Method and apparatus for sidelink drx operation in wireless communication system

Abstract

The disclosure relates to a communication method and system for aggregating a fifth generation (5G) communication system supporting higher data rates than a fourth generation (4G) system and Internet of Things (IoT) technology. The disclosure can be applied to intelligent services based on 5G communication technology and IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. The disclosure relates generally to wireless communication systems, and more specifically, the disclosure relates to a sidelink discontinuous reception (DRX) operation.

Description

Technical Field

[0001] This disclosure generally relates to wireless communication systems, and more specifically, to a sidelink discontinuous reception (DRX) operation. Background Technology

[0002] To meet the increased demand for wireless data services since the deployment of 4G communication systems, efforts have been made to develop improved 5G or pre-5G communication systems. Therefore, 5G or pre-5G communication systems are also referred to as "post-4G networks" or "post-LTE systems." 5G communication systems are considered to be implemented in higher frequency (millimeter wave) bands, such as the 60GHz band, to achieve higher data rates. To reduce radio wave propagation loss and increase transmission distance, beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive MIMO technologies have been discussed in 5G communication systems. Furthermore, in 5G communication systems, development is underway for system network improvements based on advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, coordinated multipoint (CoMP), and receiver interference cancellation. In 5G systems, hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC) as advanced coding and modulation (ACM), and filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA) and sparse code multiple access (SCMA) as advanced access technologies have been developed.

[0003] The Internet, a human-centric network for generating and consuming information, is now evolving into the Internet of Things (IoT), where distributed entities, such as things, exchange and process information without human intervention. The Internet of Everything (IoE) is an internet that combines IoT technologies and big data processing technologies through connections to cloud servers. IoT implementation requires technological elements such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology. Recently, sensor networks, machine-to-machine (M2M) communication, and machine-type communication (MTC) have been studied. This IoT environment can provide intelligent Internet technology services that create new value for human life by collecting and analyzing data generated between connected things. Through the convergence and combination of existing information technology (IT) and various industrial applications, IT can be applied to a wide range of fields, including smart homes, smart buildings, smart cities, smart or connected cars, smart grids, healthcare, smart devices, and advanced medical services.

[0004] Consistent with this, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, machine-type communication (MTC), and machine-to-machine (M2M) communication can be implemented using beamforming, MIMO, and array antennas. The application of cloud radio access networks (RAN), as a big data processing technology, can also be seen as an example of the convergence between 5G and IoT technologies.

[0005] Fifth-generation (5G) or new radio (NR) mobile communications are gaining momentum recently, fueled by worldwide technical activity from industry and academia regarding various alternative technologies. Alternatives for 5G / NR mobile communications include a wide range of antenna technologies, from traditional cellular bands to higher frequencies, to provide beamforming gain and support increased capacity; new waveforms to flexibly adapt to various services / applications with different needs (e.g., new radio access technologies (RAT)); and new multiple access schemes to support a large number of connections, etc. Summary of the Invention

[0006] [Technical Issues]

[0007] This disclosure relates to wireless communication systems, and more specifically, to sidelink DRX operation.

[0008] [Solution to the problem]

[0009] In one embodiment, a first user equipment (UE) is provided. The first UE includes a transceiver configured to receive from a second UE a first physical sidelink control channel (PSCCH) and a first physical sidelink shared channel (PSSCH) for sidelink (SL) discontinuous reception (DRX) operation. The first PSCCH and PSSCH include sidelink control information (SCI), which includes a source identifier (ID), a destination ID, and SL DRX timing information indicating when the first UE monitors or skips at least one of a second PSCCH and a second PSSCH for SL DRX operation. The first UE also includes a processor operatively connected to the transceiver, configured to configure an SLDRX timer for each pair of source IDs and destination IDs, and to configure the value of at least one of the SL DRX timers based on the SCI information. The transceiver of the first UE is further configured to receive at least one of the second PSCCH and the second PSSCH based on the SL DRX timers when SL DRX operation is applied to SL communication identified by the pair of source IDs and destination IDs.

[0010] In another embodiment, a method for a first UE is provided. The method includes: receiving a first PSCCH and a first PSSCH from a second UE for SL DRX operation, wherein the first PSCCH and the first PSSCH include an SCI, the SCI including a source ID, a destination ID, and SL DRX time information, the SL DRX time information indicating when the first UE monitors or skips at least one of a second PSCCH and a second PSSCH for SL DRX operation; configuring an SL DRX timer for each pair of source IDs and destination IDs; configuring a value for at least one of the SL DRX timers based on the SCI information; and receiving at least one of the second PSCCH and the second PSSCH based on the SL DRX timer when the SL DRX operation is applied to SL communication identified by the pair of source IDs and destination IDs.

[0011] In yet another embodiment, a second UE is provided. The second UE includes: a processor and a transceiver operably connected to the processor, the transceiver being configured to: transmit a first PSCCH and a first PSSCH to a first UE for SL DRX operation, wherein the first PSCCH and the first PSSCH include an SCI, the SCI including a source ID, a destination ID, and SL DRX time information, the SL DRX time information indicating when the first UE monitors or skips at least one of a second PSCCH and a second PSSCH for SL DRX operation; and when SL DRX operation is applied to SL communication identified by a pair of source IDs and destination IDs, transmit at least one of a second PSCCH and a second PSSCH to the first UE for SL DRX operation based on an SL DRX timer, wherein the SL DRX timer is configured for each pair of source IDs and destination IDs, and the value of at least one of the SL DRX timers is configured based on the SCI information.

[0012] Other technical features will be apparent to those skilled in the art from the following figures, description and claims. Attached Figure Description

[0013] To gain a more complete understanding of this disclosure and its advantages, reference is now made to the following description in conjunction with the accompanying drawings, wherein like reference numerals denote like parts: Figure 1 An example radio network according to an embodiment of the present disclosure is shown; Figure 2 An example gNB according to an embodiment of this disclosure is shown; Figure 3 An example UE according to an embodiment of the present disclosure is shown; Figure 4 and Figure 5An example wireless transmission and reception path according to this disclosure is shown; Figure 6 An example V2X communication on a side link according to an embodiment of the present disclosure is shown; Figure 7a The SL control plane radio control (RRC) protocol stack is shown; Figure 7b The SL user plane data radio protocol stack is shown; Figure 8 The signaling flow of a side-link DRX mechanism according to an embodiment of this disclosure is shown; Figure 9a A flowchart of a method for RX UE behavior according to an embodiment of the present disclosure is shown; Figure 9b A flowchart of a method for RX UE behavior according to an embodiment of the present disclosure is shown; Figure 10 Resource selection for an example TX UE for SL DRX according to an embodiment of this disclosure is shown; Figure 11 The following diagram illustrates a signaling stream for timer maintenance in SL DRX activity according to an embodiment of the present disclosure; and Figure 12 A flowchart of a method for sidelink DRX operation according to an embodiment of the present disclosure is shown. Detailed Implementation

[0014] Before proceeding with the following detailed description, it may be advantageous to define certain words and phrases used throughout this patent document. The term “connection” and its derivatives refer to any direct or indirect communication between two or more elements, regardless of whether those elements are physically in contact with each other. The terms “transmit,” “receive,” and “communicate,” and their derivatives include both direct and indirect communication. The terms “include” and “comprise,” and their derivatives imply non-restrictive inclusion. The term “or” is inclusive, meaning and / or. The phrase “associated with,” and its derivatives mean including, being included within, interconnected with, containing, being contained within, connected to or connected to, linked to or connected to, able to communicate with, cooperate with, intertwine, juxtapose, proximate, bound to or bound to, having, possessing the characteristics of, having a relationship to or with, etc. The term “controller” refers to any device, system, or part thereof that controls at least one operation. Such a controller may be implemented in hardware, or a combination of hardware and software and / or firmware. The functionality associated with any particular controller can be centralized or distributed, local or remote. When the phrase "at least one" is used with a list of items, it means that different combinations of one or more of the listed items can be used, and only one item from the list may be required. For example, "at least one of A, B, and C" includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C.

[0015] Furthermore, the various functions described below can be implemented or supported by one or more computer programs, each computer program being formed by computer-readable program code and contained in a computer-readable medium. The terms "application program" and "program" refer to one or more computer programs, software components, instruction sets, procedures, functions, objects, classes, instances, associated data, or portions thereof suitable for implementation in appropriate computer-readable program code. The phrase "computer-readable program code" includes any type of computer code, including source code, object code, and executable code. The phrase "computer-readable medium" includes any type of medium accessible by a computer, such as read-only memory (ROM), random access memory (RAM), hard disk drive, optical disc (CD), digital video disc (DVD), or any other type of storage. "Non-transitory" computer-readable media excludes wired, wireless, optical, or other communication links that transmit transient electrical or other signals. Non-transitory computer-readable media includes media that can permanently store data, as well as media that can store data and subsequently rewrite it, such as rewritable optical discs or erasable storage devices.

[0016] Definitions of certain other words and phrases are provided throughout this patent document. Those skilled in the art will understand that, in many (if not most) instances, such definitions apply to the prior and future use of such defined words and phrases.

[0017] The following discussion Figures 1 to 12 The various embodiments used to describe the principles of this disclosure in this patent document are merely illustrative and should not be construed as limiting the scope of this disclosure in any way. Those skilled in the art will understand that the principles of this disclosure can be implemented in any suitably arranged system or apparatus.

[0018] The following references are incorporated herein by reference, as fully set forth herein: 3GPP TS 38.211 v.16.2.0, “Physical channels and modulation”; 3GPP TS 38.212 v.16.2.0, “Multiplexing and channel coding”; 3GPP TS 38.213 v16.2.0, “NR; Physical Layer Procedures for Control”; 3GPP TS 38.214 v.16.2.0, “Physical layer procedures for data”; 3GPP TS 38.215 v.16.2.0, “Physical layer measurements”; 3GPP TS38.321 v16.1.0, “Medium Access Control (MAC) protocol specification”; 3GPP TS38.322 v.16.1.0, “Radio Link Control (RLC) protocol specification”; 3GPP TS38.323, v.16.1.0 "Packet Data Convergence Protocol (PDCP) specification"; 3GPPTS 38.331v.16.1.0, "Radio Resource Control (RRC) protocol specification"; and 3GPP TS 37.324 v.16.1.0, "Service Data Adaptation Protocol (SDAP) specification".

