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WO2022110103A1 - 一种节能nr侧链路传输和接收的方法 - Google Patents

一种节能nr侧链路传输和接收的方法 Download PDF

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Publication number
WO2022110103A1
WO2022110103A1 PCT/CN2020/132623 CN2020132623W WO2022110103A1 WO 2022110103 A1 WO2022110103 A1 WO 2022110103A1 CN 2020132623 W CN2020132623 W CN 2020132623W WO 2022110103 A1 WO2022110103 A1 WO 2022110103A1
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Prior art keywords
drx
sensing
resources
duration
resource
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PCT/CN2020/132623
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English (en)
French (fr)
Inventor
张波
Original Assignee
张波
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Publication date
Application filed by 张波 filed Critical 张波
Priority to PCT/CN2020/132623 priority Critical patent/WO2022110103A1/zh
Priority to US18/254,380 priority patent/US20240214940A1/en
Priority to CN202080107316.4A priority patent/CN116686241A/zh
Publication of WO2022110103A1 publication Critical patent/WO2022110103A1/zh

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/02—Power saving arrangements
    • H04W52/0209—Power saving arrangements in terminal devices
    • H04W52/0261—Power saving arrangements in terminal devices managing power supply demand, e.g. depending on battery level
    • H04W52/0274—Power saving arrangements in terminal devices managing power supply demand, e.g. depending on battery level by switching on or off the equipment or parts thereof
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
    • H04L1/0036—Systems modifying transmission characteristics according to link quality, e.g. power backoff arrangements specific to the receiver
    • H04L1/0038—Blind format detection
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
    • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
    • H04L1/18—Automatic repetition systems, e.g. Van Duuren systems
    • H04L1/1867—Arrangements specially adapted for the transmitter end
    • H04L1/188—Time-out mechanisms
    • H04L1/1883—Time-out mechanisms using multiple timers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
    • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
    • H04L1/18—Automatic repetition systems, e.g. Van Duuren systems
    • H04L1/1867—Arrangements specially adapted for the transmitter end
    • H04L1/1887—Scheduling and prioritising arrangements
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/02—Power saving arrangements
    • H04W52/0209—Power saving arrangements in terminal devices
    • H04W52/0212—Power saving arrangements in terminal devices managed by the network, e.g. network or access point is master and terminal is slave
    • H04W52/0216—Power saving arrangements in terminal devices managed by the network, e.g. network or access point is master and terminal is slave using a pre-established activity schedule, e.g. traffic indication frame
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/02—Power saving arrangements
    • H04W52/0209—Power saving arrangements in terminal devices
    • H04W52/0225—Power saving arrangements in terminal devices using monitoring of external events, e.g. the presence of a signal
    • H04W52/0229—Power saving arrangements in terminal devices using monitoring of external events, e.g. the presence of a signal where the received signal is a wanted signal
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W72/00—Local resource management
    • H04W72/20—Control channels or signalling for resource management
    • H04W72/25—Control channels or signalling for resource management between terminals via a wireless link, e.g. sidelink
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/20—Manipulation of established connections
    • H04W76/28—Discontinuous transmission [DTX]; Discontinuous reception [DRX]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D30/00—Reducing energy consumption in communication networks
    • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

Definitions

  • the present invention relates to the technical field of wireless communication, and in particular, to a method for energy-saving NR side link transmission and reception.
  • 5G 5th generation mobile communication system
  • 5G NR New Radio
  • UE user equipment
  • a discontinuous reception mechanism DRX (Discontinuous Reception) is introduced, that is, when the terminal is in the connected state, it does not need to continuously monitor the control channel of the base station, but intermittently monitors the control channel.
  • a DRX cycle includes a wake-up cycle and a sleep cycle, and the cycle is performed by periodically repeating the on-duration (abbreviated as On-Duration) and the off-duration (abbreviated as Off-Duration).
  • On-Duration the on-duration
  • Off-Duration off-duration
  • the UE turns on the receiver's RF to receive information
  • the off-duration the UE turns off the receiver's RF to sleep.
  • the DRX on duration should be kept short enough and the DRX off duration long enough to minimize UE power consumption.
  • DRX parameters are configured by RRC (Radio Resource Control), mainly composed of drx-onDurationTimer, drx-SlotOffset, drx-LongCycleStartOffset, drx-InactivityTimer, drx-ShortCycle, drx-ShortCycleTimer.
  • RRC Radio Resource Control
  • the MAC entity is allowed to use the DRX operation to detect the physical downlink control channel PDCCH (Physical Downlink Control Channel) discontinuously, and it is controlled by the DRX MAC-CE command or the long DRX MAC-CE command; otherwise, the MAC entity will continuously detect the PDCCH.
  • PDCCH Physical Downlink Control Channel
  • the UE detects a paging occasion in each DRX cycle.
  • a paging occasion is a set of PDCCH detection occasions, which consists of multiple time slots (eg, subframes or OFDM symbols) in which paging downlink control information DCI (Downlink Control Information) is transmitted.
  • the NR-DRX in the existing Uu link is only used for unicast transmission, while the future NR side link DRX (Sidelink DRX) is used for broadcast (Broadcast), multicast ( Groupcast) and unicast transmission (Unicast).
  • a Power Saving UE eg, P-UE or Pedestrian-UE
  • a similar procedure in the NR-DRX cycle in the Uu link can be used, all RRC parameters and corresponding sidelink DRX Operation can be controlled by the network.
  • all RRC parameters of the sidelink DRX cycle may depend on the pre-configured manner.
  • the side link DRX process needs to be greatly improved in terms of dynamically controlling the DRX cycle.
  • the on/off duration of the DRX cycle in Uu and its corresponding UE process can be used as the basis for sidelink DRX, and for both in-coverage and out-of-coverage situations, the sidelink DRX mechanism must consider different transmission types (Broadcast, Multicast and Unicast).
  • Hybrid automatic repeat request is a combination of forward error correction (FEC) and automatic repeat request (ARQ) error control. Under harsh signal conditions, HARQ performs better than normal ARQ, but it improves reception performance at the expense of reduced throughput.
  • FEC forward error correction
  • ARQ automatic repeat request
  • the Rx-UE uses the drx-HARQ- Two timers of RTT-Timer and drx-RetransmissionTimer to control the corresponding HARQ process. Since the Rx-UE does not know the timing of data packet retransmission, the Rx-UE must continuously detect the PDCCH in order to receive and decode the PDSCH associated with the same HARQ process ID (HARQ process ID).
  • HARQ process ID HARQ process ID
  • the UE For the HARQ process on the downlink (Down Link, DL for short), if the UE has received new data on the PDSCH, the UE starts the HARQ RTT timer after the DL HARQ feedback ends. If the corresponding data packet is not successfully decoded after the drx-HARQ-RTT-TimerDL timer expires, the UE will start the drx-RetransmissionTimerDL timer. When the drx-RetransmissionTimerDL timer is running, the UE needs to detect the PDCCH of the HARQ process, because during this time, the UE will possibly retransmit the data packets.
  • the Sensing Window is defined by the time slot range [nT 0 , nT proc, 0 ), where T 0 and represented by time slots.
  • the transmitting UE senses the side link channel in the sensing window and calculates the channel resource reservation.
  • the sensing window size is determined by the traffic type (periodic and aperiodic); the periodic traffic window is 1100ms and the aperiodic traffic window is 100ms.
  • the Tx-UE determines the resources that should be excluded in the Selection Window according to the sensed sidelink channel. There are two types of resources that must be excluded; one is a reserved periodic resource, and the other is a resource reserved by the Sidelink Control Information SCI (Sidelink Control Information) within a 32-slot window.
  • SCI Sidelink Control Information
  • the exclusion process is performed by the Tx-UE based on the comparison of reference signal received power RSRP (Reference Signals Received Power). Finally the Tx-UE selects from all remaining candidate resources for its transmission and reserves resources accordingly. In addition, the Tx-UE can also perform re-evaluation and preemption mechanisms to avoid resource conflicts. In Rel-16NR-V2X, the reserved interval capability of SCI is 32 time slots. If it exceeds this range, the Tx-UE can only reserve periodic resources by using the optional SCI parameter ResourceReservePeriod.
  • the purpose of the present invention is to provide an energy-saving NR side link transmission and reception method to solve the problems of DRX-based UE reception and partial sensing-based transmission.
  • UE User Equipment
  • user equipment User Equipment
  • Tx-UE Transmitter UE
  • Rx-UE (Receiver UE), receiving UE;
  • PSCCH Physical Sidelink Control Channel
  • Physical side link control channel Physical side link control channel
  • PSSCH Physical Sidelink Shared Channel
  • Physical side link shared channel Physical side link shared channel
  • PSFCH Physical Sidelink Feedback Channel
  • Physical layer side chain feedback channel Physical layer side chain feedback channel
  • PDCCH Physical Downlink Control Channel
  • Physical downlink control channel Physical downlink control channel
  • PDSCH Physical Downlink Shared Channel
  • PUSCH Physical Uplink Shared Channel
  • Physical Uplink shared channel Physical Uplink shared channel
  • DCI Downlink Control Information
  • Downlink control information Downlink control information
  • SCI Servicelink Control Information
  • side link control information side link control information
  • Power Saving UE for example, P-UE or Pedestrian-UE, energy saving UE;
  • PRR Packet Reception Ratio
  • HARQ Hybrid Automatic Repeat reQuest
  • RSRP Reference Signal Receiving Power
  • the reference signal received power is one of the key parameters that can represent the wireless signal strength and one of the physical layer measurement requirements in the LTE network. the average value of the received signal power;
  • PDB Packet Delay Budget
  • MAC-CE MAC Control Element
  • the present invention adopts the following technical solutions:
  • a method for energy-saving NR side link transmission and reception comprising:
  • the sending UE transmits the initial TB within the On-Duration (On-Duration), and uses the SCI preset format to reserve a period for retransmitting the initial TB or transmitting other TBs associated with the initial TB If the number of the periodic resources or aperiodic resources is less than or equal to N, where N is a natural number, configure at least one first DRX timer, and send the UE based on the first DRX timer. Perform channel sensing at the time slots of the sensing window and all On-Duration time slots, and
  • the reserved periodic resources or aperiodic resources are indicated by the side chain control information SCI communication, and are located in On-Duration and/or Off-Duration.
  • the sending UE may belong to an energy-saving UE (for example, Vulnerable Road Users in the V2X use case, referred to as VRU for short, or a user in the public safety and commercial use cases), or may belong to a common UE (for example, a vehicle UE); It belongs to the energy-saving UE.
  • an energy-saving UE for example, Vulnerable Road Users in the V2X use case, referred to as VRU for short, or a user in the public safety and commercial use cases
  • a common UE for example, a vehicle UE
  • the transmission type for sending the UE includes unicast, multicast or broadcast.
  • the DRX timers are of two types; the type one is when the DRX timers are running (including drx-ReservePeriodTimer, drx-ReserveInstantTimer, drx-HARQ-RTT-Timer, drx-OffDurationTimer, drx-CommonOffDurationTimer, and drx-SpecificOffDurationTimer), the receiving UE stops receiving and closes its RF chain; the second type is when the DRX timers are running (including drx-OnDurationTimer, drx-CommonOnDurationTimer, drx-SpecificOnDurationTimer, and drx-RetransmissionTimer), the receiving The UE starts receiving and turns on its RF chain.
  • the type one is when the DRX timers are running (including drx-ReservePeriodTimer, drx-ReserveInstantTimer, drx
  • the operation of the side link DRX supports extended On-Duration, and the initial TB or retransmission TB of the side link can also be sent and received during Off-Duration.
  • the receiving UE in response to the received DRX configuration parameters, enters an active state and monitors the physical side link control channel PSCCH and/or the physical side link shared channel PSSCH.
  • the receiving UE detects the initial TB within On-Duration, and the PSCCH corresponding to the initial TB indicates the time slot of the reserved resources for the retransmission TB; the receiving UE determines the DRX timer according to the resource time slot reserved by the PSCCH state, wherein the receiving UE stops detecting the PSCCH within the running time of the DRX timer.
  • the sending UE does not necessarily need to send the TB within On-Duration, as long as the SCI reserves resources for it in the previous TB.
  • the PSCCH corresponding to the retransmission TB indicates the time slot of the reserved resource for the next retransmission TB until the delay budget is reached or the receiving UE successfully decodes.
  • the first DRX timer is a timer for sensing, including drx-PeriodSensingTimer and drx-SensingTimer;
  • the second DRX timer is a timer for data packet reception, including drx-PeriodSensingTimer One or more of OnDurationTimer, drx-CommonOnDurationTimer, drx-SpecificOnDurationTimer, drx-OffDurationTimer, drx-CommonOffDurationTimer, drx-SpecificOffDurationTimer, drx-ReservePeriodTimer, drx-ReserveInstantTimer, drx-HARQ-RTT-Timer, and drx-RetransmissionTimer.
  • DRX includes two types of active time (Active Time): data packet reception active time and sensing active time; wherein, at the data packet receiving active time, the receiving UE decodes PSCCH and PSSCH, and at the sensing active time, The sending UE only decodes the PSCCH.
  • Active Time active time
  • the data packet reception activation time includes: the time slot of the reserved resource in the last transmission; or, includes that any of the following timers are running:
  • the sensing activation time includes: sending a time slot for the UE to receive within the sensing activation time; or, including any of the following timers running:
  • the receiving UE prioritizes the On-Duration timer.
  • the receiving UE preferentially detects the reserved resource time slots.
  • the UE transmits the first initial TB within On-Duration when the service starts, and the transmission interval between two adjacent TBs is less than 32 time slots, then the transmitted resources are successively lower by the SCI associated with each TB.
  • One TB is reserved; the receiving UE sets the timer drx-ReserveInstantTimer as the activation time, and only monitors the time slot of On-Duration and the relevant time slots of all reserved resources.
  • the sending UE transmits the first initial TB of the service within On-Duration, and the sending interval between two adjacent TBs is greater than 32 time slots, then the sending UE uses the SCI preset format and does not reserve any for transmission resources; the receiving UE only enters the awake state in the On-Duration time slot to receive the initial TB.
  • the receiving UE accesses the gNB network, before the gNB indicates or grants PDSCH or PUSCH resources to the receiving UE through the PDCCH, the receiving UE keeps or keeps detecting the PDCCH within the On-Duration of the DRX mode.
  • the number of time slots configured in the On-Duration is reduced to one.
  • the discontinuous reception mode includes a common DRX pattern (Common DRX Pattern), which can also be called a default DRX pattern (Default DRX Pattern), and the sending UE selects the common DRX pattern to send the initial TB; wherein, the common DRX pattern is configured In order to have a long DRX cycle and a short On-Duration, in each long DRX cycle, the energy-saving UE starts the timer drx-CommonOnDurationTimer after drx-CommonSlotOffset; when the energy-saving UE meets the conditions
  • DFN direct frame number
  • GNSS direct frame number
  • drx-CommonCycle is the cycle of general DRX
  • Slot-Number ( n) is the current slot index
  • n is a natural number
  • drx-CommonStartOffset is the DRX common offset slot.
  • the generic DRX pattern is configured such that all timeslots can be detected by energy-saving UEs, and applicable to all transmission types (unicast, multicast or broadcast).
  • DFN can be replaced by SFN (system frame number).
  • SFN system frame number
  • the transmission of the UE within the On-Duration is sent using blind retransmission (Blind Retransmission), that is, one initial TB and at least one retransmission TB, and/or the transmission of the UE within the Off-Duration is sent.
  • Blind retransmission that is, one initial TB and at least one retransmission TB
  • Retransmission based on HARQ mechanism is used.
  • performing blind retransmission in On-Duration can ensure that the receiving UE successfully receives the SCI, so as to maintain a resource reservation chain between two adjacent reserved resources.
  • the sending UE ignores the FCI information fed back by the Rx-UE, which has achieved the purpose of blind retransmission.
  • PSCCH/PSSCH resources with dedicated PSFCH resources need to be configured in each resource pool for retransmission based on the HARQ mechanism.
  • Rel-17 The sending UE can still transmit the initial TB and retransmission TB in the On-Duration, but the sending UE needs to change the behavior for the HARQ mechanism, that is, only ignore the FCI information fed back by the receiving UE in the On-Duration, that is, regardless of the receiving UE.
  • the sending UE To ACK or NAK, the sending UE must complete all retransmissions in On-Duration, but in Off-Duration, the sending UE still needs to follow the HARQ mechanism of Rel-16 and perform retransmission based on the HARQ mechanism.
  • PSCCH/PSSCH resources without dedicated PSFCH resources are configured in On-Duration for blind retransmission
  • PSCCH/PSSCH resources with dedicated PSFCH resources are configured in Off-Duration for retransmission based on HARQ mechanism.
  • the MAC layer notifies the PHY layer of the range of resource time slots included in the On-Duration when reporting candidate resources, or the PHY layer knows the specific configuration of the DRX in advance to ensure that there are enough resources in the On-Duration. candidate resource.
  • the MAC layer selects favorable resources for the initial TB to complete the transmission and blind retransmission of the initial TB by optimizing the resource selection method, and the optimized resource selection method includes at least one of the following: improving the initial TB priority; or increase the coding rate (Coding Rate) of the PSCCH corresponding to the transmission initial TB.
  • RRC in order to improve the PSCCH coding rate of transmitting the initial TB in On-Duration, RRC includes two kinds of PSCCH configurations, that is, one is the PSCCH configuration related to On-Duration, which has a higher coding rate, and the other is the PSCCH configuration related to On-Duration.
  • the discontinuous reception mode further includes a specific DRX pattern (specific DRX pattern) for a specific service, the specific DRX pattern is configured to have a short DRX cycle, and in each specific DRX configuration, the same as the QoS of the short PDB.
  • the associated DRX parameters are (pre)configured; wherein, On-Duration contains only a few time slots (at least one time slot), and the DRX period is smaller than the short PDB.
  • the UE can use the specific DRX mode on the basis of the general DRX mode, and switch between the general DRX mode and the specific DRX mode based on the requirements of a specific service.
  • switching between the general DRX mode and the specific DRX mode includes: receiving control signaling of MAC-CE or SCI to switch between the general DRX mode and the specific DRX mode; and when the specific service expires and does not The relevant data packets are then transmitted, the specific DRX mode is stopped, and the UE returns to the general DRX mode at the same time.
  • the sending UE reserves aperiodic resources, and the receiving UE correctly detects the SCI from the received PSCCH, but does not have any reserved resources, or fails to detect the required SCI related to the retransmission TB
  • the receiving UE The UE starts the timer drx-RetransmissionTimer, the receiving UE wakes up in each time slot and detects and decodes the PSCCH until the timer drx-RetransmissionTimer expires, or the receiving UE receives the retransmitted SCI; then the receiving UE enters the normal energy-saving receiving mode , wherein, the energy-saving receiving mode means that the receiving UE enters the wake-up mode only in the On-Duration and reserved resource time slots, receives the PSCCH, and decodes and receives the TB associated with the UE.
  • the receiving UE starts the timer drx-HARQ-RTT-Timer after receiving the initial TB and unsuccessfully decoded to the TB, and after feeding back NAK, the receiving UE Indirect start timer drx-RetransmissionTimer.
  • the sending UE is prohibited from re-selecting resources before the time slot of the reserved resource, and the sending UE's reselection resource is preferably close to the time slot of the reserved resource. Resources.
