Transmitting and receiving sidelink positioning reference signals

Abstract

This disclosure provides a communication device and a communication method for transmitting and receiving Sidelink Positioning Reference Signals (SL-PRS). The communication device includes a circuit that generates SL-PRS when in operation, and a transmitting unit that transmits SL-PRS based on signaling when in operation.

Description

Technical Field

[0001] The present disclosure relates to a communication device and a communication method for transmitting and receiving sidelink positioning reference signals (SL-PRS).

Background Art

[0002] Regarding sidelink (SL) positioning, as described in WID RP-223549, it is defined in the Expanded and Improved New Radio (NR) Positioning of 3GPP (registered trademark) Release 18. A work item related to sidelink positioning is newly introduced to 3GPP in Release 18 to support sidelink ranging and positioning by sidelink positioning reference signals (SL-PRS).

[0003] However, there has been no discussion yet on how to realize the transmission and reception of SL-PRS.

[0004] Therefore, there is a need for a communication device and method that provide a feasible technical solution for the transmission and reception of SL-PRS. Further, other desirable features and characteristics will become apparent from the following detailed description and the appended claims in conjunction with the accompanying drawings and the background art of the present disclosure.

Summary of the Invention

[0005] Non-limiting and exemplary embodiments contribute to providing a communication device and method for transmitting and receiving SL-PRS.

[0006] According to a first embodiment of the present disclosure, a communication device is provided which includes a circuit that generates a Sidelink Positioning Reference Signal (SL-PRS) when in operation, and a transmitting unit that transmits the SL-PRS based on signaling when in operation.

[0007] According to a second embodiment of the present disclosure, a communication device is provided, the first communication device comprising a receiving unit that, when operating, receives a Sidelink Positioning Reference Signal (SL-PRS) based on signaling, and a circuit that, when operating, decodes the SL-PRS.

[0008] According to a third embodiment of the present disclosure, a first communication device is provided, which, when in operation, generates a signaling that notifies a request to transmit or receive a Sidelink Positioning Reference Signal (SL-PRS), and a transmitting unit that, when in operation, transmits the signaling to a second communication device.

[0009] According to a fourth embodiment of the present disclosure, a communication method is provided which generates a Sidelink Positioning Reference Signal (SL-PRS) and transmits the SL-PRS based on signaling.

[0010] It should be noted that general or specific embodiments can be implemented as systems, methods, integrated circuits, computer programs, storage media, or any selective combination thereof.

[0011] Further advantages and effects of one embodiment of this disclosure will be made apparent from the specification and drawings. Such advantages and / or effects are provided by several embodiments and features described in the specification and drawings, but not all of them are necessarily provided in order to obtain one or more identical features. [Brief explanation of the drawing]

[0012] The embodiments described herein are merely examples, but will be better understood and readily apparent to those skilled in the art through the following description and in conjunction with the drawings. [Figure 1] A diagram illustrating an example architecture of a 3GPP NR Radio Access Network (NR-RAN) to which exemplary embodiments of this disclosure apply. [Figure 2] A schematic diagram illustrating the functional partitioning between an NG-RAN and a 5G Core Network (5GC) to which exemplary embodiments of this disclosure apply. [Figure 3] A sequence diagram of the setup / reconfiguration procedure for a radio resource control (RRC) connection to which exemplary embodiments of this disclosure apply. [Figure 4] A schematic diagram illustrating usage scenarios for high-speed, high-capacity communication (eMBB: enhanced Mobile Broadband), massive machine type communications (mMTC: massive Machine Type Communications), and ultra-reliable and low-latency communications (URLLC: Ultra Reliable and Low Latency Communications) to which exemplary embodiments of this disclosure apply. [Figure 5] A block diagram illustrating an exemplary 5G system architecture for V2X (vehicle to everything) communication in a non-roaming scenario to which exemplary embodiments of the present disclosure apply. [Figure 6] Diagram illustrating various signaling methods for triggering SL-PRS transmissions according to various embodiments of the present disclosure. [Figure 7] Explanation diagram of 1-to-1 resource reservation according to various embodiments of the present disclosure. [Figure 8] Explanation diagram of 1-to-multiple resource reservation according to various embodiments of the present disclosure. [Figure 9] Explanation diagram of multiple-to-1 resource reservation according to various embodiments of the present disclosure. [Figure 10] Explanation diagram of 1-to-2 resource reservation according to various embodiments of the present disclosure. [Figure 11] Explanation diagram of window-based SL-PRS transmission according to various embodiments of the present disclosure. [Figure 12] Explanation diagram of counter-based SL-PRS transmission according to various embodiments of the present disclosure. [Figure 13] Explanation diagram of various signaling for triggering SL-PRS reception according to various embodiments of the present disclosure. [Figure 14] Explanation diagram of window-based SL-PRS reception according to various embodiments of the present disclosure. [Figure 15] Explanation diagram of counter-based SL-PRS reception according to various embodiments of the present disclosure. [Figure 16] Explanation diagram of various signaling for requesting SL-PRS according to various embodiments of the present disclosure. [Figure 17] Explanation diagram of time offset allocation according to various embodiments of the present disclosure. [Figure 18] Explanation diagram of frequency offset allocation according to various embodiments of the present disclosure. [Figure 19] Explanation diagram of SL-PRS transmission triggered by a base station (gNB) or a user equipment (UE) according to various embodiments of the present disclosure. [Figure 20] Explanation diagram of SL-PRS reception triggered by a gNB or a UE according to various embodiments of the present disclosure. [Figure 21] Explanation diagram of request signaling for SL-PRS transmission according to various embodiments of the present disclosure. [Figure 22] Explanation diagram of request signaling for SL-PRS reception according to various embodiments of the present disclosure. [Figure 23] Flowcharts showing communication methods according to various embodiments of the present disclosure. [Figure 24] Schematic block diagrams of communication devices according to various embodiments of the present disclosure.

[0013] Those skilled in the art can understand that the elements in the figures are explained simply and clearly and are not necessarily drawn to a certain scale. For example, in order to better understand this embodiment, some dimensions of the elements in the figure, block diagram, or flowchart may be exaggerated with respect to other elements.

Embodiments for Carrying out the Invention

[0014] Some embodiments of the present disclosure will be described by way of example with reference to the drawings. Similar reference numerals and letters in the drawings refer to similar or equivalent elements.

[0015] In particular, the overall system architecture envisions an NG-RAN (Next Generation Radio Access Network) with gNBs, which terminate the NG radio access user plane (SDAP / PDCP / RLC / MAC / PHY) protocols and control plane (RRC) protocols for user equipment (UEs). The gNBs are interconnected with each other via the Xn interface. Furthermore, the gNBs are connected to the NGC (Next Generation Core) via the Next Generation (NG) interface, more specifically to the AMF (Access and Mobility Management Function) (e.g., a specific core entity that performs the AMF) via the NG-C interface, and to the UPF (User Plane Function) (e.g., a specific core entity that performs the UPF) via the NG-U interface. The NG-RAN architecture 100 is shown in Figure 1 (see, for example, Section 4 of 3GPP TS 38.300 v16.3.0).

[0016] The user plane protocol stack in New Radio (NR) (see, for example, Section 4.4.1 of 3GPP TS 38.300) includes the PDCP (Packet Data Convergence Protocol, see Section 6.4 of TS 38.300) sublayer, the RLC (Radio Link Control, see Section 6.3 of TS 38.300) sublayer, and the MAC (Medium Access Control, see Section 6.2 of TS 38.300) sublayer, all of which terminate at the gNB on the network side. In addition, a new access layer (AS) sublayer (SDAP, Service Data Adaptation Protocol) is introduced on top of PDCP (see, for example, Section 6.5 of 3GPP TS 38.300). The control plane protocol stack is also defined in NR (see, for example, Section 4.4.2 of TS 38.300). An overview of Layer 2 functionality is provided in Section 6 of TS 38.300. The functions of the PDCP, RLC, and MAC sublayers are described in Sections 6.4, 6.3, and 6.2 of TS 38.300, respectively. The functions of the RRC layer are described in Section 7 of TS 38.300. Furthermore, sidelink communication was introduced in 3GPP TS 38.300 v16.3.0. Sidelink supports direct communication between UEs using sidelink resource allocation mode, physical layer signals / physical layer channels, and physical layer procedures (see, for example, Section 5.7 of TS 38.300).

[0017] For example, the Medium-Access-Control (MAC) layer handles scheduling and scheduling-related functions, including logical channel multiplexing and processing of various numerologies.

[0018] The Physical Layer (PHY) is responsible for, for example, encoding, PHY HARQ processing, modulation, multi-antenna processing, and mapping signals to appropriate physical time-frequency resources. The Physical Layer also handles the mapping of transport channels to physical channels. The Physical Layer provides services to the MAC layer in the form of transport channels. A physical channel corresponds to a set of time-frequency resources used for transmitting a particular transport channel, and each transport channel is mapped to a corresponding physical channel. For example, physical channels on the uplink include the Physical Random Access Channel (PRACH), Physical Uplink Shared Channel (PUSCH), and Physical Uplink Control Channel (PUCCH), as well as the Physical Downlink Shared Channel (PDSCH), Physical Downlink Control Channel (PDCCH), and Physical Broadcast Channel (PBCH) on the downlink. Furthermore, physical sidelink channels include the Physical Sidelink Control Channel (PSCCH), Physical Sidelink Shared Channel (PSSCH), Physical Sidelink Feedback Channel (PSFCH), and Physical Sidelink Broadcast Channel (PSBCH).