[0019] The following Figures 1 to 3Various embodiments of implementing and using orthogonal frequency division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA) communication technologies in wireless communication systems are described. Figures 1 to 3 The description does not imply any limitation on the physical or architectural aspects of the different embodiments that may be implemented. Different embodiments of this disclosure can be implemented in any suitably arranged communication system.

[0020] Figure 1 An example radio network according to an embodiment of this disclosure is shown. Figure 1 The illustrated embodiment of the radio network is for illustrative purposes only. Other embodiments of the radio network 100 may be used without departing from the scope of this disclosure.

[0021] like Figure 1 As shown, the radio network includes gNB 101 (e.g., a base station BS), gNB 102, and gNB 103. gNB 101 communicates with gNB 102 and gNB 103. gNB 101 also communicates with at least one network 130, such as the Internet, a proprietary Internet Protocol (IP) network, or other data network.

[0022] gNB 102 provides wireless broadband access to network 130 to a plurality of first UEs within its coverage area 120. The plurality of first UEs includes: UE 111, which may be located in a small business; UE 112, which may be located in an enterprise (E); UE 113, which may be located in a WiFi hotspot (HS); UE 114, which may be located in a first residence (R); UE 115, which may be located in a second residence (R); and UE 116, which may be a mobile device (M), such as a cellular phone, wireless laptop computer, wireless PDA, etc. gNB 103 provides wireless broadband access to network 130 to a plurality of second UEs within its coverage area 125. The plurality of second UEs includes UE 115 and UE 116. In some embodiments, one or more of gNBs 101-103 may communicate with each other and with UEs 111-116 using 5G / NR, LTE, LTE-A, WiMAX, WiFi, or other wireless communication technologies.

[0023] Depending on the network type, the term "base station" or "BS" can refer to any component (or set of components) configured to provide radio access to a network, such as a transmitting point (TP), a transmitting-receiving point (TRP), an enhanced base station (eNodeB or eNB), a 5G / NR base station (gNB), a macro cell, a femtocell, a WiFi access point (AP), or other radio-enabled equipment. A base station can provide radio access according to one or more wireless communication protocols, such as 5G / NR 3rd Generation Partnership Project (3GPP) NR, Long Term Evolution (LTE), LTE Advanced (LTE-A), High Speed ​​Packet Access (HSPA), Wi-Fi 802.11a / b / g / n / ac, etc. For convenience, the terms "BS" and "TRP" are used interchangeably in this patent document to refer to network infrastructure components that provide radio access to remote terminals. Furthermore, depending on the network type, the term "user equipment" or "UE" can refer to any component, such as a "mobile station," "subscriber station," "remote terminal," "wireless terminal," "receiving point," or "user equipment." For convenience, the terms “user equipment” and “UE” are used in this patent document to refer to a remote wireless device that wirelessly accesses the BS, whether the UE is a mobile device (e.g., a mobile phone or smartphone) or is generally considered to be a fixed device (e.g., a desktop computer or a vending machine).

[0024] The dashed lines indicate the approximate extent of coverage areas 120 and 125, which are shown as approximately circular for illustrative and explanatory purposes only. It should be clearly understood that coverage areas associated with the gNB, such as coverage areas 120 and 125, may have other shapes, including irregular shapes, depending on the configuration of the gNB and variations in the radio environment associated with natural and man-made obstacles.

[0025] As described in more detail below, one or more of UEs 111-116 include circuitry, programming, or a combination thereof for UE auxiliary information reporting for sidelink communications. In some embodiments, one or more of gNBs 101-103 include circuitry, programming, or a combination thereof for beam management and coverage enhancement for sidelink measurements in V2X communications.

[0026] although Figure 1 An example of a radio network is shown, but it is possible to compare it with other networks. Figure 1Various modifications can be made. For example, the radio network can include any number of gNBs and any number of UEs. Furthermore, gNB 101 can communicate directly with any number of UEs and provide those UEs with wireless broadband access to network 130. Similarly, each gNB 102-103 can communicate directly with network 130 and provide UEs with direct wireless broadband access to network 130. Additionally, gNBs 101, 102, and / or 103 can provide access to other or additional external networks, such as external telephone networks or other types of data networks.

[0027] Figure 2 An example gNB 102 according to an embodiment of the present disclosure is shown. Figure 2 The embodiment of gNB 102 shown is for illustrative purposes only. Figure 1 gNBs 101 and 103 can have the same or similar configurations. However, gNBs have multiple configurations, and Figure 2 This disclosure is not intended to limit the scope to any particular implementation of gNB.

[0028] like Figure 2 As shown, gNB 102 includes multiple antennas 205a-205n, multiple RF transceivers 210a-210n, transmit (TX) processing circuitry 215, and receive (RX) processing circuitry 220. gNB 102 also includes a controller / processor 225, a memory 230, and a backhaul or network interface 235.

[0029] RF transceivers 210a-210n receive input RF signals from antennas 205a-205n, such as signals transmitted by a UE in network 100. RF transceivers 210a-210n down-convert the input RF signals to generate IF or baseband signals. The IF or baseband signals are sent to RX processing circuitry 220, which generates processed baseband signals by filtering, decoding, and / or digitizing the baseband or IF signals. RX processing circuitry 220 sends the processed baseband signals to controller / processor 225 for further processing.

[0030] TX processing circuit 215 receives analog or digital data (e.g., voice data, web data, email, or interactive video game data) from controller / processor 225. TX processing circuit 215 encodes, multiplexes, and / or digitizes the output baseband data to generate a processed baseband or IF signal. RF transceivers 210a-210n receive the processed baseband or IF signal from the output of TX processing circuit 215 and up-convert the baseband or IF signal into an RF signal transmitted via antennas 205a-205n.

[0031] The controller / processor 225 may include one or more processors or other processing devices that control the overall operation of the gNB 102. For example, the controller / processor 225 may control the reception of forward channel signals and the transmission of reverse channel signals via RF transceivers 210a-210n, RX processing circuitry 220, and TX processing circuitry 215, according to known principles. The controller / processor 225 may also support additional functions, such as more advanced wireless communication functions. For example, the controller / processor 225 may support beamforming or directional routing operations, wherein the output / input signals from / to multiple antennas 205a-205n are weighted differently to effectively manipulate the output signals in the desired direction. The controller / processor 225 may support any of a variety of other functions in the gNB 102.

[0032] The controller / processor 225 can also execute programs and other processes residing in the memory 230, such as an operating system. The controller / processor 225 can move data into or out of the memory 230 as needed during execution.

[0033] The controller / processor 225 is also coupled to a backhaul or network interface 235. The backhaul or network interface 235 allows the gNB 102 to communicate with other devices or systems via a backhaul connection or over a network. Interface 235 can support communication via any suitable wired or wireless connection. For example, when the gNB 102 is implemented as part of a cellular communication system (e.g., a system supporting 5G / NR, LTE, or LTE-A), interface 235 can allow the gNB 102 to communicate with other gNBs via a wired or wireless backhaul connection. When the gNB 102 is implemented as an access point, interface 235 can allow the gNB 102 to communicate with a larger network (e.g., the Internet) via a wired or wireless local area network or via a wired or wireless connection. Interface 235 includes any suitable architecture supporting communication over a wired or wireless connection, such as an Ethernet or RF transceiver.

[0034] The memory 230 is coupled to the controller / processor 225. A portion of the memory 230 may include RAM, while another portion of the memory 230 may include flash memory or other ROM.

[0035] although Figure 2 An example of gNB 102 is shown, but it is possible to compare it with other models. Figure 2 Various changes can be made. For example, gNB 102 can include... Figure 2Each component can be any number shown. As a specific example, an access point may include multiple interfaces 235, and the controller / processor 225 may support sidelink DRX operation. As another specific example, although shown as a single instance including TX processing circuitry 215 and a single instance including RX processing circuitry 220, the gNB 102 may include multiple instances of each circuit (e.g., one instance per RF transceiver). Furthermore, Figure 2 The various components can be combined, further subdivided, or omitted, and additional components can be added as needed.

[0036] Figure 3 An example UE 116 according to an embodiment of the present disclosure is shown. Figure 3 The embodiment of UE 116 shown is for illustrative purposes only. Figure 1 UEs 111-115 can have the same or similar configurations. However, UEs have multiple configurations, and Figure 3 This disclosure is not intended to limit the scope to any particular implementation of the UE.

[0037] like Figure 3 As shown, UE 116 includes an antenna 305, a radio frequency (RF) transceiver 310, a TX processing circuit 315, a microphone 320, and a receive (RX) processing circuit 325. UE 116 also includes a speaker 330, a processor 340, an input / output (I / O) interface (IF) 345, a touchscreen 350, a display 355, and memory 360. Memory 360 includes an operating system (OS) 361 and one or more applications 362.

[0038] RF transceiver 310 receives an input RF signal transmitted by a gNB of network 100 from antenna 305. RF transceiver 310 down-converts the input RF signal to generate an intermediate frequency (IF) or baseband signal. The IF or baseband signal is sent to RX processing circuitry 325, which generates a processed baseband signal by filtering, decoding, and / or digitizing the baseband or IF signal. RX processing circuitry 325 transmits the processed baseband signal to speaker 330 (e.g., for voice data) or processor 340 for further processing (e.g., for web browsing data).

[0039] The TX processing circuit 315 receives analog or digital voice data from the microphone 320 or other output baseband data (such as web data, email, or interactive video game data) from the processor 340. The TX processing circuit 315 encodes, multiplexes, and / or digitizes the output baseband data to generate a processed baseband or IF signal. The RF transceiver 310 receives the processed baseband or IF signal from the TX processing circuit 315 and up-converts the baseband or IF signal into an RF signal transmitted via the antenna 305.

[0040] Processor 340 may include one or more processors or other processing devices and executes OS 361 stored in memory 360 to control the overall operation of UE 116. For example, processor 340 may control the reception of forward channel signals and the transmission of reverse channel signals through RF transceiver 310, RX processing circuitry 325 and TX processing circuitry 315 according to known principles. In some embodiments, processor 340 includes at least one microprocessor or microcontroller.

[0041] Processor 340 is also capable of executing other processes and programs residing in memory 360, such as processes for sidelink DRX operations. Processor 340 can move data into or out of memory 360 as needed during execution. In some embodiments, processor 340 is configured to execute application 362 based on OS 361 or in response to signals received from gNB or operator. Processor 340 is also coupled to I / O interface 345, which provides UE 116 with the ability to connect to other devices such as laptop computers and handheld computers. I / O interface 345 is the communication path between these accessories and processor 340.

