Satellite - to - Satellite Link - Assisted UE Positioning in Non - Terrestrial Networks

Abstract

Aspects presented herein can improve the accuracy and performance of a TDOA-based UE positioning scheme associated with NTN. In one aspect, a UE receives a first PRS from a first satellite at a first reception time. The UE receives a second PRS from a second satellite at a second reception time and an indication of a transmit-receive time difference, which is a difference between a time when the second satellite transmits the second PRS to the UE and a time when the second satellite receives an RS from the first satellite. The UE calculates an RSTD between the first PRS and the second PRS based at least in part on the first reception time of the first PRS, the second reception time of the second PRS, and the transmit-receive time difference.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims the benefit of U.S. Patent Application No. 17 / 643,069, entitled "INTER - SATELLITE LINK AIDED UEPOSITIONING IN NON - TERRESTRIAL NETWORK", filed on Dec. 7, 2021, which is hereby incorporated by reference in its entirety. Technical Field

[0003] The present disclosure generally relates to communication systems, and more particularly to wireless communication regarding positioning. Background Art

[0004] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasting. A typical wireless communication system may employ multiple access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple access technologies include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single - Carrier Frequency Division Multiple Access (SC - FDMA) systems, and Time Division - Synchronous Code Division Multiple Access (TD - SCDMA) systems.

[0005] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate at the urban, national, regional, and even global levels. One example telecommunication standard is 5G New Radio (NR). 5G NR is part of the continuous evolution of mobile broadband promulgated by the Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., related to the Internet of Things (IoT)), and other requirements. 5G NR includes services associated with Enhanced Mobile Broadband (eMBB), Massive Machine - Type Communication (mMTC), and Ultra - Reliable Low - Latency Communication (URLLC). Some aspects of 5G NR may be based on the 4G Long - Term Evolution (LTE) standard. Further improvements to 5G NR technology are needed. In addition, these improvements may also be applicable to other multiple access technologies and telecommunication standards that employ these technologies.

[0006] Some communication systems may also support multiple cellular network-based positioning techniques, where the geographical location of a wireless device can be determined based on measurements of radio signals exchanged between the wireless device and other wireless devices. For example, the distance between the wireless device and a transmit receive point (TRP) can be estimated based on the time it takes for a reference signal (e.g., positioning reference signal (PRS)) transmitted from the TRP to reach the wireless device. Other examples of cellular network-based positioning techniques may include downlink-based, uplink-based, and / or downlink and uplink-based positioning methods. SUMMARY

[0007] A simplified overview of one or more aspects is presented below to provide a basic understanding of these aspects. This overview is not an extensive overview of all expected aspects and is neither intended to identify key or important elements of all aspects nor to describe the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description presented later.

[0008] In one aspect of the present disclosure, a method, computer-readable medium, and apparatus are provided. The apparatus receives a first positioning reference signal (PRS) from a first satellite at a first reception time (T _Rx_sat_1 ). The apparatus receives a second PRS and an indication of a transmit receive time difference (T _Rx_sat_2 ) from a second satellite at a second reception time (T sat_2_Tx→Rx ), where the transmit receive time difference (T sat_2_Tx→Rx ) is the difference between the time the second satellite transmits the second PRS to the UE and the time the second satellite receives a reference signal (RS) from the first satellite. The apparatus calculates a reference signal time difference (RSTD) between the first PRS and the second PRS based at least in part on the first reception time (T _Rx_sat_1 ) of the first PRS, the second reception time (T _Rx_sat_2 ) of the second PRS, and the transmit receive time difference (T sat_2_Tx→Rx ).

[0009] In one aspect of the present disclosure, a method, computer-readable medium, and apparatus are provided. The apparatus transmits an RS to a second satellite at a first transmission time. The apparatus transmits a PRS to a UE at a second transmission time. The apparatus transmits an indication of a time gap (T gap,iner-sat_RS_1→PRS_1 ) between the first transmission time and the second transmission time to the UE.

[0010] In one aspect of the present disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus receives a RS from a first satellite at a first reception time. The apparatus transmits a PRS to a UE at a first transmission time. The apparatus transmits an indication of a transmit-receive time difference (T sat_2_Tx→Rx ) between the first reception time and the first transmission time to the UE.

[0011] In one aspect of the present disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus receives a first PRS from a first satellite at a first reception time (T _Rx_sat_1 ). The apparatus receives a second PRS from a second satellite at a second reception time (T _Rx_sat_2 ), where the second PRS is transmitted from the first satellite and relayed to the UE via the second satellite. The apparatus calculates the RSTD between the first PRS and the second PRS based at least in part on the first reception time (T _Rx_sat_1 ) of the first PRS, the second reception time (T _Rx_sat_2 ) of the second PRS, and a group delay (T GD_BP ) associated with the second satellite.

[0012] In one aspect of the present disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus transmits a first PRS to a UE at a first transmission time. The apparatus transmits a second PRS to a second satellite at a second transmission time, where the second PRS is relayed to the UE via the second satellite. The apparatus transmits an indication of a time gap (T gap,PRS_2→PRS_1 ) between the first transmission time and the second transmission time to the UE.

[0013] In one aspect of the present disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus receives a PRS from a first satellite at a first reception time. The apparatus relays the PRS to the UE at a first relay time.

[0014] To achieve the foregoing and related purposes, one or more aspects include the features described comprehensively below and particularly pointed out in the claims. The following description and the drawings set forth in detail some exemplary features of one or more aspects. However, these features merely indicate some of the various ways in which the principles of the various aspects may be employed, and this specification is intended to include all such aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a diagram illustrating an example of a wireless communication system and an access network.

[0016] Figure 2A is a diagram illustrating an example of a first frame according to various aspects of the present disclosure.

[0017] Figure 2B It is a diagram showing an example of DL channels within a subframe according to various aspects of the present disclosure.

[0018] Figure 2C It is a diagram showing an example of a second frame according to various aspects of the present disclosure.

[0019] Figure 2D It is a diagram showing an example of UL channels within a subframe according to various aspects of the present disclosure.

[0020] Figure 3 It is a diagram showing an example of a base station and a user equipment (UE) in an access network.

[0021] Figure 4 It is a diagram showing an example of UE positioning based on reference signal measurements according to various aspects of the present disclosure.

[0022] Figure 5A It is a diagram showing an example of downlink positioning reference signals (DL-PRS) transmitted from multiple transmit receive points (TRP) according to various aspects of the present disclosure.

[0023] Figure 5B It is a diagram showing an example of uplink sounding reference signals (UL-SRS) transmitted from a UE according to various aspects of the present disclosure.

[0024] Figure 6 It is a diagram showing an example of estimating the positioning of a UE based on multi-round-trip time (RTT) measurements from multiple TRP according to various aspects of the present disclosure.

[0025] Figure 7 It is a diagram showing an example of UE positioning based on observed time difference of arrival (OTDOA) according to various aspects of the present disclosure.

[0026] Figure 8 It is a communication flow showing an example of a multi-RTT positioning process according to various aspects of the present disclosure.

[0027] Figure 9 It is a diagram showing an example of global positioning system (GPS) positioning according to various aspects of the present disclosure.

[0028] Figure 10 It is a diagram showing an example of real-time kinematic (RTK) positioning according to various aspects of the present disclosure.

[0029] Figure 11A It is a diagram showing an example of the individual difference between different receivers according to various aspects of the present disclosure.

[0030] Figure 11Bis a diagram showing examples of individual differences between different satellites according to various aspects of the present disclosure.

[0031] Figure 12 is a diagram showing examples of dual differences between receivers and between satellites according to various aspects of the present disclosure.

[0032] Figure 13 is a diagram showing an example of a non-terrestrial network (NTN) architecture based on a transparent payload according to various aspects of the present disclosure.

[0033] Figure 14A is a diagram showing an example network including both NTN and TN devices according to various aspects of the present disclosure.

[0034] Figure 14B is a diagram showing an example network including both NTN and TN devices according to various aspects of the present disclosure.

[0035] Figure 15 is a communication flow diagram showing an example of satellite-interlink-assisted TDOA-based UE positioning according to various aspects of the present disclosure.

[0036] Figure 16 is a communication flow diagram showing an example of satellite-interlink-assisted TDOA-based UE positioning using bent pipe operation according to various aspects of the present disclosure.

[0037] Figure 17 is a flowchart of a wireless communication method according to various aspects presented herein.

[0038] Figure 18 is a diagram showing an example of a hardware implementation for an example device according to various aspects presented herein.

[0039] Figure 19 is a flowchart of a wireless communication method according to various aspects presented herein.

[0040] Figure 20 is a diagram showing an example of a hardware implementation for an example device according to various aspects presented herein.

[0041] Figure 21 is a flowchart of a wireless communication method according to various aspects presented herein.

[0042] Figure 22 is a diagram showing an example of a hardware implementation for an example device according to various aspects presented herein.

[0043] Figure 23 is a flowchart of a wireless communication method according to various aspects presented herein.

[0044] Figure 24 is a diagram illustrating an example of a hardware implementation for an example apparatus in accordance with aspects presented herein.

[0045] Figure 25 is a flowchart of a wireless communication method in accordance with aspects presented herein.

[0046] Figure 26 is a diagram illustrating an example of a hardware implementation for an example apparatus in accordance with aspects presented herein. Detailed Description

[0047] The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form to avoid obscuring such concepts.

[0048] Several aspects of a telecommunications system will now be presented with reference to various apparatuses and methods. These apparatuses and methods will be described in detail below and illustrated in the drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as "elements"). These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

[0049] By way of example, an element, or any portion of an element, or any combination of elements may be implemented as a "processing system" that includes one or more processors. Examples of processors include a microprocessor, a microcontroller, a graphics processing unit (GPU), a central processing unit (CPU), an application processor, a digital signal processor (DSP), a reduced instruction set computing (RISC) processor, a system on a chip (SoC), a baseband processor, a field programmable gate array (FPGA), a programmable logic device (PLD), a state machine, gate logic, discrete hardware circuits, and other suitable hardware configured to perform the various functions described throughout this disclosure. Software, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise, is to be broadly construed to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, processes, functions, etc.

[0050] Thus, in one or more example embodiments, the described functionality may be implemented using hardware, software, or any combination thereof. If implemented in software, the functionality may be stored or encoded on a computer-readable medium as one or more instructions or code. Computer-readable media includes computer storage media. Storage media can be any available media that can be accessed by a computer. By way of example and not limitation, such computer-readable media may include random access memory (RAM), read only memory (ROM), electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of these types of computer-readable media, or any other medium capable of storing computer-executable code in the form of instructions or data structures that can be accessed by a computer.

[0051] While aspects and specific implementations are described herein by way of some examples for illustration, those skilled in the art will understand that additional specific implementations and use cases may arise in many different arrangements and scenarios. The innovations described herein can be implemented across many different platform types, devices, systems, shapes, sizes, and packaging arrangements. For example, specific implementations and / or uses may be generated via integrated chip implementations and other non-module component-based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail / purchasing devices, medical devices, artificial intelligence (AI)-enabled devices, etc.). While some examples may or may not specifically be directed to a use case or application, the described innovations can have a variety of applicability. Specific implementations can range from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregated, distributed, or original equipment manufacturer (OEM) devices or systems incorporating one or more aspects of the described innovations. In some practical environments, devices incorporating the described aspects and features may also include additional components and features for implementing and practicing the claimed and described aspects. For example, the transmission and reception of wireless signals necessarily includes multiple components for analog and digital purposes (e.g., hardware components including antennas, RF chains, power amplifiers, modulators, buffers, processors, interleavers, adders / summers, etc.). The innovations described herein are intended to be practiced in a variety of devices, chip-level components, systems, distributed arrangements, aggregated or disaggregated components, end-user devices, etc. of different sizes, shapes, and configurations.

[0052] Figure 1FIG. 100 is an illustration showing an example of a wireless communication system and an access network. The wireless communication system (also referred to as a wireless wide area network (WWAN)) includes a base station 102, a UE 104, an evolved packet core (EPC) 160, and another core network 190 (e.g., a 5G core (5GC)). The base station 102 may include a macro cell (high-power cellular base station) and / or a small cell (low-power cellular base station). The macro cell includes a base station. The small cell includes a femto cell, a pico cell, and a micro cell.

[0053] Aspects presented herein may improve the accuracy and performance of TDOA-based UE positioning schemes associated with NTN. Aspects presented herein provide enhanced TDOA-based UE positioning schemes that may utilize inter-satellite links to mitigate the impact of synchronization errors across different satellites.

[0054] In some aspects, the UE 104 may include an NTN UE positioning processing component 198 configured to receive PRS from different satellites for UE positioning. In one configuration, the NTN UE positioning processing component 198 may be configured to receive a first PRS from a first satellite at a first reception time (T _Rx_sat_1 ). In this configuration, the NTN UE positioning processing component 198 may receive a second PRS from a second satellite at a second reception time (T _Rx_sat_2 ) along with an indication of the transmit-receive time difference (T sat_2_Tx→Rx ), where the transmit-receive time difference (T sat_2_Tx→Rx ) is the difference between the time the second satellite transmits the second PRS to the UE and the time the second satellite receives the RS from the first satellite. In this configuration, the NTN UE positioning processing component 198 may calculate the RSTD between the first PRS and the second PRS based at least in part on the first reception time (T _Rx_sat_1 ) of the first PRS, the second reception time (T _Rx_sat_2 ) of the second PRS, and the transmit-receive time difference (T sat_2_Tx→Rx ).

[0055] In another configuration, the NTN UE positioning processing component 198 may be configured to receive a first PRS from a first satellite at a first reception time (T _Rx_sat_1 ). In this configuration, the NTN UE positioning processing component 198 may receive a second PRS from a second satellite at a second reception time (T _Rx_sat_2 ), where the second PRS is transmitted from the first satellite and relayed to the UE via the second satellite. In this configuration, the NTN UE positioning processing component 198 may calculate the RSTD between the first PRS and the second PRS based at least in part on the first reception time (T _Rx_sat_1 ) of the first PRS, the second reception time (T _Rx_sat_2) and the group delay (T associated with the second satellite GD_BP ) to calculate the RSTD of the first PRS and the second PRS.

[0056] In some aspects, the satellite may include an NTN UE positioning configuration component 199, which is configured to transmit PRS to the UE to assist UE positioning. In one configuration, the NTN UE positioning configuration component 199 may be configured to transmit an RS to the second satellite at a first transmission time. In this configuration, the NTN UE positioning configuration component 199 may transmit a PRS to the UE at a second transmission time. In this configuration, the NTN UE positioning configuration component 199 may transmit an indication of the time gap (T between the first transmission time and the second transmission time to the UE gap,iner-sat_RS_1→PRS_1 ) to the UE.

[0057] In another configuration, the NTN UE positioning configuration component 199 may be configured to receive an RS from the first satellite at a first reception time. In this configuration, the NTN UE positioning configuration component 199 may transmit a PRS to the UE at a first transmission time. In this configuration, the NTN UE positioning configuration component 199 may transmit an indication of the transmit-receive time difference (T between the first reception time and the first transmission time to the UE sat_2_Tx→Rx ) to the UE.

[0058] In another configuration, the NTN UE positioning configuration component 199 may be configured to transmit a first PRS to the UE at a first transmission time. In this configuration, the NTN UE positioning configuration component 199 may transmit a second PRS to the second satellite at a second transmission time, and the second PRS is relayed to the UE via the second satellite. In this configuration, the NTN UE positioning configuration component 199 may transmit an indication of the time gap (T between the first transmission time and the second transmission time to the UE gap,PRS_2→PRS_1 ) to the UE.

[0059] In another configuration, the NTN UE positioning configuration component 199 may be configured to receive a PRS from the first satellite at a first reception time. In this configuration, the NTN UE positioning configuration component 199 may relay the PRS to the UE at a first relay time.

[0060] The base station 102 configured for 4G LTE (collectively referred to as the evolved universal mobile telecommunications system (UMTS) terrestrial radio access network (E-UTRAN)) can interact with the EPC 160 via a first backhaul link 132 (e.g., the S1 interface). The base station 102 configured for 5G NR (collectively referred to as the next-generation RAN (NG-RAN)) can interact with the core network 190 via a second backhaul link 184. In addition to other functions, the base station 102 can perform one or more of the following functions: transmission of 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, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment tracking, radio access network information management (RIM), paging, positioning, and delivery of alarm messages. The base stations 102 can communicate directly or indirectly with each other (e.g., via the EPC 160 or the core network 190) via a third backhaul link 134 (e.g., the X2 interface). The first backhaul link 132, the second backhaul link 184, and the third backhaul link 134 can be wired or wireless.

[0061] In some aspects, the base station 102 or 180 can be referred to as a RAN and can include aggregated components or disaggregated components. As an example of a disaggregated RAN, the base station can include a central unit (CU) 103, one or more distributed units (DU) 105, and / or one or more remote units (RU) 109, as Figure 1As shown. The RAN can be decomposed by splitting between the RU 109 and the aggregated CU / DU. The RAN can be decomposed by splitting between the CU 103, DU 105, and RU 109. The RAN can be decomposed by splitting between the CU 103 and the aggregated DU / RU. The CU 103 and one or more DUs 105 can be connected via the F1 interface. The DU 105 and the RU 109 can be connected via the fronthaul interface. The connection between the CU 103 and the DU 105 can be referred to as the midhaul, and the connection between the DU 105 and the RU 109 can be referred to as the fronthaul. The connection between the CU 103 and the core network can be referred to as the backhaul. The RAN can be based on the functional split between various components of the RAN (e.g., between the CU 103, DU 105, or RU 109). The CU can be configured to perform one or more aspects of the wireless communication protocol (e.g., handle one or more layers of the protocol stack), and the DU can be configured to handle other aspects of the wireless communication protocol (e.g., other layers of the protocol stack). In different embodiments, the split between the layers handled by the CU and the layers handled by the DU can occur at different layers of the protocol stack. As a non-limiting example, the DU 105 can provide a logical node for overseeing at least a portion of the radio link control (RLC) layer, media access control (MAC) layer, and physical (PHY) layer based on the functional split. The RU can provide a logical node configured to oversee at least a portion of the PHY layer and radio frequency (RF) processing. The CU 103 can oversee higher layer functions such as the service data adaptation protocol (SDAP) layer and the packet data convergence protocol (PDCP) layer, for example, above the RLC layer. In other embodiments, the split between the layer functions provided by the CU, DU, or RU can be different.