[0019] NR use cases / deployment scenarios include high-speed, high-capacity communication (eMBB), ultra-high-reliability, low-latency communication (URLLC), and / or massive simultaneous connection communication (mMTC), and these services have diverse requirements regarding data rate, latency, and coverage. For example, eMBB is expected to support peak data rates of the order of three times that provided by IMT-Advanced (20 Gbps for downlink and 10 Gbps for uplink) and user-perceived data rates. In contrast, URLLC has more stringent requirements, including extremely low latency (user plane latency of 0.5 ms for UL and DL respectively) and high reliability (1-10 ms within 1 ms). -5 ) and are imposed. Finally, in mMTC, a high connectivity density (1,000,000 devices / km in urban environments) is preferred. 2 ), wide coverage in harsh environments, and extremely long-lasting batteries (15 years) for low-cost devices may be required.

[0020] Therefore, OFDM (orthogonal frequency-division multiplexing) numerology (e.g., subcarrier spacing, OFDM symbol length, cyclic prefix (CP) length, number of symbols per scheduling interval) that is suitable for one use case may not work well for another use case. For example, low-latency services may preferably require shorter symbol lengths (and thus larger subcarrier spacings) and / or fewer symbols per scheduling interval (also known as TTI) than mMTC services. Furthermore, in configuration scenarios with large channel delay spreads, longer CP lengths may be preferred than in scenarios with smaller delay spreads. To maintain a similar level of CP overhead, the subcarrier spacing should be optimized according to the delay spread. NR may support two or more values ​​for subcarrier spacing. Currently, subcarrier spacings of 15kHz, 30kHz, 60kHz, etc., are considered. The symbol length Tu and subcarrier spacing Δf are directly related by the equation Δf = 1 / Tu. As with LTE systems, the term "resource element" can be used to represent the smallest resource unit consisting of one subcarrier for the length of one OFDM / SC-FDMA symbol.

[0021] In the new 5G-NR wireless system, resource grids for subcarriers and OFDM symbols are defined for each numerology and carrier, for both the uplink and downlink. Each element of the resource grid is called a resource element and is identified based on its frequency index in the frequency domain and its symbol position in the time domain (see 3GPP TS 38.211 v16.3.0).

[0022] Schematic diagram 200 in Figure 2 shows the functional division between NG-RAN and 5GC. The logical nodes of NG-RAN are gNB or ng-eNB. The logical nodes of 5GC are Access and Mobility Management Function (AMF), User Plane Function (UPF), and Session Management Function (SMF).

[0023] In particular, gNB and ng-eNB handle the following key functions: — Radio resource management functions such as Radio Bearer Control, Radio Admission Control, Connection Mobility Control, and dynamic allocation (scheduling) of resources to UEs on both uplink and downlink; — Compression, encryption, and integrity protection of the IP header of the data; — Selection of the AMF when the UE attaches if routing to the AMF cannot be determined from the information provided by the UE; — Routing user plane data for UPF; — Routing of control plane information to AMF; — Setting up and disconnecting connections; — Scheduling and sending paging messages; — Scheduling and transmission of system broadcast information (originating from AMF or OAM); — Setting up measurements and reporting for mobility and scheduling; — Transport-level packet marking on the uplink; — Session management; — Support for network slicing; — Mapping for QoS flow management and data radio bearers; — Support for UEs in RRC_INACTIVE state; — Non-Access Stratum (NAS) message delivery function; — Sharing of wireless access networks; ― Dual connectivity; — Close collaboration between NR and E-UTRA

[0024] The Access and Mobility Management Function (AMF) handles the following key functions: — A function to terminate signaling in the Non-Access Stratum (NAS); — Security of NAS signaling; — Access Stratum (AS) security controls; — Core Network (CN) node-to-node signaling for mobility between 3GPP access networks; — Reachability of the UE in idle mode (including control and execution of paging retransmissions); — Management of registration areas; — Support for intra-system and inter-system mobility; — Access authentication; — Access authorization including roaming permission checks; — Mobility management and control (enrollment and policies); — Support for network slicing; — Selection of Session Management Function (SMF)

[0025] Furthermore, the User Plane Function (UPF) handles the following key functions: — Anchor points for intra-RAT mobility / inter-RAT mobility (where applicable); — External PDU (Protocol Data Unit) session points for interconnection with data networks; — Packet routing and forwarding; — Packet inspection and enforcement of policy rules in the user plane; — Reporting traffic usage; — Uplink classifier that supports routing of traffic flow to data networks; — Branching point for supporting multi-homed PDU sessions; ― QoS processing for the user plane (e.g., packet filtering, gating, UL / DL rate enforcement); — Verification of upstream link traffic (mapping to SDF QoS flow); — Downlink packet buffering and downlink data notification triggering function

[0026] Finally, the Session Management Function (SMF) handles the following main functions: — Session management; — Assignment and management of IP addresses for UEs; — UPF selection and control; — A traffic steering configuration feature in User Plane Functions (UPF) for routing traffic to the appropriate destination; — Policy enforcement and QoS for the control unit; — Notification of downlink data

[0027] Sequence diagram 300 in Figure 3 shows some of the interactions between the UE, gNB, and AMF (5GC entities) during the transition of the UE from RRC_IDLE to RRC_CONNECTED in the NAS portion (see TS 38.300 v16.3.0). The transition steps are as follows: 1. The UE requests that a new connection be set up from the RRC_IDLE state. 2 / 2a. The gNB completes the RRC setup procedure. Note: The following describes scenarios in which gNB rejects a request. 3. In RRCSetupComplete, the first NAS message from the UE, sent via piggyback, is sent to the AMF. 4 / 4a / 5 / 5a. Additional NAS messages may be exchanged between the UE and the AMF. See reference

[22] in TS 23.502 (3GPP TS 23.122: “Non-Access Layer (NAS) Functions Related to Mobile Stations in Idle Mode”). 6. The AMF prepares the UE context data (including PDU session context, security key, UE radio capability, and UE security capability, etc.) and sends it to the gNB. 7 / 7a. gNB activates AS security with UE. 8 / 8a. The gNB performs a reconfiguration to set up SRB2 and DRB. 9. The gNB notifies the AMF that the setup procedure is complete.

[0028] RRC is a higher-layer signaling protocol used for configuring UEs and gNBs. Specifically, in this transition, the AMF creates UE context data (including, for example, PDU session context, security keys, UE radio capabilities, UE security capabilities, etc.) and sends it to the gNB via an INITIAL CONTEXT SETUP REQUEST. The gNB then activates AS security with the UE, which is done by the gNB sending a SecurityModeCommand message to the UE, and the UE responding to the gNB with a SecurityModeComplete message. Subsequently, the gNB performs a reconfiguration to establish the Signaling Radio Bearer 2 (SRB2) and Data Radio Bearer (DRB), which is done by the gNB sending an RRCReconfiguration message to the UE, and the gNB receiving an RRCReconfigurationComplete from the UE in response. For signaling-only connections, the RRCReconfiguration step is omitted because SRB2 and DRB are not set up. Finally, the gNB notifies the AMF that the establishment procedure is complete by sending an INITIAL CONTEXT SETUP RESPONSE.

[0029] Schematic diagram 400 in Figure 4 illustrates several use cases for 5G NR. The 3rd generation partnership project NR (3GPP NR) considers three use cases envisioned to support a wide variety of services and applications through IMT-2020. Phase 1 technical specifications for high-speed, high-capacity communication (eMBB) have been determined. Current and future work includes further expansion of eMBB support, as well as standardization for ultra-high reliability, low-latency communication (URLLC) and massive simultaneous connection communication (mMTC). Figure 4 shows some examples of IMT usage scenarios envisioned for 2020 and beyond (see, for example, Figure 2 in ITU-R M.2083).

[0030] URLLC use cases have stringent requirements regarding capabilities such as throughput, latency, and availability, and are envisioned as one means of realizing future vertical applications such as wireless control of industrial manufacturing or production processes, telemedicine surgery, power distribution automation in smart grids, and transportation safety. The ultra-high reliability of URLLC is supported by identifying the technology to meet the requirements set by TR 38.913. For NR URLLC in Release 15, key requirements include a target user plane latency of 0.5 ms for UL (uplink) and 0.5 ms for DL ​​(downlink). Typical URLLC requirements for a single packet transmission are a BLER (block error rate) of 1E-5 for a packet size of 32 bytes with a user plane latency of 1 ms.

[0031] From a physical layer perspective, several ways to improve reliability are possible. Current approaches to reliability improvements include defining separate CQI tables for URLLC, a more compact DCI format, and PDCCH iterations. However, as NR becomes more stable and development progresses (regarding key requirements for NR URLLC), the scope for achieving ultra-high reliability may expand. Specific use cases for NR URLLC in Release 15 include augmented reality / virtual reality (AR / VR), e-health, e-safety, and mission-critical applications.