[0042] The processor 340 is also connected to the touchscreen 350 and the display 355. The operator of the UE 116 can use the touchscreen 350 to input data into the UE 116. The display 355 may be a liquid crystal display, a light-emitting diode display, or other display capable of displaying, for example, text and / or at least limited graphics from a website.

[0043] The memory 360 is coupled to the processor 340. A portion of the memory 360 may include random access memory (RAM), and another portion of the memory 360 may include flash memory or other read-only memory (ROM).

[0044] although Figure 3 An example of UE 116 is shown, but it is possible to modify it. Figure 3 Make various changes. For example, Figure 3The various components can be combined, further subdivided, or omitted, and additional components can be added as needed. As a specific example, processor 340 can be divided into multiple processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). Furthermore, although... Figure 3 The UE 116 is shown configured as a mobile phone or smartphone, but the UE can be configured to operate as other types of mobile or fixed devices.

[0045] To meet the increased demand for wireless data services since the deployment of 4G communication systems, and to enable various vertical applications, 5G / NR communication systems have been developed and are currently being deployed. 5G / NR communication systems are considered to be implemented in higher frequency (millimeter wave) bands (e.g., 28 GHz or 60 GHz bands) to achieve higher data rates, or in lower frequency bands (e.g., 6 GHz) to achieve robust coverage and mobility support. To reduce radio wave propagation loss and increase transmission distance, beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive MIMO technologies are discussed in 5G / NR communication systems.

[0046] In addition, in 5G / NR communication systems, system network improvements are being developed based on advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, coordinated multipoint (CoMP), and receiver interference cancellation.

[0047] The discussion of 5G systems and their associated frequency bands is for reference only, as some embodiments of this disclosure can be implemented in 5G systems. However, this disclosure is not limited to 5G systems or their associated frequency bands, and embodiments of this disclosure can be used in conjunction with any frequency band. For example, aspects of this disclosure can also be applied to the deployment of 5G communication systems, 6G, or even newer versions that may use terahertz (THz) frequency bands.

[0048] A communication system includes a downlink (DL) and an uplink (UL). The downlink (DL) refers to the transmission from the base station or one or more transmission points to the UE, while the uplink (UL) refers to the transmission from the UE to the base station or one or more receiving points.

[0049] The time unit used for DL ​​or UL signaling on a cell is called a time slot, and it can include one or more symbols. Symbols can also be used as additional time units. Frequency (or bandwidth (BW)) units are called resource blocks (RBs). An RB includes multiple subcarriers (SCs). For example, a time slot can have a duration of 0.5 milliseconds or 1 millisecond, include 14 symbols, and an RB can include 12 SCs with inter-SC spacing of 15 kHz or 30 kHz, etc.

[0050] DL signals include data signals that transmit information content, control signals that transmit DL control information (DCI), and reference signals (RS), also known as pilot signals. The gNB transmits data information or DCI via the corresponding Physical DL Shared Channel (PDSCH) or Physical DL Control Channel (PDCCH). The PDSCH or PDCCH can be transmitted over a variable number of time slot symbols, each consisting of one time slot symbol. For simplicity, the DCI format used to schedule UE PDSCH reception is referred to as the DL DCI format, and the DCI format used to schedule transmissions from the UE's Physical Uplink Shared Channel (PUSCH) is referred to as the UL DCI format.

[0051] The gNB transmits one or more of several types of RS, including Channel State Information RS (CSI-RS) and Demodulation RS (DMRS). CSI-RS is primarily used by the UE to perform measurements and provide CSI to the gNB. For channel measurements, the Non-Zero Power CSI-RS (NZP CSI-RS) resource is used. For Interference Measurement Reporting (IMR), the CSI Interference Measurement (CSI-IM) resource associated with the Zero Power CSI-RS (ZP CSI-RS) configuration is used. The CSI process includes both NZP CSI-RS and CSI-IM resources.

[0052] The UE can determine the CSI-RS transmission parameters via DL control signaling or higher-level signaling (such as Radio Resource Control (RRC) signaling) from the gNB. The transmission instance of CSI-RS can be indicated by DL control signaling or configured by higher-level signaling. DMRS is only transmitted in the BW of the corresponding PDCCH or PDSCH, and the UE can use DMRS to demodulate data or control information.

[0053] Figure 4 and Figure 5Example wireless transmit and receive paths according to this disclosure are shown. In the following description, transmit path 400 may be described as being implemented in a gNB (e.g., gNB 102), while receive path 500 may be described as being implemented in a UE (e.g., UE 116). However, it will be understood that receive path 500 may be implemented in the gNB, and transmit path 400 may be implemented in the UE. In some embodiments, receive path 500 is configured to support sidelink measurements in V2X communication as described in embodiments of this disclosure.

[0054] like Figure 4 The transmission path 400 shown includes a channel coding and modulation block 405, a serial-to-parallel (S-to-P) block 410, an N-size inverse fast Fourier transform (IFFT) block 415, a parallel-to-serial (P-to-S) block 420, a cyclic prefix addition block 425, and an up-converter (UC) 430. For example... Figure 5 The receiver path 500 shown includes a downconverter (DC) 555, a cyclic prefix removal block 560, a serial-to-parallel (S-to-P) block 565, a fast Fourier transform (FFT) block of size N, a parallel-to-serial (P-to-S) block 575, and a channel decoding and demodulation block 580.

[0055] As shown in Figure 400, the channel coding and modulation block 405 receives a set of information bits, applies coding (e.g., low-density parity-check (LDPC) coding), and modulates the input bits (e.g., using quadrature phase shift keying (QPSK) or quadrature amplitude modulation (QAM)) to produce a frequency domain modulated symbol sequence.

[0056] Serial-to-parallel block 410 converts (e.g., demultiplexes) serial modulation symbols into parallel data to generate N parallel symbol streams, where N is the IFFT / FFT size used in gNB 102 and UE 116. IFFT block 415 of size N performs an IFFT operation on the N parallel symbol streams to generate a time-domain output signal. Parallel-to-serial block 420 converts (e.g., multiplexes) the parallel time-domain output symbols from IFFT block 415 of size N to generate a serial time-domain signal. Cyclic prefix addition block 425 inserts a cyclic prefix into the time-domain signal. Upconverter 430 modulates (e.g., upconverts) the output of cyclic prefix addition block 425 to an RF frequency for transmission over a wireless channel. The signal can also be filtered at baseband before conversion to the RF frequency.

[0057] The transmitted RF signal from gNB 102 reaches UE 116 after passing through the wireless channel, and UE 116 performs the operation that is the reverse of the operation at gNB 102.

[0058] like Figure 5As shown, downconverter 555 downconverts the received signal to the baseband frequency, and cyclic prefix removal block 560 removes the cyclic prefix to generate a serial time-domain baseband signal. Serial-to-parallel block 565 converts the time-domain baseband signal into a parallel time-domain signal. FFT block 570 of size N performs an FFT algorithm to generate N parallel frequency-domain signals. Parallel-to-serial block 575 converts the parallel frequency-domain signals into a modulated data symbol sequence. Channel decoding and demodulation block 580 demodulates and decodes the modulated symbols to recover the original input data stream.

[0059] Each of gNBs 101-103 can implement something similar to what is sent to UEs 111-116 in the downlink, such as... Figure 4 The transmission path shown is 400, and it can achieve a similar effect to what is received from UE 111-116 in the uplink, such as... Figure 5 The receive path 500 is shown. Similarly, each of UEs 111-116 can implement a transmit path 400 for sending to gNBs 101-103 in the uplink and a receive path 500 for receiving from gNBs 101-103 in the downlink.

[0060] Figure 4 and Figure 5 Each component in the system can be implemented using only hardware or a combination of hardware and software / firmware. As a specific example, Figure 4 and Figure 5 At least some components can be implemented in software, while others can be implemented in configurable hardware, or a hybrid of software and configurable hardware. For example, FFT block 570 and IFFT block 515 can be implemented as configurable software algorithms, where the value of size N can be modified according to the implementation.

[0061] Furthermore, although described as using FFT and IFFT, this is merely illustrative and should not be construed as limiting the scope of this disclosure. Other types of transforms can be used, such as the Discrete Fourier Transform (DFT) and Inverse Discrete Fourier Transform (IDFT) functions. It will be understood that for DFT and IDFT functions, the value of variable N can be any integer (e.g., 1, 2, 3, 4, etc.), while for FFT and IFFT functions, the value of variable N can be any integer that is a power of 2 (e.g., 1, 2, 4, 8, 16, etc.).

[0062] although Figure 4 and Figure 5 An example of a wireless transmit and receive path is shown, but it is possible to modify it further. Figure 4 and Figure 5 Make various changes. For example, Figure 4 and Figure 5The various components can be combined, further subdivided, or omitted, and additional components can be added as needed. Furthermore, Figure 4 and Figure 5 This example illustrates the types of transmit and receive paths that can be used in a radio network. Any other suitable architecture can be used to support wireless communication in a radio network.

[0063] In the 3GPP wireless standards, NR has been discussed as a 5G wireless communication technology. One of the features of NR under discussion is V2X.

[0064] Figure 6 An example V2X communication on a side link 600 according to an embodiment of the present disclosure is shown. Figure 6 The embodiment of V2X communication on the side link 600 shown is for illustrative purposes only.

[0065] Figure 6 This illustrates an example scenario of vehicle-to-vehicle communication. Two or more vehicles can send and receive data / control signals via a direct link / interface between them. This direct link / interface between vehicles or between a vehicle and other things is designated as a sidelink (SL) in 3GPP. Note that... Figure 6 The description covers a scenario where vehicles can still communicate with the gNB to obtain SL resources, SL radio bearer configurations, etc. However, even without interaction with the gNB, vehicles can still communicate with each other via SL. In this case, SL resources, SL radio bearer configurations, etc., are pre-configured (e.g., via a V2X server or any other core network entity).

[0066] In the 3GPP wireless standards, NR is discussed as a form of 5G wireless communication. One of the features of NR under discussion is Vehicle-to-Everything (V2X).

[0067] Figure 6 An example V2X communication on a side link 600 according to an embodiment of the present disclosure is shown. Figure 6 The embodiment of V2X communication on the side link 600 shown is for illustrative purposes only.

[0068] Figure 6 This describes an example scenario of vehicle-to-vehicle communication. Two or more vehicles can send and receive data / control signals via a direct link / interface between them. Direct links / interfaces between vehicles or between vehicles and other things (e.g., pedestrian devices or any devices related to the transportation system) or other things are designated SL or PC5 in 3GPP standards.