[0062] The access network can include one or more integrated access and backhaul (IAB) nodes 111 that exchange wireless communications with the UE 104 or other IAB nodes 111 to provide access to and backhaul for the core network. In an IAB network with multiple IAB nodes, the anchor node can be referred to as the IAB donor. The IAB donor can be a base station 102 or 180 that provides access to the core network 190 or EPC 160 and / or control of one or more IAB nodes 111. The IAB donor can include the CU 103 and the DU 105. The IAB node 111 can include the DU 105 and a mobile terminal (MT) 113. The DU 105 of the IAB node 111 can operate as a parent node, and the MT 113 can operate as a child node.

[0063] Base station 102 can communicate wirelessly with UE 104. Each base station in base station 102 can provide communication coverage for a corresponding geographical coverage area 110. There may be overlapping geographical coverage areas 110. For example, small cell 102' may have a coverage area 110' that overlaps with the coverage area 110 of one or more macro base stations 102. A network including both small cells and macro cells may be referred to as a heterogeneous network. The heterogeneous network may also include a home evolved Node B (eNB) (HeNB), which may provide services to a restricted group called a closed subscriber group (CSG). The communication link 120 between base station 102 and UE 104 may include an uplink (UL) (also referred to as a reverse link) transmission from UE 104 to base station 102 and / or a downlink (DL) (also referred to as a forward link) transmission from base station 102 to UE 104. The communication link 120 may use multiple-input multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and / or transmit diversity. The communication link may experience one or more carriers. For each carrier allocated in carrier aggregation with a total of up to Yx MHz (x component carriers) for transmission in each direction, base station 102 / UE 104 may use a spectrum with a bandwidth of up to Y MHz (e.g., 5 MHz, 10 MHz, 15 MHz, 20 MHz, 100 MHz, 400 MHz, etc.). The carriers may or may not be adjacent to each other. The allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL compared to UL). The component carriers may include a primary component carrier and one or more secondary component carriers. The primary component carrier may be referred to as the primary cell (PCell) and the secondary component carriers may be referred to as secondary cells (SCells).

[0064] Some UEs 104 may use device-to-device (D2D) communication links 158 to communicate with each other. The D2D communication link 158 may use DL / UL WWAN spectrum. The D2D communication link 158 may use one or more sidelink channels, such as the physical sidelink broadcast channel (PSBCH), the physical sidelink discovery channel (PSDCH), the physical sidelink shared channel (PSSCH), and the physical sidelink control channel (PSCCH). D2D communication may be through various wireless D2D communication systems, such as, for example, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, LTE, or NR.

[0065] The wireless communication system may also include a Wi-Fi Access Point (AP) 150 that communicates with a Wi-Fi Station (STA) 152 via a communication link 154, e.g., in the 5 GHz unlicensed spectrum, etc. When communicating in the unlicensed spectrum, the STA 152 / AP 150 may perform a Clear Channel Assessment (CCA) before communication to determine if the channel is available.

[0066] The small cell 102' may operate in licensed and / or unlicensed spectrum. When operating in the unlicensed spectrum, the small cell 102' may employ NR and use the same unlicensed spectrum as used by the Wi-Fi AP 150 (e.g., 5 GHz, etc.). The small cell 102' that employs NR in the unlicensed spectrum may improve the coverage of the access network and / or increase the capacity of the access network.

[0067] The electromagnetic spectrum is generally subdivided into various categories, bands, channels, etc. based on frequency / wavelength. In 5G NR, two initial operating bands have been identified as the frequency range names FR1 (410 MHz - 7.125 GHz) and FR2 (24.25 GHz - 52.6 GHz). Although a part of FR1 is greater than 6 GHz, in various documents and articles, FR1 is generally (interchangeably) referred to as the "sub-6 GHz" band. Regarding FR2, a similar naming issue sometimes occurs, which is generally (interchangeably) referred to as the "millimeter wave" band in documents and articles, although it is different from the extremely high frequency (EHF) band (30 GHz - 300 GHz) identified by the International Telecommunication Union (ITU) as the "millimeter wave" band.

[0068] The frequencies between FR1 and FR2 are generally referred to as mid-band frequencies. Recent 5G NR research has identified the operating bands for these mid-band frequencies as the frequency range name FR3 (7.125 GHz - 24.25 GHz). The bands falling within FR3 may inherit the characteristics of FR1 and / or FR2, and thus can effectively extend the features of FR1 and / or FR2 to the mid-band frequencies. In addition, higher frequency bands are currently being explored to extend 5G NR operation beyond 52.6 GHz. For example, three higher operating bands have been identified as the frequency range names FR2-2 (52.6 GHz - 71 GHz), FR4 (52.6 GHz - 114.25 GHz), and FR5 (114.25 GHz - 300 GHz). Each of these higher frequency bands falls within the EHF band.

[0069] In view of the above aspects, unless otherwise specifically stated, it should be understood that if used herein, terms such as "below 6 GHz" can generally represent frequencies that can be less than 6 GHz, can be within FR1, or can include mid-band frequencies. Additionally, unless otherwise clearly stated, it should be understood that if terms such as "millimeter wave" are used herein, they can generally represent frequencies that can include mid-band frequencies, can be within FR2, FR4, FR2-2, and / or FR5, or can be within the EHF band.

[0070] Base station 102 (whether it is small cell 102' or large cell (e.g., macro base station)) can include and / or be referred to as eNB, gNodeB (gNB), or another type of base station. Some base stations (such as gNB 180) can operate in the traditional sub-6 GHz spectrum, in millimeter wave frequencies, and / or in near millimeter wave frequencies to communicate with UE 104. When gNB 180 operates in millimeter wave or near millimeter wave frequencies, gNB 180 can be referred to as a millimeter wave base station. Millimeter wave base station 180 can utilize beamforming 182 with UE 104 to compensate for path loss and short distances. Base station 180 and UE 104 can each include multiple antennas (such as antenna elements, antenna panels, and / or antenna arrays) to facilitate beamforming.

[0071] Base station 180 can transmit beamformed signals to UE 104 in one or more transmission directions 182'. UE 104 can receive beamformed signals from base station 180 in one or more reception directions 182". UE 104 can also transmit beamformed signals to base station 180 in one or more transmission directions. Base station 180 can receive beamformed signals from UE 104 in one or more reception directions. Base station 180 / UE 104 can perform beam training to determine the optimal reception direction and transmission direction for each of base station 180 / UE 104. The transmission direction and reception direction of base station 180 can be the same or different. The transmission and reception directions of UE 104 can be the same or different.

[0072] The EPC 160 may include a Mobility Management Entity (MME) 162, other MMEs 164, a Serving Gateway 166, a Multimedia Broadcast Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170, and a Packet Data Network (PDN) Gateway 172. The MME 162 may communicate with a Home Subscriber Server (HSS) 174. The MME 162 is a control node that processes signaling between the UE 104 and the EPC 160. Generally, the MME 162 provides bearer and connection management. All user Internet Protocol (IP) packets are transmitted through the Serving Gateway 166, which is itself connected to the PDN Gateway 172. The PDN Gateway 172 provides UE IP address allocation and other functions. The PDN Gateway 172 and the BM-SC 170 are connected to IP services 176. The IP services 176 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS streaming service, and / or other IP services. The BM-SC 170 may provide functions for MBMS user service provision and delivery. The BM-SC 170 may serve as an entry point for content provider MBMS transmissions, may be used to authorize and initiate MBMS bearer services in a Public Land Mobile Network (PLMN), and may be used to schedule MBMS transmissions. The MBMS Gateway 168 may be used to distribute MBMS traffic to base stations 102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area for a particular broadcast service, and may be responsible for session management (start / stop) and collecting eMBMS-related charging information.

[0073] The core network 190 may include an Access and Mobility Management Function (AMF) 192, other AMFs 193, a Session Management Function (SMF) 194, and a User Plane Function (UPF) 195. The AMF 192 may communicate with a Unified Data Management (UDM) 196. The AMF 192 is a control node for processing signaling between the UE 104 and the core network 190. Generally, the AMF 192 provides QoS flow and session management. All user Internet Protocol (IP) packets are transmitted through the UPF 195. The UPF 195 provides UE IP address allocation and other functions. The UPF 195 is connected to IP services 197. The IP services 197 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a Packet Switched (PS) stream (PSS) service, and / or other IP services.

[0074] A base station may include and / or be referred to as a gNB, Node B, eNB, access point, base station transceiver, radio base station, radio transceiver, transceiver function, basic service set (BSS), extended service set (ESS), transmission reception point (TRP), or some other suitable term. Base station 102 provides an access point to the EPC 160 or the core network 190 for the UE 104. Examples of the UE 104 include cellular phones, smart phones, session initiation protocol (SIP) phones, laptop computers, personal digital assistants (PDAs), satellite radios, global positioning systems, multimedia devices, video devices, digital audio players (e.g., MP3 players), cameras, game consoles, tablet computers, smart devices, wearable devices, vehicles, electricity meters, gas pumps, large or small kitchen appliances, healthcare devices, implants, sensors / actuators, displays, or any other device with similar functionality. Some of the UEs 104 may be referred to as IoT devices (e.g., parking meters, gas pumps, toasters, vehicles, heart monitors, etc.). The UE 104 may also be referred to as a station, mobile station, subscriber station, mobile unit, subscriber unit, radio unit, remote unit, mobile device, radio device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, cell phone, user agent, mobile client, client, or some other appropriate term. In some scenarios, the term UE may also apply to one or more companion devices, such as in a device constellation. One or more of these devices may access the network jointly and / or individually.

[0075] Figure 2A FIG. 200 is a diagram illustrating an example of a first subframe within a 5G NR frame structure. Figure 2B FIG. 230 is a diagram illustrating an example of a DL channel within a 5G NR subframe. Figure 2C FIG. 250 is a diagram illustrating an example of a second subframe within a 5G NR frame structure. Figure 2D FIG. 280 is a diagram illustrating an example of a UL channel within a 5G NR subframe. The 5G NR frame structure may be frequency division duplex (FDD) (wherein, for a specific set of subcarriers (carrier system bandwidth), the subframes within the set of subcarriers are dedicated to DL or UL), or may be time division duplex (TDD) (wherein, for a specific set of subcarriers (carrier system bandwidth), the subframes within the set of subcarriers are dedicated to both DL and UL). In Figure 2A 、 Figure 2CIn the provided example, the 5G NR frame structure is assumed to be TDD, where subframe 4 is configured with slot format 28 (where most are DL), where D is DL, U is UL, and F is flexibly usable between DL / UL, and subframe 3 is configured with slot format 1 (where all are UL). Although subframes 3 and 4 are shown with slot formats 1 and 28 respectively, any particular subframe can be configured with any of the various available slot formats 0 - 61. Slot formats 0 and 1 are all DL and all UL respectively. The other slot formats 2 - 61 include a mixture of DL, UL, and flexible symbols. The UE is configured with a slot format by the received slot format indicator (SFI) (configured dynamically via downlink control information (DCI) or semi-statically / statically via radio resource control (RRC) signaling). Note that the following description also applies to the 5G NR frame structure that is TDD.

[0076] Figures 2A to 2D The frame structure is shown, and aspects of the present disclosure can be applicable to other wireless communication technologies that may have different frame structures and / or different channels. One frame (10 ms) can be divided into 10 equally sized subframes (1 ms). Each subframe can include one or more slots. A subframe can also include mini-slots, which can include 7, 4, or 2 symbols. Each slot can include 14 or 12 symbols, depending on whether the cyclic prefix (CP) is normal or extended. For normal CP, each slot can include 14 symbols, and for extended CP, each slot can include 12 symbols. The symbols on the DL can be cyclic prefix orthogonal frequency division multiplexing (CP-OFDM) symbols. The symbols on the UL can be CP-OFDM symbols (for high throughput scenarios) or discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbols (also known as single carrier frequency division multiple access (SC-FDMA) symbols) (for power-constrained scenarios; limited to single-stream transmission). The number of slots within a subframe is based on the CP and the parameter set. The parameter set defines the subcarrier spacing (SCS), and effectively defines the symbol length / duration, which is equal to 1 / SCS.

[0077] μ <![CDATA[SCSΔf = 2 μ ·15 [kHz]]]> Cyclic prefix 0 15 Normal 1 30 Normal 2 60 Normal, extended 3 120 Normal 4 240 Normal

[0078] For normal CP (14 symbols / slot), the different parameter sets μ0 to 4 allow 1, 2, 4, 8, and 16 slots per subframe respectively. For extended CP, parameter set 2 allows 4 slots per subframe. Accordingly, for normal CP and parameter set μ, there are 14 symbols / slot and 2 μ slots / subframe. The subcarrier spacing can be equal to 2 μ*15 kHz, where μ is a parameter set from 0 to 4. Thus, the subcarrier spacing for parameter set μ = 0 is 15 kHz, and the subcarrier spacing for parameter set μ = 4 is 240 kHz. The symbol length / duration is inversely related to the subcarrier spacing. Figures 2A to 2D An example of parameter set μ = 2 with a normal CP of 14 symbols per time slot and 4 time slots per subframe is provided. The time slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 μs. Within a frame set, there may be one or more different bandwidth parts (BWPs) that are frequency division multiplexed (see Figure 2B ). Each BWP may have a specific parameter set and CP (normal or extended).

[0079] A resource grid can be used to represent the frame structure. Each time slot includes resource blocks (RBs) (also referred to as physical RBs (PRBs)) that extend over 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

[0080] As Figure 2A shown, some of the REs carry reference (pilot) signals (RSs) for the UE. The RSs can include demodulation RSs (DM-RSs) (denoted as R for one particular configuration, but other DM-RS configurations are possible) and channel state information reference signals (CSI-RSs) for channel estimation at the UE. The RSs can also include beam measurement RSs (BRSs), beam refinement RSs (BRRSs), and phase tracking RSs (PT-RSs).

[0081] Figure 2BShows examples of various DL channels within a subframe of a frame. The Physical Downlink Control Channel (PDCCH) carries DCI within one or more Control Channel Elements (CCEs) (e.g., 1, 2, 4, 8, or 16 CCEs), where each CCE includes six Resource Element Groups (REGs), and each REG includes 12 consecutive Resource Elements (REs) within an OFDM symbol of an RB. The PDCCH within a BWP can be referred to as a Control Resource Set (CORESET). The UE is configured to monitor PDCCH candidates in a PDCCH search space (e.g., common search space, UE-specific search space) during a PDCCH monitoring occasion on the CORESET, where the PDCCH candidates have different DCI formats and different aggregation levels. Additional BWPs can be located at higher and / or lower frequencies on the channel bandwidth. The Primary Synchronization Signal (PSS) can be within symbol 2 of a specific subframe of the frame. The PSS is used by the UE 104 to determine subframe / symbol timing and the physical layer identity. The Secondary Synchronization Signal (SSS) can be within symbol 4 of a specific subframe of the frame. The SSS is used by the UE to determine the physical layer cell identity group number and the radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine the Physical Cell Identifier (PCI). Based on the PCI, the UE can determine the location of the DM-RS. The Physical Broadcast Channel (PBCH) carrying the Master Information Block (MIB) can be logically grouped with the PSS and SSS to form a Synchronization Signal (SS) / PBCH block (also referred to as an SS block (SSB)). The MIB provides the number of RBs in the system bandwidth and the System Frame Number (SFN). The Physical Downlink Shared Channel (PDSCH) carries user data, broadcast system information not transmitted via the PBCH (such as System Information Blocks (SIBs)), and paging messages.

[0082] As Figure 2C shown, some of the REs carry DM-RS (indicated as R for a specific configuration, but other DM-RS configurations are possible) for channel estimation at the base station. The UE can transmit DM-RS for the Physical Uplink Control Channel (PUCCH) and the Physical Uplink Shared Channel (PUSCH). The PUSCH DM-RS can be transmitted in the previous or the previous two symbols of the PUSCH. The PUCCH DM-RS can be transmitted with different configurations depending on whether a short PUCCH or a long PUCCH is transmitted and according to the specific PUCCH format used. The UE can transmit a Sounding Reference Signal (SRS). The SRS can be transmitted in the last symbol of the subframe. The SRS can have a comb structure, and the UE can transmit the SRS on one of the combs in the comb. The SRS can be used by the base station for channel quality estimation to enable frequency-dependent scheduling of the UL.

[0083] Figure 2DShows examples of various UL channels within a subframe of a frame. The PUCCH may be located at the position indicated in one configuration. The PUCCH carries uplink control information (UCI), such as a scheduling request, a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), and a hybrid automatic repeat request (HARQ) acknowledgement (ACK) (HARQ-ACK) feedback (i.e., one or more HARQ ACK bits indicating one or more ACKs and / or negative ACKs (NACKs)). The PUSCH carries data and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and / or UCI.

[0084] Figure 3 Is a block diagram of a base station 310 in an access network communicating with a UE 350. In the DL, IP packets from the EPC 160 may be provided to a controller / processor 375. The controller / processor 375 implements layer 3 and layer 2 functionality. Layer 3 includes the radio resource control (RRC) layer, and layer 2 includes the service data adaptation protocol (SDAP) layer, the packet data convergence protocol (PDCP) layer, the radio link control (RLC) layer, and the medium access control (MAC) layer. The controller / processor 375 provides RRC layer functionality associated with the broadcast of system information (e.g., MIB, SIB), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), radio access technology (RAT) - to - RAT mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression / decompression, security (encryption, decryption, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with the transfer of upper layer packet data units (PDUs), error correction via ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs), re - segmentation of RLC data PDUs, and re - ordering of RLC data PDUs; and MAC layer functionality associated with the mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction via HARQ, priority handling, and logical channel prioritization.

