TWI783580B - Mrthods for sidelink synchronization - Google Patents

Abstract

Various examples and schemes pertaining to enhancements for sidelink (SL) synchronization in New Radio (NR) vehicle-to-everything (V2X) communications are described. A user equipment (UE) establishes synchronization with one other UE in a vehicle-to-everything (V2X) network based on a partial search or signaling. The UE performs a sidelink (SL) communication with the other UE upon the synchronization being established. The UE also maintains the SL communication during a SL synchronization reference change by either of the UEs.

Description

Method of Sidelink Synchronization

The present invention relates generally to wireless communications, and, more specifically, to new radio (New Radio, NR) vehicle-to-everything (Vehicle-to-everything, V2X) communications for sidelink (sidelink, SL) synchronization ( For example, an enhanced mechanism for SL sync).

Unless otherwise indicated, the approaches described in this section are not prior art to the claims listed below and are not admitted to be prior art by inclusion in this section.

Under the 3rd Generation Partnership Project (3GPP) specification for 5th generation (5G) NR, V2X SL communication can be performed through unicast, multicast and broadcast communication. However, for SL synchronization, there are still some problems that need to be solved. For example, how to reduce the power consumption of the user equipment (UE) while maintaining synchronization to achieve data transmission and/or reception performance during SL discontinuous reception (DRX) needs to be solved. Therefore, a solution for SL synchronization enhancement is urgently needed.

The following summary is illustrative only and not intended to be limiting in any way. That is, the following summary is provided to introduce the concepts, gist, benefits and benefits of the novel and non-obvious technology described herein. Selected embodiments are further described below in the detailed description. As such, the following Summary is not intended to identify essential features of the claimed subject matter, nor is it intended for use in determining the scope of the claimed subject matter.

An object of the present invention is to propose various schemes, concepts, designs, methods, systems and devices related to enhanced mechanisms for SL synchronization. Various schemes proposed here can provide an enhanced mechanism for SL synchronization as a solution to specific problems in V2X communication.

In one aspect, a method may include establishing synchronization in a V2X network based on partial search or signaling. The method may also include performing SL communication when establishing synchronization.

In another aspect, a method may include establishing synchronization in a V2X network. The method may also include, during a SL synchronization reference change, by using one or Multiple signaling to maintain SL communication.

The sidelink synchronization enhancement mechanism provided by the invention can reduce power consumption.

It is worth noting that while the descriptions provided herein are for specific radio access technologies, networks and network topologies such as fifth generation (5G) and NR V2X, the proposed concepts, solutions and any variants thereof/ Derivatives may be implemented in, for and over any other type of radio access technology, network and network topology, such as, but not limited to, Long-Term Evolution (LTE), LTE-Advanced (LTE-Advanced), Advanced LTE-Advanced Pro, Wireless Fidelity (Wi-Fi), and any future network and technology. Accordingly, the scope of the present invention is not limited to the examples described herein.

100, 200, 300: scenes

400: communication environment

410, 420: Devices

416, 426: Transceiver

412, 422: Processor

414, 424: memory

500, 600: process

510, 520, 610, 620: blocks

The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this invention. The drawings illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. It will be appreciated that in order to clearly illustrate the concepts of the present invention, the drawings are not necessarily drawn to scale and some components shown may be shown on a scale that exceeds the size of the actual implementation.

Figure 1 is an example scene graph according to an embodiment of the present invention.

Fig. 2 is an example scene graph according to an embodiment of the present invention.

Fig. 3 is an example scene graph according to an embodiment of the present invention.

FIG. 4 is a block diagram of an exemplary communication environment according to an embodiment of the present invention.

Figure 5 is a flowchart of an example process in accordance with an embodiment of the invention.

Figure 6 is a flowchart of an example process in accordance with an embodiment of the invention.

Detailed examples and implementations of the claimed subject matter are disclosed herein. It is to be understood, however, that the disclosed embodiments and implementations are merely illustrative of the claimed subject matter, which can be embodied in various forms. This invention, however, may be embodied in many different forms and should not be construed as limited to the exemplary embodiments and implementations set forth herein. Rather, these exemplary embodiments and implementations are provided so that this description of the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the following description, details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the presented embodiments and implementations.

overview

In the proposed scheme according to the invention, for SL synchronization, especially during SL DRX operation, the UE can perform a partial search (e.g. based on certain subframes/slots and/or certain SL Synchronization Signal (SLSS) identities (SSID) detection). Compared with full search for all subframes/slots of all SSIDs, partial search can save UE power significantly. However, during part of the search, a given synchronization reference (SyncRef) may be lost (eg, because the UE is not within the effective communication range of the SyncRef or because an object or structure obstructs the SyncRef), which may negatively affect the synchronization performance. In order to avoid such problems, the UE may transmit an SLSS transmission period for a given duration with a configured or preconfigured (herein denoted "(pre)configured") period (e.g., a SLSS transmission period of 160 milliseconds) Perform a full search within the . In this case, the UE may perform a full search of all SSIDs for some periodic duration. For example, for an SSID sent with a 160 ms period, the UE may perform a full search on a 160 ms search window with a (pre)configured period (eg, every 1 second). Therefore, the UE may perform a full search of all SSIDs at 1 second intervals or periods for a duration of 160 milliseconds. In this case, the full search applies to all SSIDs, but not to all time subframes/slots. Thus, such a full search can be considered a partial search with full SSID detection during the search window.

