Determination of Positioning Reference Signal Resources in Covered Outer Link Assisted Cooperative Positioning

Abstract

Techniques for wireless communication are disclosed. In one aspect, an assisting user equipment (UE) receives, on a sidelink between the assisting UE and a target UE, a request to perform a positioning procedure from the target UE, where both the assisting UE and the target UE are outside network coverage; determines a set of time and / or frequency resources on which to transmit one or more positioning reference signals for the positioning procedure, at least based on the request; and transmits the one or more positioning reference signals to the target UE via the set of time and / or frequency resources.

Description

[0001] Cross - Reference to Related Applications

[0002] This patent application claims the benefit of U.S. Provisional Application No. 62 / 991,895, filed on March 19, 2020, titled "DETERMINATION OF POSITIONING REFERENCE SIGNAL RESOURCES IN OUT - OF - COVERAGE SIDELINK - ASSISTED COOPERATIVE POSITIONING", and U.S. Non - Provisional Application No. 17 / 160,029, filed on January 27, 2021, titled "DETERMINATION OF POSITIONING REFERENCE SIGNAL RESOURCES IN OUT - OF - COVERAGE SIDELINK - ASSISTED COOPERATIVE POSITIONING", both of which are assigned to the assignee of this application and are hereby expressly incorporated by reference in their entirety. Field of Technology

[0003] Aspects of the present disclosure generally relate to wireless communications. Background Art

[0004] Wireless communication systems have evolved through multiple generations, including first - generation analog wireless telephone services (1G), second - generation (2G) digital wireless telephone services (including transitional 2.5G and 2.75G networks), third - generation (3G) high - speed data, Internet - enabled wireless services, and fourth - generation (4G) services (e.g., Long - Term Evolution (LTE) or WiMax). There are many different types of wireless communication systems currently in use, including cellular and Personal Communication Services (PCS) systems. Examples of known cellular systems include cellular analog Advanced Mobile Phone System (AMPS), and digital cellular systems based on Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Global System for Mobile Communications (GSM), etc.

[0005] The fifth-generation (5G) wireless standard, known as New Radio (NR), requires higher data transfer speeds, a greater number of connections, better coverage, and other improvements. According to the Next Generation Mobile Networks Alliance, the 5G standard is designed to provide data rates of tens of megabits per second for each of tens of thousands of users and data rates of 1 gigabit per second for tens of employees on an office floor. Hundreds of thousands of simultaneous connections should be supported to enable large-scale sensor deployments. Therefore, the spectral efficiency of 5G mobile communications should be significantly improved compared to the current 4G standard. In addition, compared to the current standard, signaling efficiency should be enhanced, and latency should be substantially reduced.

[0006] Among them, leveraging the increased data rate and reduced latency of 5G, vehicle-to-everything (V2X) communication technologies are being implemented to support autonomous driving applications, such as wireless communications between vehicles, between vehicles and roadside infrastructure, between vehicles and pedestrians, etc. SUMMARY OF THE INVENTION

[0007] A simplified summary related to one or more aspects disclosed herein is presented below. Accordingly, the following summary should not be considered an extensive review of all contemplated aspects, nor should the following summary be considered to identify critical or decisive elements related to all contemplated aspects or to delineate the scope associated with any particular aspect. Accordingly, the following summary has the sole purpose of presenting in simplified form certain concepts related to one or more aspects associated with the mechanisms disclosed herein prior to the detailed description presented below.

[0008] In one aspect, a method for wireless communication to be performed at an assisting user equipment (UE) includes: receiving, on a sidelink between the assisting UE and a target UE, a request to perform a positioning procedure, wherein both the assisting UE and the target UE are outside network coverage; determining, at least based on the request, a set of time and / or frequency resources on which to transmit one or more positioning reference signals for the positioning procedure; and transmitting, via the set of time and / or frequency resources, the one or more positioning reference signals to the target UE.

[0009] In one aspect, a method for wireless communication to be performed at a target user equipment (UE) includes: transmitting, on a sidelink between at least one assisting UE and the target UE, a request to perform a positioning procedure to the at least one assisting UE, wherein both the target UE and the at least one assisting UE are outside network coverage; determining, at least based on the request, a set of time and / or frequency resources on which to receive one or more positioning reference signals from the at least one assisting UE for the positioning procedure; and transmitting, via the set of time and / or frequency resources, one or more positioning reference signals to the at least one assisting UE.

[0010] In one aspect, an assisting user equipment (UE) includes: a memory; at least one transceiver; and at least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor being configured to: receive, on a sidelink between the assisting UE and a target UE, a request to perform a positioning procedure from the target UE, wherein both the assisting UE and the target UE are outside network coverage; determine, at least based on the request, a set of time and / or frequency resources on which to transmit one or more positioning reference signals for the positioning procedure; and cause the at least one transceiver to transmit the one or more positioning reference signals to the target UE via the set of time and / or frequency resources.

[0011] In one aspect, a target user equipment (UE) includes: a memory; at least one transceiver; and at least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor being configured to: cause the at least one transceiver to transmit, on a sidelink between at least one assisting UE and the target UE, a request to perform a positioning procedure to the at least one assisting UE, wherein both the target UE and the at least one assisting UE are outside network coverage; determine, at least based on the request, a set of time and / or frequency resources on which to receive one or more positioning reference signals from the at least one assisting UE for the positioning procedure; and cause the at least one transceiver to transmit the one or more positioning reference signals to the at least one assisting UE via the set of time and / or frequency resources.

[0012] In one aspect, an assisting user equipment (UE) includes: means for receiving, on a sidelink between the assisting UE and a target UE, a request to perform a positioning procedure from the target UE, wherein both the assisting UE and the target UE are outside network coverage; means for determining, at least based on the request, a set of time and / or frequency resources on which to transmit one or more positioning reference signals for the positioning procedure; and means for transmitting the one or more positioning reference signals to the target UE via the set of time and / or frequency resources.

[0013] In one aspect, a target user equipment (UE) includes: means for transmitting, on a sidelink between at least one assisting UE and the target UE, a request to perform a positioning procedure to the at least one assisting UE, wherein both the target UE and the at least one assisting UE are outside network coverage; means for determining, at least based on the request, a set of time and / or frequency resources on which to receive one or more positioning reference signals from the at least one assisting UE for the positioning procedure; and means for transmitting the one or more positioning reference signals to the at least one assisting UE via the set of time and / or frequency resources.

[0014] In one aspect, a non-transitory computer-readable medium storing an instruction set. The instruction set includes one or more instructions that, when executed by one or more processors of an assisting user equipment (UE), cause the assisting UE to: receive, on a sidelink between the assisting UE and a target UE, a request to execute a positioning procedure from the target UE, wherein both the assisting UE and the target UE are outside network coverage; determine, at least based on the request, a set of time and / or frequency resources on which to transmit one or more positioning reference signals for the positioning procedure; and transmit the one or more positioning reference signals to the target UE via the set of time and / or frequency resources.

[0015] A non-transitory computer-readable medium storing an instruction set. The instruction set includes one or more instructions that, when executed by one or more processors of a target user equipment (UE), cause the target UE to: transmit, on a sidelink between at least one assisting UE and the target UE, a request to execute a positioning procedure to the at least one assisting UE, wherein both the target UE and the at least one assisting UE are outside network coverage; determine, at least based on the request, a set of time and / or frequency resources on which to receive one or more positioning reference signals for the positioning procedure from the at least one assisting UE; and transmit the one or more positioning reference signals to the at least one assisting UE via the set of time and / or frequency resources.

[0016] Based on the figures and the detailed description, other objects and advantages associated with the aspects disclosed herein will be apparent to those skilled in the art. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings are presented to assist in describing aspects of the present disclosure and are provided only for illustration of these aspects and not for limitation thereof.

[0018] Figure 1 An example wireless communication system in accordance with aspects of the present disclosure is shown.

[0019] Figure 2A and Figure 2B An example wireless network structure in accordance with aspects of the present disclosure is shown.

[0020] Figure 3 An example of a wireless communication system supporting unicast sidelink establishment in accordance with aspects of the present disclosure is shown.

[0021] Figure 4 is a block diagram showing various components of an example user equipment (UE) in accordance with aspects of the present disclosure.

[0022] Figure 5 is a diagram showing an example frame structure for use in a wireless telecommunications system in accordance with aspects of the present disclosure.

[0023] Figure 6 FIG. 2 shows an example wireless communication system according to aspects of the present disclosure, where a vehicle user equipment (V-UE) is exchanging ranging signals with a roadside unit (RSU) and another V-UE.

[0024] Figure 7 FIG. 6 is a timeline showing a three-phase communication protocol according to aspects of the present disclosure.

[0025] Figure 8 FIG. 10 shows two resource allocation modes for transmissions on a sidelink according to aspects of the present disclosure.

[0026] Figure 9 FIG. 14 is a diagram showing how to establish a shared channel (SCH) on a sidelink between two or more UEs according to aspects of the present disclosure.

[0027] Figure 10 and Figure 11 FIG. 20 is a diagram showing an example timing of round-trip time (RTT) signals exchanged between a target UE and two assisting UEs according to aspects of the present disclosure.

[0028] Figure 12 FIG. 24 is a diagram showing the relative time and frequency relationship between an example physical sidelink shared channel (PSSCH) resource and an example positioning reference signal (PRS) resource according to aspects of the present disclosure.

[0029] Figure 13 and Figure 14 FIG. 30 shows an example method for wireless communication according to aspects of the present disclosure. DETAILED DESCRIPTION

[0030] Aspects of the present disclosure are provided in the following description and the related drawings for various examples provided for illustrative purposes. Alternative aspects can be designed without departing from the scope of the present disclosure. In addition, well-known elements of the present disclosure will not be described in detail or will be omitted so as not to obscure the relevant details of the present disclosure.

[0031] The words "exemplary" and / or "example" are used herein to mean "serving as an example, instance, or illustration". Any aspect described herein as "exemplary" and / or "example" is not necessarily to be construed as more preferred or advantageous than other aspects. Similarly, the term "aspects of the present disclosure" does not require that all aspects of the present disclosure include the discussed features, advantages, or operating modes.

[0032] Those skilled in the art will understand that any of a variety of different technologies and processes can be used to represent the information and signals described below. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the following description can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof, depending in part on the particular application, in part on the desired design, in part on the corresponding technology, and so on.

[0033] In addition, with respect to sequences of actions to be performed by elements of, for example, a computing device, many aspects are described. It will be understood that the various actions described herein can be performed by a specific circuit (e.g., an application specific integrated circuit (ASIC)), by program instructions executed by one or more processors, or by a combination of both. In addition, the sequences of actions described herein can be considered to be fully embodied within any form of computer-readable storage medium having a corresponding set of computer instructions stored therein, which, when executed, will cause or direct an associated processor of the device to perform the functionality described herein. Accordingly, the various aspects of the present disclosure can be embodied in many different forms, all of which are expected to be within the scope of the claimed subject matter. Additionally, for each of the aspects described herein, the corresponding form of any such aspect can be described herein as, for example, "logic configured to perform the described actions."

[0034] As used herein, unless otherwise specified, the terms "user equipment" (UE), "vehicle UE" (V-UE), "pedestrian UE" (P-UE), and "base station" are not intended to be specific to or otherwise limited to any particular radio access technology (RAT). Generally, a UE can be any wireless communication device used by a user to communicate over a wireless communication network (e.g., in-vehicle computers, vehicle navigation devices, mobile phones, routers, tablet computers, laptop computers, tracking devices, wearable devices (e.g., smart watches, glasses, augmented reality (AR) / virtual reality (VR) headsets, etc.), vehicles (e.g., cars, motorcycles, bicycles, etc.), Internet of Things (IoT) devices, etc.). A UE can be mobile or can be stationary (e.g., at certain times), and can communicate with a radio access network (RAN). As used herein, the term "UE" can be interchangeably referred to as "mobile device", "access terminal" or "AT", "client device", "wireless device", "subscriber device", "subscriber terminal", "subscriber station", "user terminal" or "UT", "mobile terminal", "mobile station", or variants thereof.

[0035] A V-UE is a type of UE and can be any vehicle-mounted wireless communication device, such as a navigation system, a warning system, a head-up display (HUD), a vehicle-mounted computer, etc. Alternatively, the V-UE can be a portable wireless communication device (e.g., a mobile phone, a tablet computer, etc.) carried by the driver of the vehicle or a passenger in the vehicle. Depending on the context, the term "V-UE" can refer to the vehicle-mounted wireless communication device or the vehicle itself. A P-UE is a type of UE and can be a portable wireless communication device carried by a pedestrian (i.e., a user who is not driving or riding in a vehicle). Generally, a UE can communicate with a core network via a RAN, and through the core network, the UE can connect to an external network (such as the Internet) and to other UEs. Of course, for a UE, other mechanisms for connecting to the core network and / or the Internet are also possible, such as via a wired access network, a wireless local area network (WLAN) network (e.g., based on Institute of Electrical and Electronics Engineers (IEEE) 802.11, etc.).

[0036] A base station can operate according to one of several RATs for communicating with a UE depending on the network in which it is deployed and can alternatively be referred to as an access point (AP), a network node, a NodeB, an evolved NodeB (eNB), a next-generation eNB (ng-eNB), a new radio (NR) node B (also referred to as a gNB or gNodeB), etc. The base station can be mainly used to support the wireless access of a UE, including supporting the data, voice, and / or signaling connections of the supported UE. In some systems, the base station can provide a pure edge node signaling function, while in other systems, it can provide additional control and / or network management functions. The communication link through which a UE sends signals to the base station can be referred to as an uplink (UL) channel (e.g., a reverse traffic channel, a reverse control channel, an access channel, etc.). The communication link through which the base station sends signals to the UE can be referred to as a downlink (DL) or a forward link channel (e.g., a paging channel, a control channel, a broadcast channel, a forward traffic channel, etc.). As used herein, the term traffic channel (TCH) can refer to a UL / reverse or a DL / forward traffic channel.

[0037] The term "base station" can refer to a single physical transmit - receive point (TRP) or to multiple physical TRPs, which may or may not be co - located. For example, in the case where the term "base station" refers to a single physical TRP, the physical TRP can be the antenna of the base station corresponding to the cell (or cell sectors) of the base station. In the case where the term "base station" refers to multiple co - located physical TRPs, the physical TRPs can be an antenna array of the base station (e.g., as in a multiple - input multiple - output (MIMO) system or where the base station employs beamforming). In the case where the term "base station" refers to multiple non - co - located physical TRPs, the physical TRPs can be a distributed antenna system (DAS) (a network of spatially separated antennas connected to a common source via a transmission medium) or a remote radio head (RRH) (a remote base station connected to a serving base station). Alternatively, the non - co - located physical TRP can be the serving base station that receives measurement reports from the UE and from adjacent base stations whose reference radio frequency (RF) signals the UE is measuring. Since the TRP is the point from which the base station transmits and receives wireless signals, as used herein, a reference to transmission from the base station or reception at the base station will be understood to refer to a particular TRP of the base station.