[0085] The transmit (TX) processor 316 and the receive (RX) processor 370 implement layer 1 functionality associated with various signal processing functions. Layer 1, which includes the physical (PHY) layer, may include error detection on the transport channel, forward error correction (FEC) encoding / decoding of the transport channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. The TX processor 316 processes the mapping to the signal constellation based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-phase phase shift keying (M-PSK), M-order quadrature amplitude modulation (M-QAM)). Then, the encoded and modulated symbols may be divided into parallel streams. Subsequently, each stream may be mapped to OFDM subcarriers, multiplexed with reference signals (e.g., pilots) in the time and / or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT) to generate a physical channel carrying a stream of time-domain OFDM symbols. The OFDM stream is precoded in space to generate multiple spatial streams. Channel estimates from the channel estimator 374 may be used to determine the encoding and modulation schemes, as well as for spatial processing. The channel estimates may be derived based on reference signals transmitted by the UE 350 and / or channel status feedback. Then, each spatial stream may be provided to a different antenna 320 via a separate transmitter 318TX. Each transmitter 318TX may modulate a radio frequency (RF) carrier with the corresponding spatial stream for transmission.

[0086] At the UE 350, each receiver 354RX receives signals via its corresponding antenna 352. Each receiver 354RX recovers the information modulated onto the RF carrier and provides the information to the receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functionality associated with various signal processing functions. The RX processor 356 may perform spatial processing on the information to recover any spatial streams destined for the UE 350. If multiple spatial streams are destined for the UE 350, they may be combined into a single OFDM symbol stream by the RX processor 356. Then, the RX processor 356 uses a fast Fourier transform (FFT) to convert the OFDM symbol stream from the time domain to the frequency domain. The frequency-domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, as well as the reference signals, are recovered and demodulated by determining the signal constellation points most likely transmitted by the base station 310. These soft decisions may be based on the channel estimates computed by the channel estimator 358. Then, the soft decisions are decoded and deinterleaved to recover the data and control signals originally transmitted by the base station 310 on the physical channel. Then, the data and control signals are provided to the controller / processor 359, which implements layer 3 functionality and layer 2 functionality.

[0087] The controller / processor 359 may be associated with a memory 360 that stores program code and data. The memory 360 may be referred to as a computer-readable medium. In the UL, the controller / processor 359 provides demultiplexing between transport channels and logical channels, packet reassembly, decryption, header decompression, and control signal processing to recover IP packets from the EPC 160. The controller / processor 359 is also responsible for error detection using the ACK and / or NACK protocols to support HARQ operations.

[0088] Similar to the functionality described in connection with DL transmissions performed by the base station 310, the controller / processor 359 provides RRC layer functionality associated with system information (e.g., MIB, SIB) acquisition, RRC connection, and measurement reporting; PDCP layer functionality associated with header compression / decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functionality associated with the transfer of upper layer PDUs, error correction via ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with the mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction via HARQ, priority handling, and logical channel prioritization.

[0089] The TX processor 368 may use channel estimation derived from reference signals or feedback transmitted by the base station 310 by the channel estimator 358 to select an appropriate decoding and modulation scheme and to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to different antennas 352 via a separate transmitter 354TX. Each transmitter 354TX may modulate an RF carrier using a corresponding spatial stream for transmission.

[0090] UL transmissions are processed at the base station 310 in a manner similar to that described in connection with the receiver functionality at the UE 350. Each receiver 318RX receives signals via its corresponding antenna 320. Each receiver 318RX recovers the information modulated onto the RF carrier and provides the information to the RX processor 370.

[0091] The controller / processor 375 may be associated with a memory 376 that stores program code and data. The memory 376 may be referred to as a computer-readable medium. In the UL, the controller / processor 375 provides demultiplexing between the transport channel and the logical channel, packet reassembly, decryption, header decompression, control signal processing to recover IP packets from the UE 350. The IP packets from the controller / processor 375 may be provided to the EPC 160. The controller / processor 375 is also responsible for error detection using the ACK and / or NACK protocols to support HARQ operations.

[0092] At least one of the TX processor 368, the RX processor 356, and the controller / processor 359 may be configured to perform aspects in conjunction with Figure 1 the NTN UE positioning processing component 198.

[0093] At least one of the TX processor 316, the RX processor 370, and the controller / processor 375 may be configured to perform aspects in conjunction with Figure 1 the NTN UE positioning configuration component 199.

[0094] The network may support several cellular network-based positioning techniques, such as downlink-based positioning methods, uplink-based positioning methods, and / or downlink- and uplink-based positioning methods. Downlink-based positioning methods may include, for example, Observed Time Difference of Arrival (OTDOA) (e.g., in LTE), Downlink Time Difference of Arrival (DL-TDOA) (e.g., in NR), and / or Downlink Angle of Departure (DL-AoD) (e.g., in NR). During an OTDOA or DL-TDOA positioning procedure, the UE may measure the difference between the arrival times (ToA) of received reference signals (e.g., positioning reference signals (PRS)) from base stations, which is referred to as a reference signal time difference (RSTD) measurement or time difference of arrival (TDOA) measurement, and report these differences to a positioning entity (e.g., a positioning management function (LMF)). For example, the UE may receive in assistance data (AD) the identifiers (IDs) of a reference base station (which may also be referred to as a reference cell or reference gNB) and at least one non-reference base station. Then, the UE may measure the RSTD between the reference base station and each non-reference base station. Based on the known locations of the involved base stations and the RSTD measurements, the positioning entity may estimate the location of the UE. In other words, the UE's location may be estimated based on the measurement of reference signals transmitted between the UE and one or more base stations and / or one or more transmit receive points (TRP) of the one or more base stations. Thus, the PRS enables the UE to detect and measure neighbor TRPs and perform positioning based on that measurement. For the purposes of this disclosure, the suffixes "based" and "assisted" may refer, respectively, to a node responsible for performing the positioning calculation (and may also provide measurements) and a node that provides measurements (but may not perform the positioning calculation). For example, an operation in which the UE provides measurements to a base station / positioning entity for use in calculating a positioning estimate may be described as "UE-assisted", "UE-assisted positioning", and / or "UE-assisted positioning calculation", while an operation in which the UE calculates its own location may be described as "UE-based", "UE-based positioning", and / or "UE-based positioning calculation".

[0095] In some examples, the term "TRP" may refer to one or more antennas of a base station, while the term "base station" may refer to a complete unit (e.g., base station 102 / 180) that includes aggregated components or disaggregated components, such as in conjunction with Figure 1As described. For example, as an example of a decomposed RAN, a base station may include a CU, one or more DUs, one or more RUs, and / or one or more TRPs. One or more of the decomposed components may be located in different locations. For example, different TRPs may be located in different geographical locations. In another example, a TRP may refer to a geographically co-located set of antennas (e.g., an antenna array (having one or more antenna elements)) that supports transmit point (TP) and / or receive point (RP) functionality. Thus, a base station may transmit signals to other wireless devices (e.g., UEs, another base station, etc.) and / or receive signals from such other wireless devices via one or more TRPs. For the purposes of this disclosure, in some examples, the term "TRP" may be used interchangeably with the term "base station".

[0096] For DL-AoD positioning, a positioning entity may use beam reports from a UE regarding received signal strength measurements of multiple downlink transmit beams to determine the angle between the UE and the transmitting base station. The positioning entity may then estimate the location of the UE based on the determined angle and the known location of the transmitting base station.

[0097] Uplink-based positioning methods may include UL-TDOA and UL-AoA. UL-TDOA is similar to DL-TDOA, but is based on uplink reference signals (e.g., sounding reference signals (SRS)) transmitted by the UE. For UL-AoA positioning, one or more base stations may measure the received signal strength of one or more uplink reference signals (e.g., SRS) received from the UE on one or more uplink receive beams. A positioning entity may use the signal strength measurements and the angles of the receive beams to determine the angle between the UE and the base station. Based on the determined angle and the known location of the base station, the positioning entity may then estimate the location of the UE.

[0098] Downlink- and uplink-based positioning methods may include Enhanced Cell ID (E-CID) positioning and Multi-Round Trip Time (RTT) positioning (also referred to as “Multi-Cell RTT”). During the RTT process, an initiator (base station or UE) transmits an RTT measurement signal (e.g., PRS or SRS) to a responder (UE or base station), and the responder transmits an RTT response signal (e.g., SRS or PRS) back to the initiator. The RTT response signal may include the difference between the ToA of the RTT measurement signal and the transmission time of the RTT response signal (referred to as the Receive-Transmit (Rx-Tx) time difference). The initiator may calculate the difference between the transmission time of the RTT measurement signal and the ToA of the RTT response signal (referred to as the Transmit-Receive (Tx-Rx) time difference). The propagation time (also referred to as “time of flight”) between the initiator and the responder may be calculated using the Tx-Rx and Rx-Tx time differences. Based on the propagation time and the known speed of light, the distance between the initiator and the responder may be determined. For multi-RTT positioning, the UE may perform RTT processes with multiple base stations to enable determination of the UE's position (e.g., using multilateration) based on the known positions of the respective base stations. The RTT and multi-RTT methods may be combined with other positioning techniques (such as UL-AoA and DL-AoD) to improve position accuracy.

[0099] The E-CID positioning method may be based on Radio Resource Management (RRM) measurements. In E-CID, the UE may report the serving cell ID, Timing Advance (TA), and the identifiers, estimated timing, and signal strength of the detected neighbor base stations. Then, the UE's position may be estimated based on this information and the known positions of the base stations.

[0100] To assist in the positioning operation, a location server (e.g., a location server, LMF, or SLP) may provide the UE with assistance data (AD). For example, the assistance data may include: the identifier of the base station (or the cell / TRP of the base station) from which the reference signal is measured, reference signal configuration parameters (e.g., the number of consecutive positioning subframes, the periodicity of the positioning subframes, the silence sequence, the hopping sequence, the reference signal identifier, the reference signal bandwidth, etc.) and / or other parameters applicable to a specific positioning method. Alternatively, the assistance data may directly originate from the base station (e.g., in periodically broadcast overhead messages, etc.). In some cases, the UE may be able to detect neighbor network nodes without using assistance data.

[0101] In the case of an OTDOA or DL-TDOA positioning procedure, the assistance data may further include an expected RSTD value and an associated uncertainty around the expected RSTD (e.g., a search space window). In some cases, the value range of the expected RSTD may be plus or minus (+ / -) 500 microseconds (μs). In some cases, when any resources used for positioning measurements are in FR1, the value range of the uncertainty of the expected RSTD may be + / - 32 μs. In other cases, when all resources used for positioning measurements are in FR2, the value range of the uncertainty of the expected RSTD may be + / - 8 μs. In this context, "RSTD" may refer to one or more measurements indicating the time difference of arrival between the PRS transmitted by a base station (referred to herein as the "neighbor base station" or "measuring base station") and the PRS transmitted by a reference base station. The reference base station may be selected by a location server and / or by the UE to provide good or sufficient signal strength observed at the UE such that the PRS can be acquired and / or measured more accurately and / or more quickly, such as without any special assistance from the serving base station.

[0102] Location estimation may also be referred to as positioning estimation, positioning, localization, position lock, lock, etc. The positioning estimation can be geodetic and include coordinates (e.g., latitude, longitude, and possibly altitude), or can be civic and include a street address, postal address, or some other verbal location description. The location estimation can be further defined relative to some other known location or in absolute terms (e.g., using latitude, longitude, and possibly altitude). The positioning estimation can include an expected error or uncertainty (e.g., by including an area or volume within which the location is expected to be included with a certain specified or default confidence). For the purposes of this disclosure, the reference signal can include PRS, Tracking Reference Signal (TRS), Phase Tracking Reference Signal (PTRS), Cell-Specific Reference Signal (CRS), CSI-RS, Demodulation Reference Signal (DMRS), PSS, SSS, SSB, SRS, etc., depending on whether the frame structure shown is for uplink communication or downlink communication. In some examples, 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 one or more consecutive symbols within a time slot in the time domain. In a given OFDM symbol in the time domain, the PRS resource can occupy consecutive PRBs in the frequency domain. In other examples, a "PRS resource set" can refer to the set of PRS resources used for the transmission of the PRS signal, where each PRS resource can have a PRS resource ID. Additionally, the PRS resources in a PRS resource set can be associated with the same TRP. The PRS resource set can be identified by a PRS resource set ID and can be associated with a specific TRP (identified by a TRP ID). Additionally, the PRS resources in a PRS resource set can have the same periodicity, common silent mode configuration, and / or the same cross-slot repetition factor. The periodicity can be the time from the first repetition of the first PRS resource of the first PRS instance to the same first repetition of the same first PRS resource of the next PRS instance. For example, the periodicity can have a length selected from: 2^μ*{4,5,8,10,16,20,32,40,64,80,160,320,640,1280,2560,5120,10240} time slots, where μ = 0,1,2,3. The repetition factor can have a length selected from {1,2,4,6,8,16,32} time slots. The PRS resource ID in a PRS resource set can be associated with a single beam (or beam ID) transmitted from a single TRP (where one TRP can transmit one or more beams). That is, each PRS resource in a PRS resource set can be transmitted on a different beam, and thus, a "PRS resource" (or simply "resource") can also be referred to as a "beam". In some examples, a "PRS instance" or "PRS occasion" can be an instance of a periodically repeating time window (such as a group of one or more consecutive time slots) in which the PRS is expected to be transmitted.The PRS timing may also be referred to as "PRS positioning timing", "PRS positioning instance", "positioning timing", "positioning instance", "positioning repetition", or simply as "timing", "instance", and / or "repetition", etc.

[0103] The "Positioning Frequency Layer (PFL)" (which may also be referred to as "frequency layer") can be a set of one or more PRS resource sets having the same values for certain parameters across one or more TRPs. Specifically, the set of PRS resource sets can have the same subcarrier spacing and cyclic prefix (CP) type (e.g., meaning that all parameter sets supporting PDSCH also support PRS), the same Point A, the same downlink PRS bandwidth value, the same starting PRB (and center frequency), and / or the same comb size, etc. The Point A parameter can take the value of the parameter ARFCN-ValueNR (where "ARFCN" stands for "Absolute Radio Frequency Channel Number"), and can be an identifier / code specifying the physical radio channel pair for transmission and reception. In some examples, the downlink PRS bandwidth can have a granularity of four PRBs, and the minimum value is 24 PRBs while the maximum value is 272 PRBs. In other examples, up to four frequency layers can be configured, and each frequency layer can have up to two PRS resource sets configured per TRP.

[0104] The concept of frequency layer can be similar to that of component carrier (CC) and BWP, where CC and BWP can be used by a base station (or macro cell base station and small cell base station) to transmit data channels, while the frequency layer can be used by multiple (e.g., three or more) base stations to transmit PRS. The UE can indicate the number of frequency layers it can support when the UE sends its positioning capabilities to the network (such as during a positioning protocol session). For example, the UE can indicate whether it can support one or four PFLs.

[0105] Figure 4FIG. 400 is an illustration showing an example of UE positioning based on reference signal measurements in accordance with various aspects of the present disclosure. In one example, the location of UE 404 may be estimated based on multi-cell round-trip time (multi-RTT) measurements, where multiple TRPs 402 may perform round-trip time (RTT) measurements on signals transmitted to and received from UE 404 to determine the approximate distance of UE 404 relative to each of the multiple TRPs 402. Similarly, UE 404 may perform RTT measurements on signals transmitted to and received from TRP 402 to determine the approximate distance of each TRP relative to UE 404. Then, based at least in part on the approximate distances of UE 404 relative to the multiple TRPs 402, a location management function (LMF) associated with the TRP 402 and / or UE 404 may estimate the location of UE 404. For example, TRP 406 may transmit at least one downlink positioning reference signal (DL-PRS) 410 to UE 404 and may receive at least one uplink sounding reference signal (UL-SRS) 412 transmitted from UE 404. Based at least in part on measuring the RTT 414 between the transmitted DL-PRS 410 and the received UL-SRS 412, a serving base station associated with TRP 406 or an LMF associated with TRP 406 may identify the location (e.g., distance) of UE 404 relative to TRP 406. Similarly, UE 404 may transmit UL-SRS 412 to TRP 406 and may receive DL-PRS 410 transmitted from TRP 406. Based at least in part on measuring the RTT 414 between the transmitted UL-SRS 412 and the received DL-PRS 410, UE 404 or an LMF associated with UE 404 may identify the location of TRP 406 relative to UE 404. The multi-RTT measurement mechanism may be initiated by an LMF associated with the TRP 406 / 408 and / or UE 404. The TRP may configure UL-SRS resources for the UE via radio resource control (RRC) signaling. In some examples, the UE and the TRP may report multi-RTT measurements to the LMF, and the LMF may estimate the location of the UE based on the reported multi-RTT metrics.

[0106] In other examples, the location of the UE may be estimated based on multiple antenna beam measurements, where the transmitted downlink angle of departure (DL-AoD) and / or the uplink angle of arrival (UL-AoA) between the UE and one or more TRPs may be used to estimate the location of the UE and / or the distance of the UE relative to each TRP. For example, referring back Figure 6, Regarding DL-AoD, UE 404 can perform reference signal received power (RSRP) measurements on a set 416 of DL-PRSs transmitted from multiple transmit beams (e.g., DL-PRS beams) of TRP 408, and UE 404 can provide DL-PRS beam measurements to the serving base station (or to the LMF associated with the base station). Based on the DL-PRS beam measurements, the serving TRP or LMF can derive the azimuth of departure (e.g., Φ) and the zenith angle of departure (e.g., θ) of the DL-PRS beam of TRP 408. Then, the serving TRP or LMF can estimate the location of UE 404 relative to TRP 408 based on the azimuth of departure and the zenith angle of departure of the DL-PRS beam. Similarly, for UL-AoA, the location of the UE can be estimated based on UL-SRS beam measurements made at different TRPs (such as at TRP 402). Based on the UL-SRS beam measurements, the serving base station or the LMF associated with the serving base station can derive the azimuth of arrival and the zenith angle of arrival of the UL-SRS beam from the UE, and the serving base station or LMF can estimate the location of the UE and / or the distance of the UE relative to each of the TRPs based on the azimuth of arrival and the zenith angle of arrival of the UL-SRS beam.