  • the HARQ process uses HARQ Option-2, and the receiving UE cannot detect the PSCCH related to the initial TB, then the sending UE is sent on the same On. -Retransmit the TB in the duration, or retransmit the TB in the next upcoming On-Duration within the delay budget.
  • the sending UE reserves periodic resources, and the resource reservation chain is lost due to continuous resource conflict and the sending UE triggering resource reselection, the sending UE is configured to reselect resources only during the On-Duration period , the receiving UE only enters the awake state in the relevant time slot of On-Duration and reserved periodic resources to receive the initial TB or the retransmission TB.
  • the receiving UE once the receiving UE performs TB reception within On-Duration, it will detect whether the resource is re-selected, which requires the MAC entity of the sending UE to use the DRX cycle as the counting unit to determine whether the resource needs to be re-selected, instead of Adopted in Rel-16 to count the number of TB transfers.
  • the resource re-evaluation and/or preemption mechanism is enabled in the resource pool, the resource re-evaluation and/or preemption mechanism is disabled by using sl-PreemptionEnable in the (pre)configured resource pool.
  • the energy-saving receiving mode means that the receiving UE enters the wake-up mode only in the On-Duration and reserved resource time slots, receives the PSCCH, and decodes and receives the TB associated with the UE.
  • the sending UE adopts any of the following methods to prevent the periodic resource reserved by the sending UE from being preempted by another sending UE, including:
  • the receiving UE is notified in advance through SCI or MAC-CE that the periodic resource will be reselected in the next transmission.
  • the resource reselection may be performed in On-Duration, or may not be performed in On-Duration.
  • the method further comprises: for the periodic resources reserved by the first sending UE, the second sending UE performs channel sensing using a partial sensing mechanism, and provides the sensing result to the MAC layer for resource (re)
  • the partial sensing mechanism includes:
  • the second sending UE enters the awake state to sense the SCI on the PSCCH in each time slot of the periodic resource reserved by the first sending UE; when the SCI detection fails, the second sending UE starts the timer drx-PeriodSensingTimer, and wakes up to detect PSCCH in each slot until the timer drx-PeriodSensingTimer expires, or the second sending UE successfully detects the PSCCH in the new slot;
  • the first sending UE and the second sending UE are different sending UEs.
  • the timer drx-PeriodSensingTimer in the partial sensing mechanism is equal to the ResourceReservePeriod required by QoS in a specific service.
  • the first sending UE is prohibited from selecting the resources before the reserved periodic resources as the reselection resources.
  • the method further includes: in each resource pool, at least two first sending UEs with different periodicity and/or different sending time offsets reserve periodic resources, and the second sending UE only has different periodicity and/or different sending time offsets. is awakened in the sensing cluster (Sensing Cluster) of the Sensing Cluster to perform channel sensing related thereto, and the sensing cluster is configured as at least two different overlapping time slots (Superposition Slots) of the periodic resources reserved by the first transmitting UE or Neighbor Slot, wherein the first sending UE and the second sending UE are different sending UEs.
  • the different sensing clusters include a sensing cluster close to On-Duration and a sensing cluster far from On-Duration in Off-Duration, and the second transmitting UE is woken up only in the sensing cluster far from On-Duration Perform channel sensing associated therewith.
  • the threshold is configured using the value of Th(prio RX ,prio TX ), and the second transmitting UE compares the RSRP it receives with the threshold, excludes reserved resources that do not belong to the threshold range, and selects the reserved resources from the remaining reserved resources. Subsequent selection of transmission resources is performed in the resource; wherein, prio RX is the priority for receiving data packets, and prio TX is the priority for transmitting data packets.
  • the size of the partial sensing window can be adaptively adjusted according to the traffic situation in the current resource pool during transmission.
  • the size of the partial sensing window in a specific sensing period may be different, which is also determined by the sensing UE itself.
  • one or more of the following information is obtained by sensing the part of the sensing window:
  • the time offset of the periodic resource between the sending UE and the sensing UE is the time offset of the periodic resource between the sending UE and the sensing UE.
  • whether to perform sensing in the partial sensing window depends on the implementation of the UE, for example, if the number of received NAKs is greater than a set threshold, the sensing UE can be detected in a certain sensing period.
  • the second transmitting UE may adjust the size of the partial sensing window TW according to a preset threshold.
  • the threshold for the number of reserved resources can be (pre-)configured as TH m , and N m and TH m are corresponding; the sensing UE can compare the number of reserved resources for a long period with TH m to determine T W.
  • the sensing cluster can be used as a partial sensing window, and this partial sensing window setting does not require There is no limit to the sensing period.
  • one of the specific sensing periods may be configured and used for multiple resource pools, and the partial sensing window of TW may be determined by the minimum period length and the maximum period length configured in the multiple resource pools.
  • the method further includes: for the reserved aperiodic resources, sending the UE to perform channel sensing in one or a combination of the following manners:
  • the second part of the sensing mechanism includes: after the arrival of the TB, sending the UE to start the timer drx-SensingTimer, and performing channel sensing in the first 31 time slots before the On-Duration in the DRX mode for subsequent resource selection, after which the sending UE continues sensing until the initial TB or retransmission TB is successfully received, or the timer drx-SensingTimer expires;
  • the full sensing mechanism includes: if the PDB is less than 32 time slots, the sending UE does not close the side link RF for sensing, and the first On- Sensing starts 32 slots before the Duration and stops in the slot where the last TB was successfully transmitted;
  • a random resource selection mechanism includes: for a sending UE with high energy saving requirements, the sending UE reports all candidate resources within the selection window to the MAC without including a resource exclusion process.
  • one or a combination of a comprehensive sensing mechanism, a partial sensing mechanism, and a random resource selection mechanism can be used to (pre) configure the side link sending resource pool with packet transmission.
  • the periodic partial sensing mechanism and the aperiodic partial sensing mechanism can be used at the same time, because the transmitting UE may have periodic traffic and/or aperiodic traffic, and the sensing UE must capture and Infer reserved resource information for both traffic types.
  • the resource pool is configured by SL-ResourcePool
  • the periodic list of data packets is configured by sl-ResourceReservePeriodList.
  • a resource pool can transmit periodic and aperiodic traffic at the same time, and it must be Consider both periodic and aperiodic partial sensing mechanisms; otherwise, the UE can only transmit aperiodic data packets, and at this time, the sensing process relies on the aperiodic partial sensing mechanism.
  • the present application provides a method for energy-saving NR side link transmission and reception, which solves the problem of how to control the transmission and reception of the side link in the DRX ON duration and OFF duration, and the problem of transmission based on partial sensing,
  • the deficiencies in DRX energy saving in the prior art are solved.
  • FIG. 1 is an example diagram of TB transmission and reception for scenario 1, scenario 2 and scenario 3 in Embodiment 1;
  • Embodiment 3 is an example diagram of resource selection and reservation using a general DRX mode in Embodiment 1;
  • FIG. 4 is an example diagram of a resource reservation chain failure due to no resource reservation, resource preemption, or SCI decoding failure in Embodiment 2;
  • FIG. 5 is an example diagram of triggering resource re-selection due to resource re-evaluation or resource preemption mechanism in Embodiment 2;
  • FIG. 9 is an example diagram of Tx-UE-A sending periodic TBs and Tx-UE-B performing channel sensing in Embodiment 5;
  • FIG. 10 is an example diagram of using a sensing cluster to perform partial sensing on a channel of periodic traffic in Embodiment 5;
  • FIG. 11 is an example diagram of partial sensing of a channel of aperiodic traffic by using a short sensing window in Embodiment 6;
  • FIG. 12 is an example diagram of partial sensing for a channel of aperiodic traffic in Embodiment 6.
  • FIG. 12 is an example diagram of partial sensing for a channel of aperiodic traffic in Embodiment 6.
  • Tx-UE can belong to energy-saving UE (for example, Vulnerable Road Users in V2X use case, abbreviated as VRU, or user in public safety and commercial use case), or it can belong to ordinary UE (for example, vehicle UE).
  • the Rx-UE can only belong to the energy-saving UE. It is worth noting that only saving UE power requires saving UE power consumption.
  • DRX has two types of active time (Active Time); one is called packet reception active time, and the other is called sensing active time.
  • Active Time the UE should decode PSCCH and PSSCH, and during the sensing active time, the UE only needs to decode the PSCCH.
  • timers for packet reception including drx-onDurationTimer, drx-CommonOnDurationTimer, drx-SpecificOnDurationTimer, drx-CommonOffDurationTimer, drx-SpecificOffDurationTimer, drx-ReservePeriodTimer, drx-ReserveInstantTimer, drx- HARQ-RTT-Timer and drx-RetransmissionTimer.
  • the receive activation time of the data packet includes:
  • drx-CommonOnDurationTimer • One of the following timers is running: drx-CommonOnDurationTimer, drx-SpecificOnDurationTimer, drx-onDurationTimer, drx-RetransmissionTimer.
  • the sensing activation time for partial sensing includes
  • drx-PeriodSensingTimer drx-SensingTimer
  • drx-onDurationTimer drx-CommonOnDurationTimer
  • drx-SpecificOnDurationTimer drx-SpecificOnDurationTimer.
  • This embodiment solves the problem of how the Tx-UE initially transmits/retransmission (Re-Tx for short) TB (Transport Block), and how the Rx-UE receives the initial TB and the retransmission TB.
  • the Tx-UE transmits SCI (Sidelink Control Information) in slot n in format 1-A (1st Stage) using the Physical Sidelink Control Channel (PSCCH), and then uses the associated The connected physical side link shared channel PSSCH (Physical Sidelink Shared Channel) sends data packets in the same time slot.
  • PSCCH Physical Sidelink Control Channel
  • the PSCCH can indicate resources for the initial transmission of the TB based on the sensing and resource selection process, and reserve resources for its retransmission; wherein the maximum number of reserved resources is two.
  • Tx-UE can be in 0ms according to the service type, Select periodicity between 100ms, 200ms, ..., 1000ms.
  • PSCCH selectively uses "resource reservation period" to reserve periodic resources for periodic data packets at the same time as the initial transmission of the TB.
  • the PSCCH may also use the SCI to reserve resources for initial transmission of TBs associated with different TBs.
  • the Tx-UE In sidechain DRX, once the Tx-UE starts its specific service, regardless of the type of transmission (i.e. unicast, multicast or broadcast), the Tx-UE shall ensure that the first TB (or initial TB). This is because the DRX mode must ensure that the transmission/reception between Tx-UE and Rx-UE is aligned with each other. And only within On-Duration, the Rx-UE interested in the service can ensure that the sent TB is received.
  • the Tx-UE since the Tx-UE needs to ensure that the data packet is received by the Rx-UE accurately within the On-Duration, it must be enhanced in the transmission. For example, the transmission within On-Duration uses blind retransmission (Blind Retransmission), which can improve the probability of receiving data packets. Also, when the Tx-UE selects transmission resources, it must ensure that the transmission resources can be within On-Duration.
  • the first TB may be upper layer control information or service data information.
  • three scenarios as shown in Figure 1 should be considered for transmission (retransmission)/reception.
  • periodic resources are reserved using SCI format 1-A.
  • the Tx-UE can reserve periodic resources regardless of whether the resource is On-Duration or Off-Duration. If the Tx-UE starts its corresponding service, the associated first TB must be sent during On-Duration.
  • the Rx-UE acquires the first TB during the On-Duration period, and then the Rx-UE can infer the reserved and periodic related resource information through ResourceReservePeriod.
  • ResourceReservePeriod can optionally be configured in the SCI.
  • the Rx-UE must give priority to the timing of On-Duration. If the drx-ReservePeriodTimer overlaps with other reserved resource time slots, the receiving UE preferentially detects the reserved resource time slots.
  • SCI Format 1-A may reserve resources for initial transmission of other TBs.
  • the Tx-UE starts its corresponding service, and as long as the first TB is transmitted during the On-Duration period, the Tx-UE can reserve resources regardless of whether the resources are in On-Duration or Off-Duration. If the interval of the data packets is less than 32 time slots, then transmission resources can be continuously reserved by the SCI associated with one TB for the next TB.
  • the Rx-UE will use the drx-ReserveInstantTimer timer, and the Rx-UE only needs to detect the relevant time slot of the reserved resource indicated by the SCI. This means that once the timer runs, the Rx-UE will stop receiving and turn off its RF chain.
  • a large packet may be split into terabytes, so the interval between two terabytes may be very short.
  • Each TB must be sent in short intervals to meet the overall latency requirement for large packets.
  • SCI Format 1-A does not reserve any resources. This typically occurs when servicing aperiodic traffic with a transmission interval between two initial TBs greater than 32 slots.
  • the Tx-UE must select resources in the On-Duration, so that the Rx-UE interested in the service is guaranteed to receive data packets during the On-Duration. Therefore, the Rx-UE only needs to detect all the time slots within On-Duration.
  • the Rx-UE If the Rx-UE can access the gNB network, the Rx-UE does not know the timing of its reception or transmission until the gNB indicates or grants PDSCH or PUSCH (Physical Uplink Shared Channel) resources to the Rx-UE through the PDCCH. Therefore, if DRX is (pre)configured, the UE must keep or keep detecting the PDCCH during DRX On-Duration.
  • PDSCH or PUSCH Physical Uplink Shared Channel
  • the SCI on the PSCCH not only indicates the resources for the initial transmission, but also reserves the retransmission resources for the same TB, and there can be two reserved resources at most. If the resources selected for both initial transmission and retransmission are limited to the DRX On-Duration range, the DRX On-Duration cannot be configured to be shorter than 32 slots. This results in relatively large power consumption. Therefore, the UE should allow to have Active Time (ie Active Time) also during sidelink DRX Off-Duration. For example, as with Uu DRX operation, sidelink DRX operation should support extended On-Duration, during which it is also possible to send and receive sidelink initial or retransmission packets.
  • Active Time ie Active Time
  • sidelink DRX operation should support extended On-Duration, during which it is also possible to send and receive sidelink initial or retransmission packets.
  • the Tx-UE is allowed to transmit the initial TB during the On-Duration of the sidelink DRX, but uses the corresponding PSCCH to reserve resources for retransmission in the Off-Duration. Therefore, the Rx-UE needs to be woken up to detect all the time slots within the On-Duration, and also needs to be woken up to detect the retransmitted PSCCH in the reserved time slot. This can greatly reduce the length of On-Duration while maintaining PRR (Packet Reception Ratio, packet reception rate) performance. If the traffic on the side link channel is light, the number of slots configured in On-Duration can be reduced to one. If HARQ-based retransmission is involved, it can save a lot of power for unicast and multicast, and if blind retransmission is performed, it can save a lot of power for unicast, multicast, and broadcast.
  • PRR Packet Reception Ratio, packet reception rate
  • Figure 2 illustrates the DRX process in transmission (retransmission) and reception, where the Tx-UE sends the initial TB within On-Duration and retransmits the same TB within Off-Duration. Therefore, as Active Time, the Rx-UE detects the PSCCH within On-Duration and performs its initial TB reception, and performs retransmission TB reception in the reserved time slot of Off-Duration.
  • the initial TB is transmitted in Slot-0 of On-Duration, and its corresponding PSCCH reserves resource #1 for retransmission Re-Tx1. Therefore, the Rx-UE knows the resource slots reserved by the PSCCH, ie, the Rx-UE only needs to detect the slots in On-Duration and the reserved resource slots in Slot-1 in Off-Duration. It is worth noting that if the initial TB is not the first TB at the start of the service, the Tx-UE does not have to send the TB within On-Duration, as long as the SCI reserves resources for it in the previous TB.
  • the corresponding PSCCH reserves resource #2 and resource #3 for Re-Tx2 and Re-Tx3, respectively. Therefore, the Rx-UE knows that the PSCCH will appear in the Slot-2 and Slot-3 time slots, so it only needs to detect the PSCCH in the Slot-2 and Slot-3. The same transmission and reservation process can be continued until the delay budget is reached or the Rx-UE successfully decodes the TB.
  • Generic DRX mode is defined as a DRX mode in which all time slots should be detectable by energy efficient UEs and for all transmission types (unicast, multicast or broadcast).
  • the generic DRX mode can be configured to have a longer DRX cycle and a shorter On-Duration.
  • the energy-saving UE starts the timer drx-CommonOnDurationTimer after offsetting the time slot by drx-CommonSlotOffset.
  • DFN system frame number
  • On-Duration In order to effectively reduce power consumption, On-Duration should be kept as short as possible. However, a short On-Duration can cause two problems; one is that it is easier to generate half-duplex problems between Tx-UEs, and the other is that the interference from some other Tx-UEs will be more severe, resulting in reliability problems.
  • the Tx-UE should only consider blind retransmissions (ie, one initial TB and several retransmission TBs) in On-Duration.
  • the Tx-UE In order to solve the problem of interference and efficient resource usage, the Tx-UE should consider HARQ-based retransmission in Off-Duration. In addition, it is very important to always maintain the Reservation Chain between two adjacent resources.
  • Figure 3 illustrates resource selection and reservation using generic DRX mode, where Tx-UE sends initial TB and one retransmission TB in On-Duration based on blind retransmission and retransmits in Off-Duration based on HARQ mechanism the same TB.
  • Resource #0 is dedicated to initial transmission
  • resource #1 is dedicated to blind retransmission (no PSFCH resource configured), which solves the half-duplex and initial packet reception reliability issues.
  • each resource pool is optionally configured to own PSFCH resources.
  • the configured PSFCH resource is associated with the time slot in which the PSCCH/PSSCH is transmitted.
  • PSCCH/PSSCH resources without dedicated PSFCH resources can be configured in On-Duration for blind retransmission, while PSCCH/PSSCH resources with dedicated PSFCH resources can be configured in Off-Duration In order to be used for retransmission based on the HARQ mechanism, as shown in FIG. 3 .
  • the Tx-UE must ensure that there are enough candidate resources in On-Duration when selecting resources. So that the MAC layer can smoothly select the resources in the On-Duration for the initial data packet. This requires the MAC layer to notify the PHY layer of the resource slot range that must be included in the On-Duration when reporting candidate resources, or the PHY layer to know the specific configuration of the DRX in advance.
  • the MAC layer completes the initial transmission and blind retransmission by optimizing the resource selection method and selecting favorable resources for the initial data packet. For example, when selecting a resource for an initial data packet in On-Duration, the priority of the data packet can be increased to a relatively high value (eg, the priority is 1).
  • RRC In order to improve the PSCCH coding rate for transmitting initial data packets in On-Duration, RRC must have two PSCCH configurations; that is, one is an On-Duration-related PSCCH configuration with a relatively high coding rate, and the other is an On-Duration related PSCCH configuration.
  • PSCCH/PSSCH resources with dedicated PSFCH resources need to be configured in each resource pool for retransmission based on the HARQ mechanism.
  • the Tx-UE of Rel-17 can still transmit the initial TB and retransmission TB in On-Duration, but the Tx-UE needs to change the behavior for the HARQ mechanism, that is, ignore Rx only in On-Duration - FCI information fed back by the UE. That is, regardless of receiving ACK or NAK, the Tx-UE must complete all retransmissions in On-Duration. However, in Off-Duration, the Tx-UE still needs to follow the HARQ mechanism of Rel-16 and perform retransmission based on the HARQ mechanism.
  • Embodiment 2 is a diagrammatic representation of Embodiment 1:
  • This embodiment solves the problem of how the Tx-UE sends aperiodic data packets and how the Rx-UE receives the aperiodic data packets.
