Physical Downlink Shared Channel, physical downlink shared channel
[0065] UE: User Equipment
[0066] eNB: evolved NodeB
[0067] gNB: NR base station
[0068] TTI: Transmission Time Interval, transmission time interval
[0069] OFDM: Orthogonal Frequency Division Multiplexing
[0070] CP-OFDM: Cyclic Prefix Orthogonal Frequency Division Multiplexing, orthogonal frequency division multiplexing with cyclic prefix
[0071] C-RNTI: Cell Radio Network Temporary Identifier, cell radio network temporary identifier
[0072] CSI: Channel State Information
[0073] HARQ: Hybrid Automatic Repeat Request
[0074] CSI-RS: Channel State Information Reference Signal
[0075] CRS: Cell Reference Signal, cell-specific reference signal
[0076] PUCCH: Physical Uplink Control Channel, physical uplink control channel
[0077] PUSCH: Physical Uplink Shared Channel, physical uplink shared channel
[0078] UL-SCH: Uplink Shared Channel, uplink shared channel
[0079] CG: Configured Grant, configured scheduling permission
[0080] Sidelink: Sidelink communication
[0081] SCI: Sidelink Control Information, sidelink communication control information
[0082] PSCCH: Physical Sidelink Control Channel, physical sidelink communication control channel
[0083] MCS: Modulation and Coding Scheme, modulation and coding scheme
[0084] RB: Resource Block
[0085] RE:Resource Element
[0086] CRB: Common Resource Block
[0087] CP: Cyclic Prefix
[0088] PRB: Physical Resource Block, physical resource block
[0089] PSSCH: Physical Sidelink Shared Channel, physical sidelink communication shared channel
[0090] FDM: Frequency Division Multiplexing
[0091] RRC: Radio Resource Control
[0092] RSRP: Reference Signal Receiving Power, reference signal receiving power
[0093] SRS: Sounding Reference Signal, detection reference signal
[0094] DMRS: Demodulation Reference Signal
[0095] CRC: Cyclic Redundancy Check
[0096] PSDCH: Physical Sidelink Discovery Channel, physical sidelink communication discovery channel
[0097] PSBCH: Physical Sidelink Broadcast Channel, physical sidelink communication broadcast channel
[0098] SFI: Slot Format Indication, slot format indication
[0099] TDD: Time Division Duplexing
[0100] FDD: Frequency Division Duplexing
[0101] SIB: System Information Block
[0102] SIB1: System Information Block Type 1, system information block type 1
[0103] SLSS: Sidelink synchronization Signal, sidelink communication synchronization signal
[0104] PSSS: Primary Sidelink Synchronization Signal, sidelink communication primary synchronization signal
[0105] SSSS: Secondary Sidelink Synchronization Signal, sideline communication auxiliary synchronization signal
[0106] PCI: Physical Cell ID, physical cell identifier
[0107] PSS: Primary Synchronization Signal
[0108] SSS: Secondary Synchronization Signal
[0109] BWP: BandWidth Part, bandwidth fragment / part
[0110] GNSS: Global Navigation Satellite System
[0111] SFN: System Frame Number, system (wireless) frame number
[0112] DFN: Direct Frame Number, direct frame number
[0113] IE: Information Element
[0114] SSB: Synchronization Signal Block, synchronization system information block
[0115] EN-DC: EUTRA-NR Dual Connection, LTE-NR dual connectivity
[0116] MCG: Master Cell Group
[0117] SCG: Secondary Cell Group
[0118] PCell: Primary Cell
[0119] SCell: Secondary Cell
[0120] PSFCH: Physical Sidelink Feedback Channel, physical sidelink communication feedback channel
[0121] SPS: Semi-Persistant Scheduling
[0122] TA: Timing Advance, uplink timing advance
[0123] PT-RS: Phase-Tracking Reference Signals, phase tracking reference signal
[0124] TB: Transport Block
[0125] CB: Code Block, coding block / code block
[0126] QPSK: Quadrature Phase Shift Keying, quadrature phase shift keying
[0127] 16 / 64 / 256QAM: 16 / 64 / 256Quadrature Amplitude Modulation, quadrature amplitude modulation
[0128] AGC: Auto Gain Control, automatic gain control
[0129] TDRA(field): Time Domain Resource Assignment, time domain resource allocation indication (field)
[0130] FDRA(field): Frequency Domain Resource Assignment, frequency domain resource allocation indication (field)
[0131] ARFCN: Absolute Radio Frequency Channel Number, absolute radio frequency channel number
[0132] SC-FDMA: Single Carrier-Frequency Division Multiple Access
[0133] MAC: Medium Access Control
[0134] PDU: Protocol Data Unit
[0135] DRX: Discontinuous Reception
[0136] SL-U: Sidelink unlicensed, sidelink communication on unlicensed spectrum
[0137] NR-U: NR unlicensed, NR communication on unlicensed spectrum
[0138] LBT: Listen Before Talk
[0139] TBS: Transport Block Size, transport block size
[0140] CQI: Channel Quality Information
[0141] CPE: Cyclic Prefix extension
[0142] COT: Channel Occupancy Time, channel occupancy time
[0143] MCSt:Multiple Consecutive Slots transmission, multiple consecutive time slot transmission
[0144] The following is a description of the prior art associated with the present invention. Unless otherwise specified, the same terms in the specific embodiments and the prior art have the same meanings.