[0107] Figure 5A FIG. 500A is an illustration showing an example of DL-PRSs transmitted from multiple TRPs in accordance with various aspects of the present disclosure. In one example, the serving base station can configure the DL-PRS to be transmitted from one or more TRPs within one time slot or across multiple time slots. If the DL-PRS is configured to be transmitted within one time slot, the serving base station can configure the starting resource elements from each of one or more TRPs in time and frequency. If the DL-PRS is configured to be transmitted across multiple time slots, the serving base station can configure the gaps between DL-PRS time slots, the periodicity of the DL-PRS, and / or the density of the DL-PRS within a time period. The serving base station can also configure the DL-PRS to start at any physical resource block (PRB) in the system bandwidth. In one example, the system bandwidth can range from 24 to 276 PRBs, with a step size of 4 PRBs (e.g., 24, 28, 32, 36, etc.). The serving base station can transmit the DL-PRS in a PRS beam, where the PRS beam can be referred to as a "PRS resource", and the entire set of PRS beams transmitted from a TRP at the same frequency can be referred to as a "PRS resource set" or "resource set of the PRS", such as described in connection with Figure 4 As Figure 5A shown, DL-PRSs transmitted from different TRPs and / or from different PRS beams can be multiplexed across symbols or time slots.

[0108] In some examples, each symbol of the DL-PRS may be configured with a comb structure in frequency, where the DL-PRS from a TRP of a base station may occupy every N subcarriers. The comb value N may be configured to 2, 4, 6, or 12. The length of the PRS within a time slot may be a multiple of N symbols, and the positioning of the first symbol within the time slot may be flexible as long as the time slot consists of at least N PRS symbols. FIG. 500A shows an example of a comb-6 DL-PRS configuration, where the pattern for the DL-PRS from different TRPs may repeat after six (6) symbols.

[0109] Figure 5B FIG. 500B is a diagram illustrating an example of UL-SRS transmitted from a UE in accordance with various aspects of the present disclosure. In one example, the UL-SRS from the UE may be configured with a comb-4 pattern, where the pattern for the UL-SRS may repeat after four (4) symbols. Similarly, the UL-SRS may be configured in one SRS resource of an SRS resource set, where each SRS resource may correspond to one SRS beam, and the SRS resource set may correspond to a set of SRS resources (e.g., beams) configured for a TRP. In some examples, the SRS resource may span 1, 2, 4, 8, or 12 consecutive OFDM symbols. In other examples, the comb size for the UL-SRS may be configured to 2, 4, or 8.

[0110] Figure 6 FIG. 600 is a diagram illustrating an example of estimating the location of a UE based on multi-RTT measurements from multiple TRPs in accordance with various aspects of the present disclosure. The UE 602 may be configured by a serving base station to decode DL-PRS resources 612 corresponding to and transmitted from a first TRP 604 (TRP-1), a second TRP 606 (TRP-2), a third TRP 608 (TRP-3), and a fourth TRP 610 (TRP-4). The UE 602 may also be configured to transmit UL-SRS on an UL-SRS resource set that may include a first SRS resource 614, a second SRS resource 616, a third SRS resource 618, and a fourth SRS resource 620 such that the serving cell (e.g., the first TRP 604, the second TRP 606, the third TRP 608, and the fourth TRP 610) as well as other neighboring cells may be able to measure the UL-SRS resource set transmitted from the UE 602. For multi-RTT measurements based on DL-PRS and UL-SRS, since there may be an association between the UE's measurement of the DL-PRS and the TRP's measurement of the UL-SRS, the smaller the gap between the UE's DL-PRS measurement and the UE's UL-SRS transmission, the better the accuracy of estimating the location of the UE and / or the distance of the UE relative to each TRP.

[0111] 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" may also refer to any type of reference signal that can be used for positioning, such as but not limited to: PRS, TRS, PTRS, CRS, CSI-RS, DMRS, PSS, SSS, SSB, SRS, UL-PRS, etc. as defined in LTE and NR. Additionally, the terms "positioning reference signal" and "PRS" may refer to downlink or uplink positioning reference signals, unless otherwise indicated by the context. If further differentiation of the PRS type is needed, the downlink positioning reference signal may be referred to as "DL-PRS", and the uplink positioning reference signal (e.g., SRS, PTRS for positioning) may be referred to as "UL-PRS". Additionally, for signals that can be transmitted in both the uplink and downlink (e.g., DMRS, PTRS), these signals may be prefixed with "UL" or "DL" to distinguish the direction. For example, "UL-DMRS" can be distinguished from "DL-DMRS".

[0112] Figure 7 is a diagram 700 showing an example of OTDOA-based UE positioning according to various aspects of the present disclosure. OTDOA uses multi-point positioning, where the UE can measure the TOA of signals received from multiple synchronized TRPs. The TOA from several adjacent TRPs can be subtracted from the TOA of the reference TRP to form the OTDOA. In some scenarios, as shown at 702, geometrically, each TOA can determine a hyperbola, and the point where the hyperbolas intersect (such as shown at 704) can be the UE location. In some examples, at least three timing measurements from geographically dispersed TRPs can be specified to determine two coordinates (latitude and longitude) of the UE. By incorporating additional TRPs, the performance and accuracy of UE positioning can be further improved. In other words, multiple TDOA measurements can be used for triangulation (e.g., ≥4 TRPs / cells). For example, the UE can measure three TOAs relative to the internal time base of the UE: T1, T2, and T3. The measurement from the first TRP (TRP 1) can be selected as the reference, and two OTDOAs can be formed based on the following formula: T 2,1 = T2 - T1, and T 3,1= T3 - T1. As shown at 706, each TOA measurement T(i) may have a specific accuracy and uncertainty. Thus, the hyperbolas in illustration 700 (e.g., 702) may include a specific width that accounts for the measurement uncertainty. The estimated UE location may be the intersection region of each pair of hyperbolas, as shown at 704. The measurements made by the UE for OTDOA positioning may be RSTD measurements. RSTD is the relative timing difference between two TRPs: a reference TRP and a measured neighboring TRP. In some examples, since network synchronization may be an important aspect of high-precision positioning, if the TRPs are not properly synchronized, the accuracy and precision of the UE positioning session may be reduced.

[0113] Figure 8 is a communication flow 800 that illustrates an example multi-RTT positioning process in accordance with various aspects of the present disclosure. The numbers associated with communication flow 800 do not specify a particular time order and are only used as a reference for communication flow 800. Additionally, only DL and / or only UL positioning may use one or more subsets of this multi-RTT positioning process.

[0114] At 810, the LMF 806 may request one or more positioning capabilities from the UE 802 (e.g., from a target device). In some examples, the request for one or more positioning capabilities to the UE 802 may be associated with the LTE positioning protocol (LPP). For example, the LMF 806 may use the LPP capability transfer process to request the positioning capabilities of the UE 802.

[0115] At 812, the LMF 806 may request UL SRS configuration information from the UE 802. The LMF 806 may also provide assistance data (e.g., path loss reference, spatial relationship, and / or SSB configuration, etc.) specified by the serving base station 804. For example, the LMF 806 may send an NR positioning protocol A (NRPPa) positioning information request message to the serving base station 804 to request UL information of the UE 802.

[0116] At 814, the serving base station 804 may determine the resources available for UL SRS, and at 816, the serving base station 804 may configure one or more UL SRS resource sets for the UE 802 based on the available resources.

[0117] At 818, the serving base station 804 may provide the UL SRS configuration information to the LMF 806, such as via an NRPPa positioning information response message.

[0118] At 820, the LMF 806 may select one or more candidate neighbor BS / TRPs 808, and the LMF 806 may provide UL SRS configuration to the one or more candidate neighbor BS / TRPs 808 and / or the serving base station 804, such as via an NRPPa measurement request message. The message may include information for enabling the one or more candidate neighbor BS / TRPs 808 and / or the serving base station to perform UL measurements.

[0119] At 822, the LMF 806 may send an LPP provide assistance data message to the UE 802. The message may include specified assistance data for the UE 802 to perform DL measurements.

[0120] At 824, the LMF 806 may send an LPP request location information message to the UE 802 to request multi-RTT measurements.

[0121] At 826, for semi-persistent or non-periodic UL SRS, the LMF 806 may request the serving base station 804 to activate / trigger the UL SRS in the UE 802. For example, the LMF 806 may request the activation of UE SRS transmission by sending an NRPPa positioning activation request message to the serving base station 804.

[0122] At 828, the serving base station 804 may activate UE SRS transmission and send an NRPPa positioning activation response message. In response, the UE 802 may start UL-SRS transmission according to the time-domain behavior of the UL SRS resource configuration.

[0123] At 830, the UE 802 may perform DL measurements from the one or more candidate neighbor BS / TRPs 808 and / or the serving base station 804 provided in the assistance data. At 832, each of the configured one or more candidate neighbor BS / TRPs 808 and / or the serving base station 804 may perform UL measurements.

[0124] At 834, the UE 802 may report the DL measurements to the LMF 806, such as via an LPP provide location information message.

[0125] At 836, each of the one or more candidate neighbor BS / TRPs 808 and / or the serving base station 804 may report the UL measurements to the LMF 806, such as via an NRPPa measurement response message.

[0126] At 838, the LMF 806 may determine the RTT from the UE 802 and the BS / TRP Rx-Tx time difference measurements for each of one or more candidate neighbor BS / TRPs 808 and / or the serving base station 804 that provide corresponding UL and DL measurements at 834 and 836, and the LMF 806 may compute the location of the UE 802.

[0127] In addition to network-based positioning techniques, wireless devices or UEs (such as mobile phones, cars, smartwatches, etc.) may also be able to determine their location on the earth based on the Global Navigation Satellite System (GNSS). For example, the Global Positioning System (GPS) is a satellite-based radio navigation system that can provide geographical location and time information to GPS receivers anywhere on or near the earth that have line-of-sight (LOS) to four or more GPS satellites. If there are obstacles such as physical structures (e.g., buildings, bridges) and terrain (e.g., mountains) between the GPS satellite and the GPS receiver, the GPS signals received by the GPS receiver may be attenuated and / or include offsets / delays.

[0128] Figure 9 FIG. 900 is a diagram illustrating an example of GPS positioning in accordance with various aspects of the present disclosure. The GPS receiver 904 may compute its location and time based at least in part on data received from a plurality of GPS satellites 902, where each GPS satellite 902 may carry a record of its location and time and may transmit that data (e.g., the record) to the GPS receiver 904. Each GPS satellite 902 may also include a clock that is synchronized with other clocks of the GPS satellites and with a ground clock. If the GPS satellite 902 detects a drift in the time maintained on the ground, the GPS satellite 902 may correct it. The GPS receiver 904 may also include a clock, but the clock of the GPS receiver 904 may be less stable and accurate compared to the clocks of the GPS satellites 902.

[0129] Since the speed of radio waves can be constant and independent of the satellite speed, the time delay between the time when the GPS satellite 902 transmits the signal 906 and the time when the GPS receiver 904 receives the signal 906 may be proportional to the distance from the GPS satellite 902 to the GPS receiver 904. In some examples, the GPS receiver 904 may use at least four GPS satellites to compute / estimate one or more unknowns (e.g., three location coordinates and a clock offset from the satellite time, etc.).

[0130] Each GPS satellite 902 can continuously broadcast a signal 906 (e.g., a modulated carrier wave), which may include a pseudorandom code known to the GPS receiver 904 (e.g., a sequence of ones and zeros), and may also include a message that includes the transmission time and the satellite's location at that time. In other words, each signal 906 can carry two types of information: time and a carrier wave (e.g., a modulated waveform of an input signal to be electromagnetically transmitted). Based on the signal 906 received from the GPS satellite 902, the GPS receiver 904 can measure the time of arrival (TOA) of the signal 906 and calculate the time of flight (TOF) of the signal 906. Then, based on the TOF, the GPS receiver 904 can calculate its three-dimensional location and clock bias, and the GPS receiver 904 can determine its location on the Earth. For example, the location of the GPS receiver 904 can be converted into latitude, longitude, and altitude relative to an ellipsoidal Earth model. These coordinates can be displayed on, for example, a mobile map display, or recorded or used by some other system such as a vehicle guidance system.

[0131] Although the distance between the GPS receiver and the GPS satellite can be calculated based on the time taken for the signal to propagate, the signal sequence of the GPS satellite can be delayed relative to the sequence of the GPS receiver. Thus, in some examples, a delay can be applied to the sequence of the GPS receiver so that the two sequences can be aligned. For example, to calculate the delay, the GPS receiver can align the pseudorandom binary sequence contained in the GPS satellite signal with an internally generated pseudorandom binary sequence. As the GPS satellite signal arrives at the receiver, the sequence of the satellite can be delayed relative to the sequence of the receiver. By gradually increasing the delay of the receiver's sequence, the two sequences can eventually be aligned.

[0132] The accuracy of GPS positioning can depend on various factors, such as satellite geometry, signal blockage, atmospheric conditions, and / or receiver design features / quality, etc. For example, the accuracy of a GPS receiver used in a smartphone or smartwatch may be lower than that of a GPS receiver used in a vehicle and exploration equipment.

[0133] To improve the accuracy of GPS positioning (e.g., from several meters to several centimeters), real-time kinematic (RTK) technology or mechanism can be used for positioning devices. RTK is a technology or mechanism that can be used by positioning devices (e.g., UEs, exploration equipment, automotive GPS, etc.) to improve positioning accuracy. For example, based on RTK, a positioning device (e.g., a client device) can use correction information from a base station to mitigate several error sources in the PR and CP measurements of the GPS receiver of the positioning device, which can include satellite orbits, satellite clocks, atmospheric errors, etc. Thus, RTK can allow the positioning device to achieve improved accuracy.

[0134] Figure 10FIG. 1000 is an illustration showing an example of RTK positioning according to various aspects of the present disclosure. In one example, at least two receivers may be used in association with RTK positioning, where at least one of the receivers may be fixed, which may be referred to as the base station 1003, and at least one other receiver may be mobile (e.g., may move freely), which may be referred to as the rover or rover device 1004 (e.g., GNSS / GPS receiver, UE, rover, etc.). In other words, an RTK system may include a base station and a rover, where the base station may be a fixed receiver with a known location.

[0135] The range between the satellite 1002 (e.g., GNSS / GPS satellite) and the rover device 1004 or between the satellite 1002 and the base station 1003 can be calculated by determining the number of carrier cycles between the satellite 1002 and the rover device 1004 or the base station 1003 and multiplying that number by the carrier wavelength 1008 of the carrier 1006 (e.g., carrier signal) transmitted by the satellite 1002. For example, if the satellite 1002 transmits a carrier 1006 with a carrier wavelength 1008 of ten (10) meters, and the rover device 1004 receives the carrier 1006 and determines that there are five hundred (500) carrier cycles between the satellite 1002 and the rover device 1004, the rover device 1004 can calculate the distance between the satellite 1002 and the rover device 1004 by multiplying the determined number of carrier cycles (e.g., 500) by the carrier wavelength 1008 (e.g., 10 meters), which may be five kilometers (e.g., 500 × 10 = 5000). Similarly, the base station 1003 can also receive the carrier 1006 from the satellite 1002 and determine its range from the satellite 1002 based on the carrier wavelength 1008 of the carrier 1006 and the number of carrier cycles between the base station 1003 and the satellite 1002. The rover device 1004 and / or the base station 1003 can calculate the range (e.g., distance) between the rover device 1004 / base station 1003 and multiple (e.g., four or more) satellites (e.g., satellites 1001 and 1002) to determine their geographical locations (e.g., their positions on the earth).

[0136] During RTK positioning, the rover device 1004 (e.g., UE, client device, etc.) may undergo an "ambiguity resolution" process to determine the number of carrier cycles between the satellite 1002 and the rover device 1004. In other words, when the rover device 1004 receives a carrier from the satellite 1002, the rover device 1004 may spend time calculating how many carrier cycles exist between the satellite 1002 and the rover device 1004. In some examples, a GNSS receiver with a more complex or high-end antenna / hardware (such as an automotive-grade antenna) may be able to resolve the ambiguity in a relatively short time (e.g., within seconds), while a GNSS receiver with a less complex or low-end antenna / hardware (such as an antenna for a mobile phone and / or smartwatch) may take a longer time (e.g., 10 minutes to 30 minutes or more) to resolve the ambiguity. In some examples, the ambiguity may also be referred to as an "integer ambiguity".

[0137] In some examples, the range calculated by the rover device 1004 may include errors caused by satellite clocks and ephemerides, as well as ionospheric delays and tropospheric delays, etc. Additionally, since the rover device 1004 is more likely to be mobile, the quality of the signals / carriers received from each satellite may change as the rover device moves from one location to another. For example, if the rover device 1004 moves from an open sky area to an area with buildings, the signals from one or more satellites 1001 / 1002 may be blocked / reflected by the buildings. Therefore, the range calculated by the rover device 1004 may start to drift and may include errors.

[0138] On the other hand, since base station 1003 is likely to be fixed, has a known location, and can be equipped with a more complex and high-end GNSS receiver, base station 1003 may be able to maintain an accurate calculation of the range compared to rover device 1004. For example, base station 1003 can be configured to be located at a site with minimal environmental impact (such as interference and multipath) (e.g., an open sky area). Thus, under RTK positioning, base station 1003 can be configured to calculate its position by using signals received from satellites (e.g., satellites 1001 / 1002) based on carrier phase measurements, and then base station 1003 can compare the calculated position with its known position to identify if there are any errors. If base station 1003 identifies an error, base station 1003 can generate correction data 1010 (or a correction signal) and transmit the correction data 1010 to rover device 1004 to assist rover device 1004 in correcting the error. For example, since rover device 1004 is typically configured to be located near base station 1003 (e.g., within 6 miles, 12 miles, etc.), rover device 1004 is likely to encounter similar errors as base station 1003 (e.g., similar ionospheric delay and tropospheric delay). Thus, rover device 1004 can use the correction data 1010 from base station 1003 to improve its own positioning calculated from the GNSS constellation to achieve centimeter accuracy. In other words, the base station can be configured to stay at a fixed / known position and send correction data to one or more rover devices, and one or more rover devices can use the correction data to increase the accuracy of their positioning and the speed of error correction. Thus, rover device 1004 can use an algorithm that combines ambiguity resolution and differential correction to determine its positioning. The positioning accuracy that rover device 1004 can achieve can depend on its distance from base station 1003 and the accuracy of the differential correction (e.g., correction data 1010).

[0139] In some examples, RTK positioning can also be used in association with a network, where positioning data from one or more fixed base stations (e.g., base station 1003) can be transmitted to a central processing station. When requested by a rover device (which can transmit its approximate position to the central processing station), the central station can calculate correction information (e.g., correction data 1010) or a corrected positioning and transmit it to the rover device.