[0038] In some implementations that support UE positioning, the base station may not support the UE's wireless access (e.g., may not support the UE's data, voice, and / or signaling connections), but instead may send to the UE reference RF signals to be measured by the UE, and / or may receive and measure signals sent by the UE. Such a base station can be referred to as a positioning beacon (e.g., when sending RF signals to the UE) and / or as a position measurement unit (e.g., when receiving and measuring RF signals from the UE).

[0039] An "RF signal" includes an electromagnetic wave of a given frequency that transmits information through the space between a transmitter and a receiver. As used herein, a transmitter can send a single "RF signal" or multiple "RF signals" to a receiver. However, due to the propagation characteristics of RF signals through a multipath channel, a receiver can receive multiple "RF signals" corresponding to each transmitted RF signal. The same transmitted RF signal on different paths between the transmitter and the receiver can be referred to as a "multipath" RF signal. As used herein, an RF signal can also be referred to as a "wireless signal" or simply as a "signal", where it is clear from the context that the term "signal" refers to a wireless signal or an RF signal.

[0040] Figure 1FIG. 0 shows an example wireless communication system 100. The wireless communication system 100 (also referred to as a wireless wide area network (WWAN)) may include various base stations 102 (labeled “BS”) and various UEs 104. The base stations 102 may include macro cell base stations (high-power cellular base stations) and / or small cell base stations (low-power cellular base stations). In one aspect, the macro cell base stations 102 may include eNBs and / or ng-eNBs where the wireless communication system 100 corresponds to an LTE network, or gNBs where the wireless communication system 100 corresponds to an NR network, or a combination of both, and the small cell base stations may include femto cells, pico cells, micro cells, etc.

[0041] The base stations 102 may collectively form a RAN and interface with a core network 174 (e.g., an evolved packet core (EPC) or a 5G core (5GC)) via a backhaul link 122 and reach one or more location servers 172 (which may be part of the core network 174 or may be external to the core network 174) through the core network 174. Among other functions, the base stations 102 may perform functions related to one or more of the following: transmitting user data, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, non-access stratum (NAS) message distribution, NAS node selection, synchronization, RAN sharing, multimedia broadcast multicast service (MBMS), subscriber and device tracking, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations 102 may communicate with each other directly or indirectly (e.g., through the EPC / 5GC) via a backhaul link 134, which may be wired or wireless.

[0042] Base station 102 can communicate wirelessly with UE 104. Each of the base stations 102 can provide communication coverage for a corresponding geographic coverage area 110. In one aspect, one or more cells can be supported by the base stations 102 in each geographic coverage area 110. A "cell" is a logical communication entity for communicating with a base station (e.g., on a certain frequency resource (referred to as carrier frequency, component carrier, carrier, frequency band, etc.)), and can be associated with an identifier (e.g., physical cell identifier (PCI), enhanced cell identifier (ECI), virtual cell identifier (VCI), cell global identifier (CGI), etc.) to distinguish cells operating via the same or different carrier frequencies. In some cases, different cells can be configured according to different protocol types that can provide access for different types of UEs (e.g., machine type communication (MTC), narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB), or others). Since a cell is supported by a specific base station, the term "cell" can refer to one or both of the logical communication entity and the base station that supports it, depending on the context. In some cases, the term "cell" can also refer to the geographic coverage area (e.g., sector) of a base station, as long as the carrier frequency can be detected and used for communication within a certain part of the geographic coverage area 110.

[0043] Although the geographic coverage areas 110 of adjacent macro cell base stations 102 can partially overlap (e.g., in a handover area), some of the geographic coverage areas 110 can substantially overlap with a larger geographic coverage area 110. For example, a small cell base station 102' (labeled "SC" for "small cell") can have a geographic coverage area 110' that substantially overlaps with the geographic coverage areas 110 of one or more macro cell base stations 102. A network including small cells and macro cell base stations can be referred to as a heterogeneous network. A heterogeneous network can also include a home eNB (HeNB), which can provide services to a restricted group called a closed subscriber group (CSG).

[0044] The communication link 120 between the base station 102 and the UE 104 can include an uplink (also referred to as reverse link) transmission from the UE 104 to the base station 102 and / or a downlink (DL) (also referred to as forward link) transmission from the base station 102 to the UE 104. The communication link 120 can use MIMO antenna technology, including spatial multiplexing, beamforming, and / or transmit diversity. The communication link 120 can pass through one or more carrier frequencies. The allocation of carriers can be asymmetric with respect to the downlink and uplink (e.g., more or fewer carriers can be allocated for the downlink than for the uplink).

[0045] The wireless communication system 100 may also include a Wireless Local Area Network (WLAN) Access Point (AP) 150 that communicates with a WLAN Station (STA) 152 via a communication link 154 in an unlicensed spectrum (e.g., 5 GHz). When communicating in the unlicensed spectrum, the WLAN STA 152 and / or the WLAN AP 150 may perform a Clear Channel Assessment (CCA) or Listen Before Talk (LBT) procedure before communication to determine whether the channel is available.

[0046] The small cell base station 102' may operate in licensed and / or unlicensed spectrum. When operating in the unlicensed spectrum, the small cell base station 102' may employ LTE or NR technologies and use the same 5 GHz unlicensed spectrum used by the WLAN AP 150. The small cell base station 102' adopting LTE / 5G in the unlicensed spectrum may enhance the coverage of the access network and / or increase the capacity of the access network. NR in the unlicensed spectrum may be referred to as NR-U. LTE in the unlicensed spectrum may be referred to as LTE-U, Licensed-Assisted Access (LAA), or MulteFire.

[0047] The wireless communication system 100 may also include a mmW base station 180 that may operate at mmW frequencies and / or near mmW frequencies to communicate with a UE 182. Extremely High Frequency (EHF) is a part of RF in the electromagnetic spectrum. The range of EHF is from 30 GHz to 300 GHz, and the wavelength is between 1 millimeter and 10 millimeters. The radio waves in this frequency band may be referred to as millimeter waves. Near mmW may extend down to a frequency of 3 GHz, where the wavelength is 100 millimeters. The Super High Frequency (SHF) band extends between 3 GHz and 30 GHz and is also referred to as centimeter waves. Communication using the mmW / near mmW radio frequency bands has high path loss and relatively short distances. The mmW base station 180 and the UE 182 may utilize beamforming (transmission and / or reception) on the mmW communication link 184 to compensate for the extremely high path loss and short distances. Additionally, it should be understood that in alternative configurations, one or more of the base stations 102 may also use mmW or near mmW and beamforming for transmission. Therefore, it should be understood that the foregoing description is merely an example and should not be construed as limiting the various aspects disclosed herein.

[0048] Transmit beamforming is a technique used to focus RF signals in a specific direction. Traditionally, when a network node (e.g., a base station) broadcasts an RF signal, it broadcasts the signal in all directions (omnidirectionally). With transmit beamforming, the network node determines the location of a given target device (e.g., a UE) relative to the transmitting network node and projects a stronger downlink RF signal in that specific direction, thus providing a faster (in terms of data rate) and stronger RF signal to the receiving device. To change the directivity of the RF signal during transmission, the network node can control the phase and relative amplitude of the RF signal at each of one or more transmitters that broadcast the RF signal. For example, the network node can use an antenna array (referred to as a "phased array" or "antenna array") that creates an RF beam, which can be "steered" to point in different directions without physically moving the antennas. Specifically, the RF currents from the transmitters are fed to the individual antennas in the correct phase relationship so that the radio waves from the individual antennas add together to increase the radiation in the desired direction while canceling to suppress the radiation in the undesired directions.

[0049] Transmit beams can be quasi-co-located, which means that they appear to have the same parameters to a receiver (e.g., a UE) regardless of whether the transmit antennas of the network node are physically co-located. In NR, there are four types of quasi-co-location (QCL) relationships. Specifically, a given type of QCL relationship means that certain parameters of a second reference RF signal on a second beam can be derived from information about a source reference RF signal on a source beam. Thus, if the source reference RF signal is QCL type A, the receiver can use the source reference RF signal to estimate the Doppler shift, Doppler spread, average delay, and delay spread of the second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL type B, the receiver can use the source reference RF signal to estimate the Doppler shift and Doppler spread of the second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL type C, the receiver can use the source reference RF signal to estimate the Doppler shift and average delay of the second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL type D, the receiver can use the source reference RF signal to estimate the spatial reception parameters of the second reference RF signal transmitted on the same channel.

[0050] In receive beamforming, the receiver uses receive beams to amplify RF signals detected on a given channel. For example, the receiver can increase the gain setting in a specific direction and / or adjust the phase setting of the antenna array to amplify the RF signal received from that direction (e.g., increase its gain level). Thus, when the receiver performs beamforming in a certain direction, it means that the beam gain in that direction is higher relative to the beam gains in other directions, or that the beam gain in that direction is the highest compared to the beam gains in that direction for all other receive beams available to the receiver. This results in a stronger received signal strength for the RF signal received from that direction (e.g., reference signal received power (RSRP), reference signal received quality (RSRQ), signal-to-interference-plus-noise ratio (SINR), etc.).

[0051] Transmit and receive beams can be spatially related. The spatial relationship means that the parameters of the second beam (e.g., transmit or receive beam) for the second reference signal can be derived from the information about the first beam (e.g., receive beam or transmit beam) for the first reference signal. For example, a UE can use a specific receive beam to receive a reference downlink reference signal (e.g., synchronization signal block (SSB)) from a base station. The UE can then form a transmit beam to send an uplink reference signal (e.g., sounding reference signal (SRS)) to that base station based on the parameters of the receive beam.

[0052] Note that a "downlink" beam can be a transmit beam or a receive beam, depending on the entity forming it. For example, if a base station is forming a downlink beam to send a reference signal to a UE, the downlink beam is a transmit beam. However, if a UE is forming a downlink beam, it is a receive beam for receiving the downlink reference signal. Similarly, an "uplink" beam can be a transmit beam or a receive beam, depending on the entity forming it. For example, if a base station is forming an uplink beam, it is an uplink receive beam, and if a UE is forming an uplink beam, it is an uplink transmit beam.

[0053] In 5G, the spectrum in which wireless nodes (e.g., base stations 102 / 180, UEs 104 / 182) operate is divided into multiple frequency ranges, FR1 (from 450 to 6000 MHz), FR2 (from 24250 to 52600 MHz), FR3 (above 52600 MHz), and FR4 (between FR1 and FR2). The mmW band generally includes the FR2, FR3, and FR4 frequency ranges. Thus, the terms "mmW" and "FR2" or "FR3" or "FR4" can generally be used interchangeably.

[0054] In a multi-carrier system, such as 5G, one of the carrier frequencies is referred to as the "primary carrier" or "anchor carrier" or "primary serving cell" or "PCell", and the remaining carrier frequencies are referred to as "secondary carriers" or "secondary serving cells" or "SCells". In carrier aggregation, the anchor carrier is the carrier operating on the primary frequency (e.g., FR1) used by the cell in which the UE 104 / 182 and the UE 104 / 182 perform the initial radio resource control (RRC) connection establishment procedure or initiate the RRC connection re-establishment procedure. The primary carrier carries all common and UE-specific control channels and can be a carrier in a licensed frequency (however, this is not always the case). The secondary carrier is a carrier operating on a second frequency (e.g., FR2), which can be configured when the RRC connection is established between the UE 104 and the anchor carrier and can be used to provide additional radio resources. In some cases, the secondary carrier can be a carrier in an unlicensed frequency. The secondary carrier can contain only the necessary signaling information and signals. For example, those specific to the UE may not exist in the secondary carrier because the primary uplink and downlink carriers are usually UE-specific. This means that different UEs 104 / 182 in a cell can have different downlink primary carriers. The same is true for the uplink primary carrier. The network can change the primary carrier of any UE 104 / 182 at any time. For example, this is done to balance the load on different carriers. Since a "serving cell" (whether it is a PCell or an SCell) corresponds to the carrier frequency / component carrier on which a certain base station is communicating, terms such as "cell", "serving cell", "component carrier", "carrier frequency", etc. can be used interchangeably.

[0055] For example, still referring to Figure 1 , one of the frequencies used by the macro cell base station 102 can be the anchor carrier (or "PCell"), and the other frequencies used by the macro cell base station 102 and / or the mmW base station 180 can be secondary carriers ("SCells"). The simultaneous transmission and / or reception of multiple carriers enables the UE 104 / 182 to significantly increase its data transmission and / or reception rate. For example, compared to that obtained by a single 20 MHz carrier, two 20 MHz aggregated carriers in a multi-carrier system would theoretically result in a two-fold increase in the data rate (i.e., 40 MHz).

[0056] In Figure 1 's example, one or more space vehicles (SVs) 112 of a global positioning system (SPS) in Earth orbit (e.g., satellites) can be used as the shown UE (for simplicity, in Figure 1An independent position information source shown as any one of the individual UEs 104. The UE 104 may include one or more dedicated SPS receivers specifically designed to receive the SPS signal 124 to derive geographic location information from the SV 112. SPS generally includes a system of transmitters (e.g., SV 112) positioned to enable receivers (e.g., UE 104) to determine their position above or on the Earth at least in part based on signals received from the transmitters (e.g., SPS signal 124). Such transmitters typically send signals marked with a repeating pseudo-random noise (PN) code of a set of chips. Although typically located in the SV 112, the transmitters may sometimes be located on ground-based control stations, base stations 102, and / or other UEs 104.

[0057] The use of the SPS signal 124 can be enhanced by various satellite-based augmentation systems (SBAS) that can be associated with or otherwise enabled for use with one or more global and / or regional navigation satellite systems. For example, SBAS can include augmentation systems that provide integrity information, differential corrections, etc., such as the Wide Area Augmentation System (WAAS), the European Geostationary Navigation Overlay Service (EGNOS), the Multi-functional Satellite Augmentation System (MSAS), GPS Aided Geo Augmented Navigation or GPS and Geo Augmented Navigation System (GAGAN), etc. Thus, as used herein, SPS can include any combination of one or more global and / or regional navigation satellite systems and / or augmentation systems, and the SPS signal 124 can include SPS, SPS-like, and / or other signals associated with such one or more SPSs.

[0058] Among them, leveraging the increased data rate and reduced latency of NR, vehicle-to-everything (V2X) communication technologies are being implemented to support intelligent transportation system (ITS) applications, such as wireless communication between vehicles (vehicle-to-vehicle (V2V)), between vehicles and roadside infrastructure (vehicle-to-infrastructure (V2I)), and between vehicles and pedestrians (vehicle-to-pedestrian (V2P)). The goal is to enable vehicles to sense their surrounding environment and communicate this information to other vehicles, infrastructure, and personal mobile devices. Such vehicle communication will achieve safety, mobility, and environmental improvements that current technologies cannot provide. Once fully implemented, this technology is expected to reduce unimpaired vehicle collisions by 80%.