[0145] It is worth noting that V2X and sidelink in this specification are synonymous. V2X in this document can also refer to sidelink; similarly, sidelink in this document can also refer to V2X, and no specific distinction or limitation will be made in the following text.
[0146] The resource allocation mode of V2X (sidelink) communication in the specification of the present invention can be equivalently replaced with the transmission mode of V2X (sidelink) communication. The resource allocation mode mentioned in the specification can represent the transmission mode, and the transmission mode mentioned can represent the resource allocation mode. In NR sidelink communication, transmission mode 1 represents a transmission mode (resource allocation mode) based on base station scheduling; transmission mode 2 represents a transmission mode (resource allocation mode) based on user equipment sensing and resource selection.
[0147] The PSCCH in the specification of the present invention is used to carry SCI. The PSCCH corresponding to, or corresponding to, or related to, or scheduled PSSCH involved in the specification of the present invention have the same meaning, all indicating associated PSSCH (associated PSSCH) or corresponding PSSCH (corresponding PSSCH). Similarly, the SCI (including first-level SCI and second-level SCI) corresponding to, or corresponding to, or related to the PSSCH involved in the specification have the same meaning, all indicating associated SCI (associated SCI) or corresponding SCI (corresponding SCI). It is worth noting that the first-level SCI is called 1st stage SCI or SCI format 1-A, which is transmitted in PSCCH; the second-level SCI is called 2nd stage SCI or SCI format 2-A (or, SCI format 2-B), which is transmitted in the corresponding PSSCH resources.
[0148] The NR sideline communication (SL-U for short) on the unlicensed spectrum in the specification of the present invention can also be called shared spectrum channel access. That is, on the unlicensed spectrum, there may be user devices that access the channel through Wifi technology (wireless LAN technology based on the IEEE 802.11 standard), and there may also be NR sideline communication user devices accessed through the PC5 interface.
[0149] Parameter set (numerology) in NR (including NR sidelink) and time slot (slot) in NR (including NR sidelink)
[0150] The parameter set (numerology) includes two aspects: subcarrier spacing and cyclic prefix (CP) length. NR supports five subcarrier spacings: 15k, 30k, 60k, 120k, and 240kHz (corresponding to μ = 0, 1, 2, 3, and 4). Table 4.2-1 shows the supported transmission parameter sets, as shown below.
[0151] Table 4.2-1 Subcarrier spacing supported by NR
[0152] Extended CP is supported only when μ = 2, that is, with a 60kHz subcarrier spacing. For other subcarrier spacings, only normal CP is supported. For normal CP, each slot contains 14 OFDM symbols; for extended CP, each slot contains 12 OFDM symbols. For μ = 0, that is, with a 15kHz subcarrier spacing, 1 slot = 1ms; for μ = 1, that is, with a 30kHz subcarrier spacing, 1 slot = 0.5ms; for μ = 2, that is, with a 60kHz subcarrier spacing, 1 slot = 0.25ms, and so on.
[0153] NR and LTE have the same definition of subframe, which is 1ms. For the subcarrier spacing configuration μ, the time slot number within 1 subframe (1ms) can be expressed as Range is 0 to The timeslot number within a system frame (frame, duration 10ms) can be expressed as Range is 0 to in, and The definitions of different subcarrier spacing μ are shown in the following table.