[0069] Figure 6This describes an example scenario where vehicles communicate with each other and are within the coverage area of ​​an NR network. Vehicles communicate with the gNB to obtain SL-related resource information (e.g., SL resource pool configuration), SL radio bearer configuration (SL MAC, RLC, PDCP, SDAP, RRC related configurations), etc.

[0070] Once a vehicle obtains its SL configuration from the gNB, it sends / receives data / controls to each other via the SL. Note that it is possible for vehicles to communicate with each other even without interacting with the gNB (e.g., when the vehicle is outside the coverage of the NR network). In this case, SL resources, SL radio bearer configurations, etc., are pre-configured (e.g., via a V2X server or any other core network entity). For more detailed V2X scenarios and studies, refer to the 3GPP standard specifications.

[0071] For SL communication, the radio interface layer 1 / layer 2 / layer 3 (L1 / L2 / L3) protocols include, as specified in the 3GPP standard specifications, physical (PHY) protocols, MAC, RLC, PDCP, RRC and SDAP.

[0072] Figure 7a The SL control plane radio control (e.g., RRC) protocol stack 700 is shown. Figure 7a The embodiment of the SL control plane RRC protocol stack 700 shown is for illustrative purposes only.

[0073] Figure 7b The SL user plane data radio protocol stack 750 is shown. Figure 7b The embodiment of the SL user plane data radio protocol stack 750 shown is for illustrative purposes only.

[0074] Figure 7a and Figure 7b Examples of the SL control plane radio protocol stack (for SL-RRC) and the SL user plane data radio protocol stack for NR SL communication are shown.

[0075] exist Figure 7a The SL control plane radio protocol stack (e.g., RRC) is shown in the figure, and... Figure 7b The image shows the SL user plane data radio protocol stack.

[0076] The physical protocol layer processes physical layer signals / channels and physical layer procedures (e.g., physical layer channel structure, physical layer signal encoding / decoding, SL power control procedures, SL CSI related procedures). The main physical SL channel and signals are defined as follows: (1) The PSCCH transmits SCIs for radio resources and / or other transmission parameters used by the UE for the PSSCH. The SCIs transmitted by the PSCCH are also referred to as Level 1 SCIs; (2) The PSSCH also transmits SCIs (e.g., the remaining part of the SCI information other than the SCI carried by the PSCCH) or transport blocks (TBs) of the data itself and CSI feedback information, etc. The SCI sent by PSSCH is also called the second-level SCI; (3) The Physical Sidelink Feedback Channel (PSFCH) transmits Hybrid Automatic Repeat Request (HARQ) feedback from the UE, which is the intended recipient of the PSSCH transmission, to the UE performing the transmission on the sidelink; (4) Sidelink synchronization signals include the sidelink primary synchronization signal and the sidelink secondary synchronization signal (S-PSS, S-SSS); The Physical Sidelink Broadcast Channel (PSBCH) indicates the necessary system information required for SL operation.

[0077] The MAC protocol layer performs packet filtering (e.g., determining whether a received packet is actually destined for the UE based on the L2 source and destination IDs in the MAC header), SL carrier / resource pool / resource selection within the resource pool (re)selection, priority handling between the SL and UL for a given UE, SL logical channel prioritization, corresponding packet multiplexing (e.g., multiplexing multiple MAC Service Data Units (SDUs) into a given MAC Protocol Data Unit (PDU)), and SL retransmission / reception.

[0078] The RLC protocol layer performs RLC SDU segmentation / SDU reassembly, RLC SDU resegmentation, and error correction via ARQ (for AM data transmission only). The PDCP protocol layer performs header compression / decompression, encryption and / or integrity protection, copy detection, reordering and ordered packet delivery to upper layers, and unordered packet delivery to upper layers.

[0079] The RRC protocol layer performs the transmission of SL-RRC messages between peer UEs, the maintenance and release of SL-RRC connections between two UEs, and the detection of SL radio link failures for SL-RRC connections. The SDAP protocol layer performs the mapping between Quality of Service (QoS) streams and SL data radio bearers.

[0080] Side link control information format 1-A (SCI format 1-A) is used for scheduling PSSCH and second-level SCI on PSSCH.

[0081] The following information is sent via SCI format 1-A: (1) Priority - as defined in the 3GPP standard specification (3 bits); (2) Frequency resource allocation - when the value of the higher-level parameter s1-MaxNumPerReserve is configured to 2, the frequency resource allocation is as follows: Otherwise, when the value of the higher-level parameter s1-MaxNumPerReserve is configured to 3, the frequency resources are allocated as defined in the 3GPP standard specification. (3) Time resource allocation - When the value of the higher-level parameter s1-MaxNumPerReserve is configured to 2, the time resource allocation is 5 bits; otherwise, when the value of the higher-level parameter s1-MaxNumPerReserve is configured to 3, the time resource allocation is 9 bits as defined in the 3GPP standard specification; (4) Resource reservation period - as defined in the 3GPP standard specification. The bit, where if the higher-level parameter s1-MultiReserveResource is configured, then It is the number of entries in the higher-level parameter s1-ResourceReservePeriodList; otherwise, the resource reservation period is 0; (5) DMRS mode - as defined in the 3GPP standard specification Position, among which The number of DMRS modes configured by the higher-level parameter s1-PSSCH-DMRS-TimePatternList; if s1-PSSCH-DMRS-TimePatternList is not configured, the DMRS mode is 0 bits; (6) Second-level SCI format - 2 bits as shown in Table 1; (7) Offset indicator - 2 bits provided by the higher-level parameter s1-betaOffsets2ndSCI and the table shown in Table 2; (8) Number of DMRS ports - 1 bit as defined in the table shown in Table 3; (9) Modulation and coding scheme - 5 bits as defined in the 3GPP standard specification; (10) Additional MCS table indicator - as defined in the 3GPP standard specification: 1 bit if an MCS table is configured by the higher-level parameter s1-Additional-MCS-Table; 2 bits if two MCS tables are configured by the higher-level parameter s1-Additional-MCS-Table; otherwise 0 bits; (11) PSFCH overhead indicator - 1 bit as defined in the 3GPP standard specification, if the higher-level parameter s1-PSFCH-Period = 2 or 4; otherwise 0 bits; and / or (12) Reserved - the number of bits determined by the higher-level parameter s1-NumReservedBits, where the value is set to zero.

[0082] [Table 1]

[0083] [Table 2]

[0084] [Table 3]

[0085] SCI format 2-A is used for PSSCH decoding. HARQ operation is used when the HARQ-ACK message includes ACK or NACK, or when there is no HARQ-ACK message feedback.

[0086] Send the following information via SCI format 2-A: (1) HARQ procedure number - as defined in the 3GPP standard specification. (2) New data indicator - 1 bit as defined in the 3GPP standard specification; (3) Redundancy version - 2 bits as defined in the 3GPP standard specification; (4) Source ID - 8 bits as defined in the 3GPP standard specification; (5) Destination ID - 16 bits as defined in the 3GPP standard specification; (6) HARQ feedback enable / disable indicator - 1 bit as defined in the 3GPP standard specification; (7) Broadcast type indicator - 2 bits as shown in Table 4; and / or (8) CSI request - 1 bit as defined in the 3GPP standard specification.

[0087] [Table 4]

[0088] SCI format 2-B is used for PSSCH decoding, and has HARQ operation when the HARQ-ACK message only includes NACK, or when there is no HARQ-ACK message feedback.

[0089] Send the following information via SCI format 2-B: (1) HARQ procedure number - as defined in the 3GPP standard specification. (2) New Data Indicator - 1 bit as defined in the 3GPP standard specification; (3) Redundancy Version - 2 bits as defined in the 3GPP standard specification; (4) Source ID - 8 bits as defined in the 3GPP standard specification; (5) Destination ID - 16 bits as defined in the 3GPP standard specification; (6) HARQ Feedback Enable / Disable Indicator - 1 bit as defined in the 3GPP standard specification; (7) Area ID - 12 bits as defined in the 3GPP standard specification; and / or (8) Communication Range Requirement - 4 bits as defined in the 3GPP standard specification.

[0090] Basic SL communication functions are supported and specified in the 3GPP standard specification Rel-16. For the 3GPP standard specification Rel-17, more enhanced features are planned to be introduced into SL. One feature is the introduction of SL DRX for broadcast, multicast, and unicast. Note that in the 3GPP standard specification Rel-16, UE DRX operations are specified only for DL. Detailed DL DRX operations are specified in 3GPP standard specifications (e.g., MAC).

[0091] To implement SL DRX, one example implementation is the TX UE, which includes new control information (now called DRX indicator) in SCI format 1-A. SCI format 1-A instructs the RX UE to skip monitoring of PSCCH and / or PSSCH for the source ID, or destination ID, or a combination of source ID and destination ID, or a combination of SL logical channel ID and source ID and destination ID, until the time for the next resource for transmission is indicated by the time resource allocation and / or the resource reservation period of SCI format 1-A.

[0092] This embodiment also includes the possibility that the DRX indicator can be included in SCI format 2-A / 2-B or a newly defined SCI format (e.g., SCI format 3-A). From the perspective of the RX UE(one or more), when the RX UE receives an SCI in the PSCCH and / or PSSCH (e.g., SCI format 1-A and SCI format 2-A / 2-B) (e.g., assuming this is T0), and if the SCI in the PSCCH and / or PSSCH contains a DRX indicator, and if decoding of the PSSCH associated with the data fails (e.g., a Cyclic Redundancy Check (CRC) result error), the RX UE for a given source ID, or destination ID, or a combination of source ID and destination ID, or a combination of SL logical channel ID and source ID and destination ID, can skip monitoring of the SCI in the PSCCH and / or PSSCH until the time of the next incoming resource indicated by the time resource allocation (e.g., assuming the time of the next incoming resource is T1). At T1, the UE can resume monitoring of the SCI in the PSCCH and / or PSSCH.

[0093] If the RX UE receives an SCI in the PSCCH and / or PSSCH (i.e., SCI format 1-A and SCI format 2-A / 2-B, assuming this is T0), and if the SCI in the PSCCH and / or PSSCH contains a DRX indicator, and if the resource reservation period is set to a non-zero value, the UE can skip monitoring the SCI in the PSCCH and / or PSSCH until the time of the next resource indicated by the resource reservation period received at T0 (e.g., assuming the time of the first resource after the resource reservation period is T2) (if the decoding of the relevant PSSCH for data is successful, or if the time resource allocation no longer indicates the resource for HARQ data retransmission).