Under the proposed scheme according to the present invention, the UE can periodically perform partial searches and full searches (or both types of partial searches) using (pre)configured search patterns defined based on periodicity, duration and/or start timing ). Such modes may be (pre)configured independently or jointly. The duration of the search mode may fall within the SL DRX_On duration (eg, the time period during which a UE in DRX mode or in operation wakes up to perform monitoring, transmission and/or reception) to save UE power if SL DRX is enabled. FIG. 1 depicts an example scenario 100 for power saving with SL sync search with DRX operation in accordance with the present invention. In scenario 100, the UE can be (pre)configured with a search pattern that is consistent or otherwise aligned with the pattern of DRX operation, so that the UE can perform a search pattern during or within each DRX_On duration but not at any other time A search is performed (eg, no search is performed during each DRX_Off duration, which is the time period during which a UE in DRX operation enters a low power or sleep mode to minimize power consumption).

FIG. 2 illustrates an example scenario 200 of dual-cycle SL synchronization search with DRX operation according to an embodiment of the present invention. In scenario 200, a two-period SL sync search may involve a first sync search mode (denoted "P1 search" in FIG. 2) and a second sync search mode (denoted "P2 search" in FIG. 2). Each P1 Sync Search may coincide with the corresponding DRX_On duration, and each P2 Sync Search may overlap with the corresponding P1 Sync Search, but with a longer search duration (by extending to the DRX_On Duration corresponding to the respective P1 Sync Search adjacent in time one or two DRX_Off durations). Compared with scenario 100, in scenario 200, in addition to the P1 synchronization search mode configuration, the UE can also (pre)configure another search mode (ie, P2 synchronization search mode), which is used when there is a (pre)configured periodicity ( For example, every 1 second) for a period of time (eg, for a duration of 160 milliseconds which may be an SSID transmission interval) to conduct a full search of all SSIDs. In this case, the UE can perform a two-period SL sync search to detect candidate SSIDs and find a suitable SyncRef. When the two modes of dual-period SL sync search overlap each other, the two modes can be superimposed for SL SyncRef search. Notably, the SL sync search in scenario 200 may be limited and performed during and around (eg, before and/or after) the DRX_On duration.

Under the proposed scheme according to the present invention, any (pre)configured search pattern may be used in case the UE has directly synchronized to the Global Navigation Satellite System (GNSS) and/or Base Station (BS) as the highest priority SyncRef are automatically ignored or disabled. Otherwise, the UE may apply the (pre)configured search pattern for the search. Such a search pattern can be applied independently of SL DRX operation.

Under the proposed scheme according to the present invention, Rx UEs can receive reference signals and/or data from Tx UEs to perform synchronization. Under the proposed scheme, Rx UEs can skip or reduce some or all occasions of SLSS search and detection. In addition, Tx UE can send a wakeup signal/lane to sleep or wake up Rx UE during DRX_On duration. Furthermore, during DRX operation, Rx UEs can at least use the demodulation reference signal (DMRS) of the wake-up signal/channel for synchronization, especially for unicast communication. Such a wake-up signal/lane may be sent periodically in association with each DRX_On duration. Furthermore, such wake-up signal/channel transmission may be based on configuration grants from Tx UE or BS for resource selection and/or resource reservation.

Under the proposed scheme, the wake-up signal/channel can be based on an independent two-phase (two-level) SCI transmission of the first SCI and the second SCI, where the second SCI carries information about which UE(s) to wake up for the upcoming DRX_On duration information. In this case, there is no need to associate a data channel, which can consist of a bit as an indicator of the presence (or absence) of a data channel or as a signal for a wake-up message An indicator of a new second SCI format that does not have an associated data channel. For example, a dot matrix of multiple bits may be carried in the second SCI, where each bit represents a corresponding UE or a corresponding UE identification word, so as to indicate which UE will be woken up. Alternatively, such wakeup information may be carried in an associated data channel. Furthermore, DMRS and/or profiles in the first SCI and/or the second SCI can be used for SL synchronization at the Rx UE.

FIG. 3 illustrates an example scenario 300 of synchronous search based on wake-up signal/channel with DRX operation under the proposed scheme according to the present invention. In scenario 300, the SL sync search may be based on a wake-up signal. That is, there may not be a need for a sync search during the DRX_On duration in scenario 300 . Alternatively, in scenario 300, a UE may use a wake-up signal/channel (indicated as "W" in Figure 3) to perform synchronization with another UE (e.g., Tx UE), especially in the case of unicast communication Down. Under the proposed scheme, the wake-up signal/channel may be the only signal/channel detected by the UE (eg, Rx UE) for wake-up and synchronization purposes (eg, when there is no traffic during DRX operation). Advantageously, the UE can significantly reduce power consumption.