[0032] Furthermore, the technical enhancements targeted by NR URLLC aim to improve latency and reliability. Technical enhancements for latency improvement include configurable neurology, mini-slot-based scheduling with flexible mapping, grant-free (configured grant) uplink, mini-slot-level repetition on data channels, and preemption on downlink. Preemption means that a transmission for which resources have already been allocated is aborted, and those resources are used for another transmission requested later with lower latency / higher priority requirements. Thus, a transmission that has already been permitted is preempted by a later transmission. Preemption applies regardless of the specific service type. For example, a transmission of service type A (e.g., URLLC) can be preempted by a transmission of service type B (e.g., eMBB). Technical enhancements related to reliability include a dedicated Channel Quality Indicator (CQI) / Modulation and Coding Scheme (MCS) table for the 1E-5 target BLER.

[0033] The use case for mMTC (Massively Multiple Connections Communication) is characterized by a very large number of connected devices transmitting relatively small amounts of data, which are generally less affected by latency. These devices need to be low-cost and have extremely long battery life. From a noise reduction (NR) perspective, utilizing a very narrow bandwidth is one possible solution to achieve power savings from a UE perspective and enable long battery life.

[0034] As described above, the range of reliability in NR is expected to broaden. One important requirement in all cases, especially for URLLC and mMTC, is high or very high reliability. Several mechanisms can be considered to improve reliability from both a radio and network perspective. In general, there are several important areas that can help improve reliability. These areas include compact control channel information, data channel / control channel repetition, and diversity related to the frequency domain, time domain, and / or spatial domain. These areas are generally applicable to reliability regardless of the specific communication scenario.

[0035] Regarding NR URLLC, further use cases with more stringent requirements are envisioned, such as factory automation, transportation, and power distribution. These stringent requirements include higher reliability (up to 10%), depending on the use case. -6 The advantages include higher availability, a maximum packet size of 256 bytes, time synchronization on the order of a few microseconds (values ​​ranging from 1 to several microseconds depending on the frequency range), and low latency on the order of 0.5 to 1 ms (with a target latency of 0.5 ms specifically for the user plane).

[0036] Furthermore, several technical enhancements are possible for NR URLLC from a physical layer perspective. In particular, enhancements related to the PDCCH (Physical Downlink Control Channel) include a compact DCI, PDCCH repeatability, and increased PDCCH monitoring. Enhancements related to the UCI (Uplink Control Information) include improved HARQ (Hybrid Automatic Repeat Request) and enhanced Channel State Information (CSI) feedback. Enhancements to PUSCH related to minislot-level hopping and retransmission / repeat have also been recognized. The term "minislot" refers to a transmission time interval (TTI) containing fewer symbols than a slot (a slot contains 14 symbols).

[0037] The 5G QoS (Quality of Service) model is based on QoS flows and supports both QoS flows that require a guaranteed flow bitrate (GBR QoS flows) and QoS flows that do not require a guaranteed flow bitrate (non-GBR QoS flows). Therefore, at the NAS level, QoS flows are the finest granularity of QoS differentiation within a PDU session. Within a PDU session, QoS flows are identified by a QoS flow ID (QFI) transmitted in the encapsulation header via the NG-U interface.

[0038] The 5GC establishes one or more PDU sessions for each UE. The NG-RAN establishes at least one Data Radio Bearer (DRB) with each PDU session for each UE, and can then configure additional DRBs for the QoS flow of that PDU session, as described above, for example with reference to Figure 3 (the NG-RAN decides when to configure them). The NG-RAN maps packets belonging to different PDU sessions to different DRBs. NAS-level packet filtering in the UE and 5GC associates UL and DL packets with QoS flows, and AS-level mapping rules in the UE and NG-RAN associate UL and DL QoS flows with DRBs.

[0039] Block diagram 500 in Figure 5 shows the non-roaming reference architecture for 5G NR (see Section 4.2.1.1 of TS 23.287 v16.4.0). Application functions (AFs) (e.g., external application servers handling 5G services as illustrated in Figure 4) interact with the 3GPP Core Network for the purpose of providing services. For example, they support application influence on traffic routing, access Network Exposure Functions (NEFs), or interact with policy frameworks for policy control (e.g., QoS control) (see Policy Control Functions (PCFs)). Based on the operator's deployment, application functions (AFs) that are considered trusted by the operator may be allowed to interact directly with the relevant Network Functions. Application functions that are not authorized by the operator to directly access Network Functions interact with the relevant Network Functions using an external exposure framework via the NEF.

[0040] Figure 5 further illustrates the functional units of the 5G architecture for V2X communication, namely the Unified Data Management (UDM), Policy Control Function (PCF), Network Exposure Function (NEF), Application Function (AF), Unified Data Repository (UDR), Access and Mobility Management Function (AMF), Session Management Function (SMF), and User Plane Function (UPF) in 5GC, as well as the V2X Application Server (V2AS) and Data Network (DN; e.g., operator-provided services, internet access, or third-party services). All or some of the core network functions and application services may be deployed and run in a cloud computing environment.

[0041] Reusing existing downlink (DL) positioning reference signals (PRS) for SL PRS is not straightforward because SL is transmitted between UEs, while DL is transmitted from gNB to UE. DL-PRS is scheduled by gNB, which has complete control over uplink (UL) and DL resources. SL-PRS is transmitted by each UE, and the UE does not control the SL resources required for SL-PRS transmission. In other words, SL transmissions are distributed among UEs, while DL transmissions are centralized from gNB. Transmission is either sense-based resource selection or random resource selection. In Scheme 2 (or Mode 2), because there is no central scheduling by gNB, the transmission procedure must be redesigned to account for potential airborne collision and congestion control.

[0042] Further differences are as follows: The power available to a UE for SL-PRS transmission is usually limited by battery life, whereas in DL-PRS, power is usually not an issue because the gNB is usually electrically powered. Power control for distributed UEs is not as simple as centralized gNB scheduling. Therefore, power saving is more important in SL-PRS, but less so in DL-PRS. SL positioning primarily measures the distance between UEs, while DL primarily measures the distance between the gNB and the UE. SL positioning is more relevant to safety use cases, while DL is more relevant to gNB recognition. Therefore, the delay requirements for SL positioning are more important for safety considerations. UEs transmitting or receiving SL-PRS transmissions are almost always operating on the unlicensed spectrum, whereas DL is usually operating on the licensed spectrum. The SL spectrum can be subject to interference from other technologies (e.g., Wi-Fi), while the DL spectrum is likely to be solely for DL ​​and UL scheduling by the gNB. Therefore, in order to address the differences between SL and DL, it is necessary to investigate and consider new solutions that take into account UE congestion control, power saving, public safety, and distributed scheduling in SL-PRS transmission.

[0043] Currently, SL-PRS design primarily focuses on the SL-PRS itself (i.e., sequence generation, initialization, time referencing, and frequency referencing), and is based mainly on the perspective of a single UE, without considering signaling in the air with other UEs or gNBs. SL-PRS transmission is performed by only a few methodologies concerning resource allocation from the perspective of a single UE, in terms of time and frequency. Therefore, this disclosure proposes methods for communication between UEs and gNBs, between gNBs and UEs, and between UEs for SL-PRS. Specifically, solutions for triggering SL-PRS are proposed, including various aspects of how transmission and reception can be triggered by various power-saving and congestion control techniques.

[0044] This disclosure proposes a triggering procedure for SL-PRS based on signaling to a UE. The procedure for SL-PRS may consist of sending and receiving SL-PRS. The signaling may be based on (pre)configuration, higher layer (MAC, RRC, PDCP, etc.) signaling, or PHY layer signaling. Furthermore, the signaling may come from the UE, gNB, or one or more other UEs that transmit SL-PRS. Advantageously, the signaling enables the triggering of SL-PRS transmission or reception.

[0045] A UE can be configured to transmit an SL-PRS when triggered by signaling. Referring to Figure 600, the signaling may be a higher-layer signaling 602 associated with the UE (e.g., MAC, RRC, PDCP, application layer, or other similar higher-layer signaling), first-stage or second-stage sidelink control information (SCI) 604 received from another UE, PDCCH 606 ​​from a gNB (e.g., if the UE is within the gNB's coverage), or a higher-layer signaling 608 from a gNB or another UE, allowing for flexibility in the source of the signaling depending on the application. Furthermore, by utilizing a higher-layer signaling associated with the UE, signaling can be made independent of other devices as needed. It will be understood that the various notifications 602-608 in Figure 600 are not limited to a specific order.