[0059] Still referring to Figure 1, the wireless communication system 100 may include multiple V-UEs 160, which may communicate with the base station 102 via a communication link 120 (e.g., using the Uu interface). The V-UEs 160 may also communicate directly with each other via a wireless sidelink 162, communicate with a roadside access point 164 (also referred to as a "roadside unit") via a wireless sidelink 166, or communicate with a UE 104 via a wireless sidelink 168. A wireless sidelink (or simply "sidelink") is an adaptation of the core cellular (e.g., LTE, NR) standard that allows direct communication between two or more UEs without going through the base station for this communication. Sidelink communication can be unicast or multicast and can be used for device-to-device (D2D) media sharing, V2V communication, V2X communication (e.g., cellular V2X (cV2X) communication, enhanced V2X (eV2X) communication, etc.), emergency rescue applications, etc. One or more of the group of V-UEs 160 that utilize sidelink communication may be within the geographical coverage area 110 of the base station 102. Other V-UEs 160 in this group may be outside the geographical coverage area 110 of the base station 102 or otherwise unable to receive transmissions from the base station 102. In some cases, the group of V-UEs 160 that communicate via sidelink communication may utilize a one-to-many (1:M) system, where each V-UE 160 transmits to each other V-UE 160 in the group. In some cases, the base station 102 facilitates the scheduling of resources for sidelink communication. In other cases, sidelink communication is performed between the V-UEs 160 without the participation of the base station 102.

[0060] In one aspect, the sidelinks 162, 166, 168 may operate on an interested wireless communication medium, which may be shared with other wireless communications between other vehicles and / or infrastructure access points and other RATs. The "medium" may consist of one or more time, frequency, and / or space communication resources (e.g., including one or more channels on one or more carriers) associated with wireless communication between one or more transmitter / receiver pairs.

[0061] In one aspect, the sidelinks 162, 166, 168 may be cV2X links. The first generation of cV2X has been standardized in LTE, and the next generation is expected to be defined in NR. cV2X is a cellular technology that also supports device-to-device communication. In the United States and Europe, cV2X is expected to operate in the licensed ITS band below 6 GHz (sub-6 GHz). In other countries, other frequency bands may be allocated. Thus, as a specific example, the interested medium used by the sidelinks 162, 166, 168 may correspond to at least a portion of the licensed ITS band below 6 GHz. However, the present disclosure is not limited to this frequency band or cellular technology.

[0062] In one aspect, the sidelinks 162, 166, 168 can be dedicated short range communication (DSRC) links. DSRC is a unidirectional or bidirectional short to medium range wireless communication protocol that uses the wireless access for vehicular environments (WAVE) protocol (also known as IEEE 802.11p) for V2V, V2I, and V2P communications. IEEE 802.11p is an approved amendment to the IEEE 802.11 standard and operates in the licensed ITS band at 5.9 GHz (5.85 to 5.925 GHz) in the United States. In Europe, IEEE 802.11p operates in the ITS G5A band (5.875 to 5.905 MHz). In other countries, other frequency bands may be allocated. The V2V communication briefly described above occurs over a secure channel, which is typically a 10 MHz channel dedicated for safety purposes in the United States. The remainder of the DSRC band (with a total bandwidth of 75 MHz) is intended for other services of interest to the driver, such as road rules, tolling, parking automation, etc. Thus, as a specific example, the medium of interest used by the sidelinks 162, 166, 168 can correspond to at least a portion of the licensed ITS band at 5.9 GHz.

[0063] Alternatively, the medium of interest can correspond to at least a portion of an unlicensed band shared among various RATs. Although different licensed frequency bands have been reserved for certain communication systems (e.g., by government entities such as the Federal Communications Commission (FCC) in the United States), these systems (especially those employing small cell access points) have recently extended their operation to unlicensed bands, such as the unlicensed national information infrastructure (U-NII) bands used by wireless local area network (WLAN) technologies (most notably the IEEE 802.11x WLAN technologies commonly known as "Wi-Fi"). Example systems of this type include different variants of CDMA systems, TDMA systems, FDMA systems, orthogonal FDMA (OFDMA) systems, single carrier FDMA (SC-FDMA) systems, etc.

[0064] The communication between V-UEs 160 is referred to as V2V communication, the communication between a V-UE 160 and one or more roadside access points 164 is referred to as V2I communication, and the communication between a V-UE 160 and one or more UEs 104 (where the UE 104 is a P-UE) is referred to as V2P communication. The V2V communication between V-UEs 160 may include, for example, information about the location, speed, acceleration, heading, and other vehicle data of the V-UEs 160. The V2I information received at a V-UE 160 from one or more roadside access points 164 may include, for example, road rules, parking automation information, etc. The V2P communication between a V-UE 160 and a UE 104 may include information about, for example, the location, speed, acceleration, and heading of the V-UE 160 and the location, speed (e.g., where the UE 104 is carried by a user on a bicycle), and heading of the UE 104.

[0065] Note that although Figure 1 only two of the UEs are shown as V-UEs (V-UE 160), any of the shown UEs (e.g., UEs 104, 152, 182, 190) can be a V-UE. Additionally, although only the V-UE 160 and a single UE 104 are shown as being connected via a sidelink, Figure 1 any of the UEs shown in

[0066] (whether a V-UE or a P-UE, etc.) can be capable of sidelink communication. Further, although only the UE 182 is described as being capable of beamforming, any of the shown UEs (including the V-UE 160) can be capable of beamforming. In the case where the V-UEs 160 are capable of beamforming, they can beamform towards each other (i.e., towards other V-UEs 160), towards the roadside access points 164, towards other UEs (e.g., UEs 104, 152, 182, 190), etc. Thus, in some cases, the V-UEs 160 can utilize beamforming on the sidelinks 162, 166, and 168.

[0066] The wireless communication system 100 may also include one or more UEs (such as UE 190) that are indirectly connected to one or more communication networks via one or more device-to-device (D2D) peer-to-peer (P2P) links. In Figure 1In the example, UE 190 has D2D P2P link 192 and D2D P2P link 194, where one of the UEs 104 is connected to one of the base stations 102 via D2D P2P link 192 (e.g., UE 190 can indirectly obtain a cellular connection through it), and WLAN STA 152 is connected to WLAN AP 150 via D2D P2P link 194 (UE 190 can indirectly obtain a WLAN-based Internet connection through it). In one example, D2D P2P links 192 and 194 can be supported by any well-known D2D RAT, such as LTE Direct (LTE-D), WiFi Direct (WiFi-D), etc. As another example, D2D P2P links 192 and 194 can be sidelinks, as described above with reference to sidelinks 162, 166, and 168.

[0067] Figure 2A Example wireless network structure 200 is shown. For example, 5GC 210 (also known as Next Generation Core (NGC)) can be functionally regarded as a Control Plane Function (C-Plane) 214 (e.g., UE registration, authentication, network access, gateway selection, etc.) and a User Plane Function (U-Plane) 212 (e.g., UE gateway function, access to data networks, IP routing, etc.), which cooperate to form the core network. User Plane Interface (NG-U) 213 and Control Plane Interface (NG-C) 215 connect gNB 222 to 5GC 210, and specifically connect to User Plane Function 212 and Control Plane Function 214 respectively. In an additional configuration, ng-eNB 224 can also be connected to 5GC 210 via NG-C 215 to the Control Plane Function 214 and NG-U 213 to the User Plane Function 212. In addition, ng-eNB 224 can communicate directly with gNB 222 via backhaul connection 223. In some configurations, Next Generation RAN (NG-RAN) 220 can have only one or more gNBs 222, while other configurations include one or more of both ng-eNB 224 and gNB 222. Either or both of gNB 222 or ng-eNB 224 can communicate with UE 204 (e.g., any of the UEs described herein). In one aspect, two or more UEs 204 can communicate with each other via wireless sidelink 242, which can correspond to Figure 1 the wireless sidelink 162 in

[0068] Another optional aspect may include a location server 230, which may communicate with the 5GC 210 to provide location assistance for the UE 204. The location server 230 may be implemented as multiple separate servers (e.g., physically separate servers, different software modules on a single server, different software modules distributed across multiple physical servers, etc.), or alternatively each may correspond to a single server. The location server 230 may be configured to support one or more location services for the UE 204, which may be connected to the location server 230 via the core network, 5GC 210, and / or via the Internet (not shown). Additionally, the location server 230 may be integrated into a component of the core network, or alternatively may be external to the core network.

[0069] Figure 2B Another example wireless network structure 250 is shown. For example, the 5GC 260 may be functionally regarded as including a control plane function provided by the Access and Mobility Management Function (AMF) 264 and a user plane function provided by the User Plane Function (UPF) 262, which cooperate to form the core network (i.e., 5GC 260). The user plane interface 263 and the control plane interface 265 connect the ng-eNB 224 to the 5GC 260 and specifically to the UPF 262 and the AMF 264, respectively. In an additional configuration, the gNB 222 may also be connected to the 5GC 260 via the control plane interface 265 to the AMF 264 and the user plane interface 263 to the UPF 262. Additionally, the ng-eNB 224 may communicate directly with the gNB 222 via the backhaul connection 223, with or without a direct connection to the gNB of the 5GC 260. In some configurations, the NG-RAN 220 may have only one or more gNB222s, while other configurations include one or more of both the ng-eNB 224 and the gNB 222. The base stations of the NG-RAN 220 communicate with the AMF 264 via the N2 interface and with the UPF 262 via the N3 interface. Either or both of the gNB 222 or the ng-eNB 224 may communicate with the UE 204 (e.g., any of the UEs described herein). In one aspect, two or more UEs 204 may communicate with each other via the sidelink 242, which may correspond to Figure 1 the sidelink 162 in

[0070] The functions of AMF 264 include registration management, connection management, reachability management, mobility management, lawful interception, transmission of session management (SM) messages between UE 204 and session management function (SMF) 266, transparent proxy service for routing SM messages, access authentication and access authorization, transmission of short message service (SMS) messages between UE 204 and short message service function (SMSF) (not shown), and security anchor function (SEAF). AMF 264 also interacts with authentication server function (AUSF) (not shown) and UE 204, and receives intermediate keys established as a result of the UE 204 authentication process. In the case of authentication based on UMTS (Universal Mobile Telecommunications System) Subscriber Identity Module (USIM), AMF 264 retrieves security materials from AUSF. The functions of AMF 264 also include security context management (SCM). SCM receives keys from SEAF, which are used to derive access network specific keys. The functions of AMF 264 also include location service management for regulatory services, transmission of location service messages between UE 204 and location management function (LMF) 270 (which acts as location server 230), transmission of location service messages between NG-RAN 220 and LMF 270, allocation of Evolved Packet System (EPS) bearer identifiers for interworking with EPS, and notification of mobility events of UE 204. In addition, AMF 264 also supports the functions of non-3GPP (3rd Generation Partnership Project) access networks.

[0071] The functions of the UPF 262 include acting as an anchor point for intra-RAT / inter-RAT mobility (when applicable), acting as an external protocol data unit (PDU) session point for interconnecting with a data network (not shown), providing packet routing and forwarding, packet inspection, user plane policy rule enforcement (e.g., gating, redirection, traffic steering), lawful interception (user plane collection), traffic usage reporting, user plane quality of service (QoS) processing (e.g., uplink / downlink rate enforcement, reflective QoS marking in downlink), uplink traffic verification (service data flow (SDF) to QoS flow mapping), transport level packet marking in uplink and downlink, downlink packet buffering and downlink data notification triggering, and sending and forwarding one or more "end markers" to the source RAN node. The UPF 262 may also support the transmission of location service messages via the user plane between the UE 204 and a location server (such as a secure user plane location (SUPL) location platform (SLP) 272).

[0072] The functions of SMF 266 include session management, UE Internet Protocol (IP) address allocation and management, selection and control of user plane functions, traffic steering configuration at UPF 262 for routing traffic to the appropriate destination, control of parts of policy enforcement and QoS, and downlink data notification. The interface via which SMF 266 communicates with AMF 264 is called the N11 interface.

[0073] Another optional aspect may include an LMF 270 that can communicate with the 5GC 260 to provide location assistance for the UE 204. The LMF 270 can be implemented as multiple separate servers (e.g., physically separate servers, different software modules on a single server, different software modules distributed across multiple physical servers, etc.), or alternatively can each correspond to a single server. The LMF 270 can be configured to support one or more location services for the UE 204, which can be connected to the LMF 270 via the core network, the 5GC 260, and / or via the Internet (not shown). The SLP 272 can support similar functionality to the LMF 270, but the LMF 270 can communicate with the AMF 264, the NG-RAN 220, and the UE 204 via the control plane (e.g., using interfaces and protocols intended to transmit signaling messages rather than voice or data), and the SLP 272 can communicate with the UE 204 and external clients ( Figure 2B ) to communicate (e.g., using protocols designed to carry voice and / or data, such as the Transmission Control Protocol (TCP) and / or IP).

[0074] Figure 3 An example of a wireless communication system 300 that supports wireless unicast sidelink establishment according to aspects of the present disclosure is shown. In some examples, the wireless communication system 300 can implement aspects of the wireless communication systems 100, 200, and 250. The wireless communication system 300 can include a first UE 302 and a second UE 304, which can be examples of any of the UEs described herein. As a specific example, the UEs 302 and 304 can correspond to Figure 1 V-UE 160 in Figure 1 UE 190 and UE 104 connected via D2D P2P link 192 or Figure 2A and Figure 2B UE 204 in.

[0075] exist Figure 3 In the example of , UE 302 may attempt to establish a unicast connection with UE 304 via a side link, which may be a V2X side link between UE 302 and UE 304. As a specific example, the established side link connection may correspond toFigure 1 the sidelink 162 and / or 168 in Figure 2A and Figure 2B the sidelink 242 in. A sidelink connection can be established within an omnidirectional frequency range (e.g., FR1) and / or a mmW frequency range (e.g., FR2). In some cases, the UE 302 can be referred to as the initiating UE that initiates the sidelink connection procedure, and the UE 304 can be referred to as the target UE that is the target of the sidelink connection procedure performed by the initiating UE.

[0076] To establish the unicast connection, access stratum (AS) (a functional layer in the UMTS and LTE protocol stacks between the RAN and the UE that is responsible for transmitting data via the radio link and managing radio resources, and this functional layer is part of layer 2) parameters can be configured and negotiated between the UE 302 and the UE 304. For example, the matching of transmit and receive capabilities can be negotiated between the UE 302 and the UE 304. Each UE can have different capabilities (e.g., transmit and receive, 64 - quadrature amplitude modulation (QAM), transmit diversity, carrier aggregation (CA), supported communication bands, etc.). In some cases, different services can be supported in the upper layers of the respective protocol stacks of the UE 302 and the UE 304. In addition, a security association for the unicast connection can be established between the UE 302 and the UE 304. Unicast traffic can benefit from link - level security protection (e.g., integrity protection). Security requirements may be different for different radio communication systems. For example, V2X systems and Uu systems can have different security requirements (e.g., the Uu system does not include confidentiality protection). In addition, the IP configuration (e.g., IP version, address, etc.) for the unicast connection between the UE 302 and the UE 304 can be negotiated.