Under the proposed solution according to the present invention, when the Tx UE changes the SyncRef, the Tx UE can notify the Rx UE of the SyncRef change by signaling through the wake-up channel, the first and/or second SCI and/or the data channel. The Rx UE may receive new timing information from the Tx UE for subsequence communication with the Tx UE. The signaling of new timing information from the Tx UE may indicate a timing offset as the difference between the new synchronization timing and the current synchronization timing used for communication between the Tx UE and the Rx UE. Timing offset may be indicated in terms of frame offset (eg, by multiple frames), slot offset (eg, by multiple slots), and/or symbol offset (eg, by multiple symbols). In addition, the signaling of new timing information may indicate the point or time when the new synchronization timing becomes valid (so that Tx UEs and Rx UEs will start using the new synchronization timing). Alternatively, the Rx UE may assume that after a predefined period of time (eg, X time slots or Y milliseconds), a new synchronization timing is applied. During SyncRef change, Tx UE and Rx UE can keep communicating.

Under the proposed scheme according to the present invention, the Rx UE can determine the SL radio link failure based on the SL Radio Link Monitoring (RLM) measurements performed by the Rx UE on the wake-up signal/channel (RLF) occurrence. For example, the Rx UE can measure the DMRS of the wake-up signal/channel to periodically report the measured channel quality, Out-of-Synchronization (OoS) and/or In-Synchronization (IS) for higher layers to determine the occurrence of RLF (e.g., after checking the measurement results or reporting indications) After layer 3 filtering).

Under the proposed scheme of selecting sidelink synchronization signal block (S-SSB) or DMRS/wake-up signal (WUS) as SyncRef according to the present invention, UE can be (pre)configured through signaling whether to perform: (1) Synchronization search based on SSID detection and/or (2) synchronization based on wake-up channel DMRS/sequence. In some embodiments, the UE may be (pre)configured to perform either or both synchronization methods.

Under the proposed scheme according to the present invention, in the case of multiple unicast communications from multiple Tx UEs to one Rx UE, the Rx UE can select one of the DMRSs with the strongest Reference Signal Received Power (RSRP) among the multiple Tx UEs , as a synchronization reference or SyncRef. Alternatively, the Rx UE may select a Tx UE with a DMRS associated with the highest priority among the priorities associated with the DMRSs of the multiple Tx UEs among the multiple Tx UEs as a synchronization reference. The priority order can be (pre)configured for each unicast communication or indicated in the physical control channel, such as but not limited to the first SCI and/or the second SCI of independent two-level SCI signaling. Alternatively, the Rx UE may jointly use RSRP and priority to determine which DMRS of the Tx UE to select and use for synchronization reference. For example, the Rx UE may preferentially select the DMRS of the Tx UE according to its priority order. In the case of multiple candidate Tx UEs with the same priority order, the Rx UE can select one Tx UE with the DMRS with the best channel quality (e.g., the strongest RSRP and/or the best Reference Signal Received Quality (RSRQ)) as a synchronization refer to. In addition, depending on the capabilities of the UE, the Rx UE can maintain multiple synchronization references based on the DMRS of multiple Tx UEs for multiple unicast communications.

Under the proposed scheme according to the present invention, in the case that the UE synchronizes to a priority group whose priority is higher than a predefined priority (for example, higher than the priority of a specific priority group), the UE can be at + /-x (eg, x=1 or 2) symbols (or slots) to perform synchronization Search as a limited simultaneous search. Otherwise, the UE may need to perform a full synchronization search on all subframes/slots of all SSIDs. A particular priority group may include one or more synchronization reference UEs that promote themselves as synchronization references without any synchronization with other synchronization references. Alternatively, a particular priority group may include one or more synchronization reference UEs that are synchronized to a GNSS or BS with more than Y (eg, Y>=2) hops. In either case, such a particular priority group may be considered to have a lower/lowest priority for synchronization search (relative to other synchronization references) and larger timing errors due to multiple hops or loss of synchronization.

Under the solution proposed by the present invention, considering the asynchronous cellular network, an indicator or signaling can be used to inform the UE whether limited synchronization search or full synchronization search can be performed. Such an indicator may be set per band/frequency to indicate whether all BSs are synchronized in a given band or a given frequency layer. Alternatively, such indicators may be set for multiple bands/frequencies to indicate whether all BSs are synchronized across multiple bands/frequency layers. Under the proposed scheme, the indicator in uu interface can be reused for synchronization indication or transmitted in system block (SIB), radio resource control (RRC) or SL RRC for SL operation. Where the indicator is set to "true" or "synchronized", the UE may assume that the BS and one or more synchronization reference UEs synchronized to different BSs are still synchronized (e.g., with a limited timing offset), and the UE may Perform limited simultaneous searches. Otherwise, the UE may need to perform a full synchronization search.