[0140] In one example, the pseudorange (PR) and carrier phase (CP) measurements between a satellite and a receiver can be calculated based on the following formula:

[0141] p = ρ + dρ + c(dt - dT) + d ion + d trop + ε p , and

[0142]

[0143] where p may indicate a PR measurement (m), may indicate a CP measurement (m), c may indicate the speed of light (m / s), λ may indicate the CP wavelength (m), N may indicate the CP integer ambiguity (cycles), dρ may indicate the satellite orbit error (m), dt may indicate the satellite clock error (m), d ion may indicate the ionospheric delay (m), d trop may indicate the tropospheric delay (m), ε p may indicate the pseudorange noise and multipath (m), may indicate the carrier phase noise and multipath (m), dT may indicate the receiver clock error (m), and ρ may indicate the geometric range (m) between the satellite and the receiver.

[0144] In one aspect, as shown in Figure 11A Illustration 1100A, the individual difference between different receivers (e.g., for PR and CP measurements) can be calculated based on the following formula:

[0145] and

[0146]

[0147] The rover measurement from the same satellite can be subtracted from the base station measurement, which can eliminate the satellite clock error dt, reduce the satellite orbit error dρ as a function of the baseline length, and reduce the ionospheric and tropospheric effects d ion and d trop .

[0148] Similarly, as shown in Figure 11B Illustration 1100B, the individual difference between different satellites (e.g., for PR and CP measurements) can be calculated based on the following formula:

[0149] and

[0150]

[0151] The satellite measurement can be subtracted from the reference satellite measurement of the same receiver, which can eliminate the receiver clock error dT and eliminate the common hardware biases in the receiver.

[0152] Thus, as shown in Figure 12 Illustration 1200, the double difference between receivers and between satellites can be calculated based on the following formula:

[0153] and

[0154]

[0155] Measurements from a rover can be subtracted from measurements of a base station of the same satellite. The difference between measurements from a reference satellite and measurements at other satellites can be further obtained, which can eliminate satellite clock error dt and receiver clock error dT, and reduce satellite orbit error dρ, ionospheric and tropospheric effects d ion and d trop . The double-difference integer ambiguity can be indicated. In one example, for a 20 km to 30 km baseline, the residual error can be less than half a cycle (e.g., residual error << 1 / 2 cycle).

[0156] In some scenarios, the positioning process can be associated with one or more non-terrestrial networks (NTNs). In some examples, an NTN can refer to a network or network segment that uses air (e.g., an aircraft) or satellite (e.g., a low Earth orbit (LEO) satellite, a medium Earth orbit (MEO) satellite, a geostationary (GEO) satellite, and / or a high-altitude pseudolite (HAPS), etc.) for transmission. For example, an NTN can support direct communication between a UE (e.g., a handset, a mobile device, a mobile phone, etc.) and a satellite (e.g., an LEO satellite or a GEO satellite, etc.), where the UE can transmit text messages and / or voice services to another UE via the satellite. In some aspects, determining the positioning of a UE can be an important factor for NTN operation. For example, the location information of the UE can be used in a radio access network (RAN) for initial synchronization, uplink timing and frequency pre-compensation, mobility, and / or handover, etc. Additionally, an NTN can support different types of UEs, such as UEs with global navigation satellite system (GNSS) support (e.g., the positioning of these UEs can be determined via the global positioning system (GPS)) and / or UEs without GNSS support.

[0157] One advantage of a UE performing a positioning session based on an NTN with GNSS support is that the communication link between the UE and the satellite can enable the UE to interact with the satellite. For example, a positioning reference signal (PRS) transmitted from the satellite can be customized or configured for a specific user or a specific device. Therefore, the performance and / or accuracy of GNSS-based UE positioning can be further supplemented with the assistance of an NTN, as the UE and / or the satellite can exchange positioning-related information with each other.

[0158] On the other hand, the UE can also perform an NTN-based positioning session without GNSS support. For example, for a UE without GNSS support, in combination with Figures 4 to 6The discussed network-based positioning methods and mechanisms (e.g., multi-RTT and / or OTDOA, etc.) can also be used to determine the location of the UE. For the purposes of this disclosure, NTN can include only NTN cells, or a mixture of NTN cells and terrestrial cells. Thus, for positioning operations associated with NTN, the positioning operation can involve NTN cells without terrestrial cells, a mixture of NTN and terrestrial cells, and / or a hybrid solution involving NTN cells, terrestrial cells, GNSS satellites, and / or other terrestrial-based positioning reference points (such as WiFi, Bluetooth, etc.).

[0159] Figure 13 FIG. 1300 is a diagram illustrating an example of a transparent payload-based NTN architecture in accordance with various aspects of the present disclosure. A data network 1302 (e.g., a 5G Core (5GC) network) can be connected to a base station 1304 (e.g., a gNB) via a communication interface (e.g., a Next Generation (NG) interface). The base station 1304 can be located on the ground and connected to an NTN gateway 1306, where the NTN gateway 1306 can be connected to an NTN payload 1308 (e.g., a network node carried on a satellite, an unmanned aerial vehicle system (UAS), or a HAPS, etc.) via a feeder link 1312. The NTN payload 1308 can be connected to a UE 1310 via a service link 1314 (e.g., using a UE-UTRAN (Uu) interface). Under the transparent payload NTN architecture, the base station 1304 can be a ground station, and the NTN payload 1308 (e.g., a satellite) can act like a repeater, where the NTN payload 1308 can provide radio frequency filtering, frequency conversion, and / or amplification for data / payload received from the base station 1304 via the NTN gateway 1306, and relay / transmit the data / payload to the UE 1310. Thus, the waveform signal relayed / repeated by the NTN payload 1308 can remain unchanged. In some examples, the ground area covered by the NTN payload 1308 can be referred to as a "coverage area". The coverage area of a satellite can be the ground area covered by its transponders, and the coverage area can also determine the satellite antenna diameter required to receive the signals of each transponder. In some examples, each transponder (or group of transponders) can have a different coverage map, as each transponder can be configured to cover a different area.

[0160] In some examples, the communication network can include both NTN and a terrestrial network (TN). In other words, one segment of NTN can operate based on non-terrestrial devices, while another segment of NTN can operate based on terrestrial devices. For example, Figure 14A and Figure 14BDiagrams 1400A and 1400B are illustrations showing examples of networks including both NTN and TN devices according to various aspects of the present disclosure. NTN may include one or more TN devices 1404 (e.g., terrestrial base stations and / or TRPs) and one or more NTN devices 1406 (e.g., satellites and / or aircraft), where a UE 1402 in a positioning session may transmit or receive signals (e.g., PRS, SRS, etc.) with both the TN device 1404 and one or more NTN devices 1406, such as in conjunction with Figure 6 as described. In some examples, as shown in Diagram 1400A, the serving base station may be a TN device, such that the UE 1402 may be connected to the serving base station via the TN network. In other examples, as shown in Diagram 1400B, the serving base station may be an NTN device, such that the UE 1402 may be connected to an NTN satellite base station. In both scenarios, the assistance data (AD) associated with the UE positioning session may include a mix of TN and NTN base stations. For the purposes of the present disclosure, a base station located on an NTN device (e.g., a satellite, an aircraft, or a UAS platform, etc.) may be referred to as an "NTN base station", an "NTN satellite base station", and / or an "NTN base station satellite". On the other hand, a base station located on the earth may be referred to as a "TN base station" and / or a "terrestrial base station".

[0161] DL-TDOA can be a good positioning mechanism for UE positioning associated with an NTN network (e.g., a LEO satellite network). For some small form factor devices such as smart phones, smart watches, and / or wearable devices, due to the limitations of their antennas, positioning based on high-precision carrier phase may be challenging, so DL-TDOA can enable DL-based UE positioning and UE-based positioning in an NTN network to increase accuracy and reduce the latency of UE positioning. However, satellite synchronization errors can reduce the accuracy or performance of DL-TDOA-based positioning methods, which may prevent an NTN network (e.g., an NTN network with LEO satellites) from achieving high-precision positioning. In other words, satellite synchronization can be an important factor in achieving high-precision positioning in a LEO satellite network. For example, different hardware and / or radio frequency (RF) chains in different satellites may result in synchronization errors across satellites, even if these satellites are controlled by the same gateway (e.g., gateway 1306). In other examples, different satellites may also be controlled by different gateways (e.g., two satellites may be controlled by two different gateways), which may result in additional network synchronization errors. Although one solution to eliminate satellite clock errors is to subtract the base station measurements from the mobile station measurements of the same satellite, such as in conjunction with Figure 11A , Figure 11B and Figure 12 as described, this solution may specify additional mobile stations, which may not be feasible or low-cost for commercial use cases (such as for smart phone and / or smart watch positioning).

[0162] Aspects presented herein can improve the accuracy and performance of a TDOA-based UE positioning scheme associated with NTN. Aspects presented herein provide enhanced TDOA-based UE positioning schemes that can utilize inter-satellite links to mitigate the impact of synchronization errors across different satellites.

[0163] In one aspect of the present disclosure, if one or more satellites associated with NTN are equipped with on-board baseband processing (also referred to as "baseband on-board processing"), an inter-satellite link can be established between two satellites to assist in TDOA-based UE positioning. For example, there may be one or more satellites that cover a particular region (at least for positioning services) at a particular time. If these satellites have the ability to perform on-board baseband processing, the synchronization error in the PRS transmissions across the set of satellites can be eliminated at least in part based on the inter-satellite reference signal (RS).

[0164] Figure 15 is a communication flow 1500 that shows an example of inter-satellite link-assisted TDOA-based UE positioning according to various aspects of the present disclosure. The numbers associated with the communication flow 1500 do not specify a particular time order and are only used as a reference for the communication flow 1500.

[0165] A TDOA-based UE positioning session can be established (e.g., by the LMF or serving base station) for UE 1502, where UE 1502 can be configured to receive PRS from a plurality of satellites (collectively referred to as "satellites" or "participating satellites") including a first satellite 1504, a second satellite 1506, and up to an Nth satellite 1508. In some examples, the first satellite 1504 can be referred to as the serving satellite, and the second satellite 1506 and up to the Nth satellite 1508 can be referred to as neighbor satellites. The satellites can cover a particular region at a particular time, and the satellites can include the ability to provide on-board baseband processing (e.g., the satellite is capable of receiving signals, measuring signals, and / or generating signals).

[0166] In one aspect, to eliminate the synchronization error between PRS transmissions from different satellites, the serving satellite can be configured to transmit at least one reference signal to the neighbor satellites (referred to as "inter-satellite reference signal") such that the neighbor satellites can estimate / calculate the time difference between the PRS transmission and the inter-satellite RS reception. Then, the UE can derive the RSTD of the PRS received from the serving base station and the neighbor base stations at least in part based on the reception time of the PRS and the time difference between the PRS transmission and the inter-satellite RS reception.

[0167] For example, to eliminate or reduce the synchronization error between PRSs transmitted from a first satellite 1504 (e.g., a serving satellite) and a second satellite 1506 (e.g., a neighbor satellite), at 1510, the first satellite 1504 may transmit a first PRS (PRS1) to the UE 1502, and at 1512, the first satellite 1504 may transmit a first inter-satellite RS (Inter-satRS1) to the second satellite 1506. The second satellite 1506 may cover the same area as the first satellite 1504. In some examples, the first inter-satellite RS may also be a PRS. In other words, the inter-satellite RS may also be a PRS.

[0168] After receiving the first inter-satellite RS from the first satellite 1504, at 1514, the second satellite 1506 may transmit a second PRS (PRS2) towards the UE 1502. Additionally, the second satellite 1506 may estimate / calculate the time difference between the second PRS transmission and the inter-satellite RS reception, which for the purposes of this disclosure may be represented as T sat_2_Tx→Rx . After the second satellite 1506 estimates / calculates the time difference (T sat_2_Tx→Rx ), the second satellite 1506 may transmit the estimated / calculated time difference (T sat_2_Tx→Rx ) to the UE 1502, such as transmitting it together with the second PRS or via a separate signaling or message. In some examples, since the UE 1502 may use this time difference (T sat_2_Tx→Rx ) to calculate the RSTD between the first PRS and the second PRS, each time difference (T sat_2_Tx→Rx ) may be associated with a satellite identifier (ID) identifying the satellite, a TRP ID, a PRS ID, and / or a timestamp.

[0169] At 1516, after the UE 1502 receives the first PRS (e.g., at 1510), the second PRS, and the time difference (T sat_2_Tx→Rx ) between the second PRS transmission and the inter-satellite RS reception, the UE 1502 may calculate the RSTD between the first PRS and the second PRS (denoted as RSTD_1_2) based on the following formula: RSTD_1_2 = T _Rx_sat_1 - T _Rx_sat_2 - (T gap,iner-sat_RS_1→PRS_1 + T prop,sat_1→sat_2 + T sat_2_Tx→

[0170] Rx ),

[0171] where T _Rx_sat_1 may be the reception time of the first PRS at the UE, T _Rx_sat_2 may be the reception time of the second PRS at the UE, T gap,iner-sat_RS_1→PRS_1It can be the time gap, T, between the first satellite 1504 transmitting the first inter-satellite RS and the first PRS prop,sat_1→sat_2 It can be the signal propagation time between the first satellite 1504 and the second satellite 1506 (which can be signaled to the UE 1502 by the second satellite 1506 and / or the LMF), and T sat_2_Tx→Rx It can be the time difference between the second satellite 1506 transmitting the second PRS and receiving the first inter-satellite RS, as described in connection with 1514. In some examples, as shown at 1518, since the UE 1502 may also be unaware of the inter-satellite RS transmission between the first satellite 1504 and the second satellite 1506, the first satellite 1504 can signal the time gap (T gap,iner-sat_RS_1→PRS_1 ) to the UE 1502, such as transmitting it together with the first PRS (e.g., at 1510) or via a separate signaling or message

[0172] Since the inter-satellite RS transmission between the first satellite 1504 and the second satellite 1506 (e.g., the first inter-satellite RS) can enable the UE 1502 to consider the time gap between the first satellite 1504 transmitting the first inter-satellite RS and the first PRS, the signal propagation time between the first satellite 1504 and the second satellite 1506, and the time difference between the second satellite 1506 transmitting the second PRS and receiving the first inter-satellite RS when the UE 1502 is calculating / estimating the RSTD of the PRSs received from the first satellite 1504 and the second satellite 1506, the synchronization error between the PRSs received from the first satellite 1504 and the second satellite 1506 can be eliminated or reduced, thereby providing a more accurate or improved TDOA-based UE positioning

[0173] Similarly, the synchronization error between other satellites associated with the UE positioning session can also be eliminated based on this configuration. For example, to eliminate or reduce the synchronization error between the PRSs transmitted from the first satellite 1504 and the Nth satellite 1508, at 1518, the first satellite 1504 can transmit the (N - 1)th inter-satellite RS to the Nth satellite 1508

[0174] After receiving the (N - 1)th inter-satellite RS from the first satellite 1504, at 1520, the Nth satellite 1508 can transmit the Nth PRS (PRS N) towards the UE 1502. In addition, the Nth satellite 1508 can estimate / calculate the time difference (T sat__N_Tx→Rx ) between the Nth PRS transmission and the inter-satellite RS reception, and transmit the estimated / calculated time difference (T sat__N_Tx→Rx ) to the UE 1502. Then, at 1522, after the UE 1502 receives the first PRS (e.g., at 1510), the Nth PRS, and the time difference (Tsat__N_Tx→Rx ) After that, the UE 1502 can calculate the RSTD between the first PRS and the Nth PRS (denoted as RSTD_1_N) based on the following formula:

[0175] RSTD_1_N = T _Rx_sat_1 - T _Rx_sat_N -(T gap,iner-sat_RS_(N-1)→PRS_1 + T prop,sat_1→sat_N +

[0176] T sat_N_Tx→Rx ),

[0177] where T _Rx_sat_1 can be the reception time of the first PRS at the UE, T _Rx_sat_N can be the reception time of the Nth PRS at the UE, T gap,iner-sat_RS_(N-1)→PRS_1 can be the time gap between the transmission of the N-1 inter-satellite RS by the first satellite 1504 and the first PRS, T prop,sat_1→sat_N can be the signal propagation time between the first satellite 1504 and the Nth satellite 1508, and T sat_N_Tx→Rx can be the time difference between the transmission of the Nth PRS by the Nth satellite 1508 and the reception of the N-1 inter-satellite RS, as described in connection with 1514. In some examples, as shown at 1524, since the UE 1502 may also be unaware of the inter-satellite RS transmission between the first satellite 1504 and the Nth satellite 1508, the first satellite 1504 can signal the UE 1502 the time gap (T gap,iner-sat_RS_(N-1)→PRS_1 ).

[0178] In some scenarios, for satellites with on-board baseband processing, the LMF can coordinate the gateway and the participating satellites for inter-satellite RS transmission. For example, a satellite (e.g., a serving satellite or a reference satellite) can be guided by the LMF to signal the inter-satellite RS at which time and / or frequency resources. In some examples, measurement gaps can also be configured for neighbor satellites (e.g., the second satellite 1506 and up to the Nth satellite 1508) to receive the inter-satellite RS.

[0179] In another example, the LMF can be specified to signal positioning assistance data to neighbor satellites to assist in inter-satellite RS reception, such as notifying neighbor satellites about the time and / or frequency allocation of the inter-satellite RS.

[0180] In another example, the LMF and / or the gateway associated with the satellite may also recommend transmit (Tx) and / or receive (Rx) beams to the satellite, such that the satellite may be able to determine which beam(s) can be used for transmitting the RS and / or for receiving the RS. In another example, the absolute or relative direction between the serving satellite (or reference satellite) and the neighbor satellite may be configured at the serving satellite and the neighbor satellite, which may guide the antenna selection (Tx / Rx) beamforming at the satellite for inter-satellite link transmission / reception. In another example, there may be a quasi-co-location (QCL) configuration to help the neighbor satellite find the best or most suitable Rx beam for inter-satellite RS reception.

[0181] In another aspect of the present disclosure, if one or more satellites associated with NTN are not equipped with on-board baseband processing, the synchronization error of the PRS transmission across the group of satellites may be eliminated at least partially based on the bent pipe operation.