[0077] In some cases, UE 304 may create a service announcement (e.g., a service capability message) that is sent over a cellular network (e.g., cV2X) to assist in establishing a side link connection. Conventionally, UE 302 may identify and locate candidates for side link communication based on a basic service message (BSM) broadcasted unencrypted by a neighboring UE (e.g., UE 304). The BSM may include location information, security and identity information, and vehicle information (e.g., speed, handling, size, etc.) for the corresponding UE. However, for different wireless communication systems (e.g., D2D or V2X communication), a discovery channel may not be configured so that UE 302 can detect the BSM. Accordingly, the service announcement (e.g., discovery signal) sent by UE 304 and other neighboring UEs may be an upper layer signal and broadcast (e.g., in an NR side link broadcast). In some cases, UE 304 may include one or more of its own parameters in the service announcement, including connection parameters and / or capabilities it possesses. UE 302 may then monitor and receive the broadcasted service announcement to identify potential UEs for the corresponding side link connection. In some cases, UE 302 may identify potential UEs based on the capabilities indicated by each UE in its corresponding service announcement.

[0078] The service announcement may include a method for assisting UE 302 (eg, or any initial UE) to identify the UE ( Figure 3 304 in the example of ). For example, the service announcement may include channel information in which the direct communication request may be sent. In some cases, the channel information may be RAT-specific (e.g., specific to LTE or NR) and may include a resource pool in which the UE 302 sends the communication request. In addition, if the destination address is different from the current address (e.g., the address of the UE or streaming provider sending the service announcement), the service announcement may include the specific destination address of the UE (e.g., a layer 2 destination address). The service announcement may also include a network layer or transport layer for the UE 302 to send the communication request on. For example, the network layer (also referred to as "layer 3" or "L3") or the transport layer (also referred to as "layer 4" or "L4") may indicate the port number of the application of the UE sending the service announcement. In some cases, IP addressing may not be required if the signaling (e.g., PC5 signaling) directly carries a protocol (e.g., real-time transport protocol (RTP)) or gives a locally generated random protocol. In addition, the service announcement may include the protocol type used for credential establishment and QoS-related parameters.

[0079] In identifying potential sidelink connection targets ( Figure 3 304 in the example), the initial UE ( Figure 3304) can send a connection request 315 to the identified target UE 304. In some cases, the connection request 315 can be a first RRC message (e.g., an "RRCDirectConnectionSetupRequest" message) sent by the UE 302 to request a unicast connection with the UE 304. For example, the unicast connection can utilize the PC5 interface for the sidelink, and the connection request 315 can be an RRC connection setup request message. In addition, the UE 302 can use the sidelink signaling radio bearer 305 to transmit the connection request 315.

[0080] After receiving the connection request 315, the UE 304 may determine whether to accept or reject the connection request 315. The UE 304 may base the determination on the transmit / receive capabilities, the ability to accommodate unicast connections on the sidelink, the specific service indicated for the unicast connection, the content to be sent via the unicast connection, or a combination of the above. For example, if the UE 302 wants to use the first RAT to send or receive data, but the UE 304 does not support the first RAT, the UE 304 may reject the connection request 315. Additionally or alternatively, the UE 304 may reject the connection request 315 based on the inability to accommodate unicast connections on the sidelink (due to limited radio resources, scheduling issues, etc.). Accordingly, the UE 304 may send an indication of whether the request was accepted or rejected in the connection response 320. Similar to the UE 302 and the connection request 315, the UE 304 may use the sidelink signaling radio bearer 310 to transmit the connection response 320. Additionally, the connection response 320 may be a second RRC message (eg, a “RRCDirectConnectionResponse” message) sent by the UE 304 in response to the connection request 315 .

[0081] In some cases, the sidelink signaling radio bearers 305 and 310 may be the same sidelink signaling radio bearer, or may be separate sidelink signaling radio bearers. Accordingly, a radio link control (RLC) layer acknowledgement mode (AM) may be used for the sidelink signaling radio bearers 305 and 310. A UE supporting unicast connections may monitor on a logical channel associated with the sidelink signaling radio bearer. In some cases, the AS layer (i.e., Layer 2) may deliver information directly through RRC signaling (e.g., control plane) rather than the V2X layer (e.g., data plane).

[0082] If the connection response 320 indicates that the UE 304 accepted the connection request 315, the UE 302 may then send a connection setup 325 message on the sidelink signaling radio bearer 305 to indicate that the unicast connection setup is complete. In some cases, the connection setup 325 may be a third RRC message (e.g., an "RRCDirectConnectionSetupComplete" message). Each of the connection request 315, the connection response 320, and the connection setup 325 may use basic capabilities when transmitted from one UE to another UE to enable each UE to receive and decode the corresponding transmission (e.g., RRC message).

[0083] In addition, an identifier may be used for each of the connection request 315, the connection response 320, and the connection establishment 325. For example, the identifier may indicate which UE 302 / 304 is sending which message, and / or which UE 302 / 304 the message is intended for. For physical (PHY) layer channels, RRC signaling and any subsequent data transmission may use the same identifier (e.g., layer 2 ID). However, for logical channels, the identifier may be separate for RRC signaling and for data transmission. For example, on logical channels, RRC signaling and data transmission may be handled differently and have different confirmation (ACK) feedback message transceivings. In some cases, for RRC message transceivings, physical layer ACKs may be used to ensure that the corresponding messages are correctly sent and received.

[0084] One or more information elements may be included in the connection request 315 and / or the connection response 320 for UE 302 and / or UE 304, respectively, to enable negotiation of corresponding AS layer parameters for unicast connection. For example, UE 302 and / or UE 304 may include a packet data convergence protocol (PDCP) parameter in the corresponding unicast connection establishment message to set the PDCP context for the unicast connection. In some cases, the PDCP context may indicate whether PDCP duplication is used for the unicast connection. In addition, UE 302 and / or UE 304 may include an RLC parameter when establishing a unicast connection to set the RLC context for the unicast connection. For example, the RLC context may indicate whether AM (e.g., a reordering timer (t-reordering) is used) or an unacknowledged mode (UM) is used for the RLC layer of the unicast communication.

[0085] In addition, UE 302 and / or UE 304 may include Media Access Control (MAC) parameters to set up the MAC context for the unicast connection. In some cases, the MAC context may implement a resource selection algorithm for the unicast connection, a Hybrid Automatic Repeat reQuest (HARQ) feedback scheme (e.g., ACK or Negative ACK (NACK) feedback), parameters of the HARQ feedback scheme, carrier aggregation, or a combination thereof. In addition, UE 302 and / or UE 304 may include PHY layer parameters when establishing the unicast connection to set up the PHY layer context for the unicast connection. For example, the PHY layer context may indicate the transmission format for the unicast connection (unless a transmission profile for each UE 302 / 304 is included) and radio resource configuration (e.g., Bandwidth Part (BWP), parameter set, etc.). These information elements may support different frequency range configurations (e.g., FR1 and FR2).

[0086] In some cases, a security context for the unicast connection may also be set up (e.g., after sending the connection establishment 325 message). Before establishing a security association (e.g., security context) between UE 302 and UE 304, the sidelink signaling radio bearers 305 and 310 may not be protected. After establishing the security association, the sidelink signaling radio bearers 305 and 310 may be protected. Accordingly, the security context may implement secure data transmission on the unicast connection as well as the sidelink signaling radio bearers 305 and 310. In addition, IP layer parameters (e.g., link-local IPv4 or IPv6 address) may be negotiated. In some cases, the IP layer parameters may be negotiated through an upper layer control protocol that runs after establishing the RRC signaling (e.g., establishing the unicast connection). As mentioned above, UE 304 may make a decision to accept or reject the connection request 315 based on the specific service indicated for the unicast connection and / or the content to be sent on the unicast connection (e.g., upper layer information). The specific service and / or content may also be indicated through an upper layer control protocol that runs after establishing the RRC signaling.

[0087] After establishing the unicast connection, UE 302 and UE 304 may communicate using the unicast connection on the sidelink 330, where sidelink data 335 is sent between the two UEs 302 and 304. The sidelink 330 may correspond to Figure 1 the sidelink 162 and / or 168 in Figure 2A and Figure 2BThe sidelink 242 therein. In some cases, the sidelink data 335 may include RRC messages sent between two UEs 302 and 304. To maintain this unicast connection on the sidelink 330, the UE 302 and / or the UE 304 may send keep-alive messages (e.g., "RRCDirectLinkAlive" messages, fourth RRC messages, etc.). In some cases, the keep-alive messages may be triggered periodically or on demand (e.g., event-triggered). Accordingly, the triggering and transmission of the keep-alive messages may be invoked by the UE 302 or by both the UE 302 and the UE 304. Additionally or alternatively, MAC control elements (CEs) (e.g., defined on the sidelink 330) may be used to monitor the status of the unicast connection on the sidelink 330 and maintain the connection. When the unicast connection is no longer needed (e.g., the UE 302 travels far enough away from the UE 304), the UE 302 and / or the UE 304 may initiate a release procedure to discard the unicast connection on the sidelink 330. Accordingly, subsequent RRC messages may not be able to be sent between the UE 302 and the UE 304 over the unicast connection.

[0088] Figure 4 is a block diagram showing various components of an example UE 400 according to aspects of the present disclosure. In one aspect, the UE 400 may correspond to any of the UEs described herein. As a specific example, the UE 400 may be a V-UE, such as Figure 1 the V-UE 160 therein. For simplicity, Figure 4 the various features and functions shown in the block diagram are connected together by using a common data bus, which is intended to represent that these various features and functions are operatively coupled together. Those skilled in the art will recognize that other connections, mechanisms, features, functions, etc. may be provided and adapted as needed to operatively couple and configure an actual UE. Additionally, it is recognized that one or more of the features or functions shown in the Figure 4 example may be further subdivided, or Figure 4 two or more of the features or functions shown in the

[0089] UE 400 may include at least one transceiver 404, which is connected to one or more antennas 402 and provides components (e.g., components for transmitting, components for receiving, components for measuring, components for tuning, components for suppressing transmission, etc.) for communicating with other network nodes (such as V-UE (e.g., V-UE 160)), infrastructure access points (e.g., roadside access point 164), P-UE (e.g., UE 104), base stations (e.g., base station 102), etc. via at least one specified RAT (e.g., cV2X or IEEE 802.11p) on one or more communication links (e.g., communication link 120, sidelink 162, 166, 168, mmW communication link 184). The transceiver 404 can be configured in various ways to transmit and encode signals (e.g., messages, indications, information, etc.) according to the specified RAT and conversely to receive and decode signals (e.g., messages, indications, information, pilots, etc.).

[0090] As used herein, a "transceiver" may include, in some implementations, at least one transmitter and at least one receiver in an integrated device (e.g., transmitter circuitry and receiver circuitry implemented as a single communication device), may include separate transmitter devices and separate receiver devices in some implementations, or may be implemented in other ways in other implementations. In one aspect, the transmitter may include or be coupled to multiple antennas (e.g., antenna 402), such as an antenna array, which allows the UE 400 to perform transmission "beamforming" as described herein. Similarly, the receiver may include or be coupled to multiple antennas (e.g., antenna 402), such as an antenna array, which allows the UE 400 to perform receive beamforming as described herein. In one aspect, the transmitter and the receiver may share the same multiple antennas (e.g., antenna 402), such that the UE 400 can only receive or transmit at a given time, rather than both simultaneously. In some cases, the transceiver may not be able to provide both transmit and receive functionality. For example, when it is not necessary to provide full communication, a low-functional receiver circuit may be employed in some designs to reduce cost (e.g., a receiver chip or similar circuitry that simply provides low-level logging).

[0091] UE 400 may also include a satellite positioning service (SPS) receiver 406. The SPS receiver 406 may be connected to the one or more antennas 402 and may provide components for receiving and / or measuring satellite signals. The SPS receiver 406 may include any suitable hardware and / or software for receiving and processing SPS signals (such as Global Positioning System (GPS) signals). The SPS receiver 406 requests information and operations from other systems when appropriate and performs the calculations necessary to determine the location of the UE 400 using measurements obtained by any suitable SPS algorithm.

[0092] One or more sensors 408 may be coupled to the processing system 410 and may provide components for sensing or detecting information related to the state and / or environment of the UE 400 (such as speed, heading (e.g., compass heading), headlight status, mileage, fuel consumption, etc.). As an example, one or more sensors 408 may include a speedometer, a tachometer, an accelerometer (e.g., a microelectromechanical systems (MEMS) device), a gyroscope, a geomagnetic sensor (e.g., a compass), an altimeter (e.g., a barometric altimeter), etc.

[0093] The processing system 410 may include one or more microprocessors, microcontrollers, ASICs, processing cores, digital signal processors, etc., which provide processing functions and other computing and control functionality. The processing system 410 may thus provide components for processing, such as components for determining, for calculating, for receiving, for sending, for indicating, etc. The processing system 410 may include any form of logic suitable for performing or causing the components of the UE 400 to execute at least the techniques described herein.

[0094] The processing system 410 may also be coupled to a memory 414, which provides components for storing data and software instructions for performing programmed functionality within the UE 400 (including components for retrieving, for maintaining, etc.). The memory 414 may be loaded on the processing system 410 (e.g., within the same integrated circuit (IC) package), and / or the memory 414 may be external to the processing system 410 and functionally coupled via a data bus.

[0095] The UE 400 may include a user interface 450 that provides any suitable interface system that allows a user to interact with the UE 400, such as a microphone / speaker 452, a keypad 454, and a display 456. The microphone / speaker 452 may provide voice communication services for the UE 400. The keypad 454 may include any suitable buttons for a user to input to the UE 400. The display 456 may include any suitable display, such as, for example, a backlit liquid crystal display (LCD), and may also include a touch screen display for additional user input modes. The user interface 450 may thus be a component for providing an indication (e.g., an audible and / or visual indication) to the user and / or for receiving user input (e.g., via a user actuated sensing device such as a keypad, touch screen, microphone, etc.).

[0096] In one aspect, the UE 400 may include a sidelink manager 470 coupled to the processing system 410. The sidelink manager 470 may be a hardware, software, or firmware component that, when executed, causes the UE 400 to perform the operations described herein. For example, the sidelink manager 470 may be a software module stored in the memory 414 and executable by the processing system 410. As another example, the sidelink manager 470 may be a hardware circuit (e.g., an ASIC, a field programmable gate array (FPGA), etc.) within the UE 400.

[0097] Communication on the sidelink may use a frame structure and parameter set similar to those used in LTE and NR. Figure 5 FIG. 500 is a diagram showing an example of a frame structure for use on the sidelink according to an aspect of the present disclosure. Other wireless communication technologies may have different frame structures and / or different channels.