Illustrative implementation

FIG. 4 illustrates an example communication environment 400 having an example device 410 and an example device 420 in accordance with an embodiment of the present invention. Each of the apparatus 410 and the apparatus 420 may perform various functions to implement schemes, techniques, processes and methods related to SL synchronization enhancement in NR V2X communication, including various above-mentioned schemes described in the flow below.

Each of device 410 and device 420 may be part of an electronic device, which may be a UE such as a vehicle, portable or mobile device, wearable device, wireless communication device, or computing device. For example, each of device 410 and device 420 may be used in a vehicle, smart phone, smart watch, personal digital assistant processors, digital cameras, or computing devices such as tablets, laptops, or notebooks. Each of device 410 and device 420 may also be part of a machine type device, which may be an IoT or NB-IoT device such as a fixed or static device, a home device, a wired communication device, or a computing device. For example, each of device 410 and device 420 may be implemented in a smart thermostat, a smart refrigerator, a smart door lock, a wireless speaker, or a home control center. In some embodiments, each of device 410 and device 420 may also be implemented in the form of one or more integrated circuit (IC) chips, such as but not limited to, one or more single-core processors, one or multiple multi-core processors, or one or more complex instruction set computing (Complex-Instruction-Set-Computing, CISC) processors. Each of the apparatus 410 and the apparatus 420 includes at least some of the elements shown in FIG. 4, eg, a processor 412 and a processor 422, respectively. Each of the device 410 and the device 420 may further include one or more other elements (for example, internal power supply, display device and/or user peripheral equipment) that are not related to the solution proposed by the present invention, but for simplicity and simplicity, the device 410 These other components of the device 420 are not depicted in Figure 4, nor are they described below.

In many embodiments, at least one of device 410 and device 420 may be part of an electronic device, which may be a vehicle, roadside unit (RSU), network node or base station (e.g., eNB, gNB, TRP), small cell, router or gateway. For example, at least one of the device 410 and the device 420 may be implemented as a vehicle in a V2X or V2X network, an eNodeB of an LTE, LTE-Advanced (LTE-Advanced) or LTE-Advanced Pro network, or a 5G , NR, IoT or NB-IoT network gNB. Alternatively, at least one of apparatus 410 and apparatus 420 may be implemented in the form of one or more IC chips, such as, but not limited to, one or more single-core processors, one or more multi-core processors, or one or more CISC processor.

In one aspect, each of processor 412 and processor 422 may be implemented in the form of one or more single-core processors, one or more multi-core processors, or one or more CISC processors. That is, even though the singular term "processor" is used herein to refer to processor 412 and processor 422, In accordance with the present invention, however, each of processor 412 and processor 422 may comprise multiple processors in some implementations and a single processor in other implementations. In another aspect, each of processor 412 and processor 422 may be implemented in hardware (and, optionally, firmware) with electronic components that may include, for example and without limitation, implementation based on One or more transistors, one or more diodes, one or more capacitors, one or more resistors, one or more inductors, one or more memristors configured and arranged for the specific purpose of the present invention and/or one or more varactors. In other words, according to the various embodiments of the present invention, at least in some embodiments, each of the processor 412 and the processor 422 can be used as a special-purpose machine specially designed, configured and arranged to be used according to various embodiments of the present invention. The example performs specific tasks including SL synchronization enhancements in NR V2X communication.

In some implementations, the device 410 may further include a transceiver 416 coupled to the processor 412 as a communication device, and the transceiver 416 is capable of wirelessly sending and receiving data. In some embodiments, the device 410 may further include a memory 414 coupled to the processor 412 and capable of being accessed by the processor 412 and storing data therein. In some embodiments, the device 420 may also include a transceiver 426 coupled to the processor 422 as a communication device, and the transceiver 426 is capable of wirelessly sending and receiving data. In some embodiments, the device 420 may further include a memory 424 coupled to the processor 422 and capable of being accessed by the processor 422 and storing data therein. Therefore, the device 410 and the device 420 can communicate with each other wirelessly through the transceiver 416 and the transceiver 426, respectively.

To facilitate a better understanding, the following descriptions of the operation, functionality and capabilities of each of the device 410 and the device 420 are provided in the context of the NR V2X communication environment, wherein the device 410 is implemented into or implemented as a wireless communication device, communication device or The first UE, and implements the device 420 into or as a wireless communication device, a communication device or a second UE.

Under various proposals related to SL synchronization enhancement in NR V2X communication according to the present invention, in a V2X network, the processor 422 of the device 420 as the second UE can Synchronization is established with the device 410 as the first UE through the transceiver 426 based on partial search or signaling. Additionally, processor 422 may perform SL communication with device 410 via transceiver 426 when establishing synchronization. Similarly, the processor 412 of the device 410 as the first UE may perform the same operations as described above with respect to the processor 422 .