[0182] Figure 16 is a communication flow 1600 showing an example of inter-satellite link-assisted TDOA-based UE positioning utilizing the bent pipe operation according to various aspects of the present disclosure. The numbers associated with the communication flow 1600 do not specify a particular time order and are only used as a reference for the communication flow 1600.

[0183] A TDOA-based UE positioning session may be established for the UE 1602 (e.g., by the LMF or the serving base station), where the UE 1602 may be configured to receive the PRS from a plurality of satellites including the first satellite 1604, the second satellite 1606, and up to the Nth satellite 1608 (collectively referred to as "satellites" or "participating satellites"). In some examples, the first satellite 1604 may be referred to as the serving satellite, and the second satellite 1606 and up to the Nth satellite 1608 may be referred to as neighbor satellites. The satellites may cover a specific area at a specific time, and at least the second satellite 1606 and up to the Nth satellite 1608 may have the ability to perform the bent pipe operation but may not have the ability to provide on-board baseband processing (hereinafter referred to as bent pipe satellites for the purpose of the present disclosure). The bent pipe operation may refer to a satellite receiving a signal from another satellite or a ground station and relaying / rerouting the signal to another device (e.g., to another ground station on the earth or to the UE). In other words, for a bent pipe-based satellite, the baseband samples may not be regenerated at the bent pipe satellite, and thus the baseband samples of the inter-satellite signal and the corresponding relayed signal may be the same.

[0184] In one aspect, to eliminate synchronization errors between PRSs transmitted from different satellites, a serving satellite may be configured to transmit a first PRS to a UE and a second PRS to a neighbor satellite that is a bent pipe satellite, such that the neighbor satellite may relay / reroute the second PRS to the UE. Then, the UE may derive the RSTD of the PRSs received from the serving base station and the neighbor base station based at least in part on the reception time of the PRSs and the group delay associated with the neighbor satellite.

[0185] For example, to eliminate or reduce synchronization errors between PRSs transmitted from a first satellite 1604 (e.g., the serving satellite) and a second satellite 1606 (e.g., the neighbor satellite), at 1610, the first satellite 1604 may transmit a first PRS (PRS1) to the UE 1602, and at 1612, the first satellite 1604 may transmit a second PRS (PRS2) to the second satellite 1606. The second satellite 1606 may cover the same area as the first satellite 1604.

[0186] After receiving the second PRS from the first satellite 1604, at 1614, the second satellite 1606 may relay / reroute the second PRS (PRS2') towards the UE 1602. In other words, the second satellite 1606 may bend the PRS received from the first satellite 1604 towards the UE 1602.

[0187] At 1616, after the UE 1602 receives the first PRS (e.g., at 1610) and the second PRS (e.g., at 1614), the UE 1602 may calculate the RSTD (denoted as RSTD_1_2) of the first PRS and the second PRS based on the following formula:

[0188] RSTD_1_2 = T _Rx_sat_1 - T _Rx_sat_2 -(T gap,PRS_2→PRS_1 + T prop,sat_1→sat_2 + T GD_BP )

[0189] where T _Rx_sat_1 may be the reception time of the first PRS at the UE, T _Rx_sat_2 may be the reception time of the second PRS at the UE, T gap,PRS_2→PRS_1 may be the time gap between the transmission of the first PRS and the second PRS by the first satellite 1604, T prop,sat_1→sat_2 may be the signal propagation time between the first satellite 1604 and the second satellite 1606 (which may be signaled to the UE 1602 by the LMF), and T GD_BPIt may be the group delay associated with the second satellite 1606. In some examples, as shown at 1618, since the UE 1602 may also be unaware of the inter-satellite PRS transmission between the first satellite 1604 and the second satellite 1606, the first satellite 1604 may signal to the UE 1602 a time gap (T gap,PRS_2→PRS_1 ), such as transmitting together with the first PRS (e.g., at 1610) or transmitting via a separate signaling or message.

[0190] In some examples, the group delay (T GD_BP ) of the bent pipe operation may be pre-calibrated at the UE 1602. For example, the LMF may signal to the UE 1602 the group delay (T GD_BP ) in the positioning assistance data for the UE 1602 to perform the RSTD calculation. Additionally, each group delay (T GD_BP ) may be associated with a satellite ID and / or a TRP ID. The variance of the group delay (T GD_BP ) (e.g., the dynamic range of the group delay distribution) may also be signaled in the assistance data.

[0191] Since the inter-satellite PRS transmission (e.g., the second PRS) between the first satellite 1604 and the second satellite 1606 enables the UE 1602 to consider the time gap between the first satellite 1604 transmitting the second PRS and the first PRS, the signal propagation time between the first satellite 1604 and the second satellite 1606, and the group delay associated with the second satellite 1606 when the UE 1602 is calculating / estimating the RSTD of the PRS received from the first satellite 1604 and the second satellite 1606, the synchronization error between the PRS received from the first satellite 1604 and the second satellite 1606 can be eliminated or reduced, thereby providing a more accurate or improved TDOA-based UE positioning.

[0192] Similarly, the synchronization error between other satellites associated with the UE positioning session can also be eliminated based on this configuration. For example, to eliminate or reduce the synchronization error between the PRS transmitted from the first satellite 1604 and the Nth satellite 1608 (e.g., a satellite without baseband processing capabilities), at 1618, the first satellite 1604 may transmit the Nth PRS to the Nth satellite 1608.

[0193] After receiving the Nth PRS from the first satellite 1604, at 1620, the Nth satellite 1608 may relay / reroute the Nth PRS (PRS N') towards the UE 1602. In other words, the Nth satellite 1608 may bend the PRS received from the first satellite 1604 towards the UE 1602.

[0194] At 1622, after the UE 1602 receives the first PRS (e.g., at 1610) and the Nth PRS (e.g., at 1614), the UE 1602 may calculate the RSTD (denoted as RSTD_1_N) of the first PRS and the Nth PRS based on the following formula:

[0195] RSTD_1_N = T _Rx_sat_1 - T _Rx_sat_N -(T gap,PRS_N→PRS_1 + T prop,sat_1→sat_N + T GD_BP ),

[0196] where T _Rx_sat_1 may be the reception time of the first PRS at the UE, T _Rx_sat_N may be the reception time of the Nth PRS at the UE, T gap,PRS_N→PRS_1 may be the time gap between the transmission of the first PRS and the Nth PRS by the first satellite 1604, T prop,sat_1→sat_N may be the signal propagation time between the first satellite 1604 and the Nth satellite 1608 (which may be signaled to the UE 1602 by the LMF), and T GD_BP may be the group delay associated with the Nth satellite 1608. In some examples, as shown at 1624, since the UE 1602 may also be unaware of the inter-satellite PRS transmission between the first satellite 1604 and the Nth satellite 1608, the first satellite 1604 may signal the time gap (T gap,PRS_N→PRS_1 ) to the UE 1602, such as transmitting it together with the first PRS (e.g., at 1610) or via a separate signaling or message.

[0197] In some scenarios, for bent-pipe satellites, baseband samples may not be regenerated (e.g., signals received from another satellite or a ground station), so the baseband samples of the inter-satellite PRS (e.g., PRS2, PRS N) and the corresponding relay PRS (e.g., PRS2', PRS N') may be the same. In addition, bent-pipe satellites may not be aware of the content of the baseband samples, so the LMF may be configured to coordinate the gateway and the relevant satellites for PRS relay. For example, the gateway and / or the serving satellite (or reference satellite) may be guided by the LMF to signal the inter-satellite PRS at which time and / or frequency resources. Additionally, there may be some controls / options for beam selection for serving / neighbor satellites based on the guidance from the LMF / gateway.

[0198] Figure 17This is the flowchart 1700 of a wireless communication method. This method can be executed by a UE or components of the UE (e.g., UE 104, 350, 404, 602, 802, 1310, 1402, 1502, 1602; device 1802; a processing system which may include a memory 360 and can be the entire UE 350, or components of UE 350, such as TX processor 368, RX processor 356, and / or controller / processor 359). This method can improve the accuracy and performance of a TDOA-based UE positioning scheme associated with NTN.

[0199] At 1702, the UE may receive a first PRS from a first satellite at a first reception time (T _Rx_sat_1 ), such as described in conjunction with Figure 15 . For example, at 1510, UE 1502 may receive a first PRS from a first satellite 1504 at a first reception time. The reception of the first PRS may be performed, for example, by the first PRS processing component 1840 and / or the reception component 1830 of the device 1802 in Figure 18 .

[0200] At 1704, the UE may receive a second PRS from a second satellite at a second reception time (T _Rx_sat_2 ) and an indication of the transmit-receive time difference (T sat_2_Tx→Rx ), where the transmit-receive time difference (T sat_2_Tx→Rx ) is the difference between the time when the second satellite transmits the second PRS to the UE and the time when the second satellite receives a reference signal (RS) from the first satellite, such as described in conjunction with Figure 15 . For example, at 1514, UE 1502 may receive a second PRS from a second satellite 1506 at a second reception time and an indication of the transmit-receive time difference (T sat_2_Tx→Rx ). The reception of the second PRS and / or the indication of the transmit-receive time difference may be performed by, for example, the second PRS processing component 1842 and / or the reception component 1830 of the device 1802 in Figure 18 .

[0201] At 1706, the UE may calculate a reference signal time difference (RSTD) between the first PRS and the second PRS based at least in part on the first reception time (T _Rx_sat_1 ) of the first PRS, the second reception time (T _Rx_sat_2 ) of the second PRS, and the transmit-receive time difference (T sat_2_Tx→Rx ), such as described in conjunction with Figure 15 . For example, at 1516, UE 1502 may calculate the RSTD between the first PRS and the second PRS based on the reception time of the first PRS, the reception time of the second PRS, and the transmit-receive time difference. The calculation of the RSTD may be performed, for example, by Figure 18is performed by the RSTD calculation component 1844 of the device 1802 in

[0202] In one example, the second satellite may have the ability to provide baseband on-board processing.

[0203] In another example, the RSTD (RSTD_1_2) of the first PRS and the second PRS may be calculated based on the following formula: RSTD _1_2 = T _Rx_sat_1 - T _Rx_sat_2 -(T gap,iner-sat_RS_1→PRS_1 + T prop,sat_1→sat_2 + T sat_2_Tx→Rx ), where T gap,iner-sat_RS_1→PRS_1 is the time gap between the time when the first satellite transmits the first PRS to the UE and the time when the first satellite transmits the RS to the second satellite, and T prop,sat_1→sat_2 is the signal propagation time between the first satellite and the second satellite. In such an example, the UE may receive an indication of T gap,iner-sat_RS_1→PRS_1 from the first satellite. In such an example, the UE may receive an indication of T prop,sat_1→sat_2 from the second satellite.

[0204] In another example, the transmit-receive time difference (T sat_2_Tx→Rx ) may be associated with one or more of the following: satellite ID, TRP ID, PRS ID, or timestamp.

[0205] In another example, the UE may calculate its location based at least in part on the RSTD of the first PRS and the second PRS.

[0206] Figure 18FIG. 1800 is a diagram illustrating an example of a hardware implementation for device 1802. Device 1802 may be a UE, a component of a UE, or may implement UE functionality. In some aspects, device 1802 may include a baseband processor 1804 (also referred to as a modem) coupled to at least one transceiver 1822 (e.g., one or more RF transceivers and / or antennas). The at least one transceiver 1822 may be associated with or include a receiving component 1830 and / or a transmitting component 1834. In some aspects, device 1802 may also include one or more subscriber identity module (SIM) cards 1820, an application processor 1806 coupled to a secure digital (SD) card 1808 and a screen 1810, a Bluetooth module 1812, a wireless local area network (WLAN) module 1814, a global positioning system (GPS) module 1816, or a power supply 1818. The baseband processor 1804 communicates with UE 104 and / or BS 102 / 180 via the at least one transceiver 1822. The baseband processor 1804 may include a computer-readable medium / memory (e.g., memory 1826). The computer-readable medium / memory may be non-transitory. The baseband processor 1804 and / or at least one processor 1828 are responsible for general processing, including executing software stored on the computer-readable medium / memory. The software, when executed by the baseband processor 1804 and / or at least one processor 1828, causes the baseband processor 1804 and / or at least one processor 1828 to perform the various functions described above. The computer-readable medium / memory may also be used to store data manipulated by the baseband processor 1804 when executing the software. The baseband processor 1804 further includes a receiving component 1830, a communication manager 1832, and a transmitting component 1834. In a non-limiting example, the receiving component 1830 and the transmitting component 1834 may include at least one transceiver and / or at least one antenna subsystem. The communication manager 1832 includes one or more of the illustrated components. The components within the communication manager 1832 may be stored in the computer-readable medium / memory and / or configured as hardware within the baseband processor 1804. The baseband processor 1804 may be a component of UE 350 and may include at least one of memory 360 and / or TX processor 368, RX processor 356, and controller / processor 359. In one configuration, device 1802 may be a modem chip and may include only the baseband processor 1804, and in another configuration, device 1802 may be an entire UE (e.g., see Figure 3 of 350), and includes additional modules of device 1802.

[0207] The communication manager 1832 includes a first PRS processing component 1840 configured to at a first reception time (T _Rx_sat_1)Receiving a first positioning reference signal (PRS) from a first satellite, e.g., as described in 1702 in connection with Figure 17 . The communication manager 1832 also includes a second PRS processing component 1842 configured to receive a second PRS from a second satellite at a second reception time (T _Rx_sat_2 ) and an indication of the transmit-receive time difference (T sat_2_Tx→Rx ), where the transmit-receive time difference (T sat_2_Tx→Rx ) is the difference between the time when the second satellite transmits the second PRS to the UE and the time when the second satellite receives the RS from the first satellite, e.g., as described in 1704 in connection with Figure 17 . The communication manager 1832 also includes an RSTD calculation component 1844 configured to calculate a reference signal time difference (RSTD) between the first PRS and the second PRS based at least in part on the first reception time (T _Rx_sat_1 ) of the first PRS, the second reception time (T _Rx_sat_2 ) of the second PRS, and the transmit-receive time difference (T sat_2_Tx→Rx ), e.g., as described in 1706 in connection with Figure 17 .

[0208] The device may include additional components that perform each of the blocks in the algorithm of the Figure 17 flowchart. Thus, Figure 17 each block in the flowchart of Figure 17 may be performed by a component, and the device may include one or more of those components. These components may be one or more hardware components specifically configured to perform the process / algorithm, implemented by a processor configured to perform the process / algorithm, stored in a computer-readable medium for implementation by a processor, or some combination thereof.

[0209] As shown, the device 1802 may include various components configured for various functions. In one configuration, the device 1802 and specifically the baseband processor 1804 includes means (e.g., the first PRS processing component 1840 and / or the receiving component 1830) for receiving a first positioning reference signal (PRS) from a first satellite at a first reception time (T _Rx_sat_1 ). The device 1802 includes means (e.g., the second PRS processing component 1842 and / or the receiving component 1830) for receiving a second PRS from a second satellite at a second reception time (T _Rx_sat_2 ) and an indication of the transmit-receive time difference (T sat_2_Tx→Rx ), where the transmit-receive time difference (T sat_2_Tx→Rx) is the difference between the time when the second satellite transmits the second PRS to the UE and the time when the second satellite receives the reference signal (RS) from the first satellite. The apparatus 1802 includes means (e.g., the RSTD calculation component 1844) for calculating the reference signal time difference (RSTD) between the first PRS and the second PRS based at least in part on the first reception time (T _Rx_sat_1 ) of the first PRS, the second reception time (T _Rx_sat_2 ) of the second PRS, and the transmit-receive time difference (T sat_2_Tx→Rx ).

[0210] In one configuration, the second satellite may have the ability to provide baseband on-board processing.

[0211] In another configuration, the RSTD (RSTD_1_2) between the first PRS and the second PRS can be calculated based on the following formula: RSTD _1_2 = T _Rx_sat_1 - T _Rx_sat_2 - (T gap,iner-sat_RS_1→PRS_1 + T prop,sat_1→sat_2 + T sat_2_Tx→Rx ), where T gap,iner-sat_RS_1→PRS_1 is the time gap between the time when the first satellite transmits the first PRS to the UE and the time when the first satellite transmits the RS to the second satellite, and T prop,sat_1→sat_2 is the signal propagation time between the first satellite and the second satellite. In this configuration, the apparatus 1802 includes means for receiving an indication of T gap,iner-sat_RS_1→PRS_1 from the first satellite. In this configuration, the apparatus 1802 includes means for receiving an indication of T prop,sat_1→sat_2 from the second satellite.

[0212] In another configuration, the transmit-receive time difference (T sat_2_Tx→Rx ) may be associated with one or more of the following: satellite ID, TRP ID, PRS ID, or timestamp.

[0213] In another configuration, the apparatus 1802 includes means for calculating the location of the UE based at least in part on the RSTD between the first PRS and the second PRS.

[0214] The means can be one or more components of the apparatus 1802 configured to perform the functions recited by the means. As described above, the apparatus 1802 may include the TX processor 368, the RX processor 356, and the controller / processor 359. Thus, in one configuration, the means can be the TX processor 368, the RX processor 356, and the controller / processor 359 configured to perform the functions recited by the means.

[0215] Figure 19FIG. 1900 is a flowchart of a wireless communication method. This method can be performed by a satellite or a component of a satellite (e.g., satellites 902, 1001, 1002, 1504, 1506, 1508; NTN payload 1308; one or more NTN devices 1406; device 2002; a processing system, which may include a memory 376 and can be the entire base station 310 or a component of the base station 310, such as a TX processor 316, an RX processor 370, and / or a controller / processor 375). This method can improve the accuracy and performance of a TDOA-based UE positioning scheme associated with NTN.

[0216] At 1902, a first satellite may transmit a RS to a second satellite at a first transmission time, such as described in conjunction with Figure 15 . For example, at 1512, the first satellite 1504 may transmit an inter-satellite RS to the second satellite 1506. The transmission of the RS may be performed, for example, by Figure 20 the RS configuration component 2040 and / or the transmission component 2034 of the device 2002 in

[0217] At 1904, the first satellite may transmit a PRS to the UE at a second transmission time, such as described in conjunction with Figure 15 . For example, at 1510, the first satellite 1504 may transmit a first PRS to the UE 1502. The transmission of the PRS may be performed, for example, by Figure 20 the PRS configuration component 2042 and / or the transmission component 2034 of the device 2002 in

[0218] At 1906, the first satellite may transmit an indication of a time gap (T gap,iner-sat_RS_1→PRS_1 ) between the first transmission time and the second transmission time to the UE, such as described in conjunction with Figure 15 . For example, at 1518, the first satellite 1504 may transmit an indication of the transmission time gap between the RS and the first PRS to the UE 1502. The transmission of the indication of the time gap may be performed, for example, by Figure 20 the time gap indication component 2044 and / or the transmission component 2034 of the device 2002 in

[0219] In one example, the second satellite may have the ability to provide baseband on-board processing.