[0094] At T2, the UE can resume monitoring of the SCI in the PSCCH and / or PSSCH. The UE treats T2 as the new T0 and can continuously iterate the above DRX operations. Note that during the time when the RX UE does not monitor the PSCCH and / or PSSCH, the TX UE will not send the PSCCH and / or PSSCH for a given source ID, or destination ID, or a combination of source ID and destination ID, or a combination of SL logical channel and source ID and destination ID.

[0095] For more details, the provided DRX indicator can be signaled by using the current reserved bit in PSCCH SCI format 1-A, but using other existing information fields or defining new fields are also possible options.

[0096] The above embodiments can be further extended to provide TX UEs with greater scheduling flexibility for PSCCH and / or PSSCH transmissions. For example, in addition to the DRX indicator in the new timer described above, new timers can be introduced for one or more TX UEs with a given source ID, or destination ID, or a combination of source ID and destination ID, or a combination of SL logical channel ID and source ID and destination ID, so as to continue monitoring PSCCH and / or PSSCH for a certain period of time limited by the timer.

[0097] New timers N1 and / or N2 and / or M can be introduced. Using these new timers, the RX UE can continue monitoring the SCIs in the PSCCH and / or PSSCH while the timers are running. Timer N1 is started when the RX UE receives the first SCI in the PSCCH and / or PSSCH for the first resource used for the first new packet transmission (T0 in the example above) and the first SCI in the PSCCH and / or PSSCH for the first resource used for the first new packet transmission after the resource reservation period (T2 in the example above).

[0098] Timer N2 is started when the next resource, as indicated by the time resource assignment, becomes available (e.g., T1 in the above example). When the RX UE receives an SCI in the PSCCH and / or PSSCH for another new packet transmission while N1 is running, timer M is started or restarted (if timer M is already started and running). The RX UE monitors the SCI in the PSCCH and / or PSSCH, running any one of the timers (N1, N2, and M) simultaneously. Timers can all be applied together, or only specific timers can be applied.

[0099] The TX UE also needs to maintain the timer in the same way as the RX UE, and the TX UE has more freedom to schedule PSCCH and / or PSSCH transmissions while the timer is running. It should be noted that the SCI in the PSCCH and / or PSSCH can determine the schedule for new packet transmissions or retransmissions via the New Data Indicator (NDI) in SCI format 2-A or 2-B of the PSCCH.

[0100] N1 and / or N2 and / or M can be set to integer values ​​equal to or greater than 0, such as 0 [ms], 5 [ms], or 10 [ms]. N1, N2, and M can be set to the same or different values. N1, N2, and M can be configured by dedicated RRC messages (e.g., RRC connection reconfiguration) or public RRC messages (e.g., system information) provided by the gNB or pre-configured. This embodiment also includes the possibility that the TX UE can autonomously determine the values ​​of N1, N2, and M without gNB configuration or pre-configuration. In the case of unicast communication, the SL DRX indicator / activation, N1, N2, and M values ​​can be notified or negotiated via SL-RRC (PC5-RRC) directly between two associated UEs.

[0101] In another embodiment, the TX UE includes DRX-related information in a MAC CE, which is transmitted on the associated PSSCH. The TX and RX UEs skip monitoring of the SCI in the PSCCH and / or PSSCH according to the operation of the indicator instructing the RX UE, to obtain the source ID, or destination ID, or a combination of source and destination IDs, or a combination of SL logical channel ID and source and destination IDs, until the time for the next resource for transmission, as indicated by the time resource allocation and / or resource reservation period in SCI format 1-A. N1, N2, and M are the same as described in the first example embodiment above. However, the indicator and / or N1 and / or N2 and / or M are transmitted as a MAC CE, which is transmitted via the associated PSSCH.

[0102] Figure 8Signaling flow 800 for a side-link DRX mechanism according to an embodiment of the present disclosure is shown. Figure 8 The embodiment of signaling flow 800 shown is for illustrative purposes only. Figure 8 The one or more components shown may be implemented in a dedicated circuit configured to perform the function, or the one or more components may be implemented by one or more processors that execute instructions to perform the function.

[0103] Figure 8 The signaling flow according to the above embodiment of the first example embodiment is shown. T601 instructs the RX UE to receive timers N1, N2, and M via gNB system information or a dedicated RRC (RRC connection reconfiguration). T602 instructs the TX UE to receive timers N1, N2, and M via gNB system information or a dedicated RRC (RRC connection reconfiguration). Note that the RX UE or TX UE can also receive parameters through pre-configuration. Figure 8 As shown, the TX UE is a UE configured by the upper layer for SL transmission, while the RX UE is a UE configured by the upper layer for SL reception.

[0104] If a UE is configured by the upper layer for both SL transmission and SL reception, then when the UE performs SL transmission, it can be a TX UE, and when the UE performs SL reception, it can also be an RX UE. T603 instructs the TX UE to perform a resource (re)selection procedure to allocate resources for new data packet transmissions and HARQ data retransmissions. Figure 8 As shown, resource information used for the initial transmission and two HARQ data retransmissions can be included in the SCI in the PSCCH and / or PSSCH. T611 instructs the TX UE to send the PSCCH and PSSCH for the SCI and the transmission of new data packets (initial transmission) at the appropriate times.

[0105] SCI Format 1-A can include the DRX indicator by using the current reserved bit in SCI Format 1-A. The SCI in PSCCH and / or PSSCH includes time-domain resource information for HARQ data retransmission, which is indicated by the time resource allocation in SCI Format 1-A.

[0106] Assuming the TX UE applies SL DRX, the DRX indicator is included in SCI format 1-A. From the RX UE's perspective, if the RX UE receives the SCI in the PSCCH and / or PSSCH at T611, the UE knows that the DRX indicator exists in SCI format 1-A and applies SL DRX operation. At T611, the RX UE starts timer N1, and while N1 is running, the UE monitors the SCI in the PSCCH and / or PSSCH (e.g., ...). Figure 8As shown, the monitoring period is from T611 to (T611+N1). The RX UE can determine the T612 timing based on the time resource allocation field in SCI format 1-A received in T611.

[0107] This can be easily determined by adding the duration indicated by the time resource allocation to T611. The RX UE starts or restarts (if the timer has already started and is running) from timer N2 of T612, and the RX UE monitors the SCI in the PSCCH and / or PSSCH (such as...) while N2 is running. Figure 8 As shown, the monitoring period is from T612 to (T612+N2). The RX UE can also determine the T613 timing based on the time resource allocation field in the SCI format 1-A received in T612.

[0108] This can be easily determined by adding the duration indicated by the time resource allocation to T612. The RX UE starts or restarts (if the timer has already started and is running) from timer N2 of T613, and the RX UE monitors the SCI in the PSCCH and / or PSSCH (such as...) while N2 is running. Figure 8 As shown, the monitoring period is from T613 to (T613 to N2). The RX UE can know that there are no more resources for retransmitting HARQ data from PSCCH after T613 based on the fields and time resource allocation in SCI format 1-A received at T613.

[0109] like Figure 8 As shown, during the duration from T611 to (T613+N2), the RX UE monitors the SCI in the PSCCH and / or PSSCH only during the operation of either timer N1 or N2 or M (i.e., from T611 to (T611+N1), from T612 to (T612+N2), and from T613 to (T613+N2)). Otherwise, the RX UE skips monitoring the SCI in the PSCCH and / or PSSCH. Once the RX UE knows, based on the fields and time resource allocation in SCI format 1-A received at T613, that there are no resources available for HARQ data retransmission from the PSCCH after T613, the UE skips monitoring the SCI in the PSCCH and / or PSSCH until the time of the next first resource for new packet transmission at T614.

[0110] The RX UE can determine T614 based on the field (Resource Reservation Period) in SCI format 1-A received in T611. This can be simply determined by adding the duration associated with the Resource Reservation Period to T611. As described above in T611, the RX UE initiates N1 at T614, and the RX UE monitors the SCI in the PSCCH and / or PSSCH while running N1.

[0111] like Figure 8 As shown, T615 instructs the SCI in the PSCCH and / or PSSCH to schedule resources for another new data packet transmission (initial transmission) after T614. If, during N1 operation, the RX UE receives the SCI in the PSCCH and / or PSSCH for resources scheduled for another new data packet transmission (instead of the first new packet transmission (initial transmission) after the resource reservation period, which is T614), the RX UE starts or restarts (if the timer has already started and is running) timer M, and the RX UE monitors the SCI in the PSCCH / PSSCH while M is running.

[0112] like Figure 8 As shown, when N1 and M are running (e.g., the duration from T614 to (T614+N1) and the duration from T615 to (T615+M), the RX UE monitors the SCI in the PSCCH and / or PSSCH. Note that HARQ data retransmission is omitted from T614 onwards for simplicity. Note that, as Figure 8 As shown, it is assumed that all SCIs in the PSCCH and / or PSSCH include DRX indicators; otherwise, the RX UE does not follow the DRX operation described above, but instead continuously monitors the SCIs in the PSCCH and / or PSSCH over time.

[0113] Using the DRX indicator, the RX UE monitors the SCI in the PSCCH and / or PSSCH only when any of the timers (N1, N2, and M) is running; otherwise, the RX UE skips monitoring the SCI in the PSCCH and / or PSSCH. Similarly, the TX UE maintains these timers in the same manner as the RX UE, and the TX UE can send the PSCCH and / or PSSCH when any of the timers (N1, N2, and M) is running. In T601 and T602, the additional parameter Default Interval T can be sent to the UE. The Default Interval T can be used when the resource reservation interval is not included in the SCI in the PSCCH and / or PSSCH. For example, if the resource reservation interval is not included in the SCI in the PSCCH and / or the PSSCH in T611, T614 is derived from (T611 + Default Interval T).

[0114] Figure 9a A flowchart of a method 900 for RX UE behavior according to an embodiment of the present disclosure is shown. Method 900 can be performed by a UE (e.g., as...) Figure 1 Execute as shown in 111-116). Figure 9a The embodiments of method 900 shown are for illustrative purposes only. Figure 9a The one or more components shown may be implemented in a dedicated circuit configured to perform the function, or the one or more components may be implemented by one or more processors that execute instructions to perform the function.