In some embodiments, processor 422 may perform certain operations when synchronization is established. For example, in response to being synchronized to a priority group having a higher priority than a predefined priority, processor 422 may perform a limited synchronization search within one or a few slots or symbols of the current synchronization timing. Or otherwise, processor 422 may perform a full synchronization search (eg, in case device 420 is not synchronized to any priority group with a priority higher than the predefined priority).

In some embodiments, when the synchronization is established, when the device 420 performs unicast communication with multiple UEs, the processor 422 may select the first DMRS from the device 410 as the first UE among the multiple DMRSs from the multiple UEs. DMRS acts as a synchronization reference. In some embodiments, when selecting the first DMRS from the first UE as a synchronization reference, the processor 422 may select the first DMRS in response to either or both of the following: (a) the first DMRS has a higher RSRP than the other RSRP of the DMRS; (b) the priority associated with the first DMRS is higher than the priority of other DMRSs in the plurality of DMRSs.

In some embodiments, when establishing synchronization, processor 422 may maintain multiple synchronization references based on multiple DMRSs from multiple UEs in multiple unicast communications with multiple UEs.

In some embodiments, processor 422 may perform certain operations when synchronization is established. For example, processor 422 may select one or both of S-SSB and DMRS as a synchronization reference. Additionally, processor 422 may perform synchronization based on one or both of: (a) SSID detection based synchronization search, and (b) wake channel DMRS or sequence based synchronization. In some embodiments, in selecting, the processor 422 may select based on pre-configured information or based on a configuration received in a signal.

In some embodiments, the processor 422 may perform SL communication based on the first SCI of the two-level SCI transmission, the second SCI of the two-level SCI transmission, and the DMRS in one or more of the data channels when establishing synchronization. In some embodiments, when performing SL communication, the processor 422 may receive (for example, from the device 410) a bitmap or an ID (for example, UE ID) carried in the second SCI, indicating which one or more during DRX_On The UE is to wake up in DRX operation.

In some embodiments, while performing SL communication, the processor 422 (and the processor 412 ) may maintain the SL communication between the device 410 as the first UE and the device 420 as the second UE. For example, the processor 412 may send a signal via the transceiver 416 to notify the device 420 of a change in the SL synchronization reference of the device 410 . Additionally, processor 422 may receive the signal and determine a new synchronization timing that is used by device 410 and device 420 to maintain SL communication during a change in the SL synchronization reference of device 410 . In some embodiments, the signal may indicate information related to the new sync timing by indicating either: (a) a timing offset that is the difference between the new sync timing and the current sync timing, or (b) the new sync timing The point in time when the sequence takes effect. In some embodiments, upon determining the new synchronization timing, the processor 422 may determine to apply the new synchronization timing after a predefined period of time. In some embodiments, when transmitting the signal, the processor 412 may send the signal to the device 420 via one or more of the wake-up channel, the first SCI of the two-level SCI transmission, the second SCI of the two-level SCI transmission, and the data channel. signal.

In some embodiments, when establishing synchronization, the processor 422 may perform the SL synchronization search according to the search pattern aligned with the pattern of DRX operation by performing the search during each of the multiple DRX_On durations of DRX operation. Alternatively, when establishing synchronization, the processor 422 may perform a two-cycle SL synchronization search according to a first search pattern and a second search pattern, each of the first search pattern and the second search pattern is aligned with the mode of DRX operation in the following manner: (a) performing the first search during each of the plurality of DRX_On durations of DRX operation; (b) performing the first search during and before and after each of some but not all of the plurality of DRX_On durations The first search is longer than the second search. Alternatively, when establishing synchronization, the processor 422 may send a message to the device based on the device 410 The WUS sent by 420 is synchronized with the device 410 .

Under various proposals related to SL synchronization enhancement in NR V2X communication according to the present invention, in a V2X network, the processor 422 of the device 420 as the second UE can communicate with the device as the first UE through the transceiver 426 410 Synchronization is established (eg, based on partial search or signaling). In addition, processor 422 may maintain SL communication with device 410 via transceiver 426 during SL synchronization reference changes, wherein the maintaining step is by using first SCI, second SCI transmission via wake-up channel, two-stage SCI transmission The signaling of one or more of the second SCI and the data channel is completed. Similarly, the processor 412 of the device 410 as the first UE may perform the same operations as described above with respect to the processor 422 .

In some embodiments, each of processor 412 and processor 422 may perform certain operations while maintaining SL communication between device 410 and device 420 . For example, the processor 412 may send a signal via the transceiver 416 to notify the device 420 of the SL synchronization reference change of the device 410 . Additionally, the processor 422 can receive the signal and determine a new synchronization timing used by the device 410 and the device 420 to maintain SL communication during the change of the SL synchronization reference of the device 410 .