[0220] In another example, the RS may be a second PRS.

[0221] In another example, the first satellite may receive a resource allocation for transmitting the RS from a gateway or an LMF.

[0222] In another example, the first satellite may receive a resource allocation for transmitting the RS from a gateway or an LMF.

[0223] In another example, the first satellite may receive a configuration of one or more transmit beams for transmitting RS from a gateway or an LMF.

[0224] Figure 20 FIG. 2000 is a diagram illustrating an example of a hardware implementation for device 2002. Device 2002 may be a satellite, a component of a satellite, or may implement base station functionality. In some aspects, device 2002 may include a baseband unit 2004. The baseband unit 2004 may communicate with UE 104 or with another satellite via at least one transceiver 2022 (e.g., one or more RF transceivers and / or antennas). The at least one transceiver 2022 may be associated with or include a receive component 2030 and / or a transmit component 2034. The baseband unit 2004 may include a computer-readable medium / memory (e.g., memory 2026). The baseband unit 2004 and / or at least one processor 2028 may be responsible for general processing, including executing software stored on the computer-readable medium / memory. The software, when executed by the baseband unit 2004 and / or at least one processor 2028, causes the baseband unit 2004 and / or at least one processor 2028 to perform the various functions described above. The computer-readable medium / memory may also be used to store data manipulated by the baseband unit 2004 when executing the software. The baseband unit 2004 further includes a receive component 2030, a communication manager 2032, and a transmit component 2034. In a non-limiting example, the receive component 2030 and the transmit component 2034 may include at least one transceiver and / or at least one antenna subsystem. The communication manager 2032 includes one or more of the components shown. The components within the communication manager 2032 may be stored in the computer-readable medium / memory and / or configured as hardware within the baseband unit 2004. The baseband unit 2004 may be a component of a base station and may include at least one of a memory 376 and / or a TX processor 316, an RX processor 370, and a controller / processor 375.

[0225] The communication manager 2032 includes an RS configuration component 2040 that transmits RS to a second satellite at a first transmission time, e.g., as described in 1902 in connection with Figure 19 The communication manager 2032 further includes a PRS configuration component 2042 that transmits PRS to the UE at a second transmission time, e.g., as described in 1904 in connection with Figure 19 The communication manager 2032 further includes a time gap indication component 2044 that transmits an indication of a time gap (T gap,iner-sat_RS_1→PRS_1 ) between the first transmission time and the second transmission time to the UE, e.g., as described in 1906 in connection with Figure 19

[0226] The device may include performing​Figure 19 The additional components for each box in the algorithm boxes of the flowchart. Thus, Figure 19 each box in the flowchart can be executed by a component, and the device can include one or more of those components. These components can be one or more hardware components that are specifically configured to execute the process / algorithm, implemented by a processor configured to execute the process / algorithm, stored in a computer-readable medium for implementation by a processor, or some combination thereof.

[0227] As shown, device 2002 can include various components configured for various functions. In one configuration, device 2002 and specifically baseband unit 2004 includes means (e.g., RS configuration component 2040 and / or transmit component 2034) for transmitting an RS to a second satellite at a first transmission time. Device 2002 includes means (e.g., PRS configuration component 2042 and / or transmit component 2034) for transmitting a PRS to a UE at a second transmission time. Device 2002 includes means (e.g., time gap indication component 2044 and / or transmit component 2034) for transmitting an indication of the time gap (T gap,iner-sat_RS_1→PRS_1 ) between the first transmission time and the second transmission time to the UE.

[0228] In one configuration, the second satellite can have the ability to provide baseband on-board processing.

[0229] In another configuration, the RS can be a second PRS.

[0230] In another configuration, device 2002 includes means for receiving a resource allocation for transmitting an RS from a gateway or LMF.

[0231] In another configuration, device 2002 includes means for receiving a resource allocation for transmitting an RS from a gateway or LMF.

[0232] In another configuration, device 2002 includes means for receiving a configuration of one or more transmit beams for transmitting an RS from a gateway or LMF.

[0233] The means can be one or more of the components of device 2002 that are configured to perform the functions recited by the means. As described above, device 2002 can include TX processor 316, RX processor 370, and controller / processor 375. Thus, in one configuration, the means can be TX processor 316, RX processor 370, and controller / processor 375 that are configured to perform the functions recited by the means.

[0234] Figure 21It is a flowchart 2100 of a wireless communication method. This method can be executed by a satellite or components of a satellite (e.g., satellites 902, 1001, 1002, 1504, 1506, 1508; NTN payload 1308; one or more NTN devices 1406; device 2202; a processing system, which may include a memory 376 and can be the entire base station 310 or components of the base station 310, such as a TX processor 316, an RX processor 370, and / or a controller / processor 375). This method can improve the accuracy and performance of a TDOA-based UE positioning scheme associated with NTN.

[0235] At 2102, a second satellite may receive a RS from a first satellite at a first reception time, such as described in conjunction with Figure 15 For example, at 1512, the second satellite 1506 may receive an inter-satellite RS from the first satellite 1504. The reception of the RS may be performed, for example, by Figure 22 the RS processing component 2240 and / or the reception component 2230 of the device 2202 in

[0236] At 2104, the second satellite may transmit a PRS to a UE at a first transmission time, such as described in conjunction with Figure 15 For example, at 1514, the second satellite 1506 may transmit a second PRS to the UE 1502. The transmission of the PRS may be performed, for example, by Figure 22 the PRS configuration component 2242 and / or the transmission component 2234 of the device 2202 in

[0237] At 2106, the second satellite may transmit an indication of the transmit-receive time difference (T sat_2_Tx→Rx ) between the first reception time and the first transmission time to the UE, such as described in conjunction with Figure 15 For example, at 1514, the second satellite 1506 may transmit an indication of the transmit-receive time difference (T sat_2_Tx→Rx ) to the UE 1502. The transmission of the indication of the transmit-receive time difference (T sat_2_Tx→Rx ) may be performed, for example, by Figure 22 the Tx-Rx time difference indication component 2244 and / or the transmission component 2234 of the device 2202 in

[0238] In one example, the second satellite may have the ability to provide baseband on-board processing.

[0239] In another example, the second satellite may transmit an indication of the signal propagation time (T prop,sat_1→sat_2 ) between the first satellite and the second satellite to the UE.

[0240] In another example, the transmit-receive time difference (T sat_2_Tx→Rx)May be associated with one or more of the following: satellite ID, TRP ID, PRS ID, or timestamp.

[0241] In another example, the second satellite may receive a configuration for transmitting PRS based on RS from a gateway or LMF.

[0242] In another example, the second satellite may receive a measurement gap for receiving RS from a gateway or LMF.

[0243] In another example, RS is a second PRS.

[0244] In another example, the second satellite may receive a resource allocation for receiving RS from a gateway or LMF.

[0245] In another example, the second satellite may receive a configuration of one or more receive beams for receiving RS from a gateway or LMF.

[0246] Figure 22 FIG. 2200 is a diagram illustrating an example of a hardware implementation for device 2202. Device 2202 may be a satellite, a component of a satellite, or may implement base station functionality. In some aspects, device 2202 may include a baseband unit 2204. The baseband unit 2204 may communicate with UE 104 or with another satellite via at least one transceiver 2222 (e.g., one or more RF transceivers and / or antennas). The at least one transceiver 2222 may be associated with or include a receive component 2230 and / or a transmit component 2234. The baseband unit 2204 may include a computer-readable medium / memory (e.g., memory 2226). The baseband unit 2204 and / or at least one processor 2228 may be responsible for general processing, including executing software stored on the computer-readable medium / memory. The software, when executed by the baseband unit 2204 and / or at least one processor 2228, causes the baseband unit 2204 and / or at least one processor 2228 to perform the various functions described above. The computer-readable medium / memory may also be used to store data manipulated by the baseband unit 2204 when executing the software. The baseband unit 2204 further includes a receive component 2230, a communication manager 2232, and a transmit component 2234. In a non-limiting example, the receive component 2230 and the transmit component 2234 may include at least one transceiver and / or at least one antenna subsystem. The communication manager 2232 includes one or more of the illustrated components. The components within the communication manager 2232 may be stored in the computer-readable medium / memory and / or be configured as hardware within the baseband unit 2204. The baseband unit 2204 may be a component of a base station and may include at least one of a memory 376 and / or a TX processor 316, an RX processor 370, and a controller / processor 375.

[0247] The communication manager 2232 includes an RS processing component 2240 that receives RS from a first satellite at a first reception time, e.g., as described in 2102 in connection with Figure 21 . The communication manager 2232 also includes a PRS configuration component 2242 that transmits PRS to a UE at a first transmission time, e.g., as described in 2104 in connection with Figure 21 . The communication manager 2232 also includes a Tx-Rx time difference indication component 2244 that transmits to the UE an indication of the transmit-receive time difference (T sat_2_Tx→Rx ) between the first reception time and the first transmission time, e.g., as described in 2106 in connection with Figure 21 .

[0248] The device may include additional components that perform each of the blocks of the algorithm in the flowchart of Figure 21 . Thus, each block in the flowchart of Figure 21 may be performed by a component, and the device may include one or more of those components. These components may be one or more hardware components that are specifically configured to perform the process / algorithm, implemented by a processor configured to perform the process / algorithm, stored in a computer-readable medium for implementation by a processor, or some combination thereof.

[0249] As shown, the device 2202 may include various components configured for various functions. In one configuration, the device 2202 and specifically the baseband unit 2204 include means for receiving RS from a first satellite at a first reception time (e.g., the RS processing component 2240 and / or the receiving component 2230). The device 2202 includes means for transmitting PRS to a UE at a first transmission time (e.g., the PRS configuration component 2242 and / or the transmitting component 2234). The device 2202 includes means for transmitting to the UE an indication of the transmit-receive time difference (T sat_2_Tx→Rx ) between the first reception time and the first transmission time (e.g., the Tx-Rx time difference indication component 2244 and / or the transmitting component 2234).

[0250] In one configuration, the second satellite may have the ability to provide baseband on-board processing.

[0251] In another configuration, the second satellite may transmit to the UE an indication of the signal propagation time (T prop,sat_1→sat_2 ) between the first satellite and the second satellite.

[0252] In another configuration, the transmit-receive time difference (T sat_2_Tx→Rx ) may be associated with one or more of the following: satellite ID, TRP ID, PRS ID, or timestamp.

[0253] In another configuration, device 2202 includes means for receiving, from a gateway or LMF, a configuration for transmitting a PRS based on an RS.

[0254] In another configuration, device 2202 includes means for receiving, from a gateway or LMF, a measurement gap for receiving an RS.

[0255] In another configuration, the RS is a second PRS.

[0256] In another configuration, device 2202 includes means for receiving, from a gateway or LMF, a resource allocation for receiving an RS.

[0257] In another configuration, device 2202 includes means for receiving, from a gateway or LMF, a configuration of one or more receive beams for receiving an RS.

[0258] The means can be one or more components of device 2202 configured to perform the functions recited by the means. As described above, device 2202 can include a TX processor 316, an RX processor 370, and a controller / processor 375. Thus, in one configuration, the means can be the TX processor 316, the RX processor 370, and the controller / processor 375 configured to perform the functions recited by the means.

[0259] Figure 23 is a flowchart 2300 of a wireless communication method. The method can be performed by a UE or a component of a UE (e.g., UE 104, 350, 404, 602, 802, 1310, 1402, 1502, 1602; device 2402; a processing system that can include a memory 360 and can be the entire UE 350, or a component of UE 350, such as a TX processor 368, an RX processor 356, and / or a controller / processor 359). The method can improve the accuracy and performance of a TDOA-based UE positioning scheme associated with NTN.

[0260] At 2302, the UE can receive a first PRS from a first satellite at a first reception time (T _Rx_sat_1 ), such as described in conjunction with Figure 16 . For example, at 1610, UE 1602 can receive a first PRS from a first satellite 1604 at a first reception time. The reception of the first PRS can be performed, for example, by a first PRS processing component 2440 and / or a receiving component 2430 of device 2402 in Figure 24 .

[0261] At 2304, the UE can receive a second PRS from a second satellite at a second reception time (T _Rx_sat_2)Receiving a second PRS from a second satellite, the second PRS being transmitted from a first satellite and relayed to the UE via the second satellite, such as in conjunction with Figure 16 as described. For example, at 1614, the UE 1602 may receive the second PRS from the second satellite 1606 at a second reception time. The reception of the second PRS may be performed, for example, by Figure 24 the second PRS processing component 2442 and / or the receiving component 2430 of the device 2402 in

[0262] At 2306, the UE may calculate the RSTD of the first PRS and the second PRS based at least in part on the first reception time (T _Rx_sat_1 ) of the first PRS, the second reception time (T _Rx_sat_2 ) of the second PRS, and the group delay (T GD_BP ) associated with the second satellite, such as in conjunction with Figure 16 as described. For example, at 1616, the UE 1602 may calculate the RSTD of the first PRS and the second PRS based on the reception time of the first PRS, the reception time of the second PRS, and the group delay associated with the second satellite 1606. The calculation of the RSTD may be performed, for example, by Figure 24 the RSTD calculation component 2444 of the device 2402 in

[0263] In one example, the second satellite may not have the ability to provide baseband on-board processing.

[0264] In another example, the RSTD (RSTD_1_2) of the first PRS and the second PRS may be calculated based on the following formula: RSTD _1_2 = T _Rx_sat_1 - T _Rx_sat_2 - (T gap,PRS_2→PRS_1 + T prop,sat_1→sat_2 + T GD_BP ), where T gap,PRS_2→PRS_1 is the time gap between the time when the first satellite transmits the first PRS to the UE and the time when the first satellite transmits the second PRS to the second satellite, and T prop,sat_1→sat_2 is the signal propagation time between the first satellite and the second satellite.

[0265] In another example, the UE may receive an indication of T gap,PRS_2→PRS_1 from the first satellite.

[0266] In another example, the UE may receive an indication of T prop,sat_1→sat_2 from the second satellite.

[0267] In another example, the UE may receive the group delay (T GD_BP ) from the LMF via the AD.

[0268] In another example, the group delay (T GD_BP ) may be associated with one or more of the following: satellite ID or TRP ID.

[0269] In another example, the UE may calculate its location based at least in part on the RSTD of the first PRS and the second PRS.

[0270] In another example, the second PRS may not be a regenerated signal of the first PRS.

[0271] Figure 24FIG. 2400 is a diagram illustrating an example of a hardware implementation for device 2402. Device 2402 can be a UE, a component of a UE, or implement UE functionality. In some aspects, device 2402 can include a baseband processor 2404 (also referred to as a modem) coupled to at least one transceiver 2422 (e.g., one or more RF transceivers and / or antennas). At least one transceiver 2422 can be associated with or include a receive component 2430 and / or a transmit component 2434. In some aspects, device 2402 can also include one or more subscriber identity module (SIM) cards 2420, an application processor 2406 coupled to a secure digital (SD) card 2408 and a screen 2410, a Bluetooth module 2412, a wireless local area network (WLAN) module 2414, a global positioning system (GPS) module 2416, or a power supply 2418. The baseband processor 2404 communicates with UE 104 and / or BS102 / 240 via at least one transceiver 2422. The baseband processor 2404 can include a computer-readable medium / memory (e.g., memory 2426). The computer-readable medium / memory can be non-transitory. The baseband processor 2404 and / or at least one processor 2428 are responsible for general processing, including executing software stored on the computer-readable medium / memory. The software, when executed by the baseband processor 2404 and / or at least one processor 2428, causes the baseband processor 2404 and / or at least one processor 2428 to perform the various functions described above. The computer-readable medium / memory can also be used to store data manipulated by the baseband processor 2404 when executing the software. The baseband processor 2404 also includes a receive component 2430, a communication manager 2432, and a transmit component 2434. In a non-limiting example, the receive component 2430 and the transmit component 2434 can include at least one transceiver and / or at least one antenna subsystem. The communication manager 2432 includes one or more of the illustrated components. The components within the communication manager 2432 can be stored in the computer-readable medium / memory and / or configured as hardware within the baseband processor 2404. The baseband processor 2404 can be a component of UE350 and can include at least one of a memory 360 and / or a TX processor 368, an RX processor 356, and a controller / processor 359. In one configuration, device 2402 can be a modem chip and include only the baseband processor 2404, and in another configuration, device 2402 can be an entire UE (e.g., see Figure 3 of 350), and include additional modules of device 2402.

[0272] The communication manager 2432 includes a first PRS processing component 2440 configured to receive a first PRS from a first satellite at a first reception time (T _Rx_sat_1 ), e.g., as described in connection withFigure 23 as described in 2302. The communication manager 2432 also includes a second PRS processing component 2442 configured to receive a second PRS from a second satellite at a second reception time (T _Rx_sat_2 ), where the second PRS is transmitted from a first satellite and relayed to the UE via the second satellite. For example, as described in connection with Figure 23 2304. The communication manager 2432 also includes an RSTD calculation component 2444 configured to calculate the RSTD between the first PRS and the second PRS based at least in part on a first reception time (T _Rx_sat_1 ) of the first PRS, a second reception time (T _Rx_sat_2 ) of the second PRS, and a group delay (T GD_BP ) associated with the second satellite. For example, as described in connection with Figure 23 2306.

[0273] The device may include additional components that perform each block of the algorithm in the Figure 23 flowchart. Thus, Figure 23 each block in the flowchart of

[0274] Figure 23 can be performed by a component, and the device may include one or more of those components. These components may be one or more hardware components specifically configured to perform the process / algorithm, implemented by a processor configured to perform the process / algorithm, stored in a computer-readable medium for implementation by a processor, or some combination thereof.