[0098] In LTE and NR, the system bandwidth is divided into multiple (K) orthogonal subcarriers, which are also often referred to as frequency tones, frequency slots, etc. Each subcarrier can be modulated with data. Generally speaking, modulation symbols are transmitted using orthogonal frequency division multiplexing (OFDM) in the frequency domain and using single-carrier frequency division multiplexing (SC-FDM) in the time domain. The spacing between adjacent subcarriers can be fixed, and the total number of subcarriers (K) can depend on the system bandwidth. For example, the subcarrier spacing can be 15 kHz, and the minimum resource allocation (resource block) can be 12 subcarriers (or 180 kHz). Thus, for system bandwidths of 1.25, 2.5, 5, 10, or 20 megahertz (MHz), the nominal fast Fourier transform (FFT) sizes can be equal to 128, 256, 512, 1024, or 2048, respectively. The system bandwidth can also be divided into subbands. For example, a subband can cover 1.08 MHz (i.e., 6 resource blocks), and for system bandwidths of 1.25, 2.5, 5, 10, or 20 MHz, there can be 1, 2, 4, 8, or 16 subbands, respectively.

[0099] LTE supports a single parameter set (subcarrier spacing (SCS), symbol length, etc.). In contrast, NR can support multiple parameter sets (μ), e.g., 15 kHz (μ = 0), 30 kHz (μ = 1), 60 kHz (μ = 2), 120 kHz (μ = 3), and 240 kHz (μ = 4) or larger subcarrier spacings may be available. In each subcarrier spacing, there are 14 symbols per time slot. For 15 kHz SCS (μ = 0), there is one time slot per subframe, 10 time slots per frame, the time slot duration is 1 millisecond (ms), the symbol duration is 66.7 microseconds (μs), and the maximum nominal system bandwidth (in MHz) with a 4K FFT size is 50. For 30 kHz SCS (μ = 1), there are two time slots per subframe, 20 time slots per frame, the time slot duration is 0.5 ms, the symbol duration is 33.3 μs, and the maximum nominal system bandwidth (in MHz) with a 4K FFT size is 100. For 60 kHz SCS (μ = 2), there are four time slots per subframe, 40 time slots per frame, the time slot duration is 0.25 ms, the symbol duration is 16.7 μs, and the maximum nominal system bandwidth (in MHz) with a 4K FFT size is 200. For 120 kHz SCS (μ = 3), there are eight time slots per subframe, 80 time slots per frame, the time slot duration is 0.125 ms, the symbol duration is 8.33 μs, and the maximum nominal system bandwidth (in MHz) with a 4K FFT size is 400. For 240 kHz SCS (μ = 4), there are 16 time slots per subframe, 160 time slots per frame, the time slot duration is 0.0625 ms, the symbol duration is 4.17 μs, and the maximum nominal system bandwidth (in MHz) with a 4K FFT size is 800.

[0100] In Figure 5 the example of, the parameter set of 15 kHz is used. Thus, in the time domain, a 10 ms frame is divided into 10 equal-sized subframes, each subframe being 1 ms, and each subframe includes one time slot. In Figure 5 it, time is represented horizontally (on the X-axis), where time increases from left to right, while frequency is represented vertically (on the Y-axis), where frequency increases (or decreases) from bottom to top.

[0101] A resource grid can be used to represent a time slot, and each time slot includes one or more time-parallel resource blocks (RBs) (also known as physical RBs (PRBs)) in the frequency domain. The resource grid is further divided into multiple resource elements (REs). An RE can correspond to one symbol length in the time domain and one subcarrier in the frequency domain. In Figure 5In the parameter set, for the normal cyclic prefix, an RB can contain 12 consecutive subcarriers in the frequency domain and 7 consecutive symbols in the time domain, for a total of 84 REs. For the extended cyclic prefix, an RB can contain 12 consecutive subcarriers in the frequency domain and 6 consecutive symbols in the time domain, for a total of 72 REs. The number of bits carried by each RE depends on the modulation scheme.

[0102] Various sidelink physical channels can be transmitted on the resource elements of a time slot in a radio frame. The sidelink physical channels correspond to a set of resource elements carrying information from higher layers. The following sidelink physical channels are defined for NR sidelinks: Physical Sidelink Shared Channel (PSSCH), Physical Sidelink Broadcast Channel (PSBCH), Physical Sidelink Control Channel (PSCCH), and Physical Sidelink Feedback Channel (PSFCH). These channels are described in 3GPP Technical Specification (TS) 38.211, which is publicly available and incorporated herein by reference in its entirety.

[0103] As Figure 5 shown, some of the resource elements carry physical RF signals. The sidelink physical signals correspond to a set of resource elements used by the physical layer and do not carry information from higher layers. The following sidelink physical signals are defined for NR sidelinks: Demodulation Reference Signal (DMRS), Channel State Information Reference Signal (CSI-RS), Phase Tracking Reference Signal (PT-RS), Sidelink Primary Synchronization Signal (S-PSS), and Sidelink Secondary Synchronization Signal (S-SSS). Example locations of these signals are marked as "R" in Figure 5 which. These signals are described in 3GPP TS 38.211. Additionally, the UE can transmit a Positioning Reference Signal (PRS), Tracking Reference Signal (TRS), etc. for positioning purposes.

[0104] The set of resource elements (REs) used for the transmission of PRS is referred to as a "PRS resource". The set of resource elements can span multiple PRBs in the frequency domain and 'N' (such as 1 or more) consecutive symbols within a time slot in the time domain. In a given OFDM symbol in the time domain, the PRS resource occupies consecutive PRBs in the frequency domain.

[0105] Note that the terms "positioning reference signal" and "PRS" generally refer to specific reference signals for positioning in NR and LTE systems. However, as used herein, the terms "positioning reference signal" and "PRS" refer to any type of reference signal that can be used for positioning, such as but not limited to PRS, tracking reference signal (TRS), phase-tracking reference signal (PT-RS), cell-specific reference signal (CRS), channel state information reference signal (CSI-RS), demodulation reference signal (DMRS), primary synchronization signal (PSS), secondary synchronization signal (SSS), synchronization signal block (SSB), sounding reference signal (SRS), uplink positioning reference signal (UL-PRS), etc., as defined in LTE and NR. Additionally, the terms "positioning reference signal" and "PRS" can refer to downlink, uplink, or sidelink positioning reference signals, unless otherwise indicated by context. If further differentiation of the type of PRS is needed, the downlink positioning reference signal can be referred to as "DL-PRS", the uplink positioning reference signal (e.g., SRS, PT-RS for positioning) can be referred to as "UL-PRS", and the sidelink positioning reference signal can be referred to as "SL-PRS". Additionally, for signals that can be transmitted in the uplink, downlink, and sidelink directions (e.g., DMRS, PT-RS, etc.), the signal can be prefixed with "UL", "DL", or "SL" respectively to distinguish the direction. For example, "UL-DMRS" can be distinguished from "SL-DMRS".

[0106] Link-level ranging signals can be used to estimate the distance between V-UE pairs or between a V-UE and a roadside unit (RSU). Figure 6 An example wireless communication system 600 is shown in accordance with aspects of the present disclosure, where V-UE 604 is exchanging ranging signals with RSU 610 and another V-UE 606. As Figure 6As shown, broadband (e.g., FR1) ranging signals (e.g., Zadoff Chu sequences) are sent by two endpoints (e.g., V-UE 604 and RSU 610, and V-UE 604 and V-UE 606). In one aspect, the ranging signal can be a positioning reference signal (e.g., SL-PRS). When the ranging signal is received from a transmitter (e.g., V-UE 604), the receiver (e.g., RSU 610 and / or V-UE 606) uses channel estimation to estimate the arrival time (ToA) of the first multipath of the ranging signal. The receiver then responds by sending a ranging signal to the transmitter that includes the calculated ToA. The transmitter calculates the ToA of the response signal and uses the two estimated ToAs to estimate the distance between the transmitter and the receiver. Note that this positioning procedure assumes that the V-UEs involved are time synchronized (i.e., their system frame times are the same as those of other V-UEs, or are a known offset relative to other V-UEs). Additionally, although Figure 6 two V-UEs are shown, it will be understood that they need not be V-UEs and may alternatively be any other type of UE capable of performing sidelink communication.

[0107] As will be understood, ranging accuracy improves with the bandwidth of the ranging signal. Specifically, higher bandwidths can better separate the different multipaths of the ranging signal.

[0108] A three-stage protocol can be used to transmit ranging signals (e.g., SL-PRS) for positioning. Figure 7 is a timeline 700 showing a three-stage protocol according to an aspect of the present disclosure. As Figure 7 shown, this three-stage protocol occurs periodically (such as once per second). In the first stage 710, the transmitter (e.g., V-UE 604, RSU 610) broadcasts the relative position of its antenna (compared to the center position of the transmitter), the identifier (ID) of the sequence to be sent through that antenna in the second stage 720, and the time / frequency resources on which the sequence will be sent in the second stage 720.

[0109] In the second stage 720, the transmitter sends a broadband sequence (e.g., SL-PRS) with the determined sequence ID on the determined time / frequency resources. In the third stage 730, the transmitter broadcasts its own GPS position, the pseudorange to one or more satellites, and / or its orientation during the second stage. It also broadcasts the ToA from the second stage 720. That is, it broadcasts the ToA of any SL-PRS received during the second stage 720. Note that for V2I positioning, only the RSU needs to perform the third stage 730.

[0110] In one aspect, all V-UEs and RSUs can be configured (e.g., according to applicable standards) to follow this three-phase protocol. Thus, during each phase, the transmitter can also receive signals from other V-UEs / RSUs that contain information of the same type as the information transmitted by the transmitter. In this way, both the transmitter and the receiver can estimate the distance between themselves and other V-UEs / RSUs.

[0111] Figure 8 Two resource allocation modes for transmission on the NR sidelink according to aspects of the present disclosure are shown. In the first mode 810 (labeled "Mode 1"), the base station 802 (e.g., gNB) allocates time / frequency resources for sidelink communication between the involved V-UEs. Thus, in the Figure 8 example, the base station 802 allocates time / frequency resources for the sidelink between V-UEs 804 and 806. The transmitter (e.g., V-UE 804) uses the allocated resources to transmit ranging signals (e.g., SL-PRS) according to the three-phase protocol described above with reference to Figure 7 That is, the transmitter transmits the first, second, and third phase signals on the resources allocated by the base station 802. In the second mode 820 (labeled "Mode 2"), the involved UEs 804 and 806 autonomously select the sidelink resources to be used for the transmission of the three-phase ranging signals. A V-UE can use the first mode only if it has cellular coverage, and can use the second mode regardless of whether it has cellular coverage. Note that although Figure 8 two V-UEs are shown, it will be understood that they do not need to be V-UEs, and can alternatively be any other type of UE capable of sidelink communication.

[0112] The signaling on the sidelink is the same between these two resource allocation modes. From the perspective of the receiver (e.g., V-UE 806), there is no difference between the modes. That is, for the receiver, it does not matter whether the resources for the ranging signal are allocated by the base station 802 or by the transmitting UE.

[0113] Additionally, as described above with reference to Figure 3 the NR sidelink supports HARQ retransmission. In the first mode, the base station (e.g., base station 802) provides dynamic authorization for HARQ feedback or activates the configured sidelink authorization. The sidelink feedback can be reported back to the base station by the transmitting UE (e.g., V-UE 804).

[0114] Each established sidelink includes a PSCCH carrying sidelink control information (SCI). The first-stage control (referred to as "SCI-1") is transmitted on the PSCCH and contains information for resource allocation and decoding of the second-stage control (referred to as "SCI-2"). The second-stage control is transmitted on the PSSCH and contains information for decoding data to be transmitted on the shared channel (SCH) of the sidelink. The first-stage control information can be decoded by all UEs, while the second-stage control information can include formats that can only be decoded by certain UEs. This ensures that new features can be introduced in the second-stage control while maintaining resource reservation backward compatibility in the first-stage control.

[0115] Both the first and second-stage controls use Figure 9 the physical downlink control channel (PDCCH) polarization coding chain shown in Figure 9 FIG. 900 shows how to establish an SCH on a sidelink between two or more UEs according to aspects of the present disclosure. Specifically, the information in SCI-1 902 is used for resource allocation 904 (performed by the network or the involved UEs) for SCI-2 906 and SCH 908. Additionally, the information in SCI-1 902 is used to determine / decode the content of SCI-2 906 transmitted on the allocated resources. Thus, the receiving UE requires both resource allocation 904 and SCI-1 902 to decode SCI-2 906. The information in SCI-2 906 is then used to determine / decode SCH 908.

[0116] A UE can use round-trip time (RTT) positioning techniques with multiple other UEs or RSU to determine its position based on ranging signals to / from other involved UEs / RSU and the known positions of other involved UEs / RSU. Figure 10 FIG. 1000 shows an example timing of RTT signals between a target UE 1004 (labeled "UE2") and two assisting UEs 1002 (labeled "UE1") and 1006 (labeled "UE3") according to aspects of the present disclosure. UEs 1002 to 1006 can correspond to any of the UEs described herein and can in particular be V-UEs. In Figure 10 FIG. 1000, the target UE 1004 is attempting to estimate its position, and the assisting UEs 1002 and 1006 have known positions (e.g., from GPS).

[0117] In Figure 10In the example, the target UE 1004 receives a ranging signal (e.g., SL-PRS) from the assisting UE 1002 and responds with its own ranging signal (e.g., SL-PRS). The ranging signal can be sent on time / frequency resources allocated by the network (e.g., a base station or a location server) or by one of the UEs involved, as described above with reference to Figure 8 This enables the receiving UE to know at what frequency and at what time to measure the ranging signal. In Figure 10 the example, there is a certain propagation time between the received ranging signal at the assisting UE 1002 and the target UE 1004, which is referred to as T prop,UE1-UE2 . The length of time between receiving the ranging signal from the assisting UE 1002 and the transmission of the response ranging signal by the target UE 1004 is referred to as "T UE2,Rx-Tx " or "UE2 Rx-Tx", where "Rx-Tx" means "receive to transmit". This response ranging signal can include a measurement report containing the value of T UE2,Rx-Tx , and there is a certain propagation time between the target UE 1004 and the assisting UE 1002, which is referred to as T prop,UE2-UE1 (assuming it is equal to T prop,UE1-UE2 ).

[0118] The response ranging signal from the target UE 1004 can also be received by the second assisting UE 1006 after a certain propagation time, which is referred to as T prop,UE2-UE3 . Alternatively, this can be a different ranging signal sent by the target UE 1004 at approximately the same time as the response ranging signal to the assisting UE 1002 (in Figure 10 the example). After a certain delay at the second assisting UE 1006 (which is referred to as "T UE3,Rx-Tx " or "UE3 Rx-Tx"), the second assisting UE 1006 sends a response ranging signal to the target UE 1004. This response ranging signal can include a measurement report containing the value of T UE3,Rx-Tx , and there is a certain propagation time between the assisting UE 1006 and the target UE 1004, which is referred to as T prop,UE3-UE2 (assuming it is equal to T prop,UE2-UE3 ).