In some embodiments, the signal may indicate information related to the new synchronization timing by indicating either: (a) the timing offset as the difference between the new synchronization timing and the current synchronization timing, or (b) the new synchronization timing The point in time when the sequence takes effect.

In some embodiments, upon determining the new synchronization timing, the processor 422 may determine to apply the new synchronization timing after a predefined period of time.

Illustrative process

FIG. 5 shows an example process 500 according to an embodiment of the present invention. The process 500 can be an exemplary embodiment of the proposed scheme for SL synchronization enhancement in NR V2X communication according to the present invention. The process 500 may represent characteristic implementation aspects of the apparatus 410 and the apparatus 420 . Process 500 may include one or more operations, actions or functions indicated by one or more of blocks 510 , 520 . Although the various blocks shown are discrete, however, depending on the desired implementation, each block in the process 500 can be split into more blocks, combined into fewer blocks, or some blocks can be deleted. In addition, the blocks of the process 500 may be executed in the order shown in FIG. 5, or alternatively, may be executed in a different order. Process 500 may also be repeated in part or in whole. The device 410, the device 420, and/or any suitable wireless communication device, UE, RUS, base station, or machine type device may implement the process 500. Only for the purpose of illustration and not to limit the scope, the following is the device 410 as the first UE (for example, Tx UE or Rx UE in the V2X network) and the device 420 as the second UE (for example, the Rx UE or Rx UE in the V2X network) Flow 500 is described in the context of Tx UE). Process 500 may begin at block 510 .

At block 510 , the process 500 may include the processor 422 of the device 420 serving as the second UE establishing synchronization with the device 410 serving as the first UE via the transceiver 426 in the V2X network based on partial search or signaling. The process 500 can enter block 520 from block 510 .

At block 520 , the process 500 may include the processor 422 performing SL communication with the device 410 via the transceiver 426 once synchronization is established.

In some embodiments, the process 500 may include the processor 422 performing specific operations when establishing synchronization. For example, in response to being synchronized to a priority group having a higher priority than a predefined priority, the process 500 may include the processor 422 performing a limited synchronization search within one or a few slots or symbols of the current synchronization sequence. Or otherwise, flow 500 may include processor 422 performing a full synchronization search (eg, where device 420 is not synchronized to any priority group with a priority higher than a predefined priority).

In some embodiments, when the synchronization is established, when the device 420 performs unicast communication with multiple UEs, the process 500 may include the processor 422 selecting the device 410 as the first UE from among the multiple DMRSs from the multiple UEs The first DMRS is used as a synchronization reference. In some embodiments, when selecting the first DMRS from the first UE as a synchronization reference, the process 500 may include the processor 422 selecting the first DMRS in response to either or both of: (a) the RSRP of the first DMRS higher than RSRP of other DMRS; (b) the priority associated with the first DMRS is higher than the priority of other DMRSs in the plurality of DMRSs.

In some embodiments, when establishing synchronization, the process 500 may include the processor 422 maintaining multiple synchronization references based on multiple DMRSs from multiple UEs in multiple unicast communications with multiple UEs.

In some embodiments, the process 500 may include the processor 422 performing specific operations when establishing synchronization. For example, the process 500 may include the processor 422 selecting one or both of the S-SSB and the DMRS as a synchronization reference. Additionally, the process 500 may include the processor 422 performing synchronization based on one or both of: (a) SSID detection based synchronization search, and (b) wake-up channel DMRS or sequence based synchronization. In some embodiments, during the selection, the process 500 may include the processor 422 selecting based on preconfigured information or selecting based on a configuration received in a signal.

In some embodiments, when synchronization is established, the process 500 may include the processor 422 performing SL based on the first SCI of the two-level SCI transmission, the second SCI of the two-level SCI transmission, and the DMRS in one or more of the data channels communication. In some embodiments, when performing SL communication, the process 500 may include the processor 422 receiving (for example, from the device 410) a bitmap or ID (for example, UE ID) carried in the second SCI, indicating that during DRX_On Which UE or UEs are to wake up in DRX operation.

In some embodiments, when performing SL communication, the process 500 may include the processor 422 (and the processor 412 ) maintaining the SL communication between the device 410 serving as the first UE and the device 420 serving as the second UE. For example, the process 500 may include the processor 412 sending a signal via the transceiver 416 to notify the device 420 of a change in the SL sync reference of the device 410 . Additionally, the process 500 may include the processor 422 receiving the signal and determining a new synchronization timing used by the device 410 and the device 420 to maintain SL communication during the SL synchronization reference change of the device 410 . In some embodiments, the signal may indicate information related to the new synchronization sequence by indicating any of the following: (a) as a new synchronization sequence The timing offset of the difference from the current synchronization timing, or (b) the time point at which the new synchronization timing takes effect. In some embodiments, when determining the new synchronization sequence, the process 500 may include the processor 422 determining to apply the new synchronization sequence after a predefined time period. In some embodiments, when transmitting the signal, the processor 412 may send the signal to the device 420 via one or more of the wake-up channel, the first SCI of the two-level SCI transmission, the second SCI of the two-level SCI transmission, and the data channel. signal.