[0115] Figure 9b Another flowchart illustrates a method 950 for RX UE behavior according to an embodiment of this disclosure. Method 950 can be performed by a UE (e.g., as...) Figure 1 Execute as shown in 111-116). Figure 9b The embodiments of method 950 shown are for illustrative purposes only. Figure 9b One or more components shown may be implemented in a dedicated circuit configured to perform the function, or one or more components may be implemented by one or more processors that execute instructions to perform the function.

[0116] exist Figure 9a and 9b The following describes the RX UE behavior. In step 901, the UE uses system information / RRC-specific messages (e.g., RRC connection reconfiguration) / pre-configuration to receive SL DRX parameters. These include timers N1, N2, M, and the default interval T. Also in step 901, the UE is configured for SL reception, and the UE receives a first SCI in the PSCCH and / or PSSCH for the L1 / L2 source ID and / or L1 / L2 destination ID of interest. The UE then checks whether the DRX indication / activation is applied / activated in the SCI in the PSCCH and / or PSSCH received in step 901 (e.g., also in step 911).

[0117] If DRX indication / activation is set in step 911, the UE monitors the SCI in the PSCCH and / or PSSCH in step 921 until (current time + N1). If DRX indication / activation is not set in step 911, DRX operation is not applied to the L1 / L2 source ID and / or L1 / L2 destination ID of interest in step 923 (i.e., the 3GPP standard specification Rel-16 SL receive behavior is applied).

[0118] During the monitoring of the SCI in the PSCCH and / or PSSCH in step 921, if the UE receives an SCI in the PSCCH and / or PSSCH with the L1 / L2 source ID and / or L1 / L2 destination ID of interest, and sets a DRX indication / activation in the SCI to indicate that DRX is applied / activated (step 931), and if the SCI is scheduled for the initial data transmission of new data packets (not for HARQ data retransmission) (step 933), the UE (re)starts timer M (if M has already started and is running, the UE restarts M) (step 935), and the UE monitors the SCI in the PSCCH and / or PSSCH until M expires (step 943).

[0119] During the monitoring of the SCI in the PSCCH and / or PSSCH in step 921, if the UE receives an SCI in the PSCCH and / or PSSCH with an interested L1 / L2 source ID and / or L1 / L2 destination ID, but no DRX indication / activation is set in the SCI to indicate the application / activation of DRX (step 931), then the UE does not apply DRX operation for the interested L1 / L2 source ID and / or L1 / L2 destination ID (i.e., apply 3GPP standard specification Rel-16 SL receive behavior) (step 937).

[0120] If, in step 931, the time resource allocation in the SCI of the received PSCCH and / or PSSCH indicates the next incoming resource, and the UE fails to receive the corresponding data in the PSSCH (PSSCH CRC check fails) (step 951), then the UE skips monitoring the SCI in the PSCCH and / or PSSCH until the time of the next incoming resource indicated by the time resource allocation becomes the current time slot, unless the requirement to monitor the SCI in the PSCCH and / or PSSCH in step 921 or step 943 is met (e.g., steps 953, 961). If the time of the next incoming resource indicated by the time resource allocation is the current time slot (e.g., step 961), then the UE monitors the SCI in the PSCCH and / or PSSCH until (current time slot + N2) (e.g., step 963).

[0121] If the UE successfully receives the corresponding PSCCH and / or PSSCH for HARQ data retransmission before that time (current time slot + N2), the UE does not need to monitor the SCI in the PSCCH and / or PSSCH for the remaining time. If the resource reservation period in the received PSCCH and / or PSSCH SCI indicates periodic reserved resources with an interval T in step 931 (e.g., step 971), the UE skips monitoring the SCI in the PSCCH and / or PSSCH until the interval T has elapsed, unless the need to monitor the SCI in the PSCCH and / or PSSCH is met in step 921 or step 943 (step 973). If the SCI in the received PSCCH and / or PSSCH does not include a resource reservation period in step 931 (e.g., step 971), the UE skips monitoring the SCI in the PSCCH and / or PSSCH until interval T has elapsed, unless monitoring of the SCI in the PSCCH and / or PSSCH is satisfied in step 921 or step 943 (e.g., step 975). Instead of using the default interval T in step 975, another possibility is not to apply DRX operation (i.e., apply 3GPP standard specification Rel-16 SL receive behavior). After interval T elapses in steps 973 and 975, the UE proceeds to step 921.

[0122] The TX UE behavior is very similar to the RX UE behavior in handling timers and determining the active time of the PSCCH and / or PSSCH. The differences are minor compared to the RX UE behavior. In one example, in step 901, the UE is configured for SL transmission (instead of SL reception). In another example, in steps 933 and 935, the UE not only (re)starts timer M when receiving an SCI in the PSCCH and / or PSSCH, but also (re)starts timer M when transmitting its own SCI in the PSCCH and / or PSSCH.

[0123] The UE performs a resource selection operation on the SL before the actual PSCCH and / or PSSCH transmission. In steps 921 and 943, the UE selects resources within the period of the SCI that satisfies the RX UE during the PSCCH and / or PSSCH monitoring period.

[0124] Figure 10 Resource selection for an example TX UE for SL DRX 1000 according to an embodiment of this disclosure is shown. Figure 10 The example of resource selection for the TX UE of the SL DRX 1000 shown is for illustrative purposes only.

[0125] Figure 10This describes how the TX UE performs resource selection for SL transmission. Resource selection involves two steps. It can be assumed that the UE triggers resource selection at time n. First, the UE performs channel sensing during the sensing window to identify the observed available SL channels. Channel sensing is actually performed before time n (e.g., the sensing window is from time (n-T0) to time (n-Tproc, 0)). Then, during the resource selection window, the UE selects the actual resource for transmission from the observed available SL channels.

[0126] For example, the resource selection window is from time (n+T1) to time (n+T2). To ensure that the selected resource is within the wake-up period, the RX UE monitors the SCI in the PSCCH and / or PSSCH as described in steps 921 and 943. The TX UE ensures that when the RX UE starts monitoring the SCI in the PSCCH and / or PSSCH after the DRX period and the resource selection window ends at time (e.g., slot / subframe / frame number #Y), the resource selection window starts at time (e.g., slot / subframe / frame number #X), and the time (e.g., slot / subframe / frame number #Y) is the time when the RX UE last monitored the SCI in the PSCCH and / or PSSCH. Therefore, the RX UE ends monitoring the SCI in the PSCCH and / or PSSCH after this time.

[0127] For example, after a DRX cycle (e.g., as...) Figure 8 As shown from T611 to T614, the RX UE begins monitoring the SCI in the PSCCH and / or PSSCH at T614 (where N1 begins after the DRX cycle), therefore the TX UE places the resource selection window starting from T614 (i.e., time (n+T1) is considered equal to T614). This means the TX UE can pre-perform channel sensing before T614. Furthermore, the TX UE does not place any part of the resource selection window after the time (T615+M) when the RX UE last monitored the SCI in the PSCCH and / or PSSCH, causing the RX UE to end monitoring the SCI in the PSCCH and / or PSSCH after that time. Based on the assumption that the resource selection window starts at T614, the sensing window starts and may move towards (T615+M) as the resource selection window moves towards (T615+M). However, the resource selection window may not exceed (T615+M), which means that no part of the resource selection window can be placed after (T615+M). Accordingly, the sensing window may stop when the resource selection window stops.

[0128] In summary, the resource selection window begins at the time slot / subframe where the RX UE starts monitoring SCIs in the PSCCH and / or PSSCH (e.g., the time slot / subframe where a long DRX period begins, a duration timer begins, and a HARQ RTT expires), and moves towards the time slot / frame where the RX UE last monitors SCIs in the PSCCH and / or PSSCH, and the RX UE stops monitoring SCIs in the PSCCH and / or PSSCH after that time slot / frame (e.g., the time slot / subframe where the active timer expires and the HARQ retransmission timer expires). It stops if the end of the resource selection window (n+T2) reaches the time slot / frame where the RX UE last monitors SCIs in the PSCCH and / or PSSCH, and the RX UE stops monitoring SCIs in the PSCCH and / or PSSCH after that time slot / frame (e.g., the time slot / subframe where the active timer expires and the HARQ retransmission timer expires). The sensing window can begin at the start of the resource selection window, move as the resource selection window moves, and stop when the resource selection window stops. The 3GPP standard specification describes the concepts of time slots / subframes at the start of long DRX periods, DRX duration timers, DRX HARQ RTTs, DRX activity timers, and DRX HARQ retransmission timers.

[0129] In the above description / examples, it is assumed that for a given source id (L1 / L2 source TX UE id), or destination id (L1 / L2 destination RX UE / group id), or a combination of source id and destination id, or a combination of SL logical channel id and source id and destination id, the corresponding discontinuous transmission (DTX) of the RX UE operates for each SL link.

[0130] For example, if DRX operates for each SL link for a given source ID, then for an SL link with source ID #A, one DRX operation is performed in the RX UE, and for an SL link with source ID #B, another DRX operation is performed in the RX UE. This means that different DRX operations can be performed for SL links if the source ID (L1 / L2 TX UE ID), or the destination ID (L1 / L2 destination RX UE / group ID), or a combination of source and destination IDs, or the SL logical channel ID and the combination of source and destination IDs are different. As another example, the DRX of the RX UE and / or the corresponding DTX of the TX UE can operate in different ways depending on the SL broadcast type.

[0131] For example, if the SL link is SL unicast, then for a given source ID, the DRX of the RX UE and / or the corresponding DTX of the TX UE operate on each SL link. However, if the SL link is SL multicast or broadcast, then for a given destination ID, the DRX of the RX UE and / or the corresponding DTX of the TX UE operate on each SL link. This is because DRX operation is typically closely related to the service pattern generated in the TX UE, thus meaning that DRX operates on a per-source TX UE basis. This principle works well for SL unicast; however, for SL group / broadcast where many UEs can be TX UEs (e.g., group members), if this principle is applied to SL group / broadcast, it may introduce more UE power consumption issues due to the many independent activity times.

[0132] Since all member UEs share the same application and most likely similar service patterns (or QoS levels) in multicast / broadcast with the same destination ID, it is preferable that DRX operate on the destination ID in SL multicast / broadcast. It should be noted that although DRX in the RX UE (and / or the corresponding DTX in the TX UE) operates based on the SL link with a given source ID when the SL link is SL noncast, and DRX (and / or DTX) operates based on the SL link with a given destination ID when the SL link is SL multicast / broadcast, any other combination is possible in this embodiment.