[0119] Based on the transmission and reception times of the ranging signal and the values of T UE2,Rx-Tx and T UE3,Rx-Tx , a positioning entity (e.g., the target UE 1004) can calculate the time of flight between the target UE 1004 and the assisting UEs 1002 and 1006 (i.e., T Figure 10 in the example of prop,UE1-UE2 and / or Tprop,UE2-UE1 and T prop,UE2-UE3 and / or T prop,UE3-UE2 )。Based on this time of flight and the speed of light, the positioning entity can calculate the distances between the target UE 1004 and the assisting UEs 1002 and 1006. Based on these distances, the positioning entity can estimate the relative position of the target UE 1004 with respect to the assisting UEs 1002 and 1006. If the assisting UEs 1002 and 1006 have known positions (e.g., GPS coordinates received from UEs 1002 and 1006), the positioning entity can estimate the absolute position of the target UE 1004 based on the distances between the target UE 1004 and the assisting UEs 1002 and 1006 and the known positions of the assisting UEs 1002 and 1006. In the case where the assisting UEs 1002 and 1006 provide their positions, they can also provide the uncertainty or level of precision associated with that position.

[0120] Figure 11 FIG. 1100 is a diagram showing an example timing of RTT signals exchanged between a target UE 1104 (labeled "UE2") and two assisting UEs 1102 (labeled "UE1") and 1106 (labeled "UE3") in accordance with aspects of the present disclosure. UEs 1102 to 1106 can correspond to any of the UEs described herein and can in particular be V-UEs. In Figure 11 , the target UE 1104 is attempting to estimate its position and the assisting UEs 1102 and 1106 have known positions (e.g., from GPS).

[0121] In Figure 11 the example of, the first assisting UE 1102 transmits a ranging signal (e.g., SL-PRS) which is received at the target UE 1104 after a certain propagation time T prop,UE1-UE2 and is also received / measured at the second assisting UE 1106 after a certain propagation time T prop,UE1-UE3 . In Figure 11 the example of, this is a known propagation time or can be derived since the positions of the assisting UEs 1102 and 1106 are known.

[0122] After a certain UE processing time (referred to as T UE2,Rx-Tx ) at the target UE 1104, the target UE 1104 transmits a response ranging signal which is received / measured at the first assisting UE 1102 after a propagation delay T prop,UE2-UE1 and is also received at the second assisting UE 1106 after a certain propagation delay T prop,UE2-UE3The response ranging signal is then received / measured. As described above, the response ranging signal may include a measurement report that includes the UE processing time T at the target UE 1104 UE2,Rx-Tx .

[0123] The second assisting UE 1106 determines the time difference between the ToA of the ranging signal transmitted by the first assisting UE 1102 and the ToA of the response ranging signal transmitted by the target UE 1104, and this time difference is referred to as T UE-Rx-UE-Rx or more simply referred to as T Rx-Rx . The second assisting UE 1106 sends a measurement report reporting the measured T UE-Rx-UE-Rx to a positioning entity (e.g., the target UE 1104).

[0124] Then, the distance between the second assisting UE 1106 and the target UE 1104 can be calculated based on the following observations:

[0125] T Prop,UE1-UE2 + T Rx-Tx + T Prop,UE2-UE3 = T UE Rx-Rx + T Prop,UE1-UE3

[0126] Based on these distances, the positioning entity can estimate the relative position of the target UE 1104 with respect to the assisting UEs 1102 and 1106. If the assisting UEs 1102 and 1106 have known positions (e.g., GPS coordinates received from the UEs 1102 and 1106), the positioning entity can estimate the absolute position of the target UE 1104 based on the distances between the target UE 1104 and the assisting UEs 1102 and 1106 and the known positions of the assisting UEs 1102 and 1106. In the case where the assisting UEs 1102 and 1106 provide their positions, they can also provide the uncertainty or level of precision associated with that position.

[0127] Note that although Figure 10 and Figure 11 illustrate the RTT timing between the target UE and two assisting UEs, it will be understood that there may be more or fewer than two assisting UEs.

[0128] This disclosure provides techniques for sidelink-assisted positioning. In a first scenario for sidelink-assisted positioning, the assisting UEs (e.g., assisting UEs 1102 and 1106) may have cellular coverage (i.e., a cellular connection to a base station), and the target UE (e.g., target UE 1104) may not have coverage (i.e., does not have a cellular connection to a base station). Alternatively, the target UE may have coverage, but it may be very poor such that the UE still cannot receive transmissions from the base station.

[0129] In this scenario, the target UE can initiate a location request by sending a request to each of those UEs on a sidelink established with any neighboring (secondary) UEs. The sidelink may be established at the time of the location request, or may have been previously established for other reasons. The secondary UEs receive the location requests and forward them to the network (e.g., a serving base station or location server). In response, the network allocates time / frequency resources (e.g., resource allocation 904) to each of the secondary UEs via the Uu interface for a ranging signal (e.g., SL-PRS) to be used for the corresponding positioning procedure. However, the target UE does not receive the Uu link and resource allocation information. Instead, the secondary UE sends a sidelink transmission including a ranging signal configuration to the target UE in a selected subchannel. Specifically, the secondary UE sends an SCI-2 including the ranging signal configuration received from the network. However, the secondary UE first sends an SCI-1 that enables the target UE to decode the subsequent SCI-2, as described above with reference to Figure 9 Once the target UE has the assigned ranging signal configuration to be used for the positioning procedure with each assisting UE, it can send and receive ranging signals on those resources, as described above with reference to Figure 10 and Figure 11 discussed.

[0130] In a second scenario for sidelink assisted positioning, neither the target UE nor the assisting UE may have cellular coverage. In this case, the target UE sends a location request to the assisting UE on a sidelink established with the corresponding assisting UE, and the assisting UE may select a ranging signal (e.g., SL-PRS) time / frequency resource without coordination with the network. The assisting UE then sends a sidelink transmission including the selected ranging signal configuration to the target UE in the selected subchannel. Specifically, unlike the first option, the assisting UE sends an SCI-2 including the ranging signal configuration selected without network participation. In addition, the assisting UE first sends an SCI-1 that enables the target UE to decode the subsequent SCI-2, as described above with reference to FIG. Figure 9 Once the target UE has the assigned ranging signal configuration to be used for the positioning procedure with each assisting UE, it can send and receive ranging signals on those resources, as described above with reference to Figure 10 and Figure 11 discussed.

[0131] Referring in more detail to the second scenario, when the assisting UE without coverage responds to the location request from the target UE, the assisting UE must select the time / frequency resources (e.g., REs) on which it will send the SL-PRS back to the target UE. Since multiple UEs assisting in the positioning dialogue with the target UE may not have coverage, the SL-PRS resources selected by one assisting UE may conflict with those selected by another assisting UE.

[0132] Accordingly, the present disclosure provides techniques for avoiding "PRS conflicts". In one aspect, the assisting UE selects the SL-PRS resources based on a deterministic function (described below) of various parameters derived from the time / frequency resources carrying the SCI-1 / SCI-2 containing the response of the assisting UE to the location request or the time / frequency resources of the PSCCH and / or PSSCH including the location request.

[0133] In the time domain, the time resources (e.g., symbols, time slots, subframes, repetitions, etc.) allocated for SL-PRS transmission can be derived based on a common / deterministic function. As a first option, the time domain resources for SL-PRS transmission can be derived based on a deterministic function of the subchannel of the PSCCH or PSSCH associated with the location request. One PSCCH can schedule multiple PSSCHs. Thus, in one aspect, if the PSCCH is associated with multiple PSSCHs, the assisting UE can select the index of the PSSCH with the minimum or maximum index value, for example, to derive the time domain resources for SL-PRS.

[0134] As a second option, the time domain resources for SL-PRS transmission can be derived based on a deterministic function of the source ID of the target UE that sent the location request. This option will be beneficial in the following example scenario. Specifically, the responding UE may need to send SL-PRS resources customized for a specific target UE. For example, the transmit beam and / or path loss can be specific to the target UE, and thus, for different target UEs, different SL-PRS resources will be required. However, if two different UEs happen to send location requests in the same time slot / subchannel and the source ID is not part of the determination procedure for determining the time domain resources for SL-PRS, the responding UE will not be able to send two customized SL-PRS resources to different UEs. Instead, the responding UE will select the SL-PRS resources for the two target UEs based on the time slot / subchannel associated with the location request (first option), but since in this scenario, the time slot / subchannel is the same for both UEs, the selected PRS resources will be the same for the two target UEs. Thus, it will be beneficial to derive the PRS resources based on both the time slot / subchannel and the source ID.

[0135] As a third option, the time-domain resources for PRS transmission can be derived based on a deterministic function of the destination ID of the PSCCH associated with the location request. This destination ID can indicate whether the location request is unicast (i.e., targeted at a specific assisting UE), multicast (i.e., targeted at a specific group of UEs), or broadcast (i.e., targeted at any listening UE). Making the time-domain resources for SL-PRS a function of the destination ID will allow the responding UE to send multiple SL-PRSs (even to the same target UE participating in multiple groups). Thus, this factor will make the SL-PRS transmission group-specific.

[0136] As a fourth option, the time-domain resources for SL-PRS transmission can be derived based on a deterministic function of a pseudo-random variable and / or a scrambling seed. In this case, a configured scrambling seed can be used, which is configured in both the target UE and the assisting UE from a higher layer (e.g., layer 2, layer 3, or application layer). This can provide additional randomization of the time-domain resources for SL-PRS transmission.

[0137] As a fifth option, the time-domain resources for SL-PRS transmission can be derived based on a deterministic function of a combination of the above. In this case, which of the above factors are used and the deterministic function can be configured by a higher layer (e.g., layer 2, layer 3, or application layer). Alternatively, it can be related to a frequency band or frequency range (e.g., FR1 vs. FR2). For example, the source ID (second option) is important for FR2 as it enables the responding UE to correctly form the transmission beam towards the target UE.

[0138] Regarding the selection of the frequency resources for SL-PRS transmission, there are several options. As a first option, SCI-2 can include an additional frequency-domain allocation field dedicated to signaling the frequency-domain resources for SL-PRS (e.g., sub-band ID, start / end PRB, etc.). As a second option, the frequency-domain allocation field of SCI-2, which is typically used to schedule the PSSCH, can instead be used to schedule only the SL-PRS. In this case, no PSSCH can be scheduled. As a third option, an additional frequency-domain allocation field can be added to SCI-2, which provides the PRS allocation in a different / relative manner with respect to the frequency-domain allocation field of the PSSCH. For example, if the PSSCH is in a set of sub-bands, the SL-PRS can be sent in the same sub-bands of the PSSCH plus one additional sub-band below the PSSCH and / or one additional sub-band above the PSSCH, as Figure 12 shown.

[0139] Figure 12FIG. 1200 shows the relative time and frequency relationship between an example PSSCH resource 1220 and an example PRS resource 1210 in accordance with aspects of the present disclosure. The PRS resource 1210 may be an SL-PRS resource. As can be seen, the PRS resource 1210 is transmitted in the same subband as the PSSCH resource 1220, plus at least one subband below the PSSCH resource 1220 and at least one subband above the PSSCH resource 1220.

[0140] Figure 13 FIG. 1300 shows an example method for wireless communication in accordance with aspects of the present disclosure. In one aspect, the method 1300 may be performed by an assisting UE (e.g., any of the UEs described herein). As a specific example, the assisting UE may correspond to UE 1102, UE 1106, UE 1202, or UE 1206.

[0141] At 1310, the assisting UE receives, on a sidelink between the assisting UE and the target UE, a request to perform a positioning procedure (e.g., RTT) from the target UE (e.g., any of the UEs described herein). As a specific example, the target UE may correspond to UE1104 or UE 1204. In one aspect, both the assisting UE and the target UE are outside network coverage (i.e., do not have cellular / network coverage, as in, for example, Figure 8 mode 2). In one aspect, operation 1310 may be performed by transceiver 404, processing system 410, memory 414, and / or sidelink manager 470, where any or all of the components may be considered a means for performing the operation.

[0142] At 1320, the assisting UE determines a set of time and / or frequency resources on which to transmit one or more positioning reference signals for the positioning procedure, at least based on the request. In one aspect, operation 1320 may be performed by transceiver 404, processing system 410, memory 414, and / or sidelink manager 470, where any or all of the components may be considered a means for performing the operation.

[0143] At 1330, the assisting UE transmits one or more positioning reference signals to the target UE via the set of time and / or frequency resources. In one aspect, operation 1330 may be performed by transceiver 404, processing system 410, memory 414, and / or sidelink manager 470, where any or all of the components may be considered a means for performing the operation.

[0144] Figure 14FIG. 1400 shows an example method for wireless communication in accordance with aspects of the present disclosure. In one aspect, method 1400 may be performed by a target UE (e.g., any of the UEs described herein). As a specific example, the target UE may correspond to UE 1104 or UE 1204.

[0145] At 1410, the target UE sends a request to perform a positioning procedure (e.g., RTT) to the at least one assisting UE (e.g., any of the UEs described herein) over a sidelink between the at least one assisting UE and the target UE. As a specific example, the at least one assisting UE may correspond to UE 1102, UE 1106, UE 1202, or UE 1206. In one aspect, both the target UE and the at least one assisting UE are outside network coverage (i.e., do not have cellular / network coverage, as in, for example, Figure 8 mode 2). In one aspect, operation 1410 may be performed by transceiver 404, processing system 410, memory 414, and / or sidelink manager 470, and any or all of these components may be considered as means for performing this operation.

[0146] At 1420, the target UE determines a set of time and / or frequency resources on which to send one or more positioning reference signals from the at least one assisting UE for the positioning procedure, at least based on the request. In one aspect, operation 1420 may be performed by transceiver 404, processing system 410, memory 414, and / or sidelink manager 470, and any or all of these components may be considered as means for performing this operation.

[0147] At 1430, the target UE sends the one or more positioning reference signals to the at least one assisting UE via the set of time and / or frequency resources. In one aspect, operation 1430 may be performed by transceiver 404, processing system 410, memory 414, and / or sidelink manager 470, and any or all of these components may be considered as means for performing this operation.

[0148] As will be appreciated, a technical advantage of methods 1300 and 1400 is to coordinate positioning reference signals transmitted over the sidelink and reduce or even eliminate collisions between such positioning reference signals.

[0149] As can be seen from the above detailed description, different features are combined in the examples. This disclosure should not be construed as the example clauses having more features than those expressly recited in each clause. Instead, aspects of the present disclosure may include fewer than all of the features of the individual example clauses disclosed. Accordingly, the following clauses are hereby considered incorporated in the description, where each clause may itself be considered a separate example. Although each dependent clause may refer in the clause to a particular combination with one of the other clauses, the aspects of the dependent clause are not limited to that particular combination. It should be understood that other example clauses may also include combinations of aspects of the dependent clause with the subject matter of any other dependent or independent clause, or any feature with other dependent and independent clauses. Aspects of the present disclosure expressly include these combinations, unless it is expressly stated or can be readily inferred that a particular combination is not intended (e.g., contradictory aspects such as defining an element as both an insulator and a conductor). Additionally, even if a clause is not directly dependent on an independent clause, it may be intended that aspects of the clause be included in any other independent clause.

[0150] Example implementations are described in the following numbered clauses:

[0151] Clause 1. A method for wireless communication to be performed at an auxiliary user equipment (UE), comprising: receiving, on a sidelink between the auxiliary UE and a target UE, a request to perform a positioning procedure from the target UE; determining a set of time and / or frequency resources on which to transmit one or more positioning reference signals for the positioning procedure; transmitting, on the sidelink, an indication of the set of time and / or frequency resources to the target UE; and transmitting one or more positioning reference signals on the set of time and / or frequency resources.