[0046] Depending on the type of scenario or use case, SL-PRS transmissions may be aperiodic or periodic, as indicated by trigger signaling. This allows the signaling to indicate how SL-PRS may be transmitted (periodic or aperiodic), depending on the application. In one embodiment, a time interval between periodic SL-PRS transmissions may be specified in the signaling, which may be useful to prevent collisions with other transmissions or to emphasize the urgency of the event related to the transmission (e.g., in an emergency). Aperiodic or periodic transmissions may or may not be accompanied by resource reservations for sensing-based or random resource selection. Resource reservations may be notifications sent by a UE to reserve one or more future time resources and / or frequency resources. Other UEs that receive a notification will not transmit on the reserved resources to avoid aerial collisions. Resource selection may be a one-to-one reservation, as shown in Figure 7, where the first reservation 702 reserves one resource within the reservation period 706, and the second reservation 704 reserves one resource within the reservation period 708. Alternatively, as shown in Figure 8, where the first reservation 802 reserves the first resource within the reservation period 806, the second resource within the reservation period 808, and the third resource within the reservation period 810, and the second reservation 804 reserves the first resource within the reservation period 812, the second resource within the reservation period 814, and the third resource within the reservation period 816 (for example, a one-to-three reservation would be X=3). Resource selection may also be a Y-to-1 (e.g., multiple-to-1) reservation, as shown in Figure 900 of Figure 9, where the first reservation 902 reserves one resource within the reservation period 906, and the second reservation 904 reserves the same resource within the reservation period 908 (for example, a 2-to-1 reservation is Y=2).

[0047] The reservation period may be defined by signaling or (pre-)set. The value of X may vary depending on the transmission. For example, referring to illustration 1000 in Figure 10, the first reservation 1002 may be a one-to-two resource reservation (e.g., X=2) reserving a first resource within reservation period 1006 and a second resource within reservation period 1008, while the second reservation 1004 may be a one-to-one resource reservation (e.g., X=1) reserving a resource within reservation period 1010. For Y-to-1 reservations, different reservations may transmit partial information. For example, the first reservation (e.g., the first reservation 902 in Figure 9) may indicate a time resource, and the second reservation (e.g., the second reservation 904 in Figure 9) may indicate a frequency resource. Advantageously, different modes of resource reservation can be implemented depending on the application. In contrast, DL-PRS does not require different types of reservations because the gNB can dynamically schedule the DL-PRS. In one embodiment, the reservation period and / or information may be included in the first-stage SCI, the second-stage SCI, or both. For example, the first and second reservations may be by the first-stage SCI (e.g., according to the specification of Rel. 16), and the third reservation may be by the second-stage SCI. Alternatively, the first reservation may be by the first-stage SCI, and the second and third reservations may be by the second-stage SCI. This allows the first-stage and / or second-stage SCI to be used as signaling to provide parameters for SL-PRS resource reservations.

[0048] From the standpoint of power saving and congestion control, SL-PRS transmissions can be associated with windows. For example, referring to illustration 1100 in Figure 11, SL-PRS transmissions 1102, 1104, and 1106 can be configured to be transmitted within transmission window 1108, and SL-PRS transmissions will not be transmitted outside of transmission window 1108. SL-PRS transmissions can also be associated with counters. For example, referring to illustration 1200 in Figure 12, SL-PRS transmissions 1202, 1204, and 1206 can be configured to be transmitted while the counter is active and operating, and SL-PRS transmissions will not be transmitted after the counter has expired. Alternatively, SL-PRS transmissions can be associated with timers, so that SL-PRS transmissions are not transmitted after the timer has expired. Windows, counters, or timers may be (pre-configured), specified by technical specifications or vendors, self-generated by the UE, or other similar implementations. Furthermore, a UE receiving or decoding SL-PRS may be configured to enter a power-saving mode when there is no need to receive or decode SL-PRS. In one embodiment, instead of, or in addition to, notifications of a transmit window, timer, or counter, signaling may indicate the maximum or minimum number of SL-PRS transmissions that can be transmitted, which may be useful for power consumption and / or congestion control. These measures advantageously enable power saving and congestion control in SL-PRS transmission and reception.

[0049] In one embodiment, the signaling that triggers the transmission of SL-PRS may carry all or some of several parameters relating to the SL-PRS transmission in order to flexibly provide SL-PRS parameters depending on the application. The parameters may be based on (pre)settings, obtained from gNB, obtained from one or more other UEs, self-generated by the UE transmitting the SL-PRS, or other similar implementations. SL-PRS-related parameters may include, but are not limited to, subcarrier spacing (SCS), carrier phase (CP), Point A, resource set identifier (ID), periodicity, slot offset, reputation coefficient, time interval, mute time position, SFN0 offset, combo size, bandwidth, physical resource block (PRB), symbol count, resource ID, sequence ID, resource element offset, symbol offset, quasi-colocation (QCL) information, a subset of angle of departure (AoD) prioritization, and other similar parameters.

[0050] A UE can be configured to receive and decode SL-PRS when triggered by signaling. Referring to Figure 1300 in Figure 13, the signaling can be upper-layer signaling associated with the UE 1302 (e.g., MAC, RRC, PDCP, application layer, or other similar upper-layer signaling), first-stage or second-stage sidelink control information (SCI) 1304 received from another UE, PDCCH 1306 from a gNB (e.g., if the UE is within the gNB's coverage), or upper-layer signaling 1308 from a gNB or another UE, thus allowing flexibility in the source of the signaling depending on the application. Furthermore, by utilizing upper-layer signaling associated with the UE, signaling can be made independent of other devices as needed. It will be understood that the various notifications 1302-1308 in Figure 1300 are not limited to a specific order.

[0051] From the standpoint of power saving and congestion control, SL-PRS reception may be associated with a window. For example, referring to Figure 1400 in Figure 14, SL-PRS 1402, 1404, and 1406 may be configured to be received and / or decoded within a reception window 1408, and outside of the reception window 1408, SL-PRS are not received and / or decoded. SL-PRS reception may also be associated with a counter. For example, referring to Figure 1500 in Figure 15, SL-PRS 1502, 1504, and 1506 may be configured to be received and / or decoded while the counter is active and running, and after the counter expires, SL-PRS are not received and / or decoded. Alternatively, SL-PRS reception may be associated with a timer, and after the timer expires, SL-PRS may not be received and / or decoded. The windows, counters, or timers may be (pre-configured), specified by the technical specification or vendor, self-generated by the UE, or other similar implementations. In one embodiment, instead of, or in addition to, notifications of the receive windows, timers, or counters, the signaling may indicate the maximum or minimum number of SL-PRS transmissions that can be received and / or decoded, which may be useful for power consumption and / or congestion control. Furthermore, the UE receiving and / or decoding SL-PRS may be configured to enter a power-saving mode when there is no need to receive and / or decode SL-PRS. These measures advantageously enable power saving and congestion control in SL-PRS transmission and reception.

[0052] A UE (e.g., a requesting UE) may be configured to request one or more other UEs (e.g., one or more requested UEs) to send an SL-PRS for different use cases. The requested UEs may be all UEs that received the request from the requesting UE, or only specific anchor UEs (e.g., based on UE type, such as a roadside unit (RSU) or other UE type). The requesting UE may be configured to request one or more other UEs to receive subsequent SL-PRS transmissions from the requesting UE. Requests to send or receive SL-PRS may be based on an SCI trigger or be relayed by a gNB (e.g., via a UL and then via a DL transmission). For example, the requesting UE may send a request message to its gNB via a UL (e.g., PUCCH or PUSCH), and the gNB may use a DL (e.g., PDCCH and / or PDSCH) to request other UEs to send an SL-PRS to the requesting UE (e.g., via unicast / groupcast / broadcast). In signaling, broadcast / groupcast signaling can be effectively enabled by selectively indicating which UEs should send or receive SL-PRS signals, by notifying one or more UEs or one or more types of UEs that will send or receive SL-PRS signals. Furthermore, requests to send or receive SL-PRS signals are useful in use cases where delays are unacceptable and for congestion control.

[0053] Depending on the priority or use case, the UE may be configured to request PRS transmission or reception using PHY signaling (e.g., first-stage or second-stage SCI) or higher-layer signaling (e.g., MAC-CE, RRC, or other similar higher-layer signaling) based on the priority associated with the SL-PRS transmission. This allows defining the transmission mode of the signaling according to the priority associated with the SL-PRS, providing a more efficient transmission mode for higher priorities. For example, referring to Figure 1600 in Figure 16, for high-priority use cases 1602 (e.g., priority levels 0, 1, and 2), SL-PRS transmission or reception may be requested via SCI 1604 for a simple and rapid response, which is particularly effective in safety use cases. A use case for using SCI requests as SL-PRS signaling is ranging applications to take advantage of faster processing times. However, when using SCI requests, there may be a lack of horizontal and vertical relative and / or absolute positioning parameters.

[0054] For medium-priority use cases 1606 (e.g., priority levels 3, 4, and 5), SL-PRS may be requested via MAC-CE 1608. MAC-CE requests typically take more time to measure and calculate horizontal and vertical distances (e.g., for geopositioning purposes), which may be suitable for use in locations where road structures are layered, such as viaducts and bridges. A use case for using MAC-CE requests as SL-PRS signaling is a relative positioning application where an RSU is positioned on an viaduct to help guide drivers into the correct lane.

[0055] Furthermore, for lower-priority use cases 1610 (e.g., priority levels 6 and 7), SL-PRS may be requested via RRC requests 1612. RRC requests typically provide the most accurate positioning parameters among the use cases (e.g., compared to SCI or MAC-CE requests), but are the most time-consuming and require GNSS assistance. Use cases that utilize RRC requests as signaling for SL-PRS include absolute positioning and geofencing applications (e.g., either scheme 1 or scheme 2).