[0133] The MAC protocol layer performs packet filtering operations (e.g., determining whether a received packet is actually destined for the UE (based on the L2 source and destination IDs in the MAC header), (re)selecting SL carriers / resource pools / resources within the resource pool, prioritizing the SL and UL (uplink) for a given UE, SL logical channel priority, corresponding packet multiplexing (e.g., multiplexing multiple MACSDUs into a given MAC PDU), and SL HARQ retransmission / reception.

[0134] The RLC protocol layer performs RLC SDU segmentation / SDU reassembly, RLC SDU segment resegmentation, and error correction via ARQ (used only for AM data transmission).

[0135] The PDCP protocol layer performs header compression / decompression, encryption and / or integrity protection, duplication detection, reordering and ordered packet delivery to upper layers, and unordered packet delivery to upper layers. The RRC protocol layer performs the transmission of SL-RRC messages (also known as PC5-RRC) between peer UEs, the maintenance and release of SL-RRC connections between two UEs, and the detection of SL radio link failures in SL-RRC connections. The SDAP protocol layer performs the mapping between QoS streams and SL data radio bearers. Note that the terms SL-RRC or PC5-RRC are used in this disclosure.

[0136] The SCI on the PSCCH includes two SCI formats. The first-level SCI format is SCI format 1-A, and the second-level SCI formats are SCI format 2-A and / or SCI format 2-B. Each SCI format has the following information. For more details, please refer to the 3GPP standard specifications (e.g., NR multiplexing and channel coding, and NR physical layer procedures for data).

[0137] Basic SL communication functions are supported and specified in 3GPP standard specification Rel-16. For 3GPP standard specification Rel-17, more enhancements are planned for SL, one of which is the introduction of SL DRX operations. Note that in 3GPP standard specification Rel-16, UE DRX operations are specified only for DL, and DL DRX operations are specified in detail in 3GPP standard specifications (e.g., MAC).

[0138] There are some differences between SL and DL, which need to be considered when introducing SL DRX. One example is the characteristics of the UE's Layer 1 (L1) ID, which is used to identify whether DL or SL scheduling information is sent via PDCCH for DL ​​and PSCCH and PSSCH for SL. In DL, the UE's L1 ID is the same as the UE's Layer 2 (L2) ID, which is named the Cell Radio Network Temporary Identifier (C-RNTI), and the C-RNTI is assigned by the serving gNB.

[0139] The gNB assigns a unique C-RNTI value to the RRC of the gNB of the UE in the connected cell. For example, UE#1 and UE#2 in the same serving cell do not have the same C-RNTI value. Once the C-RNTI is assigned, the UE uses its own C-RNTI to determine whether the received scheduling information (also known as downlink control information (DCI)) sent via PDCCH is for itself or for the UE. If its own C-RNTI information is included in the success CRC of the scheduling information, the UE determines that the scheduling information is for itself, and therefore the UE follows the DL / UL resource allocation or other commands in the scheduling information; otherwise, the UE ignores it. However, in SL, the UE's SL L1 ID is different from the UE's SL L2 ID, which is named the SL L2 source ID / destination ID, and the SL L2 source ID / destination ID is assigned by the UE's upper layer (e.g., the V2X layer or application layer).

[0140] Due to the long length of the SL L2 source ID / destination ID, the SL L1 ID is a part of the SL L2 source ID / destination ID. For example, the SL L1 source ID / destination ID is the N most significant bits (MSB) or least significant bits (LSB) of the SL L2 source ID / destination ID. Note that the scheduling information (also known as sidelink control information (SCI)) in the PSCCH (for the first SCI) and PSSCH (for the second SCI) includes both the SL L1 source ID and the destination ID (in the second SCI of the PSSCH).

[0141] From the perspective of the TX UE, the UE includes its own SL L1 source ID in the SL L1 source ID of the SCI, and includes the SL L1 source ID of the peer UE in the SL L1 destination ID of the SCI. From the perspective of the RX UE, the UE uses its own SL L1 source ID to determine whether the received SCI is for itself or for other UEs. If the received SCI includes its own SL L1 source ID as the SL L1 destination ID, the UE determines that the scheduling information is for itself, and therefore the UE follows the SL resource allocation or other commands in the SCI. For example, the RX UE receives data from the allocated SL resources in the SCI; otherwise, the UE ignores it.

[0142] However, although the received SCI includes the RX UE's SL L1 source ID as the SL L1 destination ID, it is not actually guaranteed that the received SCI is specific to the UE, because the SL L1 source ID / destination ID is not unique for each UE. For example, UE#1 and UE#2 may have the same N MSB / LSB values ​​used as SL L1 IDs, even though UE#1 and UE#2 have different values ​​in the remaining bits of the L2 source ID / destination ID. Therefore, since the full length of the SL L2 source ID / destination ID is included in the MAC PDU header (HD), after MAC decoding, the UE ultimately checks whether the data received in the allocated SL resources by the SCI is for itself or another UE. If the RX UE checks that the SL L2 destination ID in the MAC HD matches its own SL L2 source ID, the UE continues further processing of the MAC PDU and forwards the MAC PDU to the upper layer; otherwise, the UE ignores the received data.

[0143] In one embodiment, a mechanism for maintaining the SL DRX timer is provided to address the characteristics of the described UE's SL L1 id and SL L2 id.

[0144] Figure 11 Signaling stream 1100 for timer maintenance in SL DRX activity is shown according to an embodiment of the present disclosure. Figure 11 The example of signaling flow 1100 shown is for illustrative purposes only. Figure 11 The one or more components shown may be implemented in a dedicated circuit configured to perform the function, or the one or more components may be implemented by one or more processors that execute instructions to perform the function.

[0145] like Figure 11 As shown, the TX UE (1101) is configured to send control and data to a specific RX UE (1103). Figure 11 As shown, it is assumed that SL unicast data transmission and reception occurs between the TX UE and the RX UE, but this does not exclude SL multicast data transmission and reception. In the case of SL multicast data, there can be multiple RX UEs. The TX UE and RX UE perform SL L2 link and radio bearer establishment (1111). The purpose of SL L2 link and radio bearer establishment is to exchange UE context information, SL service information, etc., and to establish the corresponding radio bearer between the two UEs. Once the SL L2 link and radio bearer are established between the TX UE and the RX UE, the RX UE can send SL DRX related auxiliary / configuration information to the TX UE via PC5-RRC (SL-RRC) (step 1121).

[0146] It includes a timer #M, which covers the duration between the reception of the PSSCH (including data packets) and the decoding of the MAC PDU, in order to obtain the full length of the L2 source ID / destination ID from the MAC HD. In one example, timer #M may only cover the MAC processing time for decoding the MAC PDU. Once the TX UE receives (1121), the TX UE can send SL DRX configuration or SL DRX activation via PC5-RRC or SL MAC CE (in step 1125).

[0147] The SL DRX configuration is set to take into account the service mode and / or QoS on the TX UE side and the received SL DRX auxiliary information (in step 1121). The SL DRX configuration in 1125 may include a timer #M, which may have a different value than the timer #M sent in step 1121. Note that in Figure 6 In this context, it is assumed that the RX UE provides the TX UE with SL DRX related auxiliary information (including timer #M and the possible service modes of the RX UE, if the RX UE also has some data to send), and the TX UE eventually sets the SL DRX configuration and provides the SL DRX configuration to the RX UE.

[0148] However, the TX UE may also provide the RX UE with SL DRX-related auxiliary information, and the RX UE ultimately sets the SL DRX configuration and provides the SL DRX configuration to the TX UE. In the second case, prior to step 1121, there will be signaling from the TX UE via PC5-RRC regarding SL DRX auxiliary information (including the service mode or suggested DRX configuration from the TX UE), and step 1121 will be the SL DRX configuration information via PC5-RRC (including DRX cycle length, DRX offset for starting the first DRX duration timer, DRX inactivity timer, and timer #M) (instead of the SL DRX auxiliary information).

[0149] Following step 1125, it can be assumed that at T631 (time instance #631), the SL DRX and the first SL DRX start duration timer are started from the RX UE. Note that DRX is defined from the perspective of the RX UE (for discontinuous receive operations), but in order to synchronize the control / data transmission time in the TX UE and the control / data reception time in the RX UE, a similar timer also needs to be maintained from the perspective of the TX UE; otherwise, the RX UE may miss the control / data transmitted by the TX UE. Therefore, at T631, the RX UE starts the SL DRX start duration timer, and the TX UE starts T#1 (timer #1) corresponding to the length of the SL DRX start duration timer.

[0150] Note that, as Figure 11 As shown, the roles of the SL DRX Start Duration Timer, SL DRX Period Length, and SL DRX Activity Timer are very similar to those defined in the 3GPP standard specification for the DL DRX Start Duration Timer, DL DRX Period Length, and DL DRX Activity Timer. The difference between the SL DRX Start Duration Timer and the DL DRX Activity Timer is that the SL DRX UE monitors both the PSCCH and PSSCH simultaneously during the timer's operation, while for DL ​​DRX, the UE only monitors the PDCCH during the timer's operation. This difference arises because, in the SL case, the Scheduling Information (SCI) is carried from both the PSCCH (for the first SCI) and the PSSCH (for the second SCI), while for DL, the Scheduling Information (e.g., DCI) is carried only via the PDCCH.

[0151] like Figure 11 As shown, assume that the first SL DRX start duration timer starts at T631 in the RX UE and expires at T636, and correspondingly, T#1 starts at T631 in the TX UE and expires at T636. It can be assumed that the TX UE sends PSCCH and PSSCH to the RX UE at T632 (1141). Note that the PSCCH and PSSCH in step 1141 (and also in 1143) are only used for initial transmission (not for HARQ retransmission). On the RX UE side, once the signal is received in step 1141, the RX UE starts timer #M at T632 (or in the next time slot of T632), and if the RX UE checks that the full length of the SL L2 destination ID included in the MAC HD matches its own SL L2 source ID, then when T632 expires at T633, the RX UE starts or restarts the SL DRX activity timer at T633 (if the timer has already started). Otherwise, in T633, the RX UE does not start or restart the timer during SL DRX activity (if the timer has already started).

[0152] Accordingly, on the TX UE side, once the signal is sent in step 1141, the TX UE starts timer #M at T632 (or in the next time slot of T632), and then when T632 expires at T633, the TX UE starts or restarts (if the timer has already started) the timer T#2 (timer #2) in the SL DRX activity timer on the RX UE side. Assume that T#2 in both the TX UE and SL DRX activity timers expires at T634.