[0154] Table 4.3.2-1: Number of symbols in each time slot, number of time slots in each system frame, and number of time slots in each subframe in normal CP
[0155] Table 4.3.2-2: Number of symbols per time slot, number of time slots per system frame, and number of time slots per subframe for extended CP (60kHz)
[0156] On NR carriers, the system frame (or simply frame) number (SFN) ranges from 0 to 1023. The concept of a direct system frame number (DFN) is introduced for sideline communications, also ranging from 0 to 1023. The above description of the relationship between system frames and parameter sets (numerology) also applies to direct system frames. For example, the duration of a direct system frame is also equal to 10ms. For a 15kHz subcarrier spacing, a direct system frame consists of 10 time slots, and so on. DFN is used for timing on the sideline carrier.
[0157] Resource blocks RB and resource elements RE
[0158] Resource blocks RB are defined in the frequency domain as For example, for a subcarrier spacing of 15kHz, the RB is 180kHz in the frequency domain. μ , the resource element RE represents 1 subcarrier in the frequency domain and 1 OFDM symbol in the time domain.
[0159] Sidelink communication scenarios
[0160] 1) Out-of-Coverage sidewalk communication: Both UEs performing sidewalk communication have no network coverage (for example, the UE cannot detect any cell that meets the "cell selection criteria" on the frequency required for sidewalk communication, indicating that the UE has no network coverage).
[0161] 2) Sideline communication with network coverage: Both UEs performing sideline communication have network coverage (for example, the UE detects at least one cell that meets the "cell selection criteria" on the frequency required for sideline communication, indicating that the UE has network coverage).
[0162] 3) Partial-Coverage Sideline Communication: One of the UEs performing sideline communication has no network coverage, while the other UE has network coverage.
[0163] From the UE side, there are only two scenarios: no network coverage and network coverage. Partial network coverage is described from the perspective of sideline communication.
[0164] Sideline communication resource pool (sideline resource pool)
[0165] In sidewalk communication, the UE's transmission and reception resources all belong to a resource pool. For example, for a transmission mode based on base station scheduling in sidewalk communication, the base station schedules transmission resources for the sidewalk UE in the resource pool, or for a transmission mode based on UE perception in sidewalk communication, the UE determines transmission resources in the resource pool.
[0166] For NR sidelink communications, frequency domain resource allocation is supported based on sub-channels as the minimum granularity. That is, for PSSCH transmission, the resources occupied in the frequency domain are an integer number of sub-channels. A sub-channel can represent several consecutive resource blocks (RBs) in the frequency domain.
[0167] Perception-based resource allocation
[0168] For the perception-based resource allocation method (resource allocation method 2), the sidelink communication user equipment selects candidate resources within a time window (optionally, a resource selection window [n+T1, n+T2]), and determines the candidate resources that overlap with the reserved resources based on the reserved resources indicated by the PSCCH sent by other user equipment in the monitoring time slot, and excludes these overlapping candidate resources. The physical layer reports the set of candidate resources that are not excluded to the MAC layer, and the MAC layer selects transmission resources for the PSSCH / PSCCH. The set of transmission resources selected by the MAC layer is called a selected sidelink grant. The sidelink resources contained in a selected sidelink grant can be used for the initial transmission and all retransmissions of a MAC PDU (corresponding to a transport block TB), or can be used for the initial transmission and all retransmissions of multiple MAC PDUs (corresponding to multiple transport blocks TB). The present invention does not impose any restrictions on this.
[0169] The partial sensing resource allocation method means that the time slots monitored by the user equipment are discontinuous (or discrete) in the monitoring window, so it is called partial sensing.
[0170] Resource selection window [n+T1, n+T2]
[0171] In the resource allocation method based on sensing (or partial sensing), the upper layer requests or triggers the physical layer to determine the resources for PSSCH / PSCCH transmission (perform sensing or partial sensing) in time slot n. The resource selection window is defined as [n+T1, n+T2], that is, the user equipment selects the transmission resources within this window. Among them, T1 meets the condition The selection of T1 depends on the implementation of the user equipment; the RRC configuration information contains a resource selection window configuration list sl-Selection WindowList, where the list corresponds to a given priority prio TX The element of (priority of transmitting PSSCH) is represented by T 2min If the T 2min Less than the remaining packet delay budget (remaining PDB), then T2 satisfies the condition T 2min ≤T2≤remaining PDB, the selection of T2 depends on the implementation of the user equipment; otherwise T2 is set to remaining PDB. The definition of is as follows (μ SL Indicates the subcarrier spacing parameter of side communication, that is, the subcarrier spacing is ):
[0172] Table 8.1.4-2: The value of
[0173] Table 8.1.4-1: The value of
[0174] LBT (Listen Before Talk) mechanism
[0175] For wireless communications in unlicensed spectrum, some countries or regions (for example, Europe) require user devices to perform LBT (Listen Before Talk) before transmitting. This mechanism, also known as channel access, involves sensing the channel to determine its availability. Specifically, during a period before transmission, the user device will only transmit if it detects the channel is idle; otherwise, it will not transmit.