[0056] It will be understood that the various use cases 1602, 1606, and 1610 shown in Figure 1600 are not intended to be limited to a specific order or priority. Furthermore, the various use cases 1602, 1606, and 1610 are merely illustrative and not limited to any specific signaling, priority values, or use cases.

[0057] A UE (e.g., a requesting UE) may be configured to explicitly request one or more other UEs to send an SL-PRS to the requesting UE. If the request is carried by a unicast message, the requesting UE may be configured to assign different time offsets or frequency offsets to one or more other UEs to which the request is made (e.g., the requesting UE acts as a scheduling UE for SL-PRS transmissions). For example, Figure 1700 in Figure 17 shows a time offset assignment where a first SL-PRS is assigned to be received by the requesting UE from the first UE at time resource 1702, a second SL-PRS is assigned to be received by the requesting UE from the second UE at time resource 1704, and a third SL-PRS is assigned to be received by the requesting UE from the third UE at time resource 1706. By employing different levels of time offsets, time resources may be different OFDM symbols, slots, subframes, and other similar resources. As another example, Figure 1800 illustrates frequency offset assignment, where a first SL-PRS is assigned to be received by the requesting UE from the first UE at frequency resource 1802, a second SL-PRS is assigned to be received by the requesting UE from the second UE at frequency resource 1804, and a third SL-PRS is assigned to be received by the requesting UE from the third UE at frequency resource 1806. By employing different levels of frequency offset, frequency resources can be different resource elements (REs), resource blocks (RBs), subchannels, and other similar resources. It is also possible to combine both time offsets and frequency offsets in SL-PRS transmissions. Resource management for SL-PRS transmissions can be improved by notifying the time offset or frequency offset for SL-PRS transmissions when transmitting unicast signaling. When a request is carried by a groupcast or broadcast message, the requesting UE may not be able to assign an offset.Alternatively, one or more other UEs may be configured to derive the offset themselves. The derivation may be based on an identifier (ID), such as a synchronization ID, a Radio Network Temporary Identifier (RNTI), or other similar parameter.

[0058] In one example, public service vehicles may be configured to have a dedicated ID, zone ID, and resources to avoid aerial collisions with SL-PRS. These public service vehicles may be configured to transmit signaling to nearby pedestrian UEs (P-UEs) and / or vehicular UEs (V-UEs) requesting them to comply with emergency SL-PRS to clear the way. Furthermore, a P-UE may request one or more nearby V-UEs to broadcast an SL-PRS for P-UE safety considerations (particularly if the P-UE is crossing a road), and the P-UE assesses whether the P-UE is in a dangerous situation by measuring and calculating the distance based on the SL-PRS received from the V-UE.

[0059] In one embodiment, for a UE (e.g., an anchor UE) configured to periodically broadcast SL-PRS, the SL-PRS may be transmitted together with the SL-SSB (e.g., at the same frequency) or separately at different frequencies. Other UEs may be configured to use these broadcasted SL-PRS to measure and calculate relative positions. The anchor UE may be an RSU or a public service vehicle (e.g., a bus, ambulance, fire truck, police car, or other similar public service vehicle). It will be understood that UEs may be configured to transmit SL-PRS periodically or aperiodicly by broadcast, groupcast, or unicast, depending on the application.

[0060] For example, public service vehicles (e.g., ambulances, fire trucks, police cars) may be configured to periodically broadcast SL-PRS in emergencies. Other types of vehicles, upon successfully receiving and decoding the broadcasted SL-PRS, yield the right of way. One or more RSUs may be deployed on elevated bridges (especially those with complex networks) to help guide drivers to the correct lane ID (e.g., by offset assignment or resource assignment). The implementation of zone IDs in elevated bridge networks prevents vehicles on upper levels of the elevated bridge from being mistakenly considered a hazard to vehicles on lower levels. RSUs may be configured to broadcast SL-PRS associated with specific zone IDs (e.g., by offset assignment or resource assignment) to prohibit vehicles / pedestrians from entering certain restricted areas (e.g., geofencing). Furthermore, RSUs installed in multi-story malls or parking lots can broadcast, groupcast, or unicast SL-PRS to V-UEs or P-UEs on the appropriate floors (e.g., to notify of parking areas with more available spaces, to notify of emergency exits, etc.). This may involve one or more parameters such as zone ID, offset assignment, ID filtering reception, and other parameters, and may also require assistance from the application layer.

[0061] Backward compatibility between Rel.18 UEs and Rel.16 / 17 UEs is also important, especially when Rel.16 / 17 UEs and Rel.18 UEs reside in the same spectrum or resource pool. To ensure quality of service, Rel.16 / 17 UEs must be able to understand at least some of the Rel.18 signaling. For example, reservations transmitted by Rel.18 UEs must be understood by Rel.16 / 17 UEs to avoid collisions in the air. In one embodiment, for backward compatibility with Rel.16 and Rel.17 UEs, Rel.18 UEs may be configured to use the Rel.18 second-stage SCI and / or Rel.18 second-stage PSSCH to signal the use of SL-PRS. Rel.16 / 17 UEs may be configured to discard the Rel.18 second-stage SCI and / or PSSCH when decoding the fields of the first-stage SCI or second-stage SCI. Furthermore, some UEs are capable of receiving and decoding the Rel.18 PSSCH, but this is not necessary, and the PSSCH can be simply discarded for power saving purposes. Alternatively, the same Rel.16 and Rel.17 second-stage SCI may be used for transmission by a Rel.18 UE. A specific destination ID may be used for SL-PRS transmission. Rel.16 / 17 UEs may be configured to skip decoding the PSSCH after decoding the destination ID. Also, some fields of the first-stage or second-stage SCI may be set to arbitrary values ​​if PSSCH decoding is not required.

[0062] For example, a Rel.18 UE transmits an SL-PRS and a Rel.18 second-stage SCI related to the SL-PRS. Other Rel.18 UEs then receive the SL-PRS and the Rel.18 second-stage SCI. Rel.16 / 17 UEs may discard the SL-PRS and the Rel.18 second-stage SCI. Alternatively, both Rel.16 / 17 UEs and other Rel.18 UEs may receive the first-stage SCI and / or the Rel.16 and Rel.17 second-stage SCI.

[0063] Alternatively, a Rel.18 UE transmits a Rel.18 second-stage SCI regarding SL-PRS. Another Rel.18 UE receives the Rel.18 second-stage SCI and transmits an SL-PRS based on the Rel.18 second-stage SCI. A Rel.16 / 17 UE may discard the Rel.18 second-stage SCI. Alternatively, both the Rel.16 / 17 UE and the other Rel.18 UE may receive the first-stage SCI and / or the Rel.16 and Rel.17 second-stage SCI.

[0064] Specific parameters (e.g., resource set ID, destination ID) may be defined (in advance) for receive filtering so that each UE can understand which SL-PRS resources are assigned in terms of congestion control. In one embodiment, new or reused IDs may be designated as priority parameters. For example, for 2 bits of first (or second) stage SCI information, public service vehicles (e.g., ambulances, fire trucks) may be set to priority parameter 0, large vehicles (e.g., buses, trucks) to priority parameter 1, small vehicles (cars, motorcycles) to priority parameter 2, and pedestrians to priority parameter 3. Based on the set priority parameters and receive rules, the corresponding resources may be utilized. For example, a UE with resource set ID 0 may be configured to monitor all SL-PRS resources with resource set IDs 0-3, and a UE with resource set ID 3 may be configured to monitor only PRS resources with resource set ID 0. This allows SL-PRS resources to be assigned to the appropriate SL-PRS based on the identifier, improving the transmission efficiency of SL-PRS. SL-PRS generation parameters may be obtained from gNBs or other UEs, or they may be self-generated by the UE sending or receiving the SL-PRS. In other implementations, several UE property-related parameters (e.g., resource set ID) may be (pre-defined) based on the zone associated with the UE (e.g., geographical area, elevation range, land type such as road / path / building). Different types of UEs within the same zone may be configured to use the same ID. This may apply to certain scenarios, such as pedestrians requesting location information from vehicles in the same or different zones (or vice versa). Additionally, several parameters, such as small offsets (within resource blocks (RBs) or slots, e.g., resource elements (REs), OFDM symbols, or other similar resources), may be (pre-defined). Offsets may be defined together when defining the reference time and / or frequency points within trigger signaling, or they may be self-generated by the UE sending or receiving the SL-PRS.Other parameters may be set dynamically (e.g., resource ID, periodicity, large offsets such as slot / frame / PRB, and other similar parameters). Alternatively, different positioning methods may be used for distinguishing purposes (e.g., round-trip time (RTT), SL-AoA, SL-TDOA: SL time difference of arrival, and other similar positioning methods).