  • each Rx-UE When the Tx-UE sends PSCCH, at most two resources can be reserved as retransmission resources. In order to ensure the resource reservation chain of reserved resources, two conditions must be satisfied: one is that each Rx-UE must correctly decode the SCI from the received PSCCH; the other is that each (pre-)configured resource must be The resource re-evaluation (re-evaluation) and resource pre-emption (pre-emption) mechanisms are disabled in the pool through sl-PreemptionEnable. Failure to meet any one of the conditions may result in the discontinuity of the resource reservation chain.
  • the Rx-UE successfully received the SCI, but the SCI did not reserve any resources for packet retransmission
  • the resource pool is configured with PSFCH resources associated with PSCCH/PSSCH;
  • the Rx-UE cannot successfully decode the TB on the corresponding PSSCH, so the Rx-UE feeds back ACK/NAK to the Tx-UE.
  • the SCI is sent through the reserved resources of the Tx-UE, but the Rx-UE does not successfully detect the SCI;
  • the Tx-UE triggered a re-evaluation, so the reserved resources have been changed;
  • the reserved resources have been preempted by other Tx-UEs with higher priority TBs. Therefore, the Rx-UE cannot decode to the SCI, or the Rx-UE may decode to the SCI correctly, but realize that it is not the SCI it needs.
  • drx-ReserveInstantTimer drx-RetransmissionTimer
  • the former has been used in the first embodiment, ie once this timer runs, the Rx-UE stops receiving and shuts down its RF chain. While the latter is a new timer, once the Rx-UE detects the SCI correctly, but does not have any reserved resources, or fails to detect the required SCI related to retransmission, the Rx-UE will start the drx-RetransmissionTimer. Once this timer runs, the Rx-UE needs to wake up and detect and decode the PSCCH in each slot.
  • Figure 4 illustrates the interruption of the resource reservation chain between Slot-1 and Slot-2 due to no resource reservation, resource preemption, or SCI decoding failure.
  • the Tx-UE transmits the initial TB in Slot-0 while reserving resource #1 for retransmission 1 (Re-Tx1).
  • the Rx-UE successfully receives the SCI but fails to decode the TB, the Rx-UE sends an ACK/NAK to the Tx-UE, and starts a timer.
  • “drx-ReserveInstantTimer” is started, the Rx-UE stops receiving and shuts down its RF chain until it wakes up at Slot-1 to re-receive the data packets (mainly including the retransmitted TB).
  • Tx-UE retransmits TB in Slot-1 but does not reserve any resources for Re-Tx2, or Tx-UE reserves resources but is preempted by other Tx-UEs, or Tx-UE retransmits in Slot-1 TB, but the Rx-UE did not successfully decode the SCI. In either case, the Rx-UE will immediately start the "drx-RetransmissionTimer" timer. Once this timer runs, the Rx-UE is required to detect and decode the PSCCH in each slot until the timer expires or the Rx-UE receives a retransmitted SCI.
  • the Tx-UE selects resource #2 for Re-Tx2 in Slot-2, and retransmits the TB while reserving resource #3 for Re-Tx3.
  • the Rx-UE successfully detects the SCI and stops the "drx-RetransmissionTimer" timer. Subsequently, if the decoding of the data packet has not been successful, the Rx-UE starts the drx-ReserveInstantTimer timer again, and is woken up in Slot-3 to receive the retransmitted data packet.
  • the triggered and re-selected resource slot positions may affect the reception performance of the Rx-UE.
  • the re-selected resource slot position may be before or after Slot-1.
  • the reselected resource #a in Slot-1a is after Slot-1
  • the reselected resource #b in Slot-1b is before Slot-1.
  • using "drx-ReserveInstantTimer" to receive retransmission TBs will not cause any problems.
  • the Rx-UE will not be able to receive the retransmitted TB.
  • a simple but not efficient power saving solution is to reuse the HARQ timer in Rel-16.
  • This timer is defined in Rel-16 as drx-HARQ-RTT-Timer.
  • drx-HARQ-RTT-Timer This means that after receiving the initial TB and unsuccessful decoding to the TB, the Rx-UE starts the drx-HARQ-RTT-Timer. After feeding back the NAK, the Rx-UE starts the drx-RetransmissionTimer indirectly.
  • This solution does not involve drx-ReserveInstantTimer, but the disadvantage is that the Rx-UE needs to stay awake and receive PSCCH for a long time.
  • Another solution is to prohibit the Tx-UE from re-selecting resources before reserving resource slots once the resource re-evaluation/preemption mechanism is implemented. As shown in FIG. 5, the Tx-UE excludes resource #b and reselects resource #a. In addition, when determining resource #a, the Tx-UE should select a candidate resource that is closer to the reserved resource #1, so that the Rx-UE can stop the timer earlier and achieve the energy saving effect.
  • Another problem is how to solve the DTX (Discontinuous Transmission) problem in the HARQ process. If the Rx-UE cannot detect the PSCCH associated with the initial TB, the Rx-UE will not send the corresponding NAK to the Tx-UE. To the Rx-UE, such a reception failure is as if no TB transmission occurred. This will degrade the overall PRR performance.
  • DTX Continuous Transmission
  • the Tx-UE can determine the occurrence of DTX. Therefore, if the On-Duration timer is still running, the Tx-UE can retransmit the TB in the same On-Duration; if the delay budget allows, it can retransmit the TB in the next upcoming On-Duration.
  • This embodiment solves the problem of how the Tx-UE sends periodic data packets and how the Rx-UE receives periodic data packets.
  • the first TB In the transmission and reception of periodic services, once the Tx-UE initiates the service and sends the first TB to the Rx-UE, the first TB must be sent within On-Duration to ensure that the Rx-UE can receive. If the reservation of periodic resources remains unchanged until the completion of its specific service, the Rx-UE wakes up and only receives TBs on the corresponding reserved periodic resources. However, due to continuous resource conflicts and re-evaluation and preemption mechanisms that trigger resource reselection, the reservation continuity of periodic resources cannot be ensured.
  • sl-ProbResourceKeep eg, 0.2, 0.4, ..., 0.8
  • One solution is to ensure that the Tx-UE only reselects resources during DRX On-Duration. In this way, the Rx-UE only wakes up to receive periodic services in periodically reserved resources. Once the Rx-UE receives packets within On-Duration, it will detect whether the periodic resource is reselected. This requires the MAC entity to use the DRX cycle as a counting unit to decide whether to reselection resources, instead of counting the number of TB transmissions as adopted in Rel-16.
  • Figure 6 illustrates an example where resource reselection occurs in Slot-4 of On-Duration. This will ensure that the Rx-UE can detect that the periodic resource is re-selected.
  • re-evaluation and/or preemption mechanisms can also trigger reselection of periodic resources. To ensure that resource re-selection only occurs in On-Duration, resource re-evaluation and/or preemption mechanisms must be disabled by using sl-PreemptionEnable in the (pre)configured resource pool.
  • Rx-UE may not be able to detect periodic TB related SCIs reserved by ResourceReservePeriod due to resource conflicts or other low SINR reasons. Although the Rx-UE can detect the SCI and resume the reservation chain at the next reservation opportunity, it will cause the reception performance to degrade.
  • the energy-saving receiving mode means that the Rx-UE only wakes up to receive the PSCCH in the On-Duration and reserved resource time slots, and decodes data packets of services associated with the Rx-UE. For specific description, refer to Embodiment 1.
  • Figure 7 depicts an example of transmission and reception of periodic services with a specific receive timer drx-ReceivePeriodTimer, where the Tx-UE sends the initial TB in Slot-0 and reserves periodicity in Slot-1 and Slot-2 resource.
  • the Rx-UE cannot detect SCI due to Tx-UE reselection of resources. Therefore, the Rx-UE starts a timer and continues to detect the SCI in each slot until it detects again that the associated SCI reserves new periodic resources, or the drx-ReceivePeriodTimer expires.
  • the Rx-UE detects the associated SCI again and stops the timer, then the Rx-UE will enter the normal power saving reception mode.
  • the resources reserved by the Tx-UE may be preempted by another Tx-UE. Similar to the problem discussed in the second embodiment, the re-selection of resources triggered by re-evaluation/preemption or SL_RESOURCE_RESELECTION_COUNTER mechanism may precede or follow the reserved resources in Slot-2. It's worth noting that, as a worst-case scenario, this problem can result in a packet loss in periodic reception. In an example, if the reselected resource occurs before the reserved resource, the Rx-UE can detect the relevant SCI in Slot-4, thereby restoring the reserved chain. However, the Rx-UE will miss the TB sent in the Slot-3 reselection resource.
  • the Tx-UE can set a high enough priority for the transmission data packet, for example, a priority value of 1, so that other Tx-UEs do not preempt their reserved resources.
  • a priority value of 1 for example, 1, so that other Tx-UEs do not preempt their reserved resources.
  • the Rx-UE fails to detect the SCI in Slot-2, the "drx-ReceivePeriodTimer" is started immediately.
  • the Tx-UE is prohibited from re-selection of resources before Slot-2.
  • the Rx-UE fails to detect the SCI in Slot-2, "drx-ReceivePeriodTimer" is started immediately.
  • the Tx-UE configured based on DRX belongs to the UE of Rel-17, it can be simply implemented without any impact on the UE of Rel-16 at the same time.
  • the Tx-UE can notify the Rx-UE through SCI or MAC-CE that the periodic resource will be reselected in the next transmission. It is worth noting that if a single bit indication is considered, the first SCI (1st SCI) should preferably be considered. This is because the sensing UE can also see this bit in order to start its sensing timer. In this case, "drx-ReceivePeriodTimer" is started immediately after SCI is detected in Slot-1.
  • Embodiment 4 is a diagrammatic representation of Embodiment 4:
  • This embodiment solves the problem of how the Tx-UE realizes the transmission of the short PDB aperiodic data packets, and how the Rx-UE realizes the reception of the short PDB aperiodic data packets.
  • the Tx-UE For packets with very short PDB QoS requirements, the Tx-UE must send immediately. In other words, this means that the DRX cycle should be kept short enough, which will cause power consumption issues for the Rx-UE.
  • a second DRX pattern On the basis of the general DRX pattern discussed in the first embodiment, we define a second DRX pattern, called a specific DRX pattern (specific DRX pattern). This means that with the common DRX mode, all UEs can have the same DRX configuration. For a specific DRX mode, multiple DRX modes will be configured for a specific type of service or UE. Configuring multiple DRX modes can satisfy multiple services in Tx-UE and Rx-UE at the same time.
  • the DRX parameters associated with the QoS of the short PDB are (pre)configured, where the On-Duration contains only few time slots (can be at least one time slot), where the DRX period should be less than pdb.
  • common On-Duration and Off-Duration are defined as common On-Duration and common Off-Duration time in common DRX
  • specific On-Duration and Off-Duration for specific QoS flows are defined as specific On-Duration and specific Off-Duration.
  • Generic DRX can be used as a background configuration that all UEs can use at any time for their DRX pattern alignment procedures.
  • the Tx-UE can select the SpDRX_Conf(p) configuration that satisfies the QoS required by a specific service, and then send the index of p to all Rx-UEs through MAC-CE or SCI. Therefore, a specific DRX pattern can be used on the basis of the general DRX pattern. Once the specific service expires and the relevant data packets are no longer transmitted, the specific DRX mode should be stopped, and the UE should fall back to the general DRX mode.
  • the Tx-UE has to wait for Common On-Duration to transmit the first initial TB associated with the first data packet in the new service.
  • the Tx-UE sends the first initial TB, it sends the MAC-CE (or SCI in the PSCCH) at the same time, so that the specific DRX parameter (ie, the index p, can be The single index may also be a complex index) notified to the corresponding Rx-UE.
  • the Rx-UE sets specific DRX parameters. All UEs involved in the same service should keep using the same specific DRX parameters until the service expires and the specific DRX parameters are released.
  • the Rx-UE sets a specific DRX parameter, and if the index flag is A2, the Rx-UE releases the specific DRX parameter.
  • Tx-UE can use resource preemption mechanism to preempt resources in specific On-Duration resources for initial packet transmission, while in specific Off-Duration to select resources from among which are used for packet retransmission.
  • the feedback HARQ mechanism may not work properly, so as described in the first embodiment, blind retransmission or combination mechanism may be considered to complete the data packet transmission.
  • Embodiment 5 is a diagrammatic representation of Embodiment 5:
  • the Tx-UE needs to select a sensing window for channel sensing, and then select the corresponding resource in the resource selection window to transmit data packets.
  • the Rx-UE does not need to consider the sensing window, and only needs to align the selected resource slots for reception.
  • the Tx-UE can only follow the DRX On-Duration for initial packet transmission, and the Rx-UE must align to the same DRX pattern to receive packets. Therefore, sensing and receiving are fundamentally different. Although sensing accuracy may affect some PRR performance, sensing does not require information with high accuracy.
  • the main purpose of sensing is that the Tx-UE detects the PSCCH, decodes the SCI, and obtains resource information reserved by other Tx-UEs from it, so as to perform resource exclusion during resource selection, thereby avoiding resource conflict.
  • reception requires alignment and adjustment of wake-up and sleep times between Tx-UE and Rx-UE to be able to decode packets correctly.
  • the sensing window T sen (sensing window), the relationship between the selection window T sel (selection window) and the on-duration T ond (On-Duration).
  • the relationship between T sen and T sel is the same as that of Rel-16, but there is no direct relationship between T sen and Tond . This means that the determination of the sensing window does not directly depend on the position of On-Duration within the DRX cycle. However, there is a strong correlation between T sel and T ond , and at least the two windows need to partially overlap, i.e. in is the empty set.
  • the sensing mechanism should determine the sensing window T sen based on the packet arrival time (i.e., the time period T sen before the packet arrives as the sensing window), then determine the relationship between T sel and To nd , and finally Find the selection window T sel .
  • the Tx-UE should sense all the time slots within the On-Duration in addition to the time slots within the sensing window. time slots to provide more channel sensing information for transmission resource selection.
  • This embodiment solves the problem of how to sense the reserved periodic resources for the partial sensing (Partial Sensing) mechanism in the side link DRX.
  • the Tx-UE For a given candidate resource in slot ty , the Tx-UE is awake to detect the slot And determine whether to exclude candidate resources in time slot ty from resource set SA .
  • One solution is to ensure that each Tx-UE only does resource (re)selection during the DRX On-Duration, and then the Tx-UE only performs part of the sensing process during the On-Duration. This ensures that the Tx-UE recognizes the reserved resources and selects the resources accordingly for packet transmission, but the problem is that each Tx-UE has to transmit TBs in the On-Duration slot, which may change between On-Duration and The used resources are unbalanced between Off-Duration, resulting in increased resource conflicts in On-Duration time slots.
  • NR-V2X in Rel-16 supports resource reselection and preemption mechanism, resources reserved by Tx-UE can be changed after sending SCI. In this way, there is no guarantee that the re-selected resources must be within On-Duration. As a result, some sensing UEs cannot predict the re-selected resources.
  • the solution to this problem is to derive the sensing window from all periodicities configured in the resource pool.
  • the length of the sensing window is N slots and the number of cycles (or kinds) is M, assuming that there are no overlapping slots, the number of slots used for sensing is at most MN. This may turn partial sensing into full sensing, leading to Tx-UE power consumption issues.
  • the sensing mechanism with MN slots is only applicable to sensing UEs sending periodic data packets. This means that the sensing UE knows the packet arrival time and can pre-determine the selection window position.
  • this approach is not very effective, because the Tx-UE has to either prepare sensing results in advance for any selection window, or start sensing after data packets arrive. The former will cause a power consumption problem, while the latter, if the periodic resource reserved by the Tx-UE has a longer period, a larger delay will be generated when sensing the data packets sent by the UE.
  • Tx-UE-A ie, the first transmitting UE
  • Tx-UE-B ie, the first transmitting UE
  • Tx-UE-B the second transmitting UE
  • Tx-UE-B needs to send periodic services or aperiodic services
  • Tx-UE-A can only perform periodic service transmission
  • Tx-UE-B may transmit periodic services to Tx-UE-B.
  • the services offered by UE-A are not of interest.
  • Tx-UE-B For sensing, Tx-UE-B only needs to wake up and sense that Tx-UE-A reserves resource channels periodically, but Tx-UE-B may also fail to detect PSCCH signals. There are two reasons for detection failure: one is due to collision or low SINR; the other is due to resource reselection due to re-evaluation/preemption mechanism or resource reselection counter.
  • Tx-UE-B will start drx-PeriodSensingTimer and wake up to detect PSCCH in each slot. If the drx-PeriodSensingTimer expires, or if the Tx-UE-B successfully detects the PSCCH in the new slot, the Tx-UE-B will stop detecting the PSCCH. Typically, drx-PeriodSensingTimer should be set equal to the ResourceReservePeriod required by the QoS in a particular service. In the example of Figure 9, Tx-UE-A starts traffic and transmits the initial TB at Slot-0, while reselecting new resources at Slot-3.
  • the sensing UE does not need to consider its traffic type (periodic and aperiodic) before a packet arrives, and it can always be ready to provide the sensing results to the MAC layer for resource exclusion at resource selection, thereby resource (re) choose.
  • This partial sensing process is adapted to sense the reserved resource channels of periodic traffic of other Tx-UEs, and can be expressed as a periodic partial sensing process.
  • the same problem may arise as described above, that is, the re-selected resources may be before the previously reserved resources, so as the worst case, the Tx-UE may miss a sensing after Slot-2 Chance. Likewise, a workaround can be achieved by disabling selection of resources prior to the reserved resources as reselection resources.
  • the Tx-UE-B must always sense every time slot periodically reserved by other Tx-UEs.
  • multiple Tx-UEs with different periodicities and different transmission time offsets can reserve periodic resources. Therefore, the Sensing Tx-UE-B can only be woken up in a different Sensing Cluster to perform channel sensing.
  • the sensing cluster is defined as some overlapping time slots (Superposition Slot) or some adjacent time slots (Neighbor Slot) reserved by different Tx-UEs. If the sensing UE only considers these sensing clusters as channel sensing, the energy saving effect can be greatly improved.
  • the number of Tx-UEs using the same resource pool may be much larger than the periodic number, and some Tx-UEs may send packets of the same periodicity with different time offsets.
  • a threshold is configured using the value of TH(prio RX , prio TX ), and the sensing Tx-UE-B compares its received RSRP with the threshold and determines whether to exclude resources.
  • prio TX and prio RX are priorities, used to send and receive packets, respectively. Therefore, based on the same threshold, the sensing Tx-UE-B can first determine which Tx-UEs are sensing candidate UEs, so that the sensing Tx-UE-B does not need to sense all resource channels reserved by the Tx-UEs.
  • Tx-UE-1, Tx-UE-2, Tx-UE-3 send periodic data packets with different periodicities, and Tx-UE-B tries to sense the reserved resource slots and channels in On-Duration.
  • the three types of traffic with different periods will generate many sensing clusters, which contain different amounts of sensing resources. Also, some sensing clusters are far from On-Duration, and some sensing clusters are close to On-Duration. In the example, Sensing Cluster 1 and Sensing Cluster 3 are close to On-Duration, so the Tx-UE-B wakes up and senses Sensing Cluster 1 and Sensing as compared to Slot Sensing in On-Duration
  • the reserved resource information obtained for the time slots in cluster 3 may be substantially the same.
  • the Tx-UE-B wakes up and can sense to update the reserved resource information. So, it is effective that the Tx-UE-B only wakes up in sensing cluster 2 and senses the slotted channel associated with it.