[0176] Specifically, for NR communication over unlicensed spectrum (NR-U) (or, for SL-U), the basic time unit for sensing the channel can be T sl =9μs. In this time unit, if the energy detected by the base station or user equipment on the channel is lower than the energy threshold value X ThreshWhen the duration is equal to or greater than 4μs, the base station or user equipment considers that the channel is idle within the time unit (or, it is called LBT success). It is worth noting that the channel (channel) that the base station or user equipment detects energy and uses to determine whether it is idle represents a carrier containing a continuous resource block RB set, or a part of the carrier. The channel can also be called LBT bandwidth (LBT bandwidth), or LBT sub-band (LBT sub-band), or RB set (RB set). An LBT bandwidth or RB set can be equal to 20MHz in the frequency domain, that is, there can be an RB set on a 20MHz carrier. The number of resource blocks RBs corresponding to multiple RB sets contained in a carrier (carriers exceeding 20MHz, such as 40MHz, 60MHz, 80MHz) and the guard band (Guard Band, abbreviated as GB) between two continuous RB sets can be as shown in the following table:
[0177] Table 1: All RB sets on a carrier and the number of RBs contained in a GB at 15kHz and 30kHz subcarrier spacing
[0178] In the table above, using a 15kHz subcarrier spacing and a 40MHz carrier bandwidth as an example, 105-6-105 indicates that the carrier contains two consecutive RB sets, each containing 105 RBs. Between these two RB sets, there is a guard band (GB) consisting of six consecutive RBs, for a total of 216 consecutive RBs. This applies similarly to the other items in Table 1.
[0179] It is worth noting that the LBT operations performed by the (sideline communication) user equipment on different RB sets can be independent of each other (i.e., the two are unrelated). For example, the user equipment detects that the channel is idle on RB set 1, and the channel is occupied (or busy) on RB set 2. If the resources selected by the sideline communication user equipment for transmitting PSSCH / PSCCH include (all or part of) the RBs corresponding to RB set 1 and RB set 2, the user equipment can send the corresponding PSSCH / PSCCH if and only if the user equipment detects that the channel is idle on RB set 1 and RB set 2 at the same time.
[0180] MCSt (Multiple Consecutive Slots transmission)
[0181] For wireless communications on unlicensed spectrum, the user equipment is supported to transmit on multiple consecutive time slots, referred to as MCSt. Since the user equipment transmits on consecutive time slots, other user equipment (for example, WiFi user equipment) considers the current channel to be busy (not idle), which can effectively reduce the frequency (number, or demand) of the user equipment to access the channel (i.e. LBT), thereby increasing transmission efficiency. In the description of the present invention, N is used. slot,MCSt To represent the number of consecutive time slots in the time domain.
[0182] Candidate multi-slot resource
[0183] When the MAC layer provides an N greater than 1 to the physical layer slot,MCSt When , the physical layer uses the candidate multi-slot resource; otherwise, it uses the candidate single-slot resource. A candidate multi-slot resource includes N consecutive slot,MCSt time slots.
[0184] Hereinafter, specific examples and embodiments of the present invention will be described in detail. As described above, the examples and embodiments described in this disclosure are provided for illustrative purposes to facilitate understanding of the present invention and are not intended to limit the present invention.
[0185] [Example 1]
[0186] FIG1 is a schematic diagram illustrating a basic process of a method executed by a user equipment according to a first embodiment of the present invention.
[0187] The method executed by the user equipment according to the first embodiment of the present invention will be described in detail below with reference to the basic process diagram shown in FIG1 .
[0188] As shown in FIG1 , in the first embodiment of the present invention, the steps performed by the user equipment include:
[0189] In step S101, the sidelink user equipment selects to generate a selected sidelink grant, and, optionally, sidelink data is available on a logical channel.
[0190] Optionally, the selected sideline communication scheduling permission corresponds to the transmission of one or more MAC protocol data units (PDUs).