In some embodiments, when establishing synchronization, the process 500 may include the processor 422 performing a search for SL synchronization according to a search pattern aligned with the pattern of DRX operation by performing a search during each of a plurality of DRX_On durations of DRX operation . Alternatively, when establishing synchronization, the process 500 may include the processor 422 performing a two-period SL synchronization search according to the first search mode and the second search mode, each of the first search mode and the second search mode cooperates with the DRX operation in the following manner Mode alignment: (a) performing the first search during each of the plurality of DRX_On durations of DRX operation; (b) during each of some but not all of the plurality of DRX_On durations and A second search, which is longer than the first search, is performed back and forth. Alternatively, when establishing synchronization, the process 500 may include the processor 422 synchronizing with the device 410 based on the WUS sent from the device 410 to the device 420 .

FIG. 6 shows an example process 600 according to an embodiment of the present invention. The process 600 can be an exemplary embodiment of the proposed scheme for SL synchronization enhancement in NR V2X network according to the present invention. The process 600 may represent characteristic implementation aspects of the apparatus 410 and the apparatus 420 . Process 600 may include one or more operations, actions or functions represented by one or more of blocks 610 , 620 . Although each block is shown as discrete, each block in the process 600 may be divided into more blocks, combined into fewer blocks, or some blocks may be deleted depending on the desired implementation. In addition, the blocks of the process 600 may be executed in the order shown in FIG. 6, or alternatively, may be executed in a different order. Process 600 may also be repeated in part or in whole. The device 410, the device 420, and/or any suitable wireless communication device, UE, RUS, base station, or machine type device may implement the process 600. It is only for the purpose of illustration and does not limit the scope. And the process 600 is described in the context of the apparatus 420 as the second UE (eg, Rx UE or Tx UE in the V2X network). Process 600 may begin at block 610 .

At block 610, the process 600 may include the processor 422 of the device 420 serving as the second UE establishing synchronization with the device 410 serving as the first UE via the transceiver 426 in the V2X network (eg, based on partial search or signaling ). The process 600 can enter block 620 from block 610 .

At block 620, the process 600 may include the processor 422, during a SL synchronization reference change, by using one or Multiple signaling to maintain SL communication.

In some embodiments, process 600 may include each of processor 412 and processor 422 performing certain operations while maintaining SL communication between device 410 and device 420 . For example, the process 600 may include the processor 412 sending a signal via the transceiver 416 to notify the device 420 of the SL synchronization reference change of the device 410 . Additionally, process 600 may include processor 422 receiving the signal and determining a new synchronization timing used by device 410 and device 420 to maintain SL communication during the SL synchronization reference change of device 410 .

In some embodiments, the signal may indicate information related to the new synchronization timing by indicating either: (a) the timing offset as the difference between the new synchronization timing and the current synchronization timing, or (b) the new synchronization timing The point in time when the sequence takes effect.

In some embodiments, when determining the new synchronization timing, the process 600 may include the processor 422 determining to apply the new synchronization timing after a predefined time period.

Additional information

The herein described subject matter sometimes illustrates different components contained within, or connected with, various other components. It is to be understood, however, that these depicted architectures are examples only, and that in fact many other architectures can be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively "associated" such that the desired functionality is achieved. Therefore, regardless of the schema Or intermediate components, any two components herein combined to achieve a particular functionality can be seen as "associated with" each other such that the desired functionality is achieved. Likewise, any two components so related can also be viewed as being "operably connected" or "operably coupled" to each other to achieve the desired functionality, and any two components so related can also be viewed as To be "operationally connected" to each other to achieve the desired function. Specific examples of operatively coupleable include, but are not limited to, physically matable and/or physically interacting components and/or wirelessly interactable and/or wirelessly interacting components and/or logically interacting and/or Logically interactable components.

Further, with respect to any plural and/or singular terms used herein substantially, one of ordinary skill in the art may convert from the plural to the singular and/or from the singular to the plural as appropriate to the context and/or application. For the sake of clarity, various singular/plural reciprocities may be explicitly set forth herein.