[0065] Figures 19-22 show examples of signaling for SL-PRS transmission, reception, and SL-PRS requests triggered by gNB / UE. Figure 1900 in Figure 19 shows the signaling for SL-PRS transmission, where gNB or UE 1902 sends signaling 1908 to UE 1904 requesting the transmission of SL-PRS 1910, and UE 1904, based on the signaling, transmits SL-PRS 1910 to another UE 1906. Figure 2000 in Figure 20 shows the signaling for SL-PRS reception, where gNB or UE 2002 sends signaling 2008 requesting the reception of SL-PRS, and UE 2004, based on the signaling, receives two SL-PRS, 2010 and 2012, from another UE 2006. Figure 21 shows another signaling for SL-PRS transmission, where UE2104 transmits signaling 2106 requesting one or more other UE2102 to transmit SL-PRS 2108, and the other UE2102 transmit SL-PRS 2108 to UE2104 based on the signaling. Furthermore, Figure 2200 shows another signaling for SL-PRS reception, where UE2204 transmits signaling 2206 requesting one or more other UE2202 to receive SL-PRS 2208, and the other UE2202 receive SL-PRS 2208 from UE2204 based on the signaling. It will be understood by those skilled in the art that the signaling scenarios for SL-PRS transmission are not limited to the examples shown in Figures 19-22.

[0066] The solutions proposed in this disclosure are applicable to dedicated or shared resource pools, and depending on whether a dedicated or shared resource pool is used, any time / frequency offset and / or signaling can have the same or different parameters. Furthermore, the solutions proposed in this disclosure may be applied to either sidelink positioning scheme 1 (gNB central) or scheme 2 (UE autonomous).

[0067] In one embodiment, the triggering and / or requesting of the SL-PRS may be done by explicit or implicit signaling. Explicit signaling may be a gNB, a PHY from another UE, or higher-layer signaling, and may be self-generated by the UE triggering and / or requesting the SL-PRS. Implicit signaling may be an SL-PRS trigger inferred by other implicit signaling (e.g., a specific sequence for RS or PSFCH, a specific time or frequency resource allocation for PSCCH / PSSCH / PSFCH, a synchronization ID, etc.).

[0068] Figure 23 shows a flowchart 2300 illustrating a communication method according to various embodiments. In step 2302, a sidelink positioning reference signal (SL-PRS) may be generated. In step 2304, the SL-PRS may be transmitted based on signaling.

[0069] Figure 24 shows a schematic partial cross-sectional view of a communication device 2400 that can be implemented according to the various embodiments and examples shown in Figures 1 to 23. The communication device 2400 can be implemented as a UE or base station according to various embodiments.

[0070] The various functions and operations of the communication device 2400 are arranged in multiple layers according to a hierarchical model. In this model, lower layers report to higher layers and receive commands from higher layers in accordance with 3GPP technical specifications. For simplicity, the details of the hierarchical model are not described in this disclosure.

[0071] As shown in Figure 24, the communication device 2400 may comprise a circuit 2414, at least one transmitter 2402, at least one receiver 2404, and at least one antenna 2412 (for simplification, only one antenna is depicted in Figure 24 for illustrative purposes). The circuit 2414 may include at least one control unit 2406. The control unit 2406 is used to perform tasks designed to be performed by at least one control unit 2406, with the assistance of software and hardware. Tasks include controlling communication with one or more other communication devices in a wireless network. The circuit 2414 may further include at least one transmit signal generator 2408 and at least one receive signal processor 2410. At least one control unit 2406 can control, under the control of at least one control unit 2406, at least one transmit signal generation unit 2408 for generating signals (e.g., signaling for SL-PRS transmission or reception) to be transmitted to one or more other communication devices via at least one wireless transmitter 2402, and at least one receive signal processing unit 2410 for processing signals (e.g., signaling for SL-PRS transmission or reception) received from one or more other communication devices via at least one wireless receiver 2404, under the control of at least one control unit 2406. The at least one transmit signal generation unit 2408 and the at least one receive signal processing unit 2410 may be standalone modules of a communication device 2400 that communicate with at least one control unit 2406 for the functions described above, as shown in Figure 24. Alternatively, the at least one transmit signal generation unit 2408 and the at least one receive signal processing unit 2410 may be included in at least one control unit 2406. It will be apparent to those skilled in the art that the arrangement of these functional modules is flexible and may change according to actual needs and / or requirements. Data processing, virtual memory, and other related control devices can be provided on a suitable circuit board and / or within a chipset.In various embodiments, during operation, at least one wireless transmitter 2402, at least one wireless receiver 2404, and at least one antenna 2412 may be controlled by at least one control unit 2406.

[0072] The communication device 2400 provides the functions necessary for transmitting and receiving SL-PRS during operation. For example, the communication device 2400 is an UE, and circuit 2414 may generate SL-PRS during operation. The transmitter 2402 may transmit SL-PRS based on signaling during operation.

[0073] The signaling may indicate whether the SL-PRS is periodic or aperiodic, and the transmitter may be further configured to transmit the SL-PRS periodically or aperiodicly based on the signaling. The transmitter 2402 may be further configured to transmit the SL-PRS with resource reservations which are one-to-one reservations, one-to-many reservations, or many-to-one reservations. The signaling is first-stage sidelink control information (SCI) and / or second-stage SCI, and the resource reservation is based on the first-stage SCI, the second-stage SCI, or both the first-stage SCI and the second-stage SCI.

[0074] The transmitter 2402 may be further configured to transmit SL-PRS within a window, counter, or timer. The signaling may include one or more parameters associated with the SL-PRS, and the transmitter 2402 may be configured to transmit the SL-PRS based on one or more parameters. The signaling may be a higher-layer signaling associated with the communication device. The receiver may, during operation, receive signaling from other communication devices, which may be first-stage sidelink control information (SCI) and / or second-stage SCI, physical downlink control channel (PDCCH), or a higher-layer signaling associated with the other communication device.

[0075] The communication device 2400 may be a UE, and the receiving unit 2404 may receive SL-PRS based on signaling during operation. The circuit 2414 may decode SL-PRS during operation.

[0076] The receiver 2404 may be further configured to receive SL-PRS within a window, counter, or timer. The signaling may be a higher-layer signaling associated with the communication device, or the receiver 2404 may be further configured to receive signaling from another communication device, which is first-stage sidelink control information (SCI) and / or second-stage SCI, physical downlink control channel (PDCCH), or a higher-layer signaling associated with the other communication device. The communication device may be a Rel.16 / 17 user device (UE), the other communication device may be a Rel.18 UE, the second-stage SCI may be a Rel.18 second-stage SCI, the signaling may further include a Rel.18 physical sidelink shared channel (PSSCH), and the circuit 2414 may be further configured to discard the Rel.18 second-stage SCI and the Rel.18 PSSCH when decoding the signaling. The communication device may be a Rel.16 / 17 user device (UE), other communication devices may be Rel.18 UEs, the second stage SCI may be a Rel.16 / 17 second stage SCI, the signaling may include a Rel.18 PSSCH, and circuit 2414 may be further configured to skip decoding the Rel.18 PSSCH when decoding the signaling. The signaling may include a resource set identifier associated with the SL-PRS, and the receiver 2414 may be configured to receive the SL-PRS based on a comparison between the resource set identifier and an identifier associated with the communication device.

[0077] The communication device 2400 may be a first communication device, and the circuit 2414 may generate a signaling indicating a request to transmit or receive an SL-PRS when in operation. The transmitting unit 2402 may transmit a signaling to a second communication device when in operation.

[0078] The signaling may notify one or more communication devices, or one or more types of communication devices, that transmit SL-PRS. The transmitter 2402 may be further configured to transmit the signaling as physical layer (PHY) signaling or upper layer signaling based on the priority associated with the SL-PRS. The signaling may further notify time and / or frequency resources for transmitting SL-PRS. The transmitter 2402 may be further configured to periodically transmit the signaling via unicast, groupcast, or broadcast.

[0079] (Control signal) In this disclosure, the downlink control signal (information) relating to this disclosure may be a signal (information) transmitted via the PDCCH of the physical layer, or it may be a signal (information) transmitted via the MAC Control Element (CE) of the upper layer or RRC. The downlink control signal may be a predefined signal (information).

[0080] The uplink control signal (information) relating to this disclosure may be a signal (information) transmitted via PUCCH at the physical layer, or a signal (information) transmitted via MAC CE at a higher layer or RRC. Furthermore, the uplink control signal may be a predefined signal (information). The uplink control signal may be Uplink Control Information (UCI), first-stage sidelink control information (SCI), or second-stage SCI.

[0081] (base station) In this disclosure, a base station may be, for example, a transmission reception point (TRP), a cluster head, an access point, a remote radio head (RRH), an eNodeB (eNB), a gNodeB (gNB), a base station (BS), a base transceiver station (BTS), a base unit, or a gateway. In side-link communication, a terminal may be used instead of a base station. A base station may be a relay device that relays communication between a higher-level node and a terminal. A base station may be a roadside unit.

[0082] (Uphill rink / Downhill rink / Side rink) This disclosure may apply to uplinks, downlinks, and sidelinks.

[0083] For example, this disclosure may be applied to uplink channels such as PUSCH, PUCCH, and PRACH, downlink channels such as PDSCH, PDCCH, and PBCH, and sidelinks such as PSSCH (Physical Sidelink Shared Channel), PSCCH (Physical Sidelink Control Channel), and PSBCH (Physical Sidelink Broadcast Channel).

[0084] PDCCH, PDSCH, PUSCH, and PUCCH are examples of downlink control channels, downlink data channels, uplink data channels, and uplink control channels, respectively. PSCCH and PSSCH are examples of sidelink control channels and sidelink data channels, respectively. PBCH and PSBCH are examples of broadcast channels, respectively, and PRACH is an example of a random access channel.