[0153] On the RX UE side, if either the SL DRX Start Duration Timer or the SL DRX Activity Timer is running, the RX UE monitors the PSCCH and PSSCH to check for any scheduling information (i.e., the first SCI in the PSCCH and the second SCI in the PSSCH). Otherwise, if neither the SL DRX Start Duration Timer nor the SL DRX Activity Timer is running, the RX UE does not monitor the PSCCH and PSSCH to check for any scheduling information (i.e., the first SCI in the PSCCH and the second SCI in the PSSCH).

[0154] On the TX UE side, if either T#1 or T#2 is running, the TX UE can send additional PSCCH and PSSCH (SCI in the PSCCH and PSSCH, and data in the PSSCH) to the RX UE. Otherwise, if neither T#1 nor T#2 is running, the TX UE cannot send additional PSCCH and PSSCH (SCI in the PSCCH and PSSCH, and data in the PSSCH) to the RX UE. Note that if 625 includes timer #M, then timer #M at T632 and T635 is the same as timer #M in 625; otherwise, if timer #M is only included in 621, then timer #M is the same as timer #M in 621.

[0155] like Figure 11 As shown, assuming only the SL DRX start duration timer and the SL DRX activity timer are used as SL DRX activity times, this means that the RX UE monitors the PSCCH and PSSCH for the duration of receiving SCI and data destined for the RX UE, and the TX UE can send additional PSCCH and PSSCH to the RX UE for SCI and data. However, it does not exclude other SL DRX activity times, such as when the HARQ retransmission timer is running, etc. After the SL DRX cycle length from T631, the SL DRX start duration timer is restarted on the RX UE side, and T#1 is restarted on the TX UE side.

[0156] Figure 12 A flowchart of a method 1200 for side-link DRX operation according to various embodiments of the present disclosure is shown. Method 1200 can be performed by a UE (e.g., as...). Figure 1 111-116 shown). Figure 12 The embodiments of method 1200 shown are for illustrative purposes only. Figure 12One or more components described herein may be implemented in a dedicated circuit configured to perform the function, or one or more components may be implemented by one or more processors that execute instructions to perform the function.

[0157] like Figure 12 As shown, method 1200 begins at step 1202. In step 1202, the first UE receives a first PSCCH and a first PSSCH for SL DRX operation from the second UE, wherein the first PSCCH and the first PSSCH include an SCI, the SCI including a source ID, a destination ID, and SL DRX time information, the SL DRX time information indicating when the first UE monitors or skips at least one of the second PSCCH and the second PSSCH for SL DRX operation.

[0158] In step 1204, the first UE configures an SL DRX timer for each pair of source IDs and destination IDs. In step 1206, the first UE configures the value of at least one SL DRX timer based on the SCI information. In step 1208, when an SL DRX operation is applied to an SL communication identified by the source ID and destination ID pair, the UE receives at least one of a second PSCCH and a second PSSCH based on the SL DRX timer.

[0159] In one embodiment, the UE identifies a set of resources based on SCI information including time resource allocation information, configures the value of the SLDRX HARQ RTT timer corresponding to the duration between the reception time instance of the first PSCCH and PSSCH and the time instance indicated by the identified resource group, and configures the value of the SL DRX HARQ retransmission timer. If the data carried by the second PSSCH allocated by the SCI is not successfully decoded, the SL DRX HARQ RTT timer is started, and in response to the expiration of the SL DRX HARQ RTT timer, the SL DRX HARQ retransmission timer is started.

[0160] In one embodiment, the first UE skips monitoring the second PSCCH and PSSCH during the period when the SL DRX HARQ RTT timer is running, and monitors the second PSCCH and PSSCH during the period when the SL DRX HARQ retransmission timer is running. In such an embodiment, the SL DRX HARQ retransmission timer is configured by at least one of PC5 RRC signaling, system information, pre-configured information, or a fixed value.

[0161] In one embodiment, the UE identifies a group of resources based on SCI information including resource reservation period information, configures a value for a first SL DRX timer corresponding to the duration between the reception time instances of the first PSCCH and PSSCH and the time instance indicated by the identified resource group, configures a value for a second SL DRX timer, and starts the first SL DRX timer after the reception time instances of the first PSCCH and PSSCH. The second SL DRX timer is started in response to the expiration of the first SL DRX timer.

[0162] In one embodiment, the UE skips monitoring the second PSCCH and PSSCH during the period when the first SL DRX timer is running, and monitors the second PSCCH and PSSCH during the period when the second SL DRX timer is running. In such an embodiment, the second SL DRX timer is configured by at least one of PC5 RRC signaling, system information, pre-configuration information, or a fixed value.

[0163] In one embodiment, the UE uses information included in at least one of SCI, MAC Layer 2 signaling, PC5 RRC, system information, or pre-configuration information to determine whether SL DRX operation is applied to SL communication.

[0164] In one embodiment, the UE configures a first UE as an RX UE to receive SL transmissions from a second UE, the second UE being a TX UE for SL DRX operations with an RX UE.

[0165] The flowcharts above illustrate example methods that can be implemented according to the principles of this disclosure, and various modifications can be made to the methods shown in the flowcharts herein. For example, although shown as a series of steps, the individual steps in each diagram can overlap, occur in parallel, occur in different orders, or occur multiple times. In another example, steps can be omitted or replaced with other steps.

[0166] Although this disclosure has been described with reference to exemplary embodiments, various changes and modifications can be suggested by those skilled in the art. This disclosure is intended to include such changes and modifications that fall within the scope of the appended claims. Nothing described in this application should be construed as implying that any particular element, step, or function is an essential element that must be included within the scope of the claims. The scope of the patent subject matter is defined by the claims.

Claims

1. A method performed by a first user equipment (UE) operating in a sidelink discontinuous reception (DRX) mode in a wireless communication system, the method comprising: The second UE receives side link control information (SCI), wherein the SCI includes a first SCI format on the physical side link control channel (PSCCH) and a second SCI format on the physical side link shared channel (PSSCH). Based on the first time information of the resources indicated by the time resource allocation information included in the first SCI format, or the second time information of the resources indicated by the resource reservation period information included in the first SCI format, the activity time in the SLDRX operation is determined; and Monitor SCI during the activity period. Wherein, the first SCI format is SCI format 1-A, and includes the time resource allocation information and the resource reservation period information, and The second SCI format includes a new data indication.

2. The method according to claim 1, wherein, Determining the activity time also includes: Derive the SL DRX Hybrid Automatic Repeat Request (HARQ) Round Trip Time (RTT) timer from the time resource allocation information; Identify whether the SL DRX HARQ RTT timer has expired; and If the SL DRX HARQ RTT timer expires, then the SL DRX retransmission timer is started. The activity time includes the time during which the SL DRX retransmission timer is running.

3. The method according to claim 1, wherein, The activity time includes time slots determined based on the second time information of the resources indicated by the resource reservation period information.

4. A method performed by a second user equipment (UE) operating in a sidelink discontinuous reception (DRX) mode in a wireless communication system, the method comprising: The sidelink control information (SCI) is sent to the first UE, wherein the SCI includes a first SCI format on the physical sidelink control channel (PSCCH) and a second SCI format on the physical sidelink shared channel (PSSCH); and Send SCI to the first UE during the activity period. The activity time in the SL DRX operation is determined based on the first time information of the resource indicated by the time resource allocation information included in the first SCI format, or the second time information of the resource indicated by the resource reservation period information included in the first SCI format. Wherein, the first SCI format is SCI format 1-A, and includes the time resource allocation information and the resource reservation period information, and The second SCI format includes a new data indication.

5. The method according to claim 4, in, The SL DRX Hybrid Automatic Repeat Request (HARQ) Round Trip Time (RTT) timer is derived based on the aforementioned time resource allocation information. Specifically, based on the expiration of the SL DRX HARQ RTT timer, the SL DRX retransmission timer is started, and The activity time includes the time during which the SL DRX retransmission timer is running.

6. The method according to claim 4, wherein, The activity time includes time slots determined based on the resource reservation period information.

7. A first user equipment (UE) operating in a sidelink SL discontinuous reception DRX mode in a wireless communication system, the first UE comprising: transceiver; as well as The controller is configured as follows: The second UE receives side link control information (SCI), wherein the SCI includes a first SCI format on the physical side link control channel (PSCCH) and a second SCI format on the physical side link shared channel (PSSCH). Based on the first time information of the resources indicated by the time resource allocation information included in the first SCI format, or the second time information of the resources indicated by the resource reservation period information included in the first SCI format, the activity time in the SLDRX operation is determined; and Monitor SCI during the activity period. Wherein, the first SCI format is SCI format 1-A, and includes the time resource allocation information and the resource reservation period information, and The second SCI format includes a new data indication.

8. The first UE according to claim 7, wherein, The controller is also configured to: Derive the SL DRX Hybrid Automatic Repeat Request (HARQ) Round Trip Time (RTT) timer from the time resource allocation information; Identify whether the SL DRX HARQ RTT timer has expired; and If the SL DRX HARQ RTT timer expires, then the SL DRX retransmission timer is started. The activity time includes the time during which the SL DRX retransmission timer is running.

9. The first UE according to claim 7, wherein, The activity time includes time slots determined based on the second time information of the resources indicated by the resource reservation period information.

10. A second user equipment (UE) operating in a sidelink SL discontinuous reception DRX mode in a wireless communication system, the second UE comprising: transceiver; as well as The controller is configured as follows: The sidelink control information (SCI) is sent to the first UE, wherein the SCI includes a first SCI format on the physical sidelink control channel (PSCCH) and a second SCI format on the physical sidelink shared channel (PSSCH); and Send SCI to the first UE during the activity period. The activity time in the SL DRX operation is determined based on the first time information of the resource indicated by the time resource allocation information included in the first SCI format, or the second time information of the resource indicated by the resource reservation period information included in the first SCI format. Wherein, the first SCI format is SCI format 1-A, and includes the time resource allocation information and the resource reservation period information, and The second SCI format includes a new data indication.

11. The second UE according to claim 10, in, The SL DRX Hybrid Automatic Repeat Request (HARQ) Round Trip Time (RTT) timer is derived based on the aforementioned time resource allocation information. Specifically, based on the expiration of the SL DRX HARQ RTT timer, the SL DRX retransmission timer is started, and The activity time includes the time during which the SL DRX retransmission timer is running.

12. The second UE according to claim 10, wherein, The activity time includes time slots determined based on the resource reservation period information.

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