  • the sensing UE performs channel sensing and derives resources reserved by other Tx-UEs, but the other Tx-UEs may be Rel-16 UEs or UEs that do not require DRX configuration.
  • some Tx-UEs belong to Rel-17 UEs and can implement a new sensing process for resource reselection
  • some Tx-UEs can be ordinary UEs without DRX configuration, such as vehicle UEs
  • some Tx-UEs -UE belongs to Rel-16 UE and must follow the resource reselection process in Rel-16 (including reselection, re-evaluation and preemption mechanism). Therefore, the previously proposed solutions may not guarantee the overall performance, because this scenario cannot guarantee that the first initial packet initialized at the beginning of the service will definitely be transmitted in On-Duration.
  • each sensing cycle has a partial sensing window of L TW ( Partial Sensing Window).
  • T cycle and L are configured by RRC in each resource pool.
  • T MIN ⁇ T W ⁇ T MAX , T MIN and T MAX are the minimum and maximum period lengths configured in the current resource pool, respectively, And T MAX ⁇ T cycle .
  • the sensing UE wakes up in a partial sensing window and senses the sidelink channel of all slots.
  • the sensing UE may activate part or all (L) of its partial sensing windows TW within a certain sensing period.
  • the sensing UE may adjust the size of TW according to the set threshold. For example, if the received NAK number is greater than a certain threshold, the sensing UE can increase the TW number ( ⁇ L) to improve the side link channel sensing accuracy.
  • the sensing UE may adjust the size of TW according to the sensed long-period reserved resource quantity (or occurrence frequency), so as to balance the channel sensing accuracy and the energy saving effect.
  • the mechanism for adjusting the size of TW can be implemented by setting a threshold for the number of reserved resources for a long period.
  • the relationship of TW and threshold may be (pre)configured by RRC.
  • the long-period reserved resource quantity threshold may be (pre)configured as TH m and N m and TH m are corresponding.
  • the sensing UE may determine TW according to the amount of reserved resources for the sensing long period and TH m compared with TH m .
  • the sensing cluster can be used as a partial sensing window, and this partial sensing window setting does not require any Limitation of the sensing period.
  • a specific sensing period can be configured for use by multiple resource pools.
  • the partial sensing window of TW may be determined by the minimum period length T MIN and the maximum period length T MAX configured in the multiple resource pools.
  • the sensing UE wakes up in a specific sensing window and senses the sidelink channel of all slots within the specific sensing window in all resource pools. Through this specific sensing window TW , the periodically reserved resource information of all other Tx-UEs in multiple resource pools below T MAX time slots can be obtained. This maximizes energy savings.
  • the sensing UE can adjust the size of TW according to a set threshold (NAK number, the number of reserved resources for a long period, etc.). For example, if the received NAK number is greater than a certain threshold, the sensing UE can increase the TW to improve the side link channel sensing accuracy. On the contrary, if the number of received NAKs is less than a certain threshold, the sensing UE can improve the energy saving effect by reducing T W .
  • the relationship of TW and threshold may be (pre)configured by RRC.
  • Embodiment 6 is a diagrammatic representation of Embodiment 6
  • This embodiment solves the problem of how to sense reserved aperiodic resources for the partial sensing (Partial Sensing) mechanism in side link DRX.
  • the sensing mechanism for periodic traffic and aperiodic traffic is the same. But the sensing window size used is different, ie, the sensing window for periodic traffic is 1100ms, and the sensing window for aperiodic traffic is 100ms. This is because in the case of aperiodic traffic, more reserved resource information cannot be obtained with a long sensing window.
  • the selection window can be set immediately after the arrival of the aperiodic data packets. However, if some sensing UEs consider the DRX mode, after the aperiodic data packets arrive, some sensing UEs select the latest DRX On-Duration for transmission.
  • the sensing window should provide enough time (at least 31 slots) for channel sensing between the time the packet arrives and the start time of the On-Duration. This partial sensing process is adapted to sense other reserved resource channels that transmit aperiodic traffic of the UE, and can be represented as an aperiodic partial sensing process.
  • Figure 11 illustrates a partial sensing UE having aperiodic data packet transmission and performing aperiodic partial sensing process, with a short sensing window of 31 slots, so that non-periodic data reserved by other sending UEs can be completely excluded Periodic resources.
  • the sensing UE must start sensing immediately after the arrival of the packet and perform resource selection on the most recent DRX On-Duration. However, this may cause a problem that the sensing process cannot completely exclude the resources reserved by other Tx-UEs for aperiodic transmission.
  • the sensing process of aperiodic traffic can be realized by the timer drx-SensingTimer.
  • the Tx-UE starts to detect 31 time slots before the DRX On-Duration opportunity for resource selection. And the Tx-UE will continue to detect until the packet (retransmission) transmission is successfully received, or the drx-SensingTimer expires.
  • Rx-UE only needs to monitor time slots in On-Duration and time slots in reserved resources, which is implemented by drx-ReserveInstantTimer, depending on the 1st SCI decoding situation.
  • Figure 12 illustrates a partial sensing process for aperiodic traffic, where the Tx-UE starts sensing before duration 31 slots and selects the initial TB transmission resource within On-Duration. Retransmission is performed in Off-Duration by maintaining the resource reservation chain, which can ensure that the transmission and reception of data packets of Rx-UE and Tx-UE are aligned.
  • the Rx-UE will stop receiving packets. If drx-ReserveInstantTimer overlaps with drx-onDurationTimer, the Rx-UE shall give priority to drx-onDurationTimer.
  • the sensing time of the Tx-UE will be very small, so the Tx-UE must keep the sensing window less than 32. This may not exclude the resources reserved by other Tx-UEs for aperiodic transmission, thus causing resource conflict.
  • the Tx-UE should not turn off the sidelink RF for sensing during the transmission of the packets in order to ensure that all reserved resource channels can be sensed. Instead, the Tx-UE must perform Full Sensing in order to obtain channel information.
  • the Tx-UE If the Tx-UE wakes up to perform full sensing for a specific service, the Tx-UE should start the full sensing process 32 slots before the first On-Duration opportunity after the arrival of the first data packet, and the successful The full sensing process is stopped during the time slot in which the last packet is transmitted, as shown in the proposal in Figure 8.
  • Random resource selection is a random selection performed without sensing, ie the UE reports all candidate resources within the selection window to the MAC for random selection in a specific resource pool without any exclusion process.
  • packet transmission can be achieved by (pre)configuring a pool of sidelink transmit resources based on full sensing, partial sensing, random resource selection, or any combination. Therefore, by combining Tx-UEs, part of the sensing can be used for long-period traffic, and random resource selection can be used for short-period traffic.
  • Periodic partial sensing and aperiodic partial sensing mechanisms can often be used simultaneously. This is because the Tx-UE may have periodic traffic or aperiodic traffic, and the sensing UE must simultaneously capture and infer the reserved resource information for both traffic types.
  • the resource pool is configured by SL-ResourcePool, and the periodicity of data packets can be configured by selecting sl-ResourceReservePeriodList. If the periodic list is not configured, the UE can only transmit aperiodic data packets. In this case, the sensing process may rely on an aperiodic partial sensing mechanism. If a periodic list is configured, periodic and aperiodic traffic can be transmitted simultaneously in a resource pool, and both periodic and aperiodic partial sensing mechanisms must be considered.

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Abstract

本申请提供一种节能NR侧链路传输和接收的方法，包括：DRX模式下，发送UE在On-Duration内传输初始TB，预留用于重传初始TB或传输其它TB的周期性资源或非周期性资源，周期性资源或非周期性资源的个数小于等于N，N为自然数，则配置至少一个第一DRX计时器，发送UE在感测窗口的时隙和On-Duration的时隙执行信道感测，以及配置至少一个第二DRX计时器，接收UE在所有预留的周期性资源或非周期性资源的时隙和/或On-Duration的时隙唤醒接收初始TB和/或重传TB，其中，预留资源位于On-Duration和/或Off-Duration内。本申请解决了现有技术中DRX节能方面的不足。

Description

一种节能NR侧链路传输和接收的方法 技术领域
本发明涉及无线通信技术领域，尤其涉及一种节能NR侧链路传输和接收的方法。
背景技术
当前，第5代移动通信系统(5G)的研发工作正在如火如荼地进行中。根据未来的应用需求，5G系统将使用全新的空口技术-NR(New Radio)。相比LTE，5G NR需要支持更高的数据率，更大的传输带宽以及更小的传输时延，因此支持NR的用户终端(User Equipment，UE)在使用一些先进的技术以满足5G需求的同时将不可避免地消耗大量能量。
为了节省UE的能量，引入了不连续接收机制DRX(Discontinuous Reception)，即终端处于连接状态下时不需要连续地监听基站的控制信道，而是间断地监听控制信道。一个DRX周期包括唤醒周期和休眠周期，其周期是通过周期性重复开启持续时间(简称为On-Duration)和关闭持续时间(简称为Off-Duration)来进行的。在开启持续时间内，UE会开启接收机的RF接收信息，而在关闭持续时间内，UE会关闭接收机的RF进行休眠。通常，应将DRX开启持续时间保持足够短，而将DRX关闭持续时间保持足够长，从而最大程度地降低UE功耗。
DRX参数由无线资源控制RRC(Radio Resource Control)配置，主要由drx-onDurationTimer,drx-SlotOffset,drx-LongCycleStartOffset,drx-InactivityTimer,drx-ShortCycle,drx-ShortCycleTimer组成。利用这些DRX参数，在RRC_CONNECTED情况下，可以实现DRX过程，而在RRC_IDLE/RRC_INACTIVE情况下实现寻呼DRX(Paging)过程。允许MAC实体使用DRX操作不连续地检测物理下行控制信道PDCCH(Physical Downlink Control Channel)，并由DRX MAC-CE指令或长DRX MAC-CE指令加于控制；否则，MAC实体将连续检测PDCCH。当处于RRC_IDEL/RRC_INACTIVE情况下，UE在每个DRX周期中检测一个寻呼时机。寻呼时机是一组PDCCH检测时机，由其中发送寻呼下行链路控制信息DCI(Downlink Control Information)的多个时隙(例如，子帧或OFDM符号)组成。