[0085] (Data channel / Control channel) This disclosure may apply to either data channels or control channels. The channels in this disclosure may be replaced with data channels including PDSCH, PUSCH, and PSSCH, and / or control channels including PDCCH, PUCCH, PBCH, PSCCH, and PSBCH.

[0086] (reference signal) In this disclosure, a reference signal is a signal known to both the base station and the mobile station, and each reference signal may be referred to as a reference signal (RS) or pilot signal. A reference signal may be one of the following: Demodulation RS (DMRS), Channel State Information - Reference Signal (CSI-RS), Tracking Reference Signal (TRS), Phase Tracking Reference Signal (PTRS), Cell-specific Reference Signal (CRS), or Sounding Reference Signal (SRS).

[0087] (Time interval) In this disclosure, a time resource unit is not limited to one or a combination of slots and symbols, but may be a frame, superframe, subframe, slot, subslot of a time slot, minislot, or a time resource unit such as a symbol, an orthogonal frequency division multiplexing (OFDM) symbol, a single-carrier frequency division multiplexing access (SC-FDMA) symbol, or other time resource units. The number of symbols contained in one slot is not limited to the number of symbols exemplified in the embodiments described above, but may be any other number of symbols.

[0088] (Frequency band) This disclosure may apply to either the licensed band or the unlicensed band.

[0089] (communication) This disclosure may apply to any of the following: communication between a base station and a terminal (Uu-link communication), communication between terminals (side-link communication), and vehicle-to-everything (V2X) communication. The channels in this disclosure may be replaced with PSCCH, PSSCH, Physical Sidelink Feedback Channel (PSFCH), PSBCH, PDCCH, PUCCH, PDSCH, PUSCH, and PBCH.

[0090] Furthermore, this disclosure may apply to terrestrial networks or non-terrestrial networks (NTNs) that use satellites or high-altitude pseudo-satellites (HAPS). It may also apply to networks with large cell sizes or terrestrial networks with large latency relative to symbol length or slot length, such as ultra-wideband transmission networks.

[0091] (Antenna port) An antenna port refers to a logical antenna (antenna group) formed by one or more physical antennas. That is, an antenna port does not necessarily refer to a single physical antenna, but may also refer to an array antenna formed by multiple antennas. For example, the number of physical antennas forming an antenna port is not defined; instead, an antenna port is defined as the smallest unit on which a terminal can transmit a reference signal. Alternatively, an antenna port can be defined as the smallest unit for multiplying the weights of a precoding vector.

[0092] As described above, embodiments of the present disclosure provide advanced communication systems, communication methods, and communication devices that advantageously perform RA-RNTI calculation for handling RO collisions in multi-PRACH transmissions.

[0093] This disclosure can be implemented by software, by hardware, or by software working in conjunction with hardware. Each functional block used in the description of the embodiments above may be implemented in part or in whole as an integrated circuit (LSI), and each process described in the embodiments above may be controlled in part or in whole by one LSI or a combination of LSIs. An LSI may be formed individually as a chip, or a single chip may be formed to include some or all of the functional blocks. An LSI may include data input / output units coupled to itself. Depending on the degree of integration, LSIs may be referred to as ICs, system LSIs, super LSIs, or ultra LSIs. However, the technology for implementing integrated circuits is not limited to LSIs and can be implemented using dedicated circuits, general-purpose processors, or dedicated processors. Furthermore, FPGAs (field-programmable gate arrays) that can be programmed after the manufacture of the LSI, or reconfigurable processors that can reconfigure the connections and settings of circuit cells located inside the LSI, can also be used. This disclosure can be implemented as digital or analog processing. If LSIs are replaced by future integrated circuit technologies as a result of advancements in semiconductor technology or other derivative technologies, functional blocks can be integrated using those future integrated circuit technologies. Biotechnology can also be applied.

[0094] This disclosure can be implemented by any type of device, apparatus, or system having communication capabilities (collectively referred to as communication apparatus).

[0095] Such communication devices are not limited to a few examples and include a variety of combinations of telephones (e.g., mobile phones, smartphones), tablets, personal computers (PCs) (e.g., laptops, desktops, netbooks), cameras (e.g., digital still cameras / video cameras), digital players (e.g., digital audio players / video players), wearable devices (e.g., wearable cameras, smartwatches, tracking devices), game consoles, digital book readers, telehealth / telemedicine devices, and vehicles that provide communication capabilities (e.g., automobiles, airplanes, ships).

[0096] Communication devices are not limited to portable or mobile devices, but also include all kinds of non-portable or fixed devices, devices, and systems, such as smart home devices (appliances, lighting equipment, smart meters or measuring instruments, control panels, etc.), vending machines, and any other "things" that may exist on an IoT (Internet of Things) network.

[0097] Communication includes data communication via cellular systems, wireless LAN systems, and communication satellite systems, as well as data communication using combinations of these.

[0098] The communication device may include devices such as controllers and sensors coupled to a communication device that performs the communication functions described in this disclosure. For example, this may include controllers and sensors that generate control signals and data signals used by the communication device that performs the communication functions of the communication device.

[0099] Communication equipment may further include base stations, access points, and any other devices, devices, or systems that communicate with or control infrastructure equipment, such as the devices in the non-limiting examples above.

[0100] While some characteristics of various embodiments are described with reference to the apparatus, it will be understood that the corresponding characteristics also apply to the methods of various embodiments, and vice versa.

[0101] This disclosure may be referred to with the following notes.

[0102] (Note 1) A communication device comprising: a circuit that generates a Sidelink Positioning Reference Signal (SL-PRS) during operation; and a transmitting unit that transmits the SL-PRS based on signaling during operation.

[0103] Since reusing existing DL-PRS technology for SL-PRS transmission is not straightforward (as SL is transmitted between UEs), the feature of "transmitting SL-PRS based on signaling" advantageously provides a solution for introducing signaling for SL-PRS transmission and how SL-PRS can be transmitted by UEs.

[0104] (Note 2) The communication device according to Appendix 1, wherein the signaling indicates whether the SL-PRS is periodic or aperiodic, and the transmitting unit is further configured to transmit the SL-PRS periodically or aperiodicly based on the signaling.

[0105] The feature "transmitting the SL-PRS periodically or aperiodicly based on the signaling" allows the signaling to indicate how the SL-PRS is transmitted (periodicly or aperiodicly) depending on the application.

[0106] (Note 3) The communication device as described in Appendix 1, wherein the transmitting unit is further configured to transmit the SL-PRS with resource reservations that are one-to-one reservations, one-to-many reservations, or multiple-to-one reservations.

[0107] The characteristic of "transmitting the SL-PRS with resource reservations that are one-to-one, one-to-many, or multiple-to-one" allows different modes of SL-PRS resource reservations to be implemented depending on the application. In contrast, DL-PRS does not require different types of reservations because gNB can dynamically schedule DL-PRS.

[0108] (Note 4) The signaling is first-stage sidelink control information (SCI) and / or second-stage SCI, and the resource reservation is based on the first-stage SCI, the second-stage SCI, or both the first-stage SCI and the second-stage SCI, as described in Appendix 3 of the communication device.

[0109] The characteristic that "the signaling is first-stage sidelink control information (SCI) and / or second-stage SCI, and the resource reservation is based on the first-stage SCI, the second-stage SCI, or both the first-stage SCI and the second-stage SCI" means that the first-stage and / or second-stage SCI can be used as signaling to provide parameters for resource reservations in SL-PRS.

[0110] (Note 5) The communication device as described in Appendix 1, wherein the transmitting unit is further configured to transmit the SL-PRS within a window, counter, or timer.

[0111] Transmitting SL-PRS within a window, counter, or timer minimizes power consumption and enables efficient transmission for managing congestion control.

[0112] (Note 6) The communication device according to Appendix 1, wherein the signaling includes one or more parameters associated with the SL-PRS, and the transmitting unit is configured to transmit the SL-PRS based on the one or more parameters.

[0113] The feature that "the signaling includes one or more parameters associated with the SL-PRS" allows for flexible provision of SL-PRS parameters depending on the application (in addition to providing parameters by (pre)configuration, or obtained from gNB, or obtained from other SL-UE, or self-generated by the transmitting UE).

[0114] (Note 7) The signaling is a higher-layer signaling associated with the communication device, as described in Appendix 1.

[0115] By utilizing the UE's higher-layer signaling as a signaling method, it is possible to create a signaling method that is independent of other devices as needed.

[0116] (Note 8) The communication device according to Appendix 1, further comprising a receiving unit that, during operation, receives first-stage sidelink control information (SCI) and / or second-stage SCI, physical downlink control channel (PDCCH), or the signaling which is a higher-layer signaling associated with the other communication device from another communication device.

[0117] This feature allows for flexible control over the source of signaling depending on the application.

[0118] (Note 9) A communication device comprising: a receiving unit that receives a Sidelink Positioning Reference Signal (SL-PRS) based on signaling during operation; and a circuit that decodes the SL-PRS during operation.