[0152] Clause 2. The method according to Clause 1, wherein the auxiliary UE determines the set of time and / or frequency resources based on a deterministic function of one or more parameters.

[0153] Clause 3. The method according to Clause 2, wherein the one or more parameters are derived in relation to the time and / or frequency resources on which the indication of the set of time and / or frequency resources to the target UE is transmitted.

[0154] Clause 4. The method according to Clause 3, wherein the indication of the set of time and / or frequency resources is transmitted to the target UE in a first sidelink control information (SCI-1) message and / or a second sidelink control information (SCI-2) message.

[0155] Clause 5. The method according to Clause 2, wherein the one or more parameters are derived in relation to the time and / or frequency resources on which the request to perform the positioning procedure is received.

[0156] Clause 6. The method according to Clause 5, wherein the request to execute the positioning procedure is received on a physical sidelink control channel (PSCCH) and / or a physical sidelink shared channel (PSSCH) of the sidelink.

[0157] Clause 7. The method according to any one of Clauses 2 to 6, wherein one or more parameters are used to determine a time domain resource in a set of time and / or frequency resources.

[0158] Clause 8. The method according to Clause 7, wherein one of the one or more parameters includes a subchannel of the PSCCH or PSSCH on which the request to execute the positioning procedure is received.

[0159] Clause 9. The method according to any one of Clauses 7 to 8, wherein one of the one or more parameters includes a source identifier of the target UE.

[0160] Clause 10. The method according to any one of Clauses 7 to 9, wherein one of the one or more parameters includes a destination identifier of the PSCCH on which the request to execute the positioning procedure is received.

[0161] Clause 11. The method according to Clause 10, wherein the destination identifier is associated with unicast, multicast or broadcast.

[0162] Clause 12. The method according to any one of Clauses 7 to 11, wherein one of the one or more parameters includes a pseudo-random variable or a scrambling seed.

[0163] Clause 13. The method according to Clause 12, wherein the pseudo-random variable or the scrambling seed is configured by a higher layer of the assisting UE.

[0164] Clause 14. The method according to any one of Clauses 7 to 13, wherein the selection of one of the one or more parameters is configured by a higher layer of the assisting UE.

[0165] Clause 15. The method according to any one of Clauses 1 to 14, wherein the request to execute the positioning procedure includes one or more frequency domain allocation fields dedicated to signaling a frequency domain resource of a set of time and / or frequency resources.

[0166] Clause 16. The method according to Clause 15, wherein the request to execute the positioning procedure is received on the sidelink of SCI-2.

[0167] Clause 17. The method according to any one of Clauses 1 to 16, wherein the frequency domain allocation field in the request to execute the positioning procedure is only used to schedule a frequency domain resource of a set of time and / or frequency resources for one or more positioning reference signals.

[0168] Clause 18. A method according to any one of Clauses 1 to 16, wherein an additional frequency domain allocation field in a request to execute a positioning procedure is used to schedule frequency domain resources for a set of time and / or frequency resources for one or more positioning reference signals.

[0169] Clause 19. A method according to any one of Clauses 1 to 18, wherein the positioning procedure includes a round-trip time (RTT) positioning procedure.

[0170] Clause 20. An apparatus, comprising a memory and at least one processor communicatively coupled to the memory, the memory and the at least one processor being configured to execute a method according to any one of Clauses 1 to 19.

[0171] Clause 21. An apparatus, comprising components for executing a method according to any one of Clauses 1 to 19.

[0172] Clause 22. A non-transitory computer-readable medium storing computer-executable instructions, the computer-executable instructions including at least one instruction for causing a computer or a processor to execute a method according to any one of Clauses 1 to 19.

[0173] Additional implementation manner examples are described in the following numbered clauses:

[0174] Clause 1. A method for wireless communication to be performed at an assisting user equipment (UE), comprising: receiving, on a sidelink between the assisting UE and a target UE, a request to execute a positioning procedure from the target UE, wherein both the assisting UE and the target UE are outside network coverage; determining, at least based on the request, a set of time and / or frequency resources on which to transmit one or more positioning reference signals for the positioning procedure; and transmitting the one or more positioning reference signals to the target UE via the set of time and / or frequency resources.

[0175] Clause 2. The method according to Clause 1, wherein the assisting UE determines the set of time and / or frequency resources based on a deterministic function of one or more parameters.

[0176] Clause 3. The method according to Clause 2, further comprising: transmitting, via the sidelink, an indication of the set of time and / or frequency resources to the target UE.

[0177] Clause 4. The method according to Clause 3, further comprising: deriving one or more parameters related to the time and / or frequency resources on which the indication of the set of time and / or frequency resources is transmitted to the target UE.

[0178] Clause 5. The method according to Clause 4 further includes: sending an indication of a set of time and / or frequency resources to the target UE in the first sidelink control information (SCI-1) message and / or the second sidelink control information (SCI-2) message.

[0179] Clause 6. The method according to any one of Clauses 2 to 5 further includes: deriving one or more parameters related to the time and / or frequency resources on which the request to execute the positioning procedure is received.

[0180] Clause 7. The method according to any one of Clauses 2 to 6 further includes: determining the time domain resources of a set of time and / or frequency resources based on the one or more parameters.

[0181] Clause 8. The method according to any one of Clauses 2 to 7, wherein one of the one or more parameters includes the subchannel of the PSCCH or PSSCH on which the request to execute the positioning procedure is received.

[0182] Clause 9. The method according to any one of Clauses 2 to 8, wherein one of the one or more parameters includes the source identifier of the target UE.

[0183] Clause 10. The method according to any one of Clauses 2 to 9, wherein one of the one or more parameters includes the destination identifier of the PSCCH on which the request to execute the positioning procedure is received.

[0184] Clause 11. The method according to Clause 10, wherein the destination identifier is associated with unicast, multicast, or broadcast.

[0185] Clause 12. The method according to any one of Clauses 2 to 11, wherein one of the one or more parameters includes a pseudo-random variable or a scrambling seed.

[0186] Clause 13. The method according to Clause 12, wherein the pseudo-random variable or the scrambling seed is configured by a higher layer of the assisting UE.

[0187] Clause 14. The method according to any one of Clauses 2 to 13, wherein the selection of one of the one or more parameters is configured by a higher layer of the assisting UE.

[0188] Clause 15. The method according to any one of Clauses 1 to 14, wherein the request to execute the positioning procedure includes one or more frequency domain allocation fields of the frequency domain resources dedicated to signaling the set of time and / or frequency resources.

[0189] Clause 16. The method according to Clause 15, wherein the request to execute the positioning procedure is received via the sidelink in SCI-2.

[0190] Clause 17. The method according to any one of Clauses 1 to 16, wherein the frequency-domain allocation field of the sidelink control information (SCI) channel associated with the request to execute the positioning procedure is only used to schedule the frequency-domain resources of a set of time and / or frequency resources for one or more positioning reference signals.

[0191] Clause 18. The method according to any one of Clauses 1 to 17, wherein: a first set of frequency-domain allocation fields of the SCI channel associated with the request to execute the positioning procedure is used to schedule data, and a second set of frequency-domain allocation fields of the SCI channel associated with the request to execute the positioning procedure is used to schedule the frequency-domain resources of a set of time and / or frequency resources for one or more positioning reference signals.

[0192] Clause 19. The method according to Clause 18, wherein the second set of frequency-domain allocation fields provides scheduling for one or more positioning reference signals in a manner different from that for scheduling data by the first set of frequency-domain allocation fields.

[0193] Clause 20. The method according to any one of Clauses 1 to 19, wherein the request to execute the positioning procedure is received on the physical sidelink control channel (PSCCH) and / or physical sidelink shared channel (PSSCH) of the sidelink.

[0194] Clause 21. The method according to any one of Clauses 1 to 20, wherein the positioning procedure includes a round-trip time (RTT) positioning procedure.

[0195] Clause 22. A method for wireless communication to be performed at a target user equipment (UE), including: sending, on a sidelink between at least one assisting UE and the target UE, a request to execute a positioning procedure to the at least one assisting UE, wherein both the target UE and the at least one assisting UE are outside network coverage; determining, at least based on the request, a set of time and / or frequency resources on which one or more positioning reference signals from the at least one assisting UE for the positioning procedure are to be sent; and sending the one or more positioning reference signals to the at least one assisting UE via the set of time and / or frequency resources.

[0196] Clause 23. The method according to Clause 22, wherein the target UE determines the set of time and / or frequency resources based on a deterministic function of one or more parameters.

[0197] Clause 24. The method according to Clause 23, further including: sending an indication of the set of time and / or frequency resources to the at least one assisting UE via the sidelink.

[0198] Clause 25. The method according to Clause 24 further comprises: deriving one or more parameters related to the time and / or frequency resources on which an indication of a set of time and / or frequency resources is sent to at least one secondary UE.

[0199] Clause 26. The method according to Clause 25 further comprises: sending an indication of a set of time and / or frequency resources to at least one secondary UE in a first sidelink control information (SCI-1) message and / or a second sidelink control information (SCI-2) message.

[0200] Clause 27. The method according to any one of Clauses 23 to 26 further comprises: deriving one or more parameters related to the time and / or frequency resources on which a request to execute a positioning procedure is sent.

[0201] Clause 28. The method according to any one of Clauses 23 to 27 further comprises: determining a time domain resource of a set of time and / or frequency resources based on the one or more parameters.

[0202] Clause 29. The method according to any one of Clauses 23 to 28, wherein one of the one or more parameters comprises a subchannel of a PSCCH or a PSSCH on which a request to execute a positioning procedure is sent.

[0203] Clause 30. The method according to any one of Clauses 23 to 29, wherein one of the one or more parameters comprises a source identifier of a target UE.

[0204] Clause 31. The method according to any one of Clauses 23 to 30, wherein one of the one or more parameters comprises a destination identifier of a PSCCH on which a request to execute a positioning procedure is sent.

[0205] Clause 32. The method according to Clause 31, wherein the destination identifier is associated with unicast, multicast or broadcast.

[0206] Clause 33. The method according to any one of Clauses 23 to 32, wherein one of the one or more parameters comprises a pseudo-random variable or a scrambling seed.

[0207] Clause 34. The method according to Clause 33, wherein the pseudo-random variable or the scrambling seed is configured by a higher layer of the target UE.

[0208] Clause 35. The method according to any one of Clauses 23 to 34, wherein the selection of one of the one or more parameters is configured by a higher layer of the target UE.

[0209] Clause 36. A method according to any one of Clauses 22 to 35, wherein the request to execute the positioning procedure includes one or more frequency-domain allocation fields of frequency-domain resources dedicated to a set of signaling notification times and / or frequency resources.

[0210] Clause 37. A method according to Clause 36, wherein the request to execute the positioning procedure is sent via a sidelink in SCI-2.

[0211] Clause 38. A method according to any one of Clauses 22 to 37, wherein the frequency-domain allocation field of the sidelink control information (SCI) channel associated with the request to execute the positioning procedure is only used to schedule the frequency-domain resources of a set of time and / or frequency resources for one or more positioning reference signals.

[0212] Clause 39. A method according to any one of Clauses 22 to 38, wherein: a first set of frequency-domain allocation fields of the SCI channel associated with the request to execute the positioning procedure is used to schedule data, and a second set of frequency-domain allocation fields of the SCI channel associated with the request to execute the positioning procedure is used to schedule the frequency-domain resources of a set of time and / or frequency resources for one or more positioning reference signals.

[0213] Clause 40. A method according to Clause 39, wherein the second set of frequency-domain allocation fields provides scheduling for one or more positioning reference signals in a different manner than the data scheduled by the first set of frequency-domain allocation fields.

[0214] Clause 41. A method according to any one of Clauses 22 to 40, further comprising: sending a request to execute the positioning procedure on a physical sidelink control channel (PSCCH) and / or a physical sidelink shared channel (PSSCH) of the sidelink.

[0215] Clause 42. A method according to any one of Clauses 22 to 41, wherein the positioning procedure includes a round-trip time (RTT) positioning procedure.

[0216] Clause 43. An apparatus comprising a memory and at least one processor communicatively coupled to the memory, the memory and the at least one processor being configured to execute a method according to any one of Clauses 1 to 42.

[0217] Clause 44. An apparatus comprising components for executing a method according to any one of Clauses 1 to 42.

[0218] Clause 45. A non-transitory computer-readable medium storing computer-executable instructions, the computer-executable instructions including at least one instruction for causing a computer or a processor to execute a method according to any one of Clauses 1 to 42.

[0219] Those skilled in the art will understand that any of a variety of different techniques and processes can be used to represent information and signals. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof.

[0220] In addition, those skilled in the art will understand that the various illustrative logical blocks, modules, circuits, and algorithmic steps described in connection with the aspects disclosed herein can be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability of hardware and software, the various illustrative components, blocks, modules, circuits, and steps have been described generally in terms of their functionality above. Whether this functionality is implemented as hardware or software depends upon the particular application and the design constraints imposed on the overall system. The skilled person may implement the described functionality in different ways for each particular application, but such implementation decisions should not be construed as causing a departure from the scope of the present disclosure.

[0221] The various illustrative logical blocks, modules, and circuits described in connection with the aspects disclosed herein can be implemented or executed with a general-purpose processor, a digital signal processor (DSP), an ASIC, an FPGA, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0222] The methods, sequences, and / or algorithms described in connection with the aspects disclosed herein can be embodied directly in hardware, in a software module executed by a processor, or in a combination of both. The software module may reside in random access memory (RAM), flash memory, read-only memory (ROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An example storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal (e.g., a UE). In the alternative, the processor and the storage medium may reside as discrete components in the user terminal.

[0223] In one or more example aspects, the described functionality may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functionality may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. The storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0224] Although the foregoing disclosure shows illustrative aspects of the present disclosure, it should be noted that various changes and modifications may be made herein without departing from the scope of the present disclosure as defined by the appended claims. The functions, steps, and / or acts of the method claims according to the aspects of the disclosure described herein need not be performed in any particular order. Further, although elements of the present disclosure may be described or claimed in the singular, the plural is contemplated unless expressly stated to be limited to the singular.

Claims

1. A method for wireless communication to be performed at an assisting user equipment (UE), comprising: receiving, on a sidelink between the assisting UE and a target UE, a request to perform a positioning procedure from the target UE, wherein both the assisting UE and the target UE are outside network coverage; determining, at least based on the request, a set of time and / or frequency resources on which to transmit one or more positioning reference signals for the positioning procedure, wherein: a first set of frequency domain allocation fields of a sidelink control information (SCI) channel associated with the request to perform the positioning procedure is used to schedule data, and a second set of frequency domain allocation fields of the SCI channel associated with the request to perform the positioning procedure is used to schedule frequency domain resources of the set of time and / or frequency resources for the one or more positioning reference signals, wherein the second set of frequency domain allocation fields of the SCI channel is appended to the first set of frequency domain allocation fields of the SCI channel; and transmitting the one or more positioning reference signals to the target UE via the set of time and / or frequency resources.