现有的Uu链路中的NR-DRX仅用于单播传输，而未来的NR侧链路DRX(Sidelink DRX)是用于在覆盖范围内和覆盖范围外的广播(Broadcast)、组播(Groupcast)和单播 传输(Unicast)。如果节能UE(Power Saving UE，例如，P-UE或Pedestrian-UE)处于覆盖范围内，则可以使用Uu链路中的NR-DRX周期中的类似过程，所有RRC参数和对应的侧链路DRX操作可以由网络控制。但是，如果节能UE不在覆盖范围内，则侧链路DRX周期的所有RRC参数可以依赖于预配置方式。针对侧链路繁多的业务，如果使用Uu链路中的NR-DRX机制，侧链路DRX过程在动态控制DRX周期方面需要进行很大改进。
因此，可以把Uu中DRX周期的开启/关闭持续时间及其相应的UE过程作为侧链路DRX的基础，同时针对覆盖范围内和覆盖范围外的情况，侧链路DRX机制必须考虑不同传输类型(广播，组播和单播)的影响。
混合自动重发请求(Hybrid automatic repeat request，HARQ)是前向纠错(Forward error correction，FEC)和自动重发请求(Automatic repeat request，ARQ)错误控制的组合。在恶劣的信号条件下，HARQ的性能要比普通的ARQ好，但这是以降低吞吐量为代价来提高接收性能。
在DRX操作中，如果接收机UE(Receiver UE,简称为Rx-UE)正确地解码PDCCH，但错误解码物理下行链路共享信道PDSCH(Physical Downlink Shared Channel)，则Rx-UE利用drx-HARQ-RTT-Timer和drx-RetransmissionTimer的两个计时器来控制相应的HARQ过程。由于Rx-UE不知道数据包重传的时机，因此Rx-UE必须连续检测PDCCH，以便接收并解码相同HARQ进程ID(HARQ process ID)相关联的PDSCH。对于下行链路(Down Link，简称为DL)上的HARQ过程，如果UE已经在PDSCH上接收到新数据，则UE在DL HARQ反馈结束之后启动HARQ RTT计时器。如果在drx-HARQ-RTT-TimerDL计时结束也未成功解码相应数据包，则UE将启动drx-RetransmissionTimerDL计时器。当drx-RetransmissionTimerDL计时器运行时，UE需要检测该HARQ过程的PDCCH，因为在这段时间内，UE将可能进行数据包重传。
候选单时隙(即，Slot)资源R x，y被定义为时间间隔[n+T 1，n+T 2]内的L subCH个连续子信道，其中T 1取决于
Figure PCTCN2020132623-appb-000001
而T 2取决于T 2min，由UE自己实现。注意，T 2min≤T 2≤Remaining PDB(数据包延迟预算，Remaining Packet Delay Budget)；如果T 2min＞Remaining PDB，则设置T 2min＝Remaining PDB。感测窗口(Sensing Window)由时隙范围[n-T 0，n-T proc，0)定义，其中T 0和
Figure PCTCN2020132623-appb-000002
用时隙表示。如果候选单时隙资源R x，y被其他UE预留(Reservation)或抢占(Pre-emption)，则UE应排除该候选单时隙资源。如果集合S A中剩余的候选单时隙资源的数量小于X·M total，则对于优先级值Th(p i)增加3dB，并且继续 重复相同资源选择过程(例如，X＝20％)。
在Rel-16中，发送UE(Transmitter UE，简称为Tx-UE)在感测窗口中感测到侧链路信道并计算出信道资源预留情况。感测窗口大小由流量类型(周期和非周期)决定；周期性流量窗口为1100ms，非周期性流量窗口为100ms。Tx-UE根据感测到的侧链路信道，在选择窗口(Selection Window)中确定应该被排除的资源。有两种类型的资源必须被排除；一个是被预留的周期性资源，另一个是在32个时隙窗口内由侧链路控制信息SCI(Sidelink Control Information)所预留的资源。排除过程是由Tx-UE基于参考信号接收功率RSRP(Reference Signals Received Power)的比较来执行的。最后Tx-UE从所有剩余的候选资源中相应地选择用于其传输和预留资源。另外，Tx-UE也可以执行重估和抢占机制，从而避免资源冲突。在Rel-16NR-V2X中，SCI的预留间隔能力为32个时隙。如果超出此范围，Tx-UE仅能使用可选配置的SCI参数ResourceReservePeriod对周期性资源进行预留。
因此，在DRX开启持续时间和关闭持续时间中，需要考虑如何控制侧链路的发送和接收问题，以及如何为不同UE调整侧链路DRX模式(DRX Pattern)问题，以期望解决现有技术在DRX节能方面的不足。
发明内容
本发明的目的在于提供一种节能NR侧链路传输和接收的方法，以解决基于DRX的UE接收和基于部分感测的传输问题。
涉及的专业术语：
DRX(Discontinuous Reception)，不连续接收；
UE(User Equipment)，用户设备；
TB(Transport Block)，传输块，或数据包；
Tx-UE(Transmitter UE)，发送UE，用于通过单播、组播或广播向其他UE传输传输块；
Rx-UE(Receiver UE)，接收UE；
On-Duration，开启持续时间；
Off-Duration，关闭持续时间；
PSCCH(physical Sidelink Control Channel)，物理侧链路控制信道；
PSSCH(Physical Sidelink Shared Channel)，物理侧链路共享信道；
PSFCH(Physical Sidelink Feedback Channel)，物理层侧链反馈信道；
PDCCH(Physical Downlink Control Channel)，物理下行控制信道；
PDSCH(Physical Downlink Shared Channel)，物理下行链路共享信道；
PUSCH(Physical Uplink Shared Channel)，物理上行链路共享信道；
DCI(Downlink Control Information)，下行链路控制信息；
SCI(Sidelink Control Information)，侧链路控制信息；
DL(Down Link)，下行链路；
Power Saving UE(例如，P-UE或Pedestrian-UE)，节能UE；
PRR(Packet Reception Ratio)，分组接收率；
HARQ(Hybrid Automatic Repeat reQuest)，混合自动重传请求；
RSRP(Reference Signal Receiving Power)，参考信号接收功率，是LTE网络中可以代表无线信号强度的关键参数以及物理层测量需求之一，是在某个符号内承载参考信号的所有RE(资源元素)上接收到的信号功率的平均值；
PDB(Packet Delay Budget)，数据包延迟预算；
MAC-CE(MAC Control Element)，MAC层的控制元素。
为实现上述目的，本发明采用以下技术方案：
一种节能NR侧链路传输和接收的方法，包括：
不连续接收(DRX)模式下，发送UE在开启持续时间(On-Duration)内传输初始TB，以及使用SCI预设格式预留用于重传初始TB或传输与初始TB关联的其它TB的周期性资源或非周期性资源，所述周期性资源或非周期性资源的个数小于等于N，N为自然数，则配置至少一个第一DRX计时器，基于所述第一DRX计时器，发送UE在感测窗口的时隙和所有On-Duration的时隙执行信道感测，以及
配置至少一个第二DRX计时器，基于所述第二DRX计时器，接收UE在所有预留的周期性资源或非周期性资源的相关时隙、和/或所有On-Duration的时隙进入唤醒状态接收所述初始TB；
其中，所述预留的周期性资源或非周期性资源由侧链控制信息SCI通信指示，位于On-Duration和/或关闭持续时间(Off-Duration)。
优选地，发送UE可以属于节能UE(例如，V2X用例中的Vulnerable Road Users，简称为VRU，或者公共安全和商业用例中的用户)，也可以属于普通UE(例如，车辆UE)； 接收UE只属于节能UE。
优选地，在侧链路DRX中，发送UE的传输类型包括单播、组播或广播。
优选地，所述DRX计时器有两种类型；其种类一是当DRX计时器运行时(包括drx-ReservePeriodTimer，drx-ReserveInstantTimer，drx-HARQ-RTT-Timer，drx-OffDurationTimer，drx-CommonOffDurationTimer，和drx-SpecificOffDurationTimer)，所述接收UE停止接收并关闭其RF链；其种类二是当DRX计时器运行时(包括drx-OnDurationTimer，drx-CommonOnDurationTimer，drx-SpecificOnDurationTimer，和drx-RetransmissionTimer)，所述接收UE开始接收并开启其RF链。
优选地，侧链路DRX的操作支持扩展的On-Duration，在Off-Duration也可以发送和接收侧链路的初始TB或重传TB。
优选地，响应于接收到的DRX的配置参数，所述接收UE进入激活状态，并监听物理侧链路控制信道PSCCH和/或物理侧链路共享信道PSSCH。
优选地，接收UE在On-Duration内检测初始TB，所述初始TB对应的PSCCH指示为重传TB的预留资源的时隙；所述接收UE根据PSCCH预留的资源时隙确定DRX定时器的状态，其中，在所述DRX定时器的运行时间内，所述接收UE停止检测PSCCH。
优选地，若初始TB不是业务开始的第一个TB，则发送UE无需一定要在On-Duration内发送该TB，只要由SCI在前一个TB中为它预留资源即可。
优选地，重传TB对应的PSCCH指示下一次重传TB的预留资源的时隙，直到达到延迟预算或接收UE成功解码为止。
优选地，所述第一DRX计时器，是用于感测的计时器，包括drx-PeriodSensingTimer和drx-SensingTimer；所述第二DRX计时器，是用于数据包接收的计时器，包括drx-OnDurationTimer，drx-CommonOnDurationTimer，drx-SpecificOnDurationTimer，drx-OffDurationTimer，drx-CommonOffDurationTimer，drx-SpecificOffDurationTimer，drx-ReservePeriodTimer，drx-ReserveInstantTimer，drx-HARQ-RTT-Timer和drx-RetransmissionTimer中的一种或几种。
优选地，DRX包括两种类型的激活时间(Active Time)：数据包接收激活时间、以及感测激活时间；其中，在数据包接收激活时间，接收UE解码PSCCH和PSSCH，在感测激活时间，发送UE只解码PSCCH。
更优选地，当DRX周期被配置时，数据包接收激活时间包括：上一次传输中已预留资 源的时隙；或者，包括以下任一计时器正在运行：
drx-CommonOnDurationTimer,drx-SpecificOnDurationTimer，drx-onDurationTimer,drx-RetransmissionTimer。
更优选地，当DRX周期被配置时，感测激活时间包括：发送UE在感测激活时间内进行接收的时隙；或者，包括以下任一计时器正在运行：
drx-PeriodSensingTimer，drx-SensingTimer，drx-onDurationTimer，drx-CommonOnDurationTimer，drx-SpecificOnDurationTimer。
优选地，发送UE在On-Duration内传输业务开始的第一个初始TB，以及使用SCI预设格式预留用于不同的初始TB的周期性资源；接收UE在On-Duration的时隙进入唤醒状态来接收所述初始TB，以及接收UE通过ResourceReservePeriod推断出预留的周期性资源的信息，所述ResourceReservePeriod选择性地被配置于SCI中；设置计时器drx-ReservePeriodTimer＝ResourceReservePeriod作为接收UE的激活时间(Active Time)，接收UE还在所有预留的周期性预留资源的相关时隙接收不同的初始TB。
更优选地，若drx-ReservePeriodTimer与drx-onDurationTimer重叠，则接收UE优先所述On-Duration的计时器。
更优选地，若drx-ReservePeriodTimer与其他预留资源时隙重叠，则接收UE优先检测预留资源时隙。
优选地，发送UE在On-Duration内传输业务开始的第一个初始TB，且相邻两个TB的发送间隔小于32个时隙，则传输的资源由每一个TB所关联的SCI连续为下一个TB预留；接收UE设置计时器drx-ReserveInstantTimer作为激活时间，仅监视On-Duration的时隙和所有预留资源的相关时隙。
优选地，发送UE在On-Duration内传输业务开始的第一个初始TB，且相邻两个TB的发送间隔大于32个时隙，则发送UE使用SCI预设格式不预留任何用于传输的资源；接收UE仅在On-Duration的时隙进入唤醒状态来接收所述初始TB。
优选地，若接收UE访问gNB网络，在gNB通过PDCCH对接收UE指示或授予PDSCH或PUSCH资源之前，接收UE保持或者在DRX模式的On-Duration内保持检测PDCCH。
优选地，若侧链路通道上的流量很小，所述On-Duration中配置的时隙数量减少至一个。
优选地，不连续接收模式包括通用DRX模式(Common DRX Pattern)，也可以又名为默认DRX模式(Default DRX Pattern)，发送UE选用通用DRX模式发送初始TB；其 中，所述通用DRX模式被配置为具有长的DRX周期和短的On-Duration，在每个长DRX周期内，节能UE自drx-CommonSlotOffset之后启动计时器drx-CommonOnDurationTimer；当节能UE满足条件
[(DFN×10)+Slot-Number(n)]mod(drx-CommonCycle)＝drx-CommonStartOffse,
就进入唤醒状态并接收PSCCH；其中，DFN(direct frame number)是GNSS给出的直接帧号(可以在覆盖范围内和覆盖范围外获取)，drx-CommonCycle是通用DRX的周期，Slot-Number(n)是当前的时隙索引，n为自然数，drx-CommonStartOffse是DRX通用偏移时隙。更优选地，所述通用DRX模式被配置为所有时隙均能被节能UE检测到，且适用于所有传输类型(单播，组播或广播)。
更优选地，上述公式中，DFN可以用SFN(system frame number)代替。但SFN仅在蜂窝网覆盖范围内有效。为了有效降低功耗，应该尽可能保持短的On-Duration。
更优选地，通用DRX模式下，发送UE在On-Duration内的传输使用盲重传(Blind Retransmission)，即一个初始TB和至少一个重传TB，和/或发送UE在Off-Duration内的传输使用基于HARQ机制的重传。
上述内容中，在On-Duration中进行盲重传可以保证接收UE成功地接收到SCI，以便能够保持两个相邻预留资源之间的资源预留链。
进一步地，在On-Duration中，发送UE忽略Rx-UE反馈的FCI信息，已达到盲重传的目的。
上述内容中，为了和Rel-16的UE保持后向兼容，每个资源池中需要配置具有专用PSFCH资源的PSCCH/PSSCH资源以便用于基于HARQ机制的重传，在此情况下，Rel-17的发送UE还是能够在On-Duration中传输初始TB和重传TB，但发送UE需要改变针对HARQ机制的行为，即仅在On-Duration中忽略接收UE反馈的FCI信息，也就是说，不管收到ACK还是NAK，发送UE必须完成在On-Duration中的所有重传，但在Off-Duration中，发送UE还是需要遵循Rel-16的HARQ机制，执行基于HARQ机制的重传。
进一步地，在On-Duration中配置不包含专用PSFCH资源的PSCCH/PSSCH资源以便进行盲重传，在Off-Duration中配置具有专用PSFCH资源的PSCCH/PSSCH资源以便用于基于HARQ机制的重传。
进一步地，在On-Duration中，MAC层通知PHY层在汇报候选资源时包括在On-Duration中的资源时隙范围，或PHY层事先得知DRX的具体配置，以保证On-Duration 中有足够的候选资源。
进一步地，在On-Duration中，MAC层通过优化资源选择方法，为初始TB选择有利的资源来完成初始TB的传输和盲重传，所述优化资源选择方法至少包括以下之一：提高初始TB的优先级；或提高传输初始TB对应的PSCCH的编码率(Coding Rate)。
上述内容中，为了在On-Duration中传输初始TB的PSCCH编码率得到提高，RRC包括两种PSCCH的配置，即，一种是On-Duration相关的PSCCH配置，拥有较高的编码率，另一种是Off-Duration相关的PSCCH配置，拥有和Rel-16相当的编码率。
更优选地，不连续接收模式还包括针对特定业务的特定DRX模式(specific DRX pattern)，所述特定DRX模式被配置为具有短的DRX周期，在每个特定DRX配置中，与短PDB的QoS相关联的DRX参数是(预)配置的；其中，On-Duration仅包含很少的时隙(最少可以是一个时隙)，DRX周期小于短PDB。
进一步地，UE可以在通用DRX模式的基础上使用特定DRX模式，并基于特定业务的需求在通用DRX模式和特定DRX模式之间进行切换。
更进一步地，在通用DRX模式和特定DRX模式之间进行切换，包括：接收MAC-CE或SCI的控制信令以便在通用DRX模式和特定DRX模式之间切换；以及当特定业务到期并且不再传输相关数据包，所述特定DRX模式停止使用，同时UE退回至通用DRX模式。
优选地，若发送UE预留了非周期性资源，且接收UE从接收的PSCCH中正确检测SCI、但没有任何预留资源，或者未能检测到与重传TB相关的所需SCI，则接收UE启动计时器drx-RetransmissionTimer，接收UE在每个时隙被唤醒并检测解码PSCCH，直到计时器drx-RetransmissionTimer到期，或者接收UE接收到重传的SCI；之后接收UE进入正常的节能接收模式，其中，所述节能接收模式是指接收UE仅在On-Duration和被预留资源的时隙中进入唤醒模式，接收PSCCH、并解码和接收UE相关联的TB。
更优选地，若资源池中启用了资源重新评估和/或抢占机制，接收UE在接收初始TB且未成功解码到TB之后启动计时器drx-HARQ-RTT-Timer，在反馈NAK之后，接收UE间接启动计时器drx-RetransmissionTimer。
更优选地，若资源池中启用了资源重新评估和/或抢占机制，则禁止发送UE在预留资源的时隙之前重新选择资源，且发送UE重新选择资源优选与预留资源的时隙接近的资源。
更优选地，若发送UE在Off-Duration内的传输使用基于HARQ机制的重传，HARQ进程使用HARQ Option-2，且接收UE无法检测到与初始TB相关的PSCCH，则发送UE 在相同的On-Duration中重传TB，或者在延迟预算之内的下一个即将到来的On-Duration中重传TB。
优选地，若发送UE预留了周期性资源，且由于连续的资源冲突、以及发送UE触发资源重新选择而造成资源预留链丢失，则发送UE被配置为仅在On-Duration期间重新选择资源，接收UE仅在On-Duration和预留的周期性资源的相关时隙进入唤醒状态来接收初始TB或重传TB。
上述内容中，一旦接收UE在On-Duration内进行TB接收，则会检测到资源是否被重新选择，这要求发送UE的MAC实体将DRX周期作为计数单位来决定资源是否需要重新选择，而不是像Rel-16中采用的对TB传输数进行计数。
更优选地，若资源池中启用了资源重新评估和/或抢占机制，则通过在(预)配置的资源池中使用sl-PreemptionEnable来禁用资源重新评估和/或抢占机制。
优选地，若发送UE预留了周期性资源，且由于连续的资源冲突、以及发送UE触发资源重新选择而造成资源预留链丢失，则接收UE启动计时器drx-ReceivePeriodTimer，其中drx-ReceivePeriodTimer＝ResourceReservePeriod，接收UE在每个时隙被唤醒并检测解码PSCCH，直到计时器drx-ReceivePeriodTimer到期，或者接收UE再次检测到与预留的周期性资源相关的PSCCH；之后接收UE进入正常的节能接收模式，所述节能接收模式是指，接收UE仅在On-Duration和被预留资源的时隙中进入唤醒模式，接收PSCCH、并解码和接收UE相关联的TB。
更优选地，在所述资源预留链丢失之前，发送UE采取以下任一方式防止发送UE预留的周期性资源被另一个发送UE抢占，包括：
提高初始TB的优先级；或者
禁止发送UE在预留资源时隙之前重新选择资源；或者
通过SCI或MAC-CE预先通知接收UE在下一次传输中将重新选择周期性资源。
上述内容中，一旦接收UE启动计时器drx-ReceivePeriodTimer，则资源重新选择可以在On-Duration中执行，也可以不在On-Duration中执行。
优选地，所述方法还包括：针对第一发送UE预留的周期性资源，第二发送UE采用部分感测机制执行信道感测，并将感测结果提供给MAC层以进行资源(重新)选择，所述部分感测机制包括：
第二发送UE在每个第一发送UE预留的周期性资源的时隙进入唤醒状态感测PSCCH 上的SCI；当SCI检测失败，则第二发送UE启动计时器drx-PeriodSensingTimer，并唤醒检测每个时隙中的PSCCH，直到计时器drx-PeriodSensingTimer到期，或者第二发送UE成功检测到新的时隙中的PSCCH为止；