[0119] Since reusing existing DL-PRS technology for SL-PRS transmission is not straightforward (as SL is transmitted between UEs), the "receiving SL-PRS based on signaling" feature introduces signaling for SL-PRS reception and advantageously provides a solution for how SL-PRS can be received by UEs.

[0120] (Note 10) The communication device as described in Appendix 9, wherein the receiving unit is further configured to receive the SL-PRS within a window, counter, or timer.

[0121] Receiving SL-PRS within a window, counter, or timer minimizes power consumption and enables efficient reception for managing congestion control.

[0122] (Note 11) The communication device according to Appendix 9, wherein the signaling is a higher-layer signaling associated with the communication device, or the receiving unit is further configured to receive from another communication device the signaling which is a first-stage sidelink control information (SCI) and / or a second-stage SCI, a physical downlink control channel (PDCCH), or a higher-layer signaling associated with the other communication device.

[0123] By utilizing the UE's higher-layer signaling as a signaling method, it is possible to create a signaling method that is independent of other devices as needed. Furthermore, it is possible to receive signaling from other UEs, allowing for flexible control over the signaling source depending on the application.

[0124] (Note 12) The communication device as described in Appendix 11, wherein the communication device is Rel.16 / 17 User Equipment (UE), the other communication device is Rel.18 UE, the second stage SCI is Rel.18 second stage SCI, the signaling further includes Rel.18 Physical Sidelink Shared Channel (PSSCH), and the circuit is further configured to discard the Rel.18 second stage SCI and the Rel.18 PSSCH when decoding the signaling.

[0125] This feature allows for advantageous backward compatibility with Rel.16 / 17 UEs when receiving Rel.18-based signaling from Rel.18 UEs.

[0126] (Note 13) The communication device as described in Appendix 11, wherein the communication device is a Rel.16 / 17 user equipment (UE), the other communication device is a Rel.18 UE, the second stage SCI is a Rel.16 / 17 second stage SCI, the signaling includes a Rel.18 PSSCH, and the circuit is further configured to skip decoding the Rel.18 PSSCH when decoding the signaling.

[0127] This feature allows for advantageous backward compatibility with Rel.16 / 17 UEs when receiving Rel.18 UEs based on Rel.16 / 17 signals.

[0128] (Note 14) The communication device according to Appendix 9, wherein the signaling includes a resource set identifier associated with the SL-PRS, and the receiving unit is configured to receive the SL-PRS based on a comparison between the resource set identifier and an identifier associated with the communication device.

[0129] The feature of "receiving the SL-PRS based on a comparison between the resource set identifier and the identifier associated with the communication device" allows for the allocation of SL-PRS resources to the appropriate SL-PRS based on the identifier, thereby improving the transmission efficiency of the SL-PRS.

[0130] (Note 15) A first communication device comprising: a circuit that generates a signaling that notifies a request to transmit or receive a Sidelink Positioning Reference Signal (SL-PRS) during operation; and a transmitting unit that transmits the signaling to a second communication device during operation.

[0131] Since reusing existing DL-PRS technology for SL-PRS transmission is not easy (because SL is transmission between UEs), the feature "generates ~ and transmits ~ the signaling" introduces signaling for SL-PRS transmission and advantageously provides a solution for how SL-PRS can be transmitted by UEs.

[0132] (Note 16) The signaling is a first communication device as described in Appendix 15, which notifies one or more communication devices, or one or more types of communication devices, that transmit the SL-PRS.

[0133] In signaling, by notifying one or more communication devices, or one or more types of communication devices, that transmit SL-PRS, it is possible to enable broadcast / groupcast signaling while selectively notifying which communication devices should transmit SL-PRS.

[0134] (Note 17) The first communication device as described in Appendix 15, wherein the transmitting unit is further configured to transmit the signal as physical layer (PHY) signaling or upper layer signaling based on the priority associated with the SL-PRS.

[0135] The feature of "transmitting the signal as physical layer (PHY) signaling or upper layer signaling based on the priority associated with the SL-PRS" allows for defining the signaling transmission mode according to the priority associated with the SL-PRS, and provides a more efficient transmission mode for higher priorities.

[0136] (Note 18) The signaling further indicates the time and / or frequency resources for transmitting the SL-PRS, as described in Appendix 16, for the first communication device.

[0137] By notifying of time and / or frequency resources for SL-PRS transmission, resource management for signaling-based SL-PRS transmission can be implemented.

[0138] (Note 19) The first communication device according to Appendix 16, wherein the transmitting unit is further configured to periodically transmit the signaling via unicast, groupcast, or broadcast.

[0139] This feature allows signaling to be sent periodically (e.g., from an anchor UE) via unicast, groupcast, or broadcast, depending on the application.

[0140] (Note 20) A communication method for generating a Sidelink Positioning Reference Signal (SL-PRS) and transmitting the SL-PRS based on signaling.

[0141] Since reusing existing DL-PRS technology for SL-PRS transmission is not straightforward (as SL is transmitted between UEs), the feature of "transmitting SL-PRS based on signaling" advantageously provides a solution for introducing signaling for SL-PRS transmission and how SL-PRS can be transmitted by UEs.

[0142] Those skilled in the art will understand that numerous variations and / or modifications can be made to the Disclosure, as shown in the specific embodiments, without departing from the broader spirit or scope of the Disclosure. Therefore, these embodiments should be considered illustrative and not restrictive in all respects.

Claims

1. During operation, a circuit generates a Sidelink Positioning Reference Signal (SL-PRS), The system includes a transmitting unit that transmits the SL-PRS based on signaling during operation. Communication device.

2. The signaling notifies whether the SL-PRS is periodic or aperiodic, and the transmitting unit is further configured to transmit the SL-PRS periodically or aperiodicly based on the signaling. The communication device according to claim 1.

3. The transmitting unit is further configured to transmit the SL-PRS with resource reservations that are one-to-one, one-to-many, or multiple-to-one. The communication device according to claim 1.

4. The signaling is first-stage sidelink control information (SCI) and / or second-stage SCI, and the resource reservation is based on the first-stage SCI, the second-stage SCI, or both the first-stage SCI and the second-stage SCI. The communication device according to claim 3.

5. The transmitting unit is further configured to transmit the SL-PRS within a window, counter, or timer. The communication device according to claim 1.

6. The signaling includes one or more parameters associated with the SL-PRS, and the transmitting unit is configured to transmit the SL-PRS based on the one or more parameters. The communication device according to claim 1.

7. The aforementioned signaling is a higher-layer signaling associated with the communication device. The communication device according to claim 1.

8. The system further includes a receiving unit that, during operation, receives first stage sidelink control information (SCI) and / or second stage SCI, physical downlink control channel (PDCCH), or the signaling associated with the other communication device, which is a higher layer signaling. The communication device according to claim 1.

9. During operation, the system includes a receiver that receives a Sidelink Positioning Reference Signal (SL-PRS) based on signaling, The system includes a circuit for decoding the SL-PRS during operation. Communication device.

10. The receiving unit is further configured to receive the SL-PRS within a window, counter, or timer. The communication device according to claim 9.

11. The signaling is a higher-layer signaling associated with the communication device, or the receiving unit is further configured to receive from another communication device the signaling which is a first-stage sidelink control information (SCI) and / or a second-stage SCI, a physical downlink control channel (PDCCH), or a higher-layer signaling associated with the other communication device. The communication device according to claim 9.

12. The communication device is User Equipment (UE) of Rel. 16 / 17, the other communication device is UE of Rel. 18, the second stage SCI is the second stage SCI of Rel. 18, the signaling further includes a Physical Sidelink Shared Channel (PSSCH) of Rel. 18, and the circuit is further configured to discard the second stage SCI of Rel. 18 and the PSSCH of Rel. 18 when decoding the signaling. The communication device according to claim 11.

13. The communication device is a user equipment (UE) of Rel. 16 / 17, the other communication device is a UE of Rel. 18, the second stage SCI is a second stage SCI of Rel. 16 / 17, the signaling includes a PSSCH of Rel. 18, and the circuit is further configured to skip decoding the PSSCH of Rel. 18 when decoding the signaling. The communication device according to claim 11.

14. The signaling includes a resource set identifier associated with the SL-PRS, and the receiving unit is configured to receive the SL-PRS based on a comparison between the resource set identifier and an identifier associated with the communication device. The communication device according to claim 9.

15. A circuit that generates a signaling signal to notify a request to transmit or receive a Sidelink Positioning Reference Signal (SL-PRS) during operation, The system includes a transmitting unit that transmits the signaling to a second communication device during operation. The first communication device.

16. The signaling notifies one or more communication devices, or one or more types of communication devices, that transmit the SL-PRS. The first communication device according to claim 15.

17. The transmitting unit is further configured to transmit the signal as physical layer (PHY) signaling or upper layer signaling based on the priority associated with the SL-PRS. The first communication device according to claim 15.

18. The signaling further indicates the time and / or frequency resources for transmitting the SL-PRS. The first communication device according to claim 16.

19. The transmitting unit is further configured to periodically transmit the signaling via unicast, groupcast, or broadcast. The first communication device according to claim 16.

20. It generates a Sidelink Positioning Reference Signal (SL-PRS), Based on the signaling, the SL-PRS is transmitted. Communication method.

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