In addition, those of ordinary skill in the art will understand that terms used herein, and in particular terms used in the appended claims (eg, the subject matter of the appended claims), generally mean "Open-ended" terms, for example, the term "comprising" shall be construed as "including but not limited to", the term "has" shall be construed as "having at least" and the term "comprising" shall be construed as "including but not limited to", wait. Those of ordinary skill in the art will also understand that if a specific number of an incorporated claim recitation was intended, such intent would be expressly recited in the claim, and in the absence of such recitation no such kind of intention. For example, as an aid to understanding, the appended claims may contain usage of the introductory phrases "at least one" and "one or more". However, use of such phrases should not be construed to imply that the introduction of a claim list through the indefinite article "a" or "an" limits any particular claim containing such an introduced claim list to only includes an implementation of this enumeration even when the same claim includes the introductory phrase "one or more" or "at least one" and an indefinite article such as "a" or "an", for example, "one and /or a" shall be construed to mean "at least one" or "One or more", the same applies to the use of the definite article used to introduce the enumeration of claims. Furthermore, even if a specific number of the cited claims is explicitly recited, one of ordinary skill in the art will recognize that such a recitation should be construed to mean at least the recited number, e.g., in the absence of In the case of other modifiers, an unambiguous listing of "two listings" means at least two listings or two or more listings. Furthermore, where a convention like "at least one of A, B, and C, etc." is used, it is generally meant to be construed in the sense that a person of ordinary skill in the art would understand this convention (eg, " A system having at least one of A, B, and C" will include, but is not limited to, A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A system that has A, B, and C, etc. together). Where a convention like "at least one of A, B, or C, etc." is used, it is generally meant to be interpreted in the sense that a person of ordinary skill in the art would understand this convention (e.g., "has A A system of at least one of , B, or C" will include, but is not limited to, having A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B and C etc. system). Those skilled in the art will also understand that any transitional words and/or phrases that actually represent two or more alternatives, whether in the description, the scope of claims or the drawings, should be understood as Consider the possibility of including one of these items, either of these items, or both. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B."

From the foregoing, it will be appreciated that various embodiments of the present invention have been described herein for purposes of illustration and that various modifications may be made without departing from the scope and spirit of the invention. Accordingly, the various embodiments disclosed herein are not meant to be limiting, with the true scope and spirit to be determined by the appended claims.

500: Process

510, 520: block

Claims (9)

A sidelink synchronization method, comprising: establishing a synchronization in a vehicle networking network based on partial search or signaling; and when establishing the synchronization, performing a sidelink communication, wherein the step of establishing the synchronization includes : In response to being synchronized to a priority group with a priority higher than a predefined priority, perform a limited synchronization search within one or more slots or symbols of the current synchronization timing; or otherwise, perform a full synchronization search. The sidelink synchronization method as claimed in claim 1, wherein the step of establishing the synchronization comprises: in response to performing unicast communication with multiple user equipments, in multiple demodulations from the multiple user equipments Among the reference signals, a first demodulation reference signal from the first UE is selected as a synchronization reference. The sidelink synchronization method according to claim 1, wherein the step of establishing the synchronization includes: when performing multiple unicast communications with multiple user equipments, based on multiple Demodulate the reference signal to maintain multiple synchronization references. The sidelink synchronization method according to claim 1, wherein the step of establishing the synchronization includes: selecting one or both of the sidelink synchronization signal block and the demodulation reference signal as a synchronization reference; and based on the following Synchronization is performed by one or both: synchronization search based on detection of sidelink sync signal markers, and wake-up channel demodulation reference signal or sequence based synchronization. The sidelink synchronization method as claimed in claim 1, wherein the step of establishing the synchronization includes: first sidelink control information based on two-stage sidelink control information transmission, the two The second sidelink control information of the first-stage sidelink control information transmission and the demodulation reference signal in one or more of the data lanes are used to perform the sidelink communication. The sidelink synchronization method as claimed in claim 1, wherein the step of performing the sidelink communication includes: maintaining the sidelink between the first user equipment and the second user equipment through the following steps communication: sending a signal to the second user equipment through the first user equipment to notify the second user equipment of a sidelink synchronization reference change of the first user equipment; and through the second user equipment The device determines a new synchronization timing used by the first UE and the second UE to maintain the sidelink during a sidelink synchronization reference change of the first UE road communication. The sidelink synchronization method as claimed in claim 1, wherein the step of establishing the synchronization comprises: performing a search during each of a plurality of DRX activation durations of the DRX operation according to the The mode-aligned search mode of discontinuous reception operation is used to perform sidelink synchronization search. The sidelink synchronization method as claimed in claim 1, wherein the step of establishing the synchronization includes: performing a double-period sidelink synchronization search according to the first search mode and the second search mode, wherein each first Both the search mode and the second search mode are aligned with a mode of discontinuous reception operation by performing the first search during each of a plurality of discontinuous reception durations of the discontinuous reception operation; A second search that is longer than the first search is performed during and around each of some but not all of the discontinuous reception durations. A sidelink synchronization method, comprising: establishing a synchronization in a vehicle network; and During a sidelink synchronization reference change, by using a first sidelink control information via a wake-up channel, a two-stage sidelink control information transmission, a one of the two-stage sidelink control information transmission The second sidelink control information and signaling of one or more of a data channel to maintain the sidelink communication, the step of maintaining the sidelink communication includes: maintaining the first user equipment by the following manner The sidelink communication with the second UE: sending a signal by the first UE to notify the second UE of a sidelink synchronization reference change of the first UE; and determining, by the second UE, a new synchronization timing used by the first UE and the second UE, so as to maintain the sidelink during a sidelink synchronization reference change of the first UE link communication.

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