其中，第一发送UE和第二发送UE为不同的发送UE。
更优选地，所述部分感测机制中的计时器drx-PeriodSensingTimer等于特定业务中QoS要求的ResourceReservePeriod。
更优选地，在部分感测机制中，禁止第一发送UE选择预留的周期性资源之前的资源作为重新选择资源。
优选地，所述方法还包括：在每个资源池中，不同周期性和/或不同发送时间偏移的至少两个第一发送UE均预留了周期性资源，第二发送UE仅在不同的感测簇(Sensing Cluster)中被唤醒执行与其相关的信道感测，所述感测簇被配置为至少两个不同的第一发送UE预留的周期性资源的重叠时隙(Superposition Slot)或相邻时隙(Neighbor Slot)，其中，第一发送UE和第二发送UE为不同的发送UE。
更优选地，不同的感测簇包括在Off-Duration中靠近On-Duration的感测簇和远离On-Duration的感测簇，第二发送UE仅在远离On-Duration的感测簇中被唤醒执行与其相关的信道感测。
更优选地，使用Th(prio RX,prio TX)的值配置阈值，第二发送UE将其接收到的RSRP与所述阈值进行比较，排除不属于阈值范围的预留资源，从剩余的预留资源中执行后续的发送资源选择；其中，prio RX是用于接收数据包的优先级，prio TX是用于发送数据包的优先级。
优选地，所述方法还包括：当发送UE预留了周期性资源，感测UE建立具有T cycle时隙的特定感测周期(Specific Sensing Cycle)，每个特定感测周期被配置为拥有L个T W的部分感测窗口(Partial Sensing Window)，每个部分感测窗口的位置由感测UE自己决定，或者由RRC在每个资源池中利用时隙偏移Δ W，l(Window Offset)来配置，感测UE在所述部分感测窗口被唤醒并感测所有时隙的PSCCH；其中，T W为部分感测窗口的周期长度，其满足T MIN≤T W≤T MAX，T MIN和T MAX分别是当前资源池中配置的最小周期长度和最大周期长度，L为部分感测窗口的个数，
Figure PCTCN2020132623-appb-000003
而T MAX＜＜T cycle，l＝1,2,…,L。
更优选地，所述部分感测窗口的大小可以根据当前资源池中正在进行传输中的流量情况而自适应调整。
更优选地，如果L>1，在特定感测周期中的部分感测窗口大小可以不同，也是由感测 UE自己决定。
更优选地，通过感测所述部分感测窗口获得以下信息中的一种或几种：
当前资源池中正在进行传输中的流量周期性数和相应的周期长度；
发送UE与感测UE之间的周期资源的时间偏移。
更优选地，基于信道条件，是否在所述部分感测窗口中执行感测取决于UE的实现，例如，如果接收到的NAK数大于一设定阈值，则感测UE可以在特定感测周期内激活其部分或全部的部分感测窗口T W。
更优选地，基于感测到的长周期的预留资源数量(或出现频度)，第二发送UE可以根据预设的阈值调节部分感测窗口T W的大小。
更优选地，T W和阈值的关系可以由RRC(预)配置；其中，资源池中的周期数和相应的周期长度分别为M和N m，m＝1,2,…,M；长周期的预留资源数量阈值可以被(预)配置为TH m，而N m和TH m是相对应的；感测UE可以根据感测长周期的预留资源数量和TH m相比，从而决定T W。
在一种优选实施例中，如果在每个资源池中配置了最小感测窗口(如T MAX)，则可以将感测簇作为部分感测窗口，而这种部分感测窗口设定不需要有任何感测周期的限制。
更优选地，一个所述特定感测周期可以为多个资源池配置使用，T W的部分感测窗口可以由多个资源池中配置的最小周期长度和最大周期长度决定。
优选地，所述方法还包括：针对预留的非周期性资源，发送UE采用以下方式中的一种或几种的组合执行信道感测：
第二部分感测机制，所述第二部分感测机制包括：在TB到达后，发送UE启动计时器drx-SensingTimer，在DRX模式下的On-Duration之前的前31个时隙进行信道感测以进行后续的资源选择，之后发送UE继续进行感测，直到初始TB或重传TB被成功接收，或者计时器drx-SensingTimer到期为止；
全面感测机制(Full Sensing)，所述全面感测机制包括：若PDB小于32个时隙，发送UE不关闭感测的侧链路RF，在第一个TB到达后的第一个On-Duration的32个时隙之前开始感测，而在成功传输最后一个TB的时隙中停止执行感测；
随机资源选择机制，所述随机资源选择机制包括：对于高节能要求的发送UE，发送UE将选择窗口内的所有候选资源报告给MAC，而不包括资源排除过程。
上述内容中，在Rel-17中，可以基于全面感测机制，部分感测机制，随机资源选择机 制中的一种或几种的组合来(预)配置侧链路发送资源池拥有数据包传输。
上述内容中，周期性的部分感测机制和非周期性的部分感测机制，可以同时使用，这是因为发送UE可能具有周期性流量和/或非周期性流量，感测UE必须同时捕获和推断两种流量类型的预留资源信息。
上述内容中，资源池由SL-ResourcePool配置，其中数据包的周期性选择周期性列表sl-ResourceReservePeriodList进行配置，此时，一个资源池里可以同时传输周期性和非周期性的业务量，并且必须同时考虑周期性和非周期性的部分感测机制；否则，UE只能传输非周期性的数据包，此时，感测过程依赖于非周期性的部分感测机制。
本申请提供一种节能NR侧链路传输和接收的方法，解决了在DRX开启持续时间和关闭持续时间中，如何控制侧链路的发送和接收问题，以及基于部分感测的传输的问题，解决了现有技术中DRX节能方面的不足。
附图说明
构成本申请的一部分附图用来提供对本申请的进一步理解，本申请的示意性实施例及其说明用于解释本申请，并不构成对本申请的不当限定。在附图中：
图1是实施例一中针对场景1、场景2和场景3的TB发送和接收示例图；
图2是实施例一中DRX操作的发送(重送)和接收示例图；
图3是实施例一中使用通用DRX模式的资源选择和预留示例图；
图4是实施例二中由于无资源预留、资源被抢占或SCI解码失败而导致资源预留链故障示例图；
图5是实施例二中由于资源重新评估或资源被抢占机制，而触发资源重新选择示例图；
图6是实施例三中始终在“开启持续时间”内进行资源重选示例图；
图7是实施例三中使用接收计时器的定期流量传输和接收示例图；
图8是实施例四中用于通用DRX和特定DRX的Dual-DRX配置示例图；
图9是实施例五中Tx-UE-A发送周期性TB，而Tx-UE-B进行信道感测示例图；
图10是实施例五中使用感测集群对周期性流量的信道进行部分感测示例图；
图11是实施例六中使用短感测窗口对非周期性流量的信道进行部分感测示例图；
图12是实施例六中针对非周期性流量的信道进行部分感测示例图。
具体实施方式
以下内容中，Tx-UE可以属于节能UE(例如，V2X用例中的Vulnerable Road Users，简称为VRU，或者公共安全和商业用例中的用户)，也可以属于普通UE(例如，车辆UE)。但是，Rx-UE只能属于节能UE。值得注意是，仅节能UE需要节省UE功耗。
以下内容中，DRX有两种类型的激活时间(Active Time)；一个称为数据包接收激活时间，另一个称为感测激活时间。在前一个数据包接收激活时间期间，UE应该解码PSCCH和PSSCH，而在感测激活时间期间，UE只需要解码PSCCH。
在侧链路DRX中，我们引入了用于数据包接收的计时器，包括drx-onDurationTimer，drx-CommonOnDurationTimer，drx-SpecificOnDurationTimer，drx-CommonOffDurationTimer，drx-SpecificOffDurationTimer，drx-ReservePeriodTimer，drx-ReserveInstantTimer，drx-HARQ-RTT-Timer和drx-RetransmissionTimer。当配置了侧链路DRX周期时，数据包的接收激活时间包括：
●上次传输中已预留资源的时隙；或
●以下任一定时器正在运行：drx-CommonOnDurationTimer,drx-SpecificOnDurationTimer，drx-onDurationTimer,drx-RetransmissionTimer。
在侧链路DRX中，我们引入了用于部分感测的计时器，包括drx-PeriodSensingTimer和drx-SensingTimer。当配置了侧链路DRX周期时，部分感测的感测激活时间包括
●UE在部分感测激活时间内进行接收的时隙；或
●以下任一定时器正在运行：drx-PeriodSensingTimer，drx-SensingTimer，drx-onDurationTimer，drx-CommonOnDurationTimer，drx-SpecificOnDurationTimer。
实施例一：
本实施例解决了Tx-UE如何初始传输/重传(Retransmission，简称为Re-Tx)TB(Transport Block)，以及Rx-UE如何接收初始TB和重传TB的问题。
在NR-V2X中，Tx-UE使用物理侧链路控制信道PSCCH(Physical Sidelink Control Channel)以格式1-A(1st Stage)在时隙n中发送SCI(Sidelink Control Information)，并且随后使用与其相关联的物理侧链路共享信道PSSCH(Physical Sidelink Shared Channel)在同一时隙中发送数据包。PSCCH能够基于感测和资源选择过程来指示用于TB的初始传输的资源，并为其重新传输预留资源；其中所预留的资源的最大数量为两个。Tx-UE可以根据业务类型在0ms，
Figure PCTCN2020132623-appb-000004
100ms，200ms，…，1000ms之间选择周期性。PSCCH在TB的初始传输同时选择性的利用“resource reservation period”为周期性数据包 预留周期性资源。可选性地，PSCCH也可以使用SCI为与不同TB相关联的TB的预留初始传输的资源。
在侧链DRX中，一旦Tx-UE开始其特定业务，无论传输的类型是什么(即单播，群播或广播)，Tx-UE都应确保在On-Duration内传输第一个TB(或初始TB)。这是因为，DRX模式必须保证Tx-UE和Rx-UE之间发送/接收相互对齐。而只有在On-Duration内，对业务感兴趣的Rx-UE才能确保接收到发送的TB。
另外，由于Tx-UE需要确保数据包在On-Duration内准确无误地被Rx-UE接收，在传输方面必须进行增强。例如，在On-Duration内的传输使用盲重传(Blind Retransmission)，这样可以提高数据包的接收概率。还有，Tx-UE在选择发送资源时，必须保证发送资源能够在On-Duration内。
值得注意是，一旦Tx-UE开始其特定业务，第一个TB可能是高层控制信息或业务数据信息。为了实现侧链路DRX的节能，针对发送(重传)/接收，应考虑如图1所示的三个场景。
场景-1:
在场景1中，使用SCI格式1-A预留周期性资源。Tx-UE可以预留周期性资源，而无需考虑该资源是处于On-Duration还是处于Off-Duration。如果Tx-UE开始其相应的业务，则相关联的第一个TB必须在On-Duration期间被发送。
一旦Tx-UE开始其相应的业务，Rx-UE会在On-Duration期间获取第一个TB，然后，Rx-UE可以通过ResourceReservePeriod来推断出预留的和周期性相关资源信息。ResourceReservePeriod可以选择性地被配置在SCI中。通过设置计时器drx-ReservePeriodTimer＝ResourceReservePeriod，作为UE的激活时间(Active Time)，Rx-UE只需检测预留资源相关的时隙。这意味着，一旦计时器运行，Rx-UE将停止接收并关闭其RF链。值得注意的是，如果drx-ReservePeriodTimer与drx-onDurationTimer重叠，则Rx-UE必须优先考虑On-Duration的计时。如果drx-ReservePeriodTimer与其他预留资源时隙重叠，则接收UE优先检测预留资源时隙。
场景-2:
在场景2中，SCI格式1-A可以预留用于其他TB的初始传输的资源。同样地，Tx-UE开始其相应的业务，只要在On-Duration期间传输第一个TB，Tx-UE就可以预留资源而无需考虑资源是处在On-Duration还是Off-Duration。如果数据包的间隔小于32个时隙，则 传输资源可以由与一个TB关联的SCI连续为下一个TB预留。
在这种情况下，Rx-UE将使用drx-ReserveInstantTimer计时器，Rx-UE只需检测通过SCI指示的预留资源的相关时隙。这意味着，一旦计时器运行，Rx-UE将停止接收并关闭其RF链。
作为大数据包的用例，一个大数据包可能被分割成多个TB，因此两个TB之间的间隔可能会非常短。每个TB必须以短间隔形式被发送，从而满足大数据包整体的迟延要求。
场景-3:
在场景3中，SCI格式1-A不保留任何资源。这通常发生在为非周期性流量提供业务时，其两个初始TB之间的传输间隔大于32个时隙。在这种情况下，Tx-UE必须在On-Duration中选择资源，以便对业务感兴趣的Rx-UE在On-Duration期间保证能接收数据包。因此，Rx-UE仅需要检测在On-Duration内的所有的时隙。
如果Rx-UE能够访问gNB网络，在gNB通过PDCCH对Rx-UE指示或授予PDSCH或PUSCH(Physical Uplink Shared Channel)资源之前，Rx-UE是不知道其接收或发送的时机。因此，如果DRX被(预)配置的话，则UE必须保持或者在DRX On-Duration期间保持检测PDCCH。
但是在NR-V2X中，PSCCH接收或传输与PDSCH接收或传输的有着根本的区别。在初始传输中，PSCCH上的SCI不仅指示用于初始传输的资源，而且还预留了用于同一TB的重传资源，最多预留资源可以有两个。如果为初始传输和重传选择的资源都限制在DRX On-Duration范围内，则DRX On-Duration不能配置为短于32个时隙。这会导致比较大的功耗。因此，UE应该允许在侧链路DRX Off-Duration期间也可以拥有激活时间(即，Active Time)。例如，和Uu DRX操作一样，侧链路DRX操作应该支持扩展On-Duration，在Off-Duration期间也可以发送和接收侧链路初始或重传数据包。
具体地说，Tx-UE允许在侧链路DRX的On-Duration期间传输初始TB，但是利用相应的PSCCH在Off-Duration中预留重传的资源。因此，Rx-UE需要被唤醒来检测On-Duration内的所有时隙以外，还需要被唤醒来检测预留时隙中的被重传的PSCCH。这样可以大大减小On-Duration的长度同时保持PRR(Packet Reception Ratio，数据包接收率)性能。如果侧链路通道上的流量很小，则可以将On-Duration中配置的时隙数减少至一个。如果涉及基于HARQ的重传，则可以为单播和组播节省大量功耗，如果执行盲重传(Blind Retransmission)，则可以为单播，组播和广播节省大量功耗。
图2示例了发送(重传)和接收中的DRX进程，其中Tx-UE在On-Duration内发送初始TB，在Off-Duration内重送相同TB。因此，作为激活时间(Active Time)，Rx-UE在On-Duration内检测PSCCH并进行其初始TB接收，以及在Off-Duration的预留时隙中进行重传TB接收。
在示例中，具体地，初始TB在On-Duration的Slot-0中被传输，并且其相应的PSCCH为重传Re-Tx1预留资源#1。因此，Rx-UE知道由PSCCH预留的资源时隙，即，Rx-UE仅需要检测On-Duration内的时隙，以及Off-Duration内的Slot-1中的被预留资源时隙。值得注意是，如果初始TB不是业务开始的第一个TB的话，则Tx-UE无需一定要在On-Duration内发送该TB，只要由SCI在前一个TB中为它预留资源即可。
此外，在重传Re-Tx1中，相应的PSCCH分别为Re-Tx2和Re-Tx3预留资源#2和资源#3。因此，Rx-UE知道PSCCH将在Slot-2和Slot-3时隙出现，因此只需要检测Slot-2和Slot-3中的PSCCH。相同的传输和保留过程可以被持续，直到达到延迟预算或Rx-UE成功解码TB。
如果Tx-UE想要向Rx-UE发送初始数据包，并且Rx-UE被(预)配置了DRX，则Tx-UE必须考虑使用通用DRX模式(Common DRX Pattern)或默认DRX模式(Default DRX Pattern)，以便Tx-UE发送的数据包能够被Rx-UE接收。通用DRX模式被定义为一种DRX模式，其中所有时隙都应当能被节能UE检测到，而且是针对所有传输类型(单播，组播或广播)的。
可以将通用DRX模式配置为具有较长的DRX周期和较短的On-Duration。在每个DRX周期内，节能UE通过drx-CommonSlotOffset偏移时隙之后启动计时器drx-CommonOnDurationTimer。如果节能UE满足以下条件，就需要唤醒并接收PSCCH，[(DFN×10)+Slot-Number(n)]mod(drx-CommonCycle)＝drx-CommonStartOffse,其中，DFN(direct frame number)是GNSS给出的直接帧号，drx-CommonCycle是通用DRX的周期，Slot-Number是当前的时隙索引，drx-CommonStartOffse是通用DRX开始偏移量。
值得注意是，使用DFN来代替SFN(system frame number)的原因是所有UE都可以对齐通用DRX模式，而不用介意是否在覆盖范围内还是在覆盖范围外。
为了有效降低功耗，应该尽可能保持短的On-Duration。但是，短On-Duration会导致两个问题；一个是更容易在Tx-UE之间产生半双工问题，另一个是来自其他一些Tx-UE的 干扰会更加严重，从而产生可靠性问题。为了解决半双工和可靠性问题，Tx-UE应该仅在On-Duration中考虑盲重传(即，一个初始TB和若干个重传TB)。为了解决干扰和资源使用有效率问题，Tx-UE应该在Off-Duration中考虑基于HARQ的重传。另外，能够始终保持两个相邻资源之间的资源预留链(Reservation Chain)是非常重要的。
图3举例说明了使用通用DRX模式进行的资源选择和预留，其中Tx-UE基于盲重传在On-Duration中发送初始TB和一个重传TB，并基于HARQ机制在Off-Duration中重传相同的TB。资源#0专用于初始传输，而资源#1专用于盲重传(没有配置的PSFCH资源)，这就解决了半双工和初始数据包接收可靠性问题。另外，资源
Figure PCTCN2020132623-appb-000005
被预留用于基于HARQ机制的重传，以提高资源使用有效率和PRR性能。特别注意的是，在On-Duration中进行盲重传可以保证Rx-UE成功地接收到SCI，以便能够保持两个相邻资源之间的资源预留链。
在Rel-16中，每个资源池可选地被配置拥有PSFCH资源。被配置的PSFCH资源与发送PSCCH/PSSCH的时隙相关联。在Rel-17中，为了实现盲重传和基于HARQ机制的重传组合，我们考虑灵活配置专用于通用DRX模式的资源池。这意味着，在配置的资源池中，可以在On-Duration中配置不包含专用PSFCH资源的PSCCH/PSSCH资源以便进行盲重传，而在Off-Duration中配置具有专用PSFCH资源的PSCCH/PSSCH资源以便用于基于HARQ机制的重传，如图3所示。
另外，Tx-UE在选择资源时必须保证有足够的候选资源在On-Duration中。以便MAC层可以顺利地为初始数据包选择On-Duration中的资源。这就需要MAC层通知PHY层在汇报候选资源时候必须包括在On-Duration中的资源时隙范围，或PHY层事先得知DRX的具体配置。MAC层通过优化资源选择方法，为初始数据包选择有利的资源来完成初始传输和盲重传输。比如，在On-Duration中为初始数据包选择资源时，可以把数据包的优先度提高到比较高的数值(如，优先度为1)。也可以为在On-Duration中用作传输初始数据包的PSCCH提高编码率(Coding Rate)，以便保证所有的Rx-UE能够成功解码PSCCH，从而获得SCI信息，确保两个相邻资源之间的资源预留链。
为了在On-Duration中传输初始数据包的PSCCH编码率得到提高，RRC必须要有两种PSCCH的配置；即，一种是On-Duration相关的PSCCH配置，拥有比较高的编码率，而另一种是Off-Duration相关的PSCCH配置，拥有和Rel-16相当的编码率。
为了和Rel-16的UE保持后向兼容，每个资源池中需要配置具有专用PSFCH资源的 PSCCH/PSSCH资源以便用于基于HARQ机制的重传。在这种情况下，Rel-17的Tx-UE还是能够在On-Duration中传输初始TB和重传TB，但是Tx-UE需要改变针对HARQ机制的行为，即，仅在On-Duration中忽略Rx-UE反馈的FCI信息。也就是说，不管收到ACK还是NAK，Tx-UE必须完成在On-Duration中的所有重传。但是，在Off-Duration中，Tx-UE还是需要遵循Rel-16的HARQ机制，执行基于HARQ机制的重传。
实施例二：
本实施例解决了Tx-UE如何发送非周期性数据包，Rx-UE如何接收非周期性数据包的问题。
Tx-UE发送PSCCH时最多能预留两个资源作为重传资源。为了确保预留资源的资源预留链，必须满足两个条件：一个是，每个Rx-UE必须正确地从接收的PSCCH中解码SCI；另一个是，必须在每个(预)配置的资源池中通过sl-PreemptionEnable来关闭资源重新评估(re-evaluation)和资源抢占(pre-emption)机制。无法满足任何一个条件都可能产生资源预留链非连续性问题。
针对初始TB的可靠性问题，我们已经在实施例一中提出了解决方案。但针对在成功解码初始TB的SCI后如何保证资源预留链连续性问题，我们考虑一种增强方案，而解决方案是针对以下两种场景的：
●Rx-UE成功接收到SCI，但SCI没有为数据包重传预留任何资源
Figure PCTCN2020132623-appb-000006
假设资源池被配置了和PSCCH/PSSCH关联的PSFCH资源；
Figure PCTCN2020132623-appb-000007
Rx-UE无法在相应的PSSCH上成功解码TB，因此Rx-UE反馈ACK/NAK给Tx-UE。
●Rx-UE在初始传输中成功接收到SCI，但是在当前时隙中没有成功检测到SCI。以下场景被考虑：