[0191] In step S102, the user equipment performs a transmission resource selection (reselection) process for the one selected sidelink communication scheduling grant.
[0192] Optionally, the user equipment selects a number N of consecutive time slots for transmitting MCSt in a plurality of consecutive time slots. slot,MCSt .
[0193] Optionally, the number of consecutive time slots N slot,MCSt Greater than 1.
[0194] Optionally, the user equipment selects the number of HARQ retransmissions.
[0195] Optionally, for shared spectrum channel access (or for the sideline communication on the unlicensed spectrum), and / or for the multiple consecutive time slot transmissions (MCSt), then,
[0196] The user equipment selects a time-frequency resource from a candidate resource set indicated by the physical layer,
[0197] and, optionally,
[0198] If the user equipment selects one or more HARQ retransmissions, and / or the selected HARQ retransmission number (+1) is greater than the number of consecutive time slots N slot,MCSt , then, the user equipment selects available resources from the candidate resources indicated by the physical layer for the HARQ retransmission. Optionally, the user equipment expects (or assumes) that the selected HARQ retransmission number (+1) is the number of consecutive time slots N slot,MCSt An integer multiple of, or, the selected HARQ retransmission number (+1) is greater than the number of consecutive time slots N slot,MCSt , or, the selected HARQ retransmission number (+1) is equal to the number of consecutive time slots N slot,MCSt , or, the selected HARQ retransmission number (+1) is greater than or equal to the number of consecutive time slots N slot,MCSt .
[0199] [Example 2]
[0200] FIG2 is a schematic diagram illustrating a basic process of a method executed by a user equipment according to a second embodiment of the present invention.
[0201] The method executed by the user equipment according to the second embodiment of the present invention will be described in detail below with reference to the basic process diagram shown in FIG2 .
[0202] As shown in FIG2 , in the second embodiment of the present invention, the steps performed by the user equipment include:
[0203] In step S201, on the unlicensed spectrum (or on the shared spectrum), for resource allocation mode 2, the higher layer (or upper layer) requests (or triggers) the sideline communication user equipment (physical layer) to determine a resource subset for PSSCH / PSCCH transmission.
[0204] Optionally, the higher layer provides at least the following parameters for PSSCH / PSCCH transmission in time slot n:
[0205] Indicates the number of consecutive time slots N for multiple consecutive time slot transmission MCSt slot,MCSt .
[0206] Optionally, the number of consecutive time slots N slot,MCSt Greater than 1. The user equipment applies (in the process of determining the resource subset for PSSCH / PSCCH transmission) a candidate multi-slot resource.
[0207] Optionally, the resource allocation mode 2 represents a resource allocation mode based on perception (full sensing) or a resource allocation mode based on partial sensing (partial sensing).
[0208] In step S202, the user equipment determines candidate time slots in the partial sensing resource allocation mode.
[0209] Optionally, for periodic transmission, the user equipment selects Y candidate time slots; for aperiodic transmission, the user equipment selects Y′ candidate time slots. Optionally, Y ≥ N slot,MCSt , Y′≥N slot,MCSt .
[0210] In step S203, the user equipment performs an exclusion process for candidate resources and reports the (excluded) candidate resource set to the MAC layer.
[0211] FIG3 is a block diagram illustrating a user equipment (UE) according to the present invention. As shown in FIG3 , the user equipment (UE) 30 includes a processor 301 and a memory 302. Processor 301 may include, for example, a microprocessor, a microcontroller, or an embedded processor. Memory 302 may include, for example, a volatile memory (e.g., a random access memory (RAM), a hard disk drive (HDD), a non-volatile memory (e.g., a flash memory), or other memory. Memory 302 stores program instructions. When executed by processor 301, these instructions may execute the method described in detail herein.
[0212] The method and related devices of the present invention have been described above in conjunction with preferred embodiments. Those skilled in the art will appreciate that the methods described above are merely exemplary and that the various embodiments described above can be combined with one another without conflict. The methods of the present invention are not limited to the steps and sequence shown above. The network nodes and user equipment shown above may include additional modules, such as modules that are currently being developed or will be developed in the future and may be used in base stations, MMEs, or UEs. The various identifiers shown above are merely exemplary and non-restrictive, and the present invention is not limited to the specific information elements used as examples of these identifiers. Based on the teachings of the illustrated embodiments, those skilled in the art may make numerous variations and modifications.