2. The method according to claim 1, wherein, the assisting UE determines the set of time and / or frequency resources based on a deterministic function of one or more parameters.

3. The method according to claim 2, further comprising: transmitting an indication of the set of time and / or frequency resources to the target UE via the sidelink.

4. The method according to claim 3, further comprising: deriving the one or more parameters related to the time and / or frequency resources on which the indication of the set of time and / or frequency resources is transmitted to the target UE.

5. The method according to claim 4, further comprising: transmitting the indication of the set of time and / or frequency resources to the target UE in a first sidelink control information (SCI-1) message and / or a second sidelink control information (SCI-2) message.

6. The method according to claim 2, further comprising: deriving the one or more parameters related to the time and / or frequency resources on which the request to perform the positioning procedure is received.

7. The method according to claim 2, further comprising: determining a time domain resource of the set of time and / or frequency resources based on the one or more parameters.

8. The method according to claim 2, wherein, one of the one or more parameters includes a subchannel of a physical sidelink control channel (PSCCH) or a physical sidelink shared channel (PSSCH) on which the request to perform the positioning procedure is received.

9. The method according to claim 2, wherein, one of the one or more parameters includes a source identifier of the target UE.

10. The method according to claim 2, wherein, one of the one or more parameters includes a destination identifier of a PSCCH on which the request to perform the positioning procedure is received.

11. The method according to claim 10, wherein, the destination identifier is associated with unicast, multicast, or broadcast.

12. The method according to claim 2, wherein, One of the one or more parameters includes a pseudo-random variable or a scrambling seed.

13. The method according to claim 12, wherein, the pseudo-random variable or the scrambling seed is configured by a higher layer of the auxiliary UE.

14. The method according to claim 2, wherein, the selection of the one of the one or more parameters is configured by a higher layer of the auxiliary UE.

15. The method according to claim 1, wherein, the request to execute the positioning procedure includes one or more frequency-domain allocation fields of frequency-domain resources dedicated to signaling a set of time and / or frequency resources.

16. The method according to claim 15, wherein, the request to execute the positioning procedure is received via the sidelink in SCI-2.

17. The method according to claim 1, wherein, the frequency-domain allocation field of the sidelink control information SCI channel associated with the request to execute the positioning procedure is only used to schedule the frequency-domain resources of the set of time and / or frequency resources for the one or more positioning reference signals.

18. The method according to claim 1, wherein, the second set of frequency-domain allocation fields provides scheduling for the one or more positioning reference signals in a different manner than the scheduling of the data by the first set of frequency-domain allocation fields.

19. The method according to claim 1, wherein, the request to execute the positioning procedure is received on the physical sidelink control channel PSCCH and / or the physical sidelink shared channel PSSCH of the sidelink.

20. The method according to claim 1, wherein, the positioning procedure includes a round-trip time RTT positioning procedure.

21. A method for wireless communication to be performed at a target user equipment UE, comprising: sending, on a sidelink between at least one auxiliary UE and the target UE, a request to execute a positioning procedure to the at least one auxiliary UE, wherein both the target UE and the at least one auxiliary UE are outside network coverage; determining, at least based on the request, a set of time and / or frequency resources on which to send one or more positioning reference signals for the positioning procedure from the at least one auxiliary UE, wherein: a first set of frequency-domain allocation fields of a sidelink control information SCI channel associated with the request to execute the positioning procedure is used to schedule data, and a second set of frequency-domain allocation fields of the SCI channel associated with the request to execute the positioning procedure is used to schedule the frequency-domain resources of the set of time and / or frequency resources for the one or more positioning reference signals, wherein the second set of frequency-domain allocation fields of the SCI channel is appended to the first set of frequency-domain allocation fields of the SCI channel; and sending the one or more positioning reference signals to the at least one auxiliary UE via the set of time and / or frequency resources.

22. The method according to claim 21, wherein, the target UE determines the set of time and / or frequency resources based on a deterministic function of one or more parameters.

23. The method according to claim 22, further comprising: sending an indication of the set of the time and / or frequency resources to the at least one assisting UE via the sidelink.

24. The method according to claim 23, further comprising: deriving the one or more parameters related to the time and / or frequency resources on which the indication of the set of the time and / or frequency resources is sent to the at least one assisting UE.

25. The method according to claim 24, further comprising: sending the indication of the set of the time and / or frequency resources to the at least one assisting UE in a first sidelink control information SCI-1 message and / or a second sidelink control information SCI-2 message.

26. The method according to claim 22, further comprising: deriving the one or more parameters related to the time and / or frequency resources on which the request for performing the positioning procedure is sent.

27. The method according to claim 22, further comprising: determining the time domain resources of the set of the time and / or frequency resources based on the one or more parameters.

28. The method according to claim 22, wherein, one of the one or more parameters includes a subchannel of a PSCCH or a PSSCH on which the request for performing the positioning procedure is sent.

29. The method according to claim 22, wherein, one of the one or more parameters includes a source identifier of the target UE.

30. The method according to claim 22, wherein, one of the one or more parameters includes a destination identifier of a PSCCH on which the request for performing the positioning procedure is sent.

31. The method according to claim 30, wherein, the destination identifier is associated with unicast, multicast or broadcast.

32. The method according to claim 22, wherein, one of the one or more parameters includes a pseudo-random variable or a scrambling seed.

33. The method according to claim 32, wherein, the pseudo-random variable or the scrambling seed is configured by a higher layer of the target UE.

34. The method according to claim 22, wherein, the selection of the one of the one or more parameters is configured by a higher layer of the target UE.

35. The method according to claim 21, wherein, the request for performing the positioning procedure includes one or more frequency domain allocation fields dedicated to signaling the frequency domain resources of the set of the time and / or frequency resources.

36. The method according to claim 35, wherein, the request for performing the positioning procedure is sent via the sidelink in SCI-2.

37. The method according to claim 21, wherein, a frequency domain allocation field of a sidelink control information SCI channel associated with the request for performing the positioning procedure is only used for scheduling the frequency domain resources of the set of the time and / or frequency resources for the one or more positioning reference signals.

38. The method according to claim 21, wherein, The set of second frequency domain allocation fields provides scheduling for the one or more positioning reference signals in a manner different from that in which the data is scheduled by the set of first frequency domain allocation fields.

39. The method according to claim 21, further comprising: sending, on a physical sidelink control channel (PSCCH) and / or a physical sidelink shared channel (PSSCH) of the sidelink, the request for performing the positioning procedure.

40. The method according to claim 21, wherein, the positioning procedure includes a round-trip time (RTT) positioning procedure.

41. An assisting user equipment (UE), comprising: a memory; at least one transceiver; and at least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor being configured to: receive, on a sidelink between the assisting UE and a target UE, a request for performing a positioning procedure from the target UE, wherein both the assisting UE and the target UE are outside network coverage; determine, at least based on the request, a set of time and / or frequency resources on which to transmit one or more positioning reference signals for the positioning procedure, wherein: a first set of frequency domain allocation fields of a sidelink control information (SCI) channel associated with the request for performing the positioning procedure is used for scheduling data, and a second set of frequency domain allocation fields of the SCI channel associated with the request for performing the positioning procedure is used for scheduling frequency domain resources of the set of time and / or frequency resources for the one or more positioning reference signals, wherein the second set of frequency domain allocation fields of the SCI channel is appended to the first set of frequency domain allocation fields of the SCI channel; and cause the at least one transceiver to transmit the one or more positioning reference signals to the target UE via the set of time and / or frequency resources.

42. The assisting UE according to claim 41, wherein, the at least one processor determines the set of time and / or frequency resources based on a deterministic function of one or more parameters.

43. The assisting UE according to claim 42, wherein, the at least one processor is further configured to: cause the at least one transceiver to transmit an indication of the set of time and / or frequency resources to the target UE via the sidelink.

44. The assisting UE according to claim 43, wherein, the at least one processor is further configured to: derive the one or more parameters related to the time and / or frequency resources on which the indication of the set of time and / or frequency resources is transmitted to the target UE.

45. The assisting UE according to claim 44, wherein, the at least one processor is further configured to: cause the at least one transceiver to transmit the indication of the set of time and / or frequency resources to the target UE in a first sidelink control information (SCI-1) message and / or a second sidelink control information (SCI-2) message.

46. The assisting UE according to claim 42, wherein, the at least one processor is further configured to: Derive one or more parameters related to the time and / or frequency resources on which the request to execute the positioning procedure was received.

47. The assisting UE according to claim 42, wherein, the at least one processor is further configured to: Determine the time domain resources of the set of time and / or frequency resources based on the one or more parameters.

48. The assisting UE according to claim 42, wherein, one of the one or more parameters includes the sub-channel of the PSCCH or PSSCH on which the request to execute the positioning procedure was received.

49. The assisting UE according to claim 42, wherein, one of the one or more parameters includes the source identifier of the target UE.

50. The assisting UE according to claim 42, wherein, one of the one or more parameters includes the destination identifier of the PSCCH on which the request to execute the positioning procedure was received.

51. The assisting UE according to claim 50, wherein, the destination identifier is associated with unicast, multicast or broadcast.

52. The assisting UE according to claim 42, wherein, one of the one or more parameters includes a pseudo-random variable or a scrambling seed.

53. The assisting UE according to claim 52, wherein, the pseudo-random variable or the scrambling seed is configured by a higher layer of the assisting UE.

54. The assisting UE according to claim 42, wherein, the selection of the one of the one or more parameters is configured by a higher layer of the assisting UE.

55. The assisting UE according to claim 41, wherein, the request to execute the positioning procedure includes one or more frequency domain allocation fields dedicated to signaling the frequency domain resources of the set of time and / or frequency resources.

56. The assisting UE according to claim 55, wherein, the request to execute the positioning procedure is received via the sidelink in SCI-2.

57. The assisting UE according to claim 41, wherein, the frequency domain allocation field of the sidelink control information SCI channel associated with the request to execute the positioning procedure is only used to schedule the frequency domain resources of the set of time and / or frequency resources for the one or more positioning reference signals.

58. The assisting UE according to claim 41, wherein, the second set of frequency domain allocation fields provides scheduling for the one or more positioning reference signals in a different manner than the scheduling of the data by the first set of frequency domain allocation fields.

59. The assisting UE according to claim 41, wherein, the request to execute the positioning procedure is received on the physical sidelink control channel PSCCH and / or physical sidelink shared channel PSSCH of the sidelink.

60. The assisting UE according to claim 41, wherein, the positioning procedure includes a round-trip time RTT positioning procedure.

61. A target user equipment UE, comprising: a memory; at least one transceiver; and At least one processor, communicatively coupled to the memory and the at least one transceiver, the at least one processor being configured to: Cause the at least one transceiver to send, on a sidelink between at least one assisting UE and a target UE, a request to execute a positioning procedure to the at least one assisting UE, wherein both the target UE and the at least one assisting UE are outside network coverage; Determine, at least based on the request, a set of time and / or frequency resources on which one or more positioning reference signals from the at least one assisting UE for the positioning procedure are to be sent, wherein: A first set of frequency domain allocation fields of a sidelink control information (SCI) channel associated with the request to execute the positioning procedure is used to schedule data, and A second set of frequency domain allocation fields of the SCI channel associated with the request to execute the positioning procedure is used to schedule frequency domain resources for the set of time and / or frequency resources for the one or more positioning reference signals, wherein the second set of frequency domain allocation fields of the SCI channel is appended to the first set of frequency domain allocation fields of the SCI channel; and Cause the at least one transceiver to send the one or more positioning reference signals to the at least one assisting UE via the set of time and / or frequency resources.

62. The target UE according to claim 61, wherein, The at least one processor determines the set of time and / or frequency resources based on a deterministic function of one or more parameters.

63. The target UE according to claim 62, wherein, The at least one processor is further configured to: Cause the at least one transceiver to send an indication of the set of time and / or frequency resources to the at least one assisting UE via the sidelink.

64. The target UE according to claim 63, wherein, The at least one processor is further configured to: Derive the one or more parameters related to the time and / or frequency resources on which the indication of the set of time and / or frequency resources is sent to the at least one assisting UE.

65. The target UE according to claim 64, wherein, The at least one processor is further configured to: Cause the at least one transceiver to send the indication of the set of time and / or frequency resources to the at least one assisting UE in a first sidelink control information (SCI-1) message and / or a second sidelink control information (SCI-2) message.

66. The target UE according to claim 62, wherein, The at least one processor is further configured to: Derive the one or more parameters related to the time and / or frequency resources on which the request to execute the positioning procedure is sent.

67. The target UE according to claim 62, wherein, The at least one processor is further configured to: Determine the time domain resources of the set of time and / or frequency resources based on the one or more parameters.

68. The target UE according to claim 62, wherein, One of the one or more parameters includes a subchannel of a PSCCH or PSSCH on which the request to execute the positioning procedure is sent.

69. The target UE according to claim 62, wherein, one of the one or more parameters includes a source identifier of the target UE.

70. The target UE according to claim 62, wherein, one of the one or more parameters includes a destination identifier of a PSCCH on which the request to execute the positioning procedure is sent.

71. The target UE according to claim 70, wherein, the destination identifier is associated with unicast, multicast, or broadcast.

72. The target UE according to claim 62, wherein, one of the one or more parameters includes a pseudo-random variable or a scrambling seed.

73. The target UE according to claim 72, wherein, the pseudo-random variable or the scrambling seed is configured by a higher layer of the target UE.

74. The target UE according to claim 62, wherein, the selection of the one of the one or more parameters is configured by a higher layer of the target UE.

75. The target UE according to claim 61, wherein, the request to execute the positioning procedure includes one or more frequency-domain allocation fields of frequency-domain resources dedicated to signaling a set of time and / or frequency resources.

76. The target UE according to claim 75, wherein, the request to execute the positioning procedure is sent via the sidelink in SCI-2.

77. The target UE according to claim 61, wherein, the frequency-domain allocation field of the sidelink control information SCI channel associated with the request to execute the positioning procedure is only used to schedule the frequency-domain resources of the set of time and / or frequency resources for the one or more positioning reference signals.

78. The target UE according to claim 61, wherein, the second set of frequency-domain allocation fields provides scheduling for the one or more positioning reference signals in a manner different from that of scheduling the data by the first set of frequency-domain allocation fields.

79. The target UE according to claim 61, wherein, the request to execute the positioning procedure is received on a physical sidelink control channel PSCCH and / or a physical sidelink shared channel PSSCH of the sidelink.

80. The target UE according to claim 61, wherein, the positioning procedure includes a round-trip time (RTT) positioning procedure.

81. A user equipment, comprising components for performing the method according to any one of claims 1-40.

82. A non-transitory computer-readable medium storing a set of instructions, the set of instructions including one or more instructions that, when executed by one or more processors of a user equipment, cause the user equipment to perform the method according to any one of claims 1-40.

83. A computer program product including computer instructions that, when executed by a processor, cause the processor to perform the method according to any one of claims 1-40.

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