Figure PCTCN2020132623-appb-000008
SCI是通过Tx-UE预留资源发送的，但是Rx-UE没有成功检测到SCI；
Figure PCTCN2020132623-appb-000009
Tx-UE触发了重新评估，因此预留资源已被更改；
Figure PCTCN2020132623-appb-000010
预留的资源已被拥有更高优先级TB的其他Tx-UE抢占。因此，Rx-UE无法解码到SCI，或者Rx-UE可能正确解码到了SCI，但认识到它不是其所需的SCI。
为了解决上述问题，我们提出两个计时器，分别称为drx-ReserveInstantTimer和drx-RetransmissionTimer。前者已在实施例一中使用，即，一旦此计时器运行，Rx-UE停止接收并关闭其RF链。而后者是新计时器，一旦Rx-UE正确检测到SCI，但没有任何预 留资源，或者未能检测到与重传相关的所需SCI，Rx-UE就会启动drx-RetransmissionTimer。一旦此计时器运行，Rx-UE就需要被唤醒并检测解码每个时隙中的PSCCH。
图4示例说明了由于无资源预留、资源抢占或SCI解码失败而导致Slot-1和Slot-2之间的资源预留链中断。在该示例中，Tx-UE在Slot-0中传输初始TB，同时预留了用于重传1(Re-Tx1)的资源#1。Rx-UE成功接收到SCI但没有成功解码TB，Rx-UE发送ACK/NAK给Tx-UE，并启动计时器。当“drx-ReserveInstantTimer”被启动，Rx-UE停止接收并关闭其RF链，直到在Slot-1被唤醒重新接收数据包(主要包括被重传的TB)。
Tx-UE在Slot-1中重传TB，但没有为Re-Tx2预留任何资源，或者Tx-UE预留了资源但被其他Tx-UE抢占，或者Tx-UE在Slot-1中重传TB，但Rx-UE对SCI的解码没有成功。任何一种情况的发生，Rx-UE会马上启动“drx-RetransmissionTimer”计时器。一旦此计时器运行，Rx-UE被要求检测解码每个时隙中的PSCCH，直到定时器到期，或者Rx-UE接收到重传的SCI。
Tx-UE在Slot-2中选择用于Re-Tx2的资源#2，并重传TB，同时为Re-Tx3预留资源#3。Rx-UE成功检测到SCI并停止“drx-RetransmissionTimer”计时器。随后，如果数据包解码还没有成功，Rx-UE再次启动drx-ReserveInstantTimer计时器，在Slot-3中被唤醒接收重传的数据包。
如果在资源池中启用了重新评估/抢占机制，被触发而重新选择的资源时隙位置可能影响Rx-UE的接收性能。和被Slot-0中SCI预留的资源位置(Slot-1)相比，重新选择的资源时隙位置可能在Slot-1之前，也可能在Slot-1之后。如图5所示，Slot-1a中的重新选择的资源#a是在Slot-1之后，而Slot-1b中的重新选择的资源#b是在Slot-1之前。对于前者，利用“drx-ReserveInstantTimer”来接收重传TB将不会产生任何问题。但是，对于后者，Rx-UE将无法接收到重传的TB。
一种简单但并非有效的节能解决方案是重用Rel-16中的HARQ计时器。该计时器在Rel-16中定义为drx-HARQ-RTT-Timer。这意味着，在接收初始TB且未成功解码到TB之后，Rx-UE启动drx-HARQ-RTT-Timer。在反馈NAK之后，Rx-UE间接启动drx-RetransmissionTimer。该解决方案不涉及drx-ReserveInstantTimer，但缺点是，Rx-UE需要保持唤醒状态并长时间接收PSCCH。
另一种解决方案是，一旦执行资源重新评估/抢占机制，禁止Tx-UE在预留资源时隙之 前重新选择资源。如图5所示，Tx-UE排除资源#b，重新选择资源#a。此外，在确定资源#a的时候，Tx-UE应该选择与预留资源#1较为接近的候选资源，这样使Rx-UE能够更早地停止计时器并达到节能效果。
另一个问题是，如何在HARQ过程中解决不连续传输DTX(Discontinuous Transmission)问题。如果Rx-UE无法检测到与初始TB相关的PSCCH，Rx-UE将不会发送相应的NAK给Tx-UE。对Rx-UE来说，这样的接收失败就好像没有TB传输发生一样。这将会降低整体PRR性能。
如果HARQ进程使用HARQ Option-2，Tx-UE可以判断到发生的DTX。因此，如果On-Duration计时器仍在运行，则Tx-UE可以在相同的On-Duration中重传TB；如果延迟预算允许，则可以在下一个即将到来的On-Duration中重传TB。
实施例三：
本实施例解决了Tx-UE如何发送周期性数据包，Rx-UE如何接收周期性数据包的问题。
在周期业务的发送和接收中，一旦Tx-UE发起业务并将第一个TB发送到Rx-UE，则第一个TB必须在On-Duration内发送，以便保证Rx-UE能够接收。如果周期资源的预留在完成其特定业务之前保持不变，则Rx-UE会唤醒并只要在相应预留的周期资源上接收TB。但是，由于连续的资源冲突以及触发资源重新选择的重估和抢占机制的原因，周期资源的预留持续性是无法被确保的。
当SL_RESOURCE_RESELECTION_COUNTER＝0，并且Tx-UE基于在间隔[0，1]中随机选择的值小于或等于sl-ProbResourceKeep(例如，0.2，0.4，…，0.8)时，则Tx-UE触发资源重选。因此，Rx-UE可能失去用于周期性数据包的资源预留链。
一种解决方案是确保Tx-UE仅在DRX On-Duration期间重新选择资源。这样，Rx-UE仅唤醒在周期性预留的资源中接收周期业务。一旦Rx-UE在On-Duration内进行数据包接收，它就会检测到周期资源是否被重选。这要求MAC实体将DRX周期作为计数单位来决定资源是否重选，而不是像Rel-16中采用的对TB传输数进行计数。图6说明了一个示例，其中资源重新选择发生在On-Duration的Slot-4中。这将确保了Rx-UE能够检测到重新被选择周期性资源。
但是，这种解决方案的缺点是，许多Tx-UE可能会在相同的On-Duration中重新选择资源，从而增加了在On-Duration中的资源冲突。
除了资源重选机制之外，重估和/或抢占机制也可以触发周期性资源的重选。为了确保 仅在On-Duration中发生资源重新选择，必须通过在(预)配置的资源池中使用sl-PreemptionEnable来禁用资源重新评估和/或抢占机制。
另一个问题是，由于资源冲突或其他低SINR的原因，Rx-UE可能无法检测到被ResourceReservePeriod预留的周期性TB相关的SCI。尽管Rx-UE可以在下一个预留时机检测到SCI并恢复预留链，但这会导致接收性能下降。
我们提出一个特定的计时器来解决恢复资源预留链的问题。如果Rx-UE检测到资源预留链的丢失，Rx-UE将启动drx-ReceivePeriodTimer计时器，其中drx-ReceivePeriodTimer＝ResourceReservePeriod。一旦drx-ReceivePeriodTimer运行，Rx-UE就会唤醒并检测每个时隙中的PSCCH。如果drx-ReceivePeriodTimer到期，或者Rx-UE再次检测到周期业务相关的PSCCH，Rx-UE将进入正常的节能接收模式。这样，Tx-UE就不需要强加资源重新选择一定要在On-Duration中执行。
其中，节能接收模式指的是，Rx-UE仅唤醒接收在On-Duration和被预留资源时隙中的PSCCH，并解码和Rx-UE相关联业务的数据包。具体描述可以参考实施例一。
图7描述了具有特定接收定时器drx-ReceivePeriodTimer的周期性业务的发送和接收示例，其中，Tx-UE在Slot-0中发送初始TB，并在Slot-1和Slot-2中预留周期性资源。在Slot-2中，由于Tx-UE重新选择了资源，Rx-UE无法检测到SCI。因此，Rx-UE启动计时器并继续检测每个时隙中的SCI，直到它再次检测到关联的SCI预留了新的周期性资源，或者drx-ReceivePeriodTimer到期为止。在示例Slot-3中，Rx-UE再次检测到相关联的SCI，并停止计时器，然后，Rx-UE将进入正常的节能接收模式。
如果在资源池中启用了重新评估/抢占机制，则由Tx-UE预留的资源可能将被另一个Tx-UE抢占。与实施例二中讨论的问题相同，由重新评估/抢占或SL_RESOURCE_RESELECTION_COUNTER机制而触发的重新选择资源可能在Slot-2中已预留资源之前或之后。值得注意的是，作为最坏情况，此问题可能导致周期性接收中一个数据包丢失。在示例中，如果重新选择的资源出现在预留资源之前，Rx-UE可以在Slot-4中检测到相关的SCI，从而恢复预留链。但是，Rx-UE会错过在Slot-3重新选择资源中被发送的TB。
在这里，我们考虑解决此问题的三种机制：
作为第一种机制，Tx-UE可以为传输数据包设置足够高的优先级，例如，优先级值为1，以使其他Tx-UE不再抢占其预留的资源。在这种情况下，如果Rx-UE在Slot-2中未能检测 到SCI之后，立即启动“drx-ReceivePeriodTimer”。
作为第二种机制，禁止Tx-UE在Slot-2之前重新选择资源。在这种情况下，如果Rx-UE在Slot-2中未能检测到SCI之后，立即启动“drx-ReceivePeriodTimer”。
值得注意的是，在以上两种机制中，由于基于DRX配置的Tx-UE属于Rel-17的UE，因此可以简单地实现同时对Rel-16的UE不会产生任何影响。
作为第三种机制，在Slot-1中，如果SL_RESOURCE_RESELECTION_COUNTER＝1，则Tx-UE可以通过SCI或MAC-CE通知Rx-UE在下一次传输中将重新选择周期性资源。值得注意的是，如果考虑单一比特指示，则第一SCI(1st SCI)应该被优选考虑。这是因为感测UE也可以看到该比特，以便启动其感测计时器。在这种情况下，在Slot-1中检测到SCI之后立即启动“drx-ReceivePeriodTimer”。
实施例四：
本实施例解决了Tx-UE如何实现针对短PDB非周期数据包的传输，Rx-UE如何实现针对短PDB非周期数据包的接收的问题。
对于QoS要求非常短PDB的数据包，则Tx-UE必须立即发送。换句话说，这意味着DRX周期应保持足够短，这将引起Rx-UE的功耗问题。
在实施例一中讨论的通用DRX模式的基础上，我们定义了第二个DRX模式，称为特定DRX模式(specific DRX pattern)。这意味着，使用通用DRX模式，所有UE都能够有相同的DRX配置。对于特定DRX模式，针对特定类型的业务或UE将配置多个DRX模式。配置多个DRX模式可同时满足Tx-UE和Rx-UE中的多种业务。
在每个特定DRX配置中，与短PDB的QoS相关联的DRX参数是(预)配置的，其中On-Duration仅包含很少的时隙(最少可以是一个时隙)，其中DRX周期应小于PDB。在此，将通用On-Duration和Off-Duration定义为通用DRX中的common On-Duration和common Off-Duration时间，而针对特定QoS流将特定On-Duration和Off-Duration则定义为specific On-Duration和specific Off-Duration。假定P个QoS要求PDB(p)具有高优先级，那么可以分别使用CoDRX_Conf和SpDRX_Conf(p)来(预)配置通用DRX和特定DRX模式，其中，p＝1,2,…,P。通用DRX可以用作背景配置，所有UE可以随时使用该背景配置来进行其DRX模式对准过程。此外，Tx-UE可以选择满足特定业务所需QoS的SpDRX_Conf(p)配置，然后通过MAC-CE或SCI将p的索引发送给所有Rx-UE。因此，可以在通用DRX模式的基础上使用特定DRX模式。一旦特定业务到期并且不再传输 相关数据包，则应停止使用特定DRX模式，同时UE应退回到通用DRX模式。
一旦新业务开始，Tx-UE就必须等待Common On-Duration来传输第一初始TB，而该初始TB与新业务中的第一数据包相关联。如图8所示，在Slot-0中，Tx-UE发送第一个初始TB时，同时发送MAC-CE(或者在PSCCH中传送SCI)，从而将特定DRX参数(即，索引p，可以是单一索引也可以是复数索引)通知给的相应的Rx-UE。根据和MAC-CE或SCI中的配置索引p，Rx-UE设置特定的DRX参数。涉及相同业务的所有UE都应保持使用相同的特定DRX参数，直到业务到期并释放特定的DRX参数为止。
在图8的示例中，如果索引标志是A1，则Rx-UE设置特定的DRX参数，而如果索引标志是A2，则Rx-UE释放特定的DRX参数。
通常具有短PDB的非周期性数据包要求较高的优先级，因此Tx-UE可以利用资源抢占机制在specific On-Duration的资源中抢占资源来用于初始数据包传输，而在specific Off-Duration中从选择资源来用于数据包重传。此外，由于短PDB原因，反馈HARQ机制可能无法正常工作，因此如实施例一中所述可以考虑盲重传或组合机制来完成数据包传输。
实施例五：
Tx-UE需要选择一个感测窗口进行信道感测，然后在资源选择窗口选择相应的资源传输数据包。而Rx-UE不需要考虑感测窗口，只需要对齐相被选择的资源时隙进行接收。如在实施例一中讨论的，如果没有先前发送的预留资源，Tx-UE只能遵循DRX On-Duration进行初始数据包传输，并且Rx-UE必须对齐相同的DRX模式来接收数据包。因此，感测和接收从根本上是不同的。尽管感测精度可能会影响一些PRR性能，但是感测不需要具有高精度的信息。感测的主要目的是，Tx-UE检测PSCCH，解码SCI，从中得到其他Tx-UE预留的资源信息，以便在资源选择时进行资源排除，从而避免资源冲突。但是，接收需要在Tx-UE和Rx-UE之间进行唤醒和睡眠时间的对齐和调整，从而能够正确解码数据包。
在Tx-UE感测过程中，最重要的是调整好感测窗口T sen(sensing window)，选择窗口T sel(selection window)和开启持续时间T ond(On-Duration)之间的关系。T sen和T sel之间的关系与Rel-16的相同，但是T sen和T ond之间却没有直接关系。这意味着，感测窗口的确定不直接依赖于On-Duration在DRX周期内的位置。但是，T sel和T ond之间有着很强的相互关系，至少两个窗口需要有部分重叠，即
Figure PCTCN2020132623-appb-000011
其中
Figure PCTCN2020132623-appb-000012
是空集。这是因为从Tx-UE角度来看，选择的候选资源用于数据包传输，而从Rx-UE角度来看，则在相同的资源上需要接收数据包。这就要求至少针对初始数据包的发送和接收，Tx-UE和Rx-UE之间 需要对齐开启持续时间。
因此，感测机制应该基于数据包到达时间来确定感测窗口T sen(即，在数据包到达前T sen的时间段作为感测窗口)，然后确定T sel和T ond之间的关系，最后找出选择窗口T sel。
值得注意的是，不管开启持续时间与感测窗口和选择窗口之间的关系如何，Tx-UE除了感测在感测窗口中的时隙以外，还应该感测所有的在On-Duration内的时隙，以便为发送资源选择提供更多的信道感测信息。
本实施例解决了对于侧链路DRX中的部分感测(Partial Sensing)机制，如何感测被预留的周期性资源的问题。
对于时隙t y中的给定候选资源，Tx-UE处于唤醒状态，以检测时隙
Figure PCTCN2020132623-appb-000013
并确定是否将时隙t y中的候选资源从资源集S A中排除。其中P′ n是时隙中的逻辑时隙，从物理时隙P n转换而来，n＝1，2，3，...。
NR中的流量周期性可以是多种多样的，并且可以在SL-ResourceReservePeriod中(预)配置，其中sl-ResourceReservePeriod1＝100×n，其中n＝0，1，…，10；或sl-ResourceReservePeriod2＝INTEGER(1..99)。因此，不可能找到单一的感测模式来感测所有正在进行业务的相关周期种类数(每个资源池最大配置周期数为16)。另外，Tx-UE发送的时间偏移也不同，这样更加增加了感测模式的难度。
一种解决方案是确保每个Tx-UE仅在DRX On-Duration期间进行资源(重新)选择，然后，Tx-UE仅在On-Duration内执行部分感测过程。这样可以确保Tx-UE识别预留的资源并相应地选择资源进行数据包传输，但是问题在于，每个Tx-UE必须在On-Duration的时隙中传输TB，这可能会在On-Duration和Off-Duration之间使被使用的资源失衡，从而导致On-Duration时隙中的资源冲突增加。
此外，由于Rel-16中的NR-V2X支持资源重选和抢占机制，因此在发送SCI之后可以更改Tx-UE预留的资源。这样就无法保证重新选择的资源一定在On-Duration之内。从而造成部分感测UE不能预测重新选择的资源。
针对此问题的解决方案是根据资源池中配置的所有周期性，派生感测窗口。在这种情况下，如果感测窗口的长度是N个时隙并且周期数(或种类)是M，假设不存在重叠时隙，则用于感测的时隙的数量最大是MN个。这可能将部分感测变成了全面感测，从而导致Tx-UE功耗问题。
此外，具有MN时隙的感测机制仅适用于发送周期性数据包的感测UE。这意味着，感 测UE知道数据包到达时间并且能够预先决定选择窗口位置。但是，对于非周期性流量的感测UE，这种方法不是很有效，因为Tx-UE必须要么为任何选择窗口提前准备感测结果，要么在数据包到达后开始感测。前者，会引起功耗问题，而后者，如果Tx-UE预留的周期资源具有较长的周期，则感测UE所发送的数据包会产生较大的延迟。
为了解决此问题，我们先给出如图9所示的示例，其中Tx-UE-A(即，第一发送UE)基于预留的周期性资源发送周期TB，而Tx-UE-B(即，第二发送UE)尝试使用部分感测机制来感测侧链路信道。值得注意的是，本实施例中，Tx-UE-B需要发送周期性业务或非周期性业务，而Tx-UE-A仅能执行用于周期性业务传输，Tx-UE-B可能对Tx-UE-A提供的业务不感兴趣。
为了进行感测，Tx-UE-B只需要唤醒感测Tx-UE-A定期预留资源信道，但Tx-UE-B也有可能无法检测到PSCCH信号。检测失败的原因有两个：一种是由于冲突或低SINR的原因；另一种是由于重新评估/抢占机制或资源重新选择计数器所造成的资源重新选择的原因。
一旦Tx-UE-B检测SCI失败，Tx-UE-B将启动drx-PeriodSensingTimer并唤醒检测每个时隙中的PSCCH。如果drx-PeriodSensingTimer到期，或者Tx-UE-B成功检测到新时隙中的PSCCH，Tx-UE-B将停止检测PSCCH。通常，drx-PeriodSensingTimer应设置为等于特定业务中QoS要求的ResourceReservePeriod。在图9的示例中，Tx-UE-A开始业务并在Slot-0传输初始TB，同时在Slot-3重新选择新资源。
这样，感测UE无需在数据包到达之前考虑其流量类型(周期和非周期)，并且它可以随时准备将感测结果提供给MAC层以便在资源选择时进行资源排除，从而进行资源(重新)选择。这种部分感测过程适应于感测其他Tx-UE的周期性流量的预留资源信道，可以表示为周期性的部分感测过程。
如实施例三所述，上述可能会出现相同的问题，即重新选择的资源可能在先前预留的资源之前，因此，作为最坏情况，Tx-UE可能会错过Slot-2之后的一个感测机会。同样地，可以通过禁止选择预留资源之前的资源作为重新选择资源作为解决方法。
另一个与功耗密切相关的问题是，Tx-UE-B必须始终感测由其他Tx-UE定期预留的每个时隙。在每个侧链路资源池中，不同周期性和不同发送时间偏移的多个Tx-UE可以预留周期性资源。因此，感测Tx-UE-B可以仅在不同感测簇(Sensing Cluster)中被唤醒执行信道感测。感测簇定义为不同Tx-UE预留的一些重叠时隙(Superposition Slot)或一些相邻时隙(Neighbor Slot)。如果感测UE仅考虑这些感测簇群作为信道感测，可以大大提高 节能效果。
使用同一资源池的Tx-UE的数量可能比周期性的数量大得多，某些Tx-UE可以用不同的时间偏移发送相同周期的数据包。在NR-V2X中，使用TH(prio RX，prio TX)的值配置阈值，感测Tx-UE-B将其接收到的RSRP与阈值进行比较，并确定是否排除资源。其中prio TX和prio RX是优先级，分别用于发送和接收数据包。因此，基于同样的阈值，感测Tx-UE-B可以先确定哪些Tx-UE是感测候选UE，这样感测Tx-UE-B就不需要感测所有Tx-UE预留的资源信道。
如图10所示，Tx-UE-1，Tx-UE-2，Tx-UE-3发送具有不同周期性的周期数据包，而Tx-UE-B尝试感测这三个Tx-UE所预留的资源时隙和On-Duration中的信道。具有不同周期的三种流量会生成许多感测簇群，其中所包含的需感测资源数量会有所不同。还有，有些感测簇离On-Duration远，有些感测簇离On-Duration近。在示例中，感测簇1和感测簇3接近于On-Duration，因此，和在On-Duration中时隙感测相比，Tx-UE-B唤醒并感测感测簇1和感测簇3中的时隙所得到的预留资源信息可能基本相同。相反，感测簇2在两个On-Duration之间，Tx-UE-B唤醒并能感测到更新预留资源信息。所以，有效的方法是，Tx-UE-B仅在感测簇2唤醒并感测与其相关的时隙信道。
在先前的解决方案中，我们假设所有Tx-UE都属于Rel-17节能UE，同时依靠DRX的配置来发送数据包。另外，感测UE进行信道感测并推导由其他Tx-UE保留的资源，但其他Tx-UE可以是Rel-16的UE或不需要DRX配置的UE。比如，某些Tx-UE属于Rel-17的UE，可以实现新的感测过程以进行资源重选，而某些Tx-UE可以是没有DRX配置的普通UE，例如车辆UE，而某些Tx-UE则属于Rel-16的UE，必须遵循Rel-16中的资源重选过程(包括重选，重评估和抢占机制)。因此，先前提出的解决方案可能无法保证整体性能，因为这种场景无法确保在业务开始时初始化的第一次初始数据包一定能够在On-Duration中传输。
我们提出了一种部分感测增强解决方案，其中感测UE将建立具有T cycle时隙的特定感测周期(Specific Sensing Cycle)，每个感测周期拥有L个T W的部分感测窗口(Partial Sensing Window)。T cycle和L是由RRC在每个资源池中配置的。每个部分感测窗口位置可以由感测UE自己决定，也可以由RRC在每个资源池中利用时隙偏移Δ W，l(Window Offset)来配置，l＝1，2，...，L。其中，T MIN≤T W≤T MAX，T MIN和T MAX分别是当前资源池中配置的 最小和最大周期长度，