[0213] It should be understood that the above embodiments of the present invention can be implemented through software, hardware, or a combination of software and hardware. For example, the various components within the base station and user equipment in the above embodiments can be implemented through a variety of devices, including but not limited to analog circuit devices, digital circuit devices, digital signal processing (DSP) circuits, programmable processors, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), programmable logic devices (CPLDs), and the like.
[0214] In this application, "base station" refers to a mobile communication data and control switching center with high transmission power and wide coverage area, including functions such as resource allocation and scheduling, and data reception and transmission. "User equipment" refers to a user's mobile terminal, such as a mobile phone or laptop, that can communicate wirelessly with a base station or micro base station.
[0215] In addition, the embodiments of the present invention disclosed herein can be implemented on a computer program product. More specifically, the computer program product is a product as follows: having a computer-readable medium, on which computer program logic is encoded, and when executed on a computing device, the computer program logic provides relevant operations to implement the above-mentioned technical solutions of the present invention. When executed on at least one processor of a computing system, the computer program logic causes the processor to perform the operations (methods) described in the embodiments of the present invention. This arrangement of the present invention is typically provided as software, code and / or other data structures arranged or encoded on a computer-readable medium such as an optical medium (e.g., CD-ROM), a floppy disk or a hard disk, or other media such as firmware or microcode on one or more ROM or RAM or PROM chips, or downloadable software images, shared databases, etc. in one or more modules. Software or firmware or this configuration can be installed on a computing device so that one or more processors in the computing device execute the technical solutions described in the embodiments of the present invention.
[0216] In addition, each functional module or each feature of the base station equipment and terminal equipment used in each of the above embodiments can be implemented or executed by a circuit, and the circuit is generally one or more integrated circuits. The circuit designed to perform the various functions described in this specification may include a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC) or a general-purpose integrated circuit, a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic, or a discrete hardware component, or any combination of the above devices. The general-purpose processor may be a microprocessor, or the processor may be an existing processor, a controller, a microcontroller or a state machine. The general-purpose processor or each circuit may be configured by a digital circuit, or may be configured by a logic circuit. In addition, when, due to advances in semiconductor technology, an advanced technology that can replace current integrated circuits emerges, the present invention may also use the integrated circuit obtained using the advanced technology.
[0217] Although the present invention has been described above in conjunction with the preferred embodiments of the present invention, it will be understood by those skilled in the art that various modifications, substitutions, and changes may be made to the present invention without departing from the spirit and scope of the present invention. Therefore, the present invention should not be limited by the above-described embodiments, but should be limited by the appended claims and their equivalents.
Claims
1. A method performed by a user equipment, comprising the following steps: Selecting to generate a selected sidewalk communication scheduling permission; as well as A transmission resource selection or reselection process is performed for the one selected sideline communication scheduling grant.
2. The method according to claim 1, wherein: The selected sideline communication scheduling permission corresponds to the transmission of one or more MAC protocol data units PDU.
3. The method according to claim 1, wherein: The steps for performing the transmit resource selection or reselection process include: The number of consecutive time slots for multiple consecutive time slot transmissions is selected.
4. The method according to claim 3, wherein: The steps for performing the transmit resource selection or reselection process include: Select the number of HARQ retransmissions.
5. The method according to claim 4, wherein: The steps for performing the transmit resource selection or reselection process include: If one or more HARQ retransmissions are selected, and / or the number of selected HARQ retransmissions is greater than the number of consecutive time slots, an available resource is selected from the candidate resources indicated by the physical layer for the HARQ retransmission.
6. A method performed by a user equipment, comprising the following steps: In the unlicensed spectrum, for resource allocation mode 2, determine the resource subset used for PSSCH / PSCCH transmission; determining candidate time slots in a partially-aware resource allocation scheme; as well as Perform a candidate resource elimination process.
7. The method according to claim 6, wherein: The steps of determining a resource subset for PSSCH / PSCCH transmission include: In case the number of consecutive time slots of the multiple consecutive time slot transmission is greater than 1, the candidate multi-slot resource is applied.
8. The method according to claim 6, wherein: The steps of determining candidate time slots include: For periodic transmission, a first number of candidate time slots is selected, and for aperiodic transmission, a second number of candidate time slots is selected.
9. The method according to claim 8, wherein: Both the first number and the second number are not less than the number of consecutive time slots.
10. A user equipment, comprising: processor; as well as Memory, which stores instructions, Wherein, when the instructions are executed by the processor, the method according to any one of claims 1-9 is performed.
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