Figure PCTCN2020132623-appb-000014
而T MAX＜＜T cycle。感测UE在部分感测窗口唤醒并感测所有的时隙的侧链路信道。部分感测窗口的大小可以根据当前资源池中正在进行传输中的流量情况而自适应。例如，T cycle＝1000时隙，T W＝100时隙，L＝1，这样通过此部分感测窗口T W可以获取到所有Tx-UE在100时隙以下的周期性预留资源信息。并且和全面感测UE相比，部分感测UE可以达到90％的节能。如果L＞1，在特定感测周期中的部分感测窗口大小可以不同，也是由感测UE自己决定。
以下信息可以通过感测部分感测窗口获得：
●当前资源池中正在进行传输中的流量周期性数和相应的周期长度；
●Tx-UE与感测UE之间的周期资源的时间偏移。
基于信道条件，如何或是否在特定的部分感测窗口中执行感测取决于UE的实现。例如，如果接收到的NAK数大于一定的阈值，则感测UE可以在特定感测周期内激活其部分或全部(L个)的部分感测窗口T W。可替代地，感测UE可以根据设定的阈值，调节T W的大小。例如，如果接收到的NAK数大于一定的阈值，感测UE可以通过增加T W数(≦L)，来提高侧链路信道感测精度。可替代地，感测UE可以根据感测到的长周期的预留资源数量(或出现频度)，来调节T W的大小，从而平衡信道感测精度和节能效果。这是因为，对信道感测精度，长周期的预留资源要比短周期的预留资源影响要小，减小T W对整体的系统性能不会太过敏感。同样地，调节T W大小机制可以通过设定长周期的预留资源数量阈值来实现。
可替代地，T W和阈值的关系可以由RRC(预)配置。例如，资源池中的周期数和相应的周期长度分别为M和N m，m＝1,2,…,M。长周期的预留资源数量阈值可以被(预)配置为TH m而N m和TH m是相对应的。感测UE可以根据感测长周期的预留资源数量和TH m相比，从而决定T W。
可替代地，如果在每个资源池中配置了最小感测窗口(如，T MAX)，则可以将感测簇作为部分感测窗口，而这种部分感测窗口设定是不需要有任何感测周期的限制。
由于Tx-UE可以同时使用多个资源池，因此一个特定感测周期可以为多个资源池配置使用。T W的部分感测窗口可以由多个资源池中配置的最小周期长度T MIN和最大周期长度T MAX决定。感测UE在特定感测窗口唤醒，并感测所有资源池中的特定感测窗口内的所有时隙的侧链路信道。通过此特定感测窗口T W可以获取到所有其他Tx-UE在多个资源池中的T MAX时隙以下的周期性预留资源信息。这样可以达到节能最大化。
同样地，感测UE可以根据设定的阈值(NAK数，长周期的预留资源数量等)，调节T W的大小。例如，如果接收到的NAK数大于一定的阈值，感测UE可以通过增加T W，来提高侧链路信道感测精度。相反，如果接收到的NAK数小于一定的阈值，感测UE可以通过减小T W，来提高节能效果。T W和阈值的关系可以由RRC(预)配置。
实施例六：
本实施例解决了对于侧链路DRX中的部分感测(Partial Sensing)机制，如何感测被预留的非周期性资源的问题。
在Rel-16中，用于周期性业务和非周期性业务的感测机制是相同的。但是使用的感测窗口大小有所不同，即，用于周期性业务的感测窗口是1100ms，而用于非周期性业务的感测窗口是100ms。这是因为在非周期性业务的情况下，长感测窗口无法获得更多的预留资源信息。
如果部分感测UE不考虑DRX模式，则可以在非周期性数据包到达之后立即设定选择窗口。但如果部分感测UE考虑DRX模式，则非周期性数据包到达之后，部分感测UE选择最近的DRX On-Duration进行传输。感测窗口应提供足够的时间(至少31个时隙)，以便在数据包到达的时间与On-Duration的开始时间之间进行信道感测。这种部分感测过程适应于感测其他发送UE的非周期性流量的预留资源信道，可表示为非周期性部分感测过程。
图11举例说明了部分感测UE拥有非周期性数据包传输和进行非周期性部分感测过程，具有31个时隙的短感测窗口，这样以便可以完全排除被其他发送UE预留的非周期性资源。
如果数据包延迟预算比较短，感测UE必须在数据包到达后立即开始感测，并在最近的DRX On-Duration上进行资源选择。但是，这可能会引起一个问题，即感测过程无法完全排除其他Tx-UE为非周期性传输预留的资源。
非周期性流量的感测过程可以通过计时器drx-SensingTimer来实现。当Tx-UE的数据包到达后，Tx-UE开始在DRX On-Duration时机之前检测31个时隙以进行资源选择。并且Tx-UE会继续进行检测，直到数据包(重传)传输被成功接收为止，或者drx-SensingTimer到期。Rx-UE仅需要监视On-Duration中的时隙和预留资源中的时隙，由drx-ReserveInstantTimer实施，具体取决于1st SCI解码情况。
图12举例说明了非周期性流量的部分感测过程，其中Tx-UE在持续时间31个时隙之前开始感测，并在On-Duration之内选择初始TB传输资源。通过维护资源预留链在 Off-Duration中执行重传，这能确保Rx-UE与Tx-UE的数据包收发对齐。
值得注意是，一旦drx-ReserveInstantTimer运行，Rx-UE将停止接收数据包。如果drx-ReserveInstantTimer与drx-onDurationTimer重叠，则Rx-UE应优先考虑drx-onDurationTimer。
如果PDB小于32个时隙，为了满足PDB要求，Tx-UE的感测时间会很少，因此Tx-UE必须保持感测窗口小于32。这可能会无法排除其他Tx-UE为非周期性传输预留的资源，从而引起资源冲突问题。另外，如果其他Tx-UE拥有高优先级数据包，Tx-UE在传输数据包期间，为了确保可以感测所有预留资源信道，则Tx-UE不应关闭感测的侧链路RF。取而代之的是，Tx-UE必须进行全面感测(Full Sensing)以便获取信道信息。
如果Tx-UE唤醒要对特定业务进行全面感测，则Tx-UE应该在第一个数据包到达后的第一个On-Duration时机的32个时隙之前开始全面感测过程，而在成功传输最后一个数据包的时隙中停止执行全面感测过程，如图8中的提案所示。
如果Tx-UE有高要求节能，则可以进行随机资源选择(Random Resource Selection)。随机资源选择是，在没有感测的情况下执行随机选择，即UE将在选择窗口内所有候选资源报告给MAC，以用于特定资源池中的随机选择，而没有任何排除过程。
在Rel-17中，可以基于全面感测、部分感测、随机资源选择或任何组合来(预)配置侧链路发送资源池，来实现数据包传输。因此，通过组合Tx-UE可以将部分感测用于长周期业务，而将随机资源选择用于短周期业务。
周期性部分感测和非周期性部分感测机制通常可同时使用。这是因为Tx-UE可能具有周期性流量或非周期性流量，感测UE必须同时捕获和推断两种流量类型的预留资源信息。
资源池由SL-ResourcePool配置的，其中数据包的周期性可以选择sl-ResourceReservePeriodList加以配置。如果周期性列表没有被配置，则UE只能传输非周期性的数据包。在这种情况下，感测过程可以依赖于非周期性部分感测机制。如果配置了周期性列表，则在一个资源池里可以同时传输周期性和非周期性的业务量，并且必须同时考虑周期性和非周期性的部分感测机制。
以上对本发明的具体实施例进行了详细描述，但其只是作为范例，本发明并不限制于以上描述的具体实施例。对于本领域技术人员而言，任何对本发明进行的等同修改和替代也都在本发明的范畴之中。因此，在不脱离本发明的精神和范围下所作的均等变换和修改，都应涵盖在本发明的范围内。

Claims (28)

  1. 一种节能NR侧链路传输和接收的方法，其特征在于，包括：
    不连续接收DRX模式下，发送UE在On-Duration内传输初始TB，以及使用SCI预设格式预留用于重传初始TB或传输与初始TB关联的其它TB的周期性资源或非周期性资源，所述周期性资源或非周期性资源的个数小于等于N，N为自然数，则配置至少一个第一DRX计时器，基于所述第一DRX计时器，发送UE在感测窗口的时隙和所有On-Duration的时隙执行信道感测，以及
    配置至少一个第二DRX计时器，基于所述第二DRX计时器，接收UE在所有预留的周期性资源或非周期性资源的相关时隙、和/或所有On-Duration的时隙进入唤醒状态接收所述初始TB；
    其中，所述预留的周期性资源或非周期性资源由侧链控制信息SCI通信指示，位于On-Duration和/或Off-Duration。
  2. 根据权利要求1所述的一种节能NR侧链路传输和接收的方法，其特征在于，若初始TB不是业务开始的第一个TB，则发送UE无需一定要在On-Duration内发送该TB，只要由SCI在前一个TB中为它预留资源即可。
  3. 根据权利要求1所述的一种节能NR侧链路传输和接收的方法，其特征在于，重传TB对应的PSCCH指示下一次重传TB的预留资源的时隙，直到达到延迟预算或接收UE成功解码为止。
  4. 根据权利要求1所述的一种节能NR侧链路传输和接收的方法，其特征在于，所述第一DRX计时器，是用于感测的计时器，包括drx-PeriodSensingTimer和drx-SensingTimer；所述第二DRX计时器，是用于数据包接收的计时器，包括drx-OnDurationTimer，drx-CommonOnDurationTimer，drx-SpecificOnDurationTimer，drx-OffDurationTimer，drx-CommonOffDurationTimer，drx-SpecificOffDurationTimer,drx-ReservePeriodTimer，drx-ReserveInstantTimer，drx-HARQ-RTT-Timer和drx-RetransmissionTimer中的一种或几种。
  5. 根据权利要求1所述的一种节能NR侧链路传输和接收的方法，其特征在于，发送UE在On-Duration内传输业务开始的第一个初始TB，以及使用SCI预设格式在On-Duration和/或Off-Duration内预留用于不同的初始TB的周期性资源；接收UE在 On-Duration的时隙进入唤醒状态来接收所述初始TB，以及接收UE通过ResourceReservePeriod推断出预留的周期性资源的信息，所述ResourceReservePeriod选择性地被配置于SCI中；设置计时器drx-ReservePeriodTimer＝ResourceReservePeriod作为接收UE的激活时间，接收UE还在所有预留的周期性资源的相关时隙接收不同的初始TB；其中，若drx-ReservePeriodTimer与drx-onDurationTimer重叠，则接收UE优先所述On-Duration的计时器；若drx-ReservePeriodTimer与其他预留资源时隙重叠，则接收UE优先检测预留资源时隙。
  6. 根据权利要求1所述的一种节能NR侧链路传输和接收的方法，其特征在于，发送UE在On-Duration内传输业务开始的第一个初始TB，且相邻两个TB的发送间隔小于32个时隙，则传输的资源由每一个TB所关联的SCI连续为下一个TB预留；接收UE设置计时器drx-ReserveInstantTimer作为激活时间，仅监视On-Duration的时隙和所有预留资源的相关时隙。
  7. 根据权利要求1所述的一种节能NR侧链路传输和接收的方法，其特征在于，发送UE在On-Duration内传输业务开始的第一个初始TB，且相邻两个TB的发送间隔大于32个时隙，则发送UE使用SCI预设格式不预留任何用于传输的资源；接收UE仅在On-Duration的时隙进入唤醒状态来接收所述初始TB。
  8. 根据权利要求1所述的一种节能NR侧链路传输和接收的方法，其特征在于，不连续接收模式包括通用DRX模式，又名为默认DRX模式，发送UE选用通用DRX模式发送初始TB；其中，
    所述通用DRX模式被配置为具有长的DRX周期和短的On-Duration，在每个长DRX周期内，节能UE自drx-CommonSlotOffset之后启动计时器drx-CommonOnDurationTimer；当节能UE满足条件
    [(DFN×10)+Slot-Number(n)]mod(drx-CommonCycle)＝drx-CommonStartOffse,就进入唤醒状态并接收PSCCH；其中，DFN(direct frame number)是GNSS给出的直接帧号，可以在覆盖范围内和覆盖范围外获取，drx-CommonCycle是通用DRX的周期，Slot-Number(n)是当前的时隙索引，n为自然数，drx-CommonStartOffse是DRX通用偏移时隙。
  9. 根据权利要求8所述的一种节能NR侧链路传输和接收的方法，其特征在于，通用DRX模式下，发送UE在On-Duration内的传输使用盲重传，即一个初始TR和至少一个重 传TB，和/或发送UE在Off-Duration内的传输使用基于HARQ机制的重传。
  10. 根据权利要求9所述的一种节能NR侧链路传输和接收的方法，其特征在于，在On-Duration中配置不包含专用PSFCH资源的PSCCH/PSSCH资源以便进行盲重传，在Off-Duration中配置具有专用PSFCH资源的PSCCH/PSSCH资源以便用于基于HARQ机制的重传。
  11. 根据权利要求9所述的一种节能NR侧链路传输和接收的方法，其特征在于，在On-Duration中，MAC层通过优化资源选择方法，为初始TB选择有利的资源来完成初始TB的传输和盲重传，所述优化资源选择方法至少包括以下之一：
    提高初始TB的优先级；或
    提高传输初始TB对应的PSCCH的编码率。
  12. 根据权利要求8所述的一种节能NR侧链路传输和接收的方法，其特征在于，不连续接收模式还包括针对特定业务的特定DRX模式，所述特定DRX模式被配置为具有短的DRX周期，在每个特定DRX配置中，与短PDB的QoS相关联的DRX参数是预配置的；其中，On-Duration包含至少一个时隙，DRX周期小于短PDB。
  13. 根据权利要求12所述的一种节能NR侧链路传输和接收的方法，其特征在于，UE在通用DRX模式的基础上使用特定DRX模式，并基于特定业务的需求在通用DRX模式和特定DRX模式之间进行切换；其中，
    所述在通用DRX模式和特定DRX模式之间进行切换，包括：接收MAC-CE或SCI的控制信令以便在通用DRX模式转换和特定DRX模式之间切换；以及当特定业务到期并且不再传输相关数据包，所述特定DRX模式停止使用，同时UE退回至通用DRX模式。
  14. 根据权利要求1所述的一种节能NR侧链路传输和接收的方法，其特征在于，若发送UE预留了非周期性资源，且接收UE从接收的PSCCH中正确检测SCI、但没有任何预留资源，或者未能检测到与重传TB相关的所需SCI，则接收UE启动计时器drx-RetransmissionTimer，接收UE在每个时隙被唤醒并检测解码PSCCH，直到计时器drx-RetransmissionTimer到期，或者接收UE接收到重传的SCI；之后接收UE进入正常的节能接收模式，其中，所述节能接收模式是指接收UE仅在On-Duration和被预留资源的时隙中进入唤醒模式，接收PSCCH、并解码和接收UE相关联的TB。
  15. 根据权利要求14所述的一种节能NR侧链路传输和接收的方法，其特征在于，若资源池中启用了资源重新评估和/或抢占机制，接收UE在接收初始TB且未成功解码到TB 之后启动计时器drx-HARQ-RTT-Timer，在反馈NAK之后，接收UE间接启动计时器drx-RetransmissionTimer。
  16. 根据权利要求14所述的一种节能NR侧链路传输和接收的方法，其特征在于，若资源池中启用了资源重新评估和/或抢占机制，则禁止发送UE在预留资源的时隙之前重新选择资源，且发送UE重新选择资源优选与预留资源的时隙接近的资源。
  17. 根据权利要求14所述的一种节能NR侧链路传输和接收的方法，其特征在于，若发送UE在Off-Duration内的传输使用基于HARQ机制的重传，HARQ进程使用HARQOption-2，且接收UE无法检测到与初始TB相关的PSCCH，则发送UE在相同的On-Duration中重传TB，或者在延迟预算之内的下一个即将到来的On-Duration中重传TB。
  18. 根据权利要求1所述的一种节能NR侧链路传输和接收的方法，其特征在于，若发送UE预留了周期性资源，且由于连续的资源冲突、以及发送UE触发资源重新选择而造成资源预留链丢失，则发送UE被配置为仅在On-Duration期间重新选择资源，接收UE仅在On-Duration和预留的周期性资源的相关时隙进入唤醒状态来接收初始TB或重传TB；其中，发送UE的MAC实体将DRX周期作为计数单位来决定资源是否需要重新选择。
  19. 根据权利要求18所述的一种节能NR侧链路传输和接收的方法，其特征在于，若资源池中启用了资源重新评估和/或抢占机制，则通过在预配置的资源池中使用sl-PreemptionEnable来禁用资源重新评估和/或抢占机制。
  20. 根据权利要求1所述的一种节能NR侧链路传输和接收的方法，其特征在于，若发送UE预留了周期性资源，且由于连续的资源冲突、以及发送UE触发资源重新选择而造成资源预留链丢失，则接收UE启动计时器drx-ReceivePeriodTimer，其中drx-ReceivePeriodTimer＝ResourceReservePeriod，接收UE在每个时隙被唤醒并检测解码PSCCH，直到计时器drx-ReceivePeriodTimer到期，或者接收UE再次检测到与预留的周期性资源相关的PSCCH；之后接收UE进入正常的节能接收模式，所述节能接收模式是指，接收UE仅在On-Duration和被预留资源的时隙中进入唤醒模式，接收PSCCH、并解码和接收UE相关联的TB。
  21. 根据权利要求20所述的一种节能NR侧链路传输和接收的方法，其特征在于，在所述资源预留链丢失之前，发送UE采取以下任一方式防止发送UE预留的周期性资源被另一个发送UE抢占，包括：
    提高初始TB的优先级；或者
    禁止发送UE在预留资源时隙之前重新选择资源；或者
    通过SCI或MAC-CE预先通知接收UE在下一次传输中将重新选择周期性资源。
  22. 根据权利要求1所述的一种节能NR侧链路传输和接收的方法，其特征在于，所述方法还包括：针对第一发送UE预留的周期性资源，第二发送UE采用部分感测机制执行信道感测，并将感测结果提供给MAC层以进行资源选择或资源重新选择，所述部分感测机制包括：
    第二发送UE在每个第一发送UE预留的周期性资源的时隙进入唤醒状态感测PSCCH上的SCI；当SCI检测失败，则第二发送UE启动计时器drx-PeriodSensingTimer，并唤醒检测每个时隙中的PSCCH，直到计时器drx-PeriodSensingTimer到期，或者第二发送UE成功检测到新的时隙中的PSCCH为止；
    其中，第一发送UE和第二发送UE为不同的发送UE。
  23. 根据权利要求1所述的一种节能NR侧链路传输和接收的方法，其特征在于，所述方法还包括：在每个资源池中，不同周期性和/或不同发送时间偏移的至少两个第一发送UE均预留了周期性资源，第二发送UE仅在不同的感测簇中被唤醒执行与其相关的信道感测，所述感测簇被配置为至少两个不同的第一发送UE预留的周期性资源的重叠时隙或相邻时隙，其中，第一发送UE和第二发送UE为不同的发送UE。
  24. 根据权利要求1所述的一种节能NR侧链路传输和接收的方法，其特征在于，所述方法还包括：当发送UE预留了周期性资源，感测UE建立具有T cycle时隙的特定感测周期，每个特定感测周期被配置为拥有L个T W的部分感测窗口，每个部分感测窗口的位置由感测UE自己决定，或者由RRC在每个资源池中利用时隙偏移Δ W，l来配置，感测UE在所述部分感测窗口被唤醒并感测所有时隙的PSCCH；其中，T W为部分感测窗口的周期长度，其满足T MIN≤T W≤T MAX，T MIN和T MAX分别是当前资源池中配置的最小周期长度和最大周期长度，L为部分感测窗口的个数，
    Figure PCTCN2020132623-appb-100001
    而T MAX＜＜T cycle，l＝1,2,…,L；
    其中，通过感测所述部分感测窗口获得以下信息中的一种或几种：
    当前资源池中正在进行传输中的流量周期性数和相应的周期长度；
    发送UE与感测UE之间的周期资源的时间偏移。
  25. 根据权利要求24所述的一种节能NR侧链路传输和接收的方法，其特征在于，第二发送UE根据预设的阈值来决定是否激活特定感测周期内部分感测窗口T W，和/或调节部 分感测窗口T W的大小；
    其中，预设的阈值为接收到的NAK数，或者为感测到的长周期的预留资源数量或出现频度。
  26. 根据权利要求25所述的一种节能NR侧链路传输和接收的方法，其特征在于，T W和阈值的关系由RRC配置或预配置；
    其中，资源池中的周期数和相应的周期长度分别为M和N m，m＝1,2,…,M；长周期的预留资源数量阈值被配置或预配置为TH m，而N m和TH m是相对应的；感测UE根据感测长周期的预留资源数量和TH m相比，从而决定T W。
  27. 根据权利要求24所述的一种节能NR侧链路传输和接收的方法，其特征在于，针对多个资源池，一个特定感测周期被配置为多个资源池使用；T W的部分感测窗口由多个资源池中配置的最小周期长度T MIN和最大周期长度T MAX决定。
  28. 根据权利要求1所述的一种节能NR侧链路传输和接收的方法，其特征在于，所述方法还包括：针对预留的非周期性资源，发送UE采用以下方式中的一种或几种的组合执行信道感测：
    第二部分感测机制，所述第二部分感测机制包括：在TB到达后，发送UE启动计时器drx-SensingTimer，在DRX模式下的On-Duration之前的前31个时隙进行信道感测以进行后续的资源选择，之后发送UE继续进行感测，直到初始TB或重传TB被成功接收，或者计时器drx-SensingTimer到期为止；
    全面感测机制，所述全面感测机制包括：若PDB小于32个时隙，发送UE不关闭感测的侧链路RF，在第一个TB到达后的第一个On-Duration的32个时隙之前开始感测，而在成功传输最后一个TB的时隙中停止执行感测；
    随机资源选择机制，所述随机资源选择机制包括：对于高节能要求的发送UE，发送UE将选择窗口内的所有候选资源报告给MAC，而不包括资源排除过程。
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