[0274] As shown, device 2402 may include various components configured for various functions. In one configuration, device 2402 and specifically baseband processor 2404 includes means (e.g., first PRS processing component 2440 and / or receiving component 2430) for receiving a first PRS from a first satellite at a first reception time (T _Rx_sat_1 ). Device 2402 includes means (e.g., second PRS processing component 2442 and / or receiving component 2430) for receiving a second PRS from a second satellite at a second reception time (T _Rx_sat_2 ), where the second PRS is transmitted from a first satellite and relayed to the UE via the second satellite. Device 2402 includes means (e.g., RSTD calculation component 2444) for calculating the RSTD between the first PRS and the second PRS based at least in part on a first reception time (T _Rx_sat_1 ) of the first PRS, a second reception time (T _Rx_sat_2 ) of the second PRS, and a group delay (T GD_BP ) associated with the second satellite.

[0275] In one configuration, the second satellite may not have the ability to provide baseband on-board processing.

[0276] In another configuration, the RSTD (RSTD_1_2) of the first PRS and the second PRS can be calculated based on the following formula: RSTD _1_2 = T _Rx_sat_1 - T _Rx_sat_2 -(T gap,PRS_2→PRS_1 + T prop,sat_1→sat_2 + T GD_BP ), where T gap,PRS_2→PRS_1 is the time gap between the time when the first satellite transmits the first PRS to the UE and the time when the first satellite transmits the second PRS to the second satellite, and T prop,sat_1→sat_2 is the signal propagation time between the first satellite and the second satellite.

[0277] In another configuration, device 2402 includes means for receiving an indication of T gap,PRS_2→PRS_1 from the first satellite.

[0278] In another configuration, device 2402 includes means for receiving an indication of T prop,sat_1→sat_2 from the second satellite.

[0279] In another configuration, device 2402 includes means for receiving the group delay (T GD_BP ) from the LMF via the AD.

[0280] In another configuration, the group delay (T GD_BP ) can be associated with one or more of the following: satellite ID or TRPID.

[0281] In another configuration, device 2402 includes means for calculating the location of the UE at least partially based on the RSTD of the first PRS and the second PRS.

[0282] In another configuration, the second PRS may not be a regenerated signal of the first PRS.

[0283] Figure 25 is the flowchart 2500 of a wireless communication method. This method can be executed by a satellite or a component of a satellite (e.g., satellites 902, 1001, 1002, 1504, 1506, 1508, 1604; NTN payload 1308; one or more NTN devices 1406; device 2602; a processing system, which may include a memory 376 and can be the entire base station 310 or a component of the base station 310, such as a TX processor 316, an RX processor 370, and / or a controller / processor 375). This method can improve the accuracy and performance of a TDOA-based UE positioning scheme associated with NTN.

[0284] At 2502, a first satellite may transmit a first PRS to a UE at a first transmission time, such as described in conjunction with Figure 16 . For example, at 1610, the first satellite 1604 may transmit a first PRS to the UE 1602. The transmission of the first PRS may be performed, for example, by the first PRS configuration component 2640 and / or the transmission component 2634 of the device 2602 in Figure 26 .

[0285] At 2504, the first satellite may transmit a second PRS to a second satellite at a second transmission time, and the second PRS is relayed to the UE via the second satellite, such as described in conjunction with Figure 16 . For example, at 1612, the first satellite 1604 may transmit a second PRS to the second satellite 1606. The transmission of the second PRS may be performed, for example, by the second PRS configuration component 2642 and / or the transmission component 2634 of the device 2602 in Figure 26 .

[0286] At 2506, the first satellite may transmit an indication of a time gap (T gap,PRS_2→PRS_1 ) between the first transmission time and the second transmission time to the UE, such as described in conjunction with Figure 16 . For example, at 1618, the first satellite 1604 may transmit an indication of the transmission time gap between the first PRS and the second PRS to the UE 1602. The transmission of the indication of the time gap may be performed, for example, by the time gap indication component 2644 and / or the transmission component 2634 of the device 2602 in Figure 26 .

[0287] In one example, the second satellite may not have the ability to provide baseband on-board processing.

[0288] In another example, the UE may receive resource allocation for transmitting the second PRS from a gateway or an LMF.

[0289] In another example, the UE may receive configuration of one or more transmission beams for transmitting the second PRS from a gateway or an LMF.

[0290] Figure 26FIG. 2600 is an illustration showing an example of a hardware implementation for device 2602. Device 2602 may be a satellite, a component of a satellite, or may implement base station functionality. In some aspects, device 2602 may include a baseband unit 2604. The baseband unit 2604 may communicate with UE 104 or with another satellite via at least one transceiver 2622 (e.g., one or more RF transceivers and / or antennas). The at least one transceiver 2622 may be associated with or include a receiving component 2630 and / or a transmitting component 2634. The baseband unit 2604 may include a computer-readable medium / memory (e.g., memory 2626). The baseband unit 2604 and / or at least one processor 2628 may be responsible for general processing, including executing software stored on the computer-readable medium / memory. The software, when executed by the baseband unit 2604 and / or at least one processor 2628, causes the baseband unit 2604 and / or at least one processor 2628 to perform the various functions described above. The computer-readable medium / memory may also be used to store data manipulated by the baseband unit 2604 when executing the software. The baseband unit 2604 further includes a receiving component 2630, a communication manager 2632, and a transmitting component 2634. In a non-limiting example, the receiving component 2630 and the transmitting component 2634 may include at least one transceiver and / or at least one antenna subsystem. The communication manager 2632 includes one or more of the components shown. The components within the communication manager 2632 may be stored in the computer-readable medium / memory and / or configured as hardware within the baseband unit 2604. The baseband unit 2604 may be a component of a base station and may include at least one of a memory 376 and / or a TX processor 316, an RX processor 370, and a controller / processor 375.

[0291] The communication manager 2632 includes a first PRS configuration component 2640 that transmits a first PRS to the UE at a first transmission time, e.g., as described in Figure 25 in connection with 2502. The communication manager 2632 further includes a second PRS configuration component 2642 that transmits a second PRS to a second satellite at a second transmission time, and the second PRS is relayed to the UE via the second satellite, e.g., as described in Figure 25 in connection with 2504. The communication manager 2632 further includes a time gap indication component 2644 that transmits an indication of a time gap (T gap,PRS_2→PRS_1 ) between the first transmission time and the second transmission time to the UE, e.g., as described in Figure 25 in connection with 2506.

[0292] The device may include additional components that perform each of the blocks in the algorithm of the Figure 25 flowchart. Thus, Figure 25Each block in the flowchart can be executed by a component, and the device can include one or more of those components. These components can be one or more hardware components that are specifically configured to execute the process / algorithm, implemented by a processor configured to execute the process / algorithm, stored in a computer-readable medium for implementation by a processor, or some combination thereof.

[0293] As shown, device 2602 can include various components configured for various functions. In one configuration, device 2602 and specifically baseband unit 2604 includes means (e.g., first PRS configuration component 2640 and / or transmission component 2634) for transmitting a first PRS to a UE at a first transmission time. Device 2602 includes means (e.g., second PRS configuration component 2642 and / or transmission component 2634) for transmitting a second PRS to a second satellite at a second transmission time, and the second PRS is relayed to the UE via the second satellite. Device 2602 includes means (e.g., time gap indication component 2644 and / or transmission component 2634) for transmitting an indication of a time gap (T gap,PRS_2→PRS_1 ) between the first transmission time and the second transmission time to the UE.

[0294] In one configuration, the second satellite may not have the ability to provide baseband on-board processing.

[0295] In another configuration, device 2602 includes means for receiving a resource allocation for transmitting the second PRS from a gateway or LMF.

[0296] In another configuration, device 2602 includes means for receiving a configuration of one or more transmission beams for transmitting the second PRS from a gateway or LMF.

[0297] The means can be one or more of the components of device 2602 configured to perform the functions recited by the means. As described above, device 2602 can include TX processor 316, RX processor 370, and controller / processor 375. Thus, in one configuration, the means can be TX processor 316, RX processor 370, and controller / processor 375 configured to perform the functions recited by the means.

[0298] It should be understood that the specific order or hierarchy of the blocks in the disclosed process / flowchart is merely illustrative of an example method. It should be understood that the specific order or hierarchy of the blocks in the process / flowchart can be rearranged based on design preferences. Further, some blocks can be combined or omitted. The appended method claims present the elements of the various blocks in a sample order, but are not meant to be limited to the specific order or hierarchy presented.

[0299] The foregoing description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the language of the claims, where the elements recited in the singular are not intended to mean "one and only one" unless specifically so stated, but rather "one or more." Terms such as "if," "when," and "while" are to be construed as meaning "under the condition that," rather than implying an immediate temporal relationship or reaction. That is, these phrases, such as "when," do not mean an immediate action in response to or during the occurrence of an action, but simply imply that the action will occur if the condition is met, without requiring a specific or immediate time limitation for the occurrence of the action. The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" is not necessarily to be construed as preferred or having an advantage over other aspects. Unless specifically stated otherwise, the term "some" refers to one or more. Combinations such as "at least one of A, B, or C," "one or more of A, B, or C," "at least one of A, B, and C," "one or more of A, B, and C," and "any combination of A, B, C, or them" include any combination of A, B, and / or C, and may include multiple A's, multiple B's, or multiple C's. Specifically, combinations such as "at least one of A, B, or C," "one or more of A, B, or C," "at least one of A, B, and C," "one or more of A, B, and C," and "any combination of A, B, C, or them" can be only A, only B, only C, A and B, A and C, B and C, or A and B and C, where any such combination may include one or more members of A, B, or C. All structural and functional equivalents of the elements of the various aspects described throughout this disclosure that are known or later will be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be covered by the claims. Furthermore, nothing disclosed herein is intended to be dedicated to the public, whether or not such disclosure is expressly recited in the claims. The words "module," "mechanism," "element," "device," etc. shall not be used in place of the word "means." Thus, no claim element shall be construed as a means-plus-function element unless the element is expressly recited using the phrase "means for."

[0300] The following aspects are merely illustrative and may be combined with other aspects or teachings described herein without limitation.

[0301] Aspect 1: A device for wireless communication, comprising: a memory; at least one transceiver; and at least one processor, the at least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor being configured to: receive a first PRS from a first satellite at a first reception time (T _Rx_sat_1 ); receive a second PRS from a second satellite at a second reception time (T _Rx_sat_2 ) and an indication of a transmit-receive time difference (T sat_2_Tx→Rx ), the transmit-receive time difference (T sat_2_Tx→Rx ) being the difference between the time the second satellite transmits the second PRS to the UE and the time the second satellite receives an RS from the first satellite; and calculate a RSTD between the first PRS and the second PRS based at least in part on the first reception time (T _Rx_sat_1 ) of the first PRS, the second reception time (T _Rx_sat_2 ) of the second PRS, and the transmit-receive time difference (T sat_2_Tx→Rx ).

[0302] Aspect 2 is the device according to aspect 1, wherein the second satellite has the ability to provide baseband on-board processing.

[0303] Aspect 3 is the device according to any one of aspects 1 and 2, wherein the RSTD (RSTD _1_2 ) between the first PRS and the second PRS is calculated based on the following formula: RSTD _1_2 = T _Rx_sat_1 - T _Rx_sat_2 - (T gap,iner-sat_RS_1→PRS_1 + T prop,sat_1→sat_2 + T sat_2_Tx→Rx ), where the T gap,iner-sat_RS_1→PRS_1 is the time gap between the time the first satellite transmits the first PRS to the UE and the time the first satellite transmits the RS to the second satellite, and the T prop,sat_1→sat_2 is the signal propagation time between the first satellite and the second satellite.

[0304] Aspect 4 is the device according to any one of aspects 1 to 3, wherein the at least one processor is further configured to: receive an indication of the T gap,iner-sat_RS_1→PRS_1 from the first satellite.

[0305] Aspect 5 is the device according to any one of aspects 1 to 4, wherein the at least one processor is further configured to: receive an indication of the T prop,sat_1→sat_2 from the second satellite.

[0306] Aspect 6 is the apparatus according to any one of Aspects 1 to 5, wherein the transmit-receive time difference (T sat_2_Tx→Rx ) is associated with one or more of: satellite ID, TRP ID, PRS ID, or timestamp.

[0307] Aspect 7 is the apparatus according to any one of Aspects 1 to 6, wherein the at least one processor is further configured to: calculate a location of the UE based at least in part on the RSTD of the first PRS and the second PRS.

[0308] Aspect 8 is a wireless communication method for implementing any one of Aspects 1 to 7.

[0309] Aspect 9 is a device for wireless communication, including means for implementing any one of Aspects 1 to 7.

[0310] Aspect 10 is a computer-readable medium storing computer-executable code, wherein the code, when executed by a processor, causes the processor to implement any one of Aspects 1 to 7.

[0311] Aspect 11: A device for wireless communication, including: a memory; at least one transceiver; and at least one processor, the at least one processor communicatively connected to the memory and the at least one transceiver, the at least one processor being configured to: transmit an RS to a second satellite at a first transmit time; and transmit a PRS to a UE at a second transmit time; and transmit an indication of a time gap (T gap,iner-sat_RS_1→PRS_1 ) between the first transmit time and the second transmit time to the UE.

[0312] Aspect 12 is the apparatus according to Aspect 11, wherein the second satellite has the ability to provide baseband on-board processing.

[0313] Aspect 13 is the apparatus according to any one of Aspects 11 to 12, wherein the RS is a second PRS.

[0314] Aspect 14 is the apparatus according to any one of Aspects 11 to 13, wherein the at least one processor is further configured to: receive a resource allocation for transmitting the RS from a gateway or an LMF.

[0315] Aspect 15 is the apparatus according to any one of Aspects 11 to 14, wherein the at least one processor is further configured to: receive a resource allocation for transmitting the RS from a gateway or an LMF.

[0316] Aspect 16 is the apparatus according to any one of Aspects 11 to 15, wherein the at least one processor is further configured to: receive, from a gateway or an LMF, a configuration for one or more transmission beams for transmitting the RS.

[0317] Aspect 17 is a wireless communication method for implementing any one of Aspects 11 to 16.

[0318] Aspect 18 is a device for wireless communication, comprising means for implementing any one of Aspects 11 to 16.

[0319] Aspect 19 is a computer-readable medium storing computer-executable code, wherein the code, when executed by a processor, causes the processor to implement any one of Aspects 11 to 16.

[0320] Aspect 20: A device for wireless communication, comprising: a memory; at least one transceiver; and at least one processor, the at least one processor communicatively connected to the memory and the at least one transceiver, the at least one processor being configured to: receive, from a first satellite, an RS at a first reception time; and transmit, at a first transmission time, a PRS to a UE; and transmit to the UE an indication of a transmit-receive time difference (T sat_2_Tx→Rx ) between the first reception time and the first transmission time.

[0321] Aspect 21 is the apparatus according to Aspect 20, wherein the second satellite has the ability to provide baseband on-board processing.

[0322] Aspect 22 is the apparatus according to any one of Aspects 20 and 21, wherein the at least one processor is further configured to: transmit to the UE an indication of a signal propagation time (T prop,sat_1→sat_2 ) between the first satellite and the second satellite.

[0323] Aspect 23 is the apparatus according to any one of Aspects 20 to 22, wherein the transmit-receive time difference (T sat_2_Tx→Rx ) is associated with one or more of the following: satellite ID, TRP ID, PRS ID, or timestamp.

[0324] Aspect 24 is the apparatus according to any one of Aspects 20 to 23, wherein the at least one processor is further configured to: receive, from a gateway or an LMF, a configuration for transmitting the PRS based on the RS.

[0325] Aspect 25 is the apparatus according to any one of Aspects 20 to 24, wherein the at least one processor is further configured to: receive, from a gateway or an LMF, a measurement gap for receiving the RS.

[0326] Aspect 26 is the apparatus according to any one of aspects 20 to 25, wherein the RS is a second PRS.

[0327] Aspect 27 is the apparatus according to any one of aspects 20 to 26, wherein the at least one processor is further configured to: receive, from a gateway or an LMF, a resource allocation for receiving the RS.

[0328] Aspect 28 is the apparatus according to any one of aspects 20 to 27, wherein the at least one processor is further configured to: receive, from a gateway or an LMF, a configuration of one or more reception beams for receiving the RS.

[0329] Aspect 29 is a wireless communication method for implementing any one of aspects 20 to 28.

[0330] Aspect 30 is a device for wireless communication, including an apparatus for implementing any one of aspects 20 to 28.

[0331] Aspect 31 is a computer-readable medium storing computer-executable code, wherein the code, when executed by a processor, causes the processor to implement any one of aspects 20 to 28.

[0332] Aspect 32: A device for wireless communication, including: a memory; at least one transceiver; and at least one processor communicatively connected to the memory and the at least one transceiver, the at least one processor being configured to: receive a first PRS from a first satellite at a first reception time (T _Rx_sat_1 ); receive a second PRS from a second satellite at a second reception time (T _Rx_sat_2 ), the second PRS being transmitted from the first satellite and relayed to the UE via the second satellite; and calculate an RSTD between the first PRS and the second PRS based at least in part on the first reception time (T _Rx_sat_1 ) of the first PRS, the second reception time (T _Rx_sat_2 ) of the second PRS, and a group delay (T GD_BP ) associated with the second satellite.

[0333] Aspect 33 is the apparatus according to aspect 32, wherein the second satellite does not have the ability to provide baseband on-board processing.

[0334] Aspect 34 is the apparatus according to any one of aspects 32 and 33, wherein the RSTD (RSTD _1_2 ) between the first PRS and the second PRS is calculated based on the following formula: RSTD _1_2 = T _Rx_sat_1 - T_Rx_sat_2 -(T gap,PRS_2→PRS_1 +T prop,sat_1→sat_2 +T GD_BP ), where the T gap,PRS_2→PRS_1 is the time gap between the time when the first satellite transmits the first PRS to the UE and the time when the first satellite transmits the second PRS to the second satellite, and the T prop,sat_1→sat_2 is the signal propagation time between the first satellite and the second satellite.

[0335] Aspect 35 is the apparatus according to any one of Aspects 32 to 34, wherein the at least one processor is further configured to: receive an indication of the T gap,PRS_2→PRS_1 from the first satellite.

[0336] Aspect 36 is the apparatus according to any one of Aspects 32 to 35, wherein the at least one processor is further configured to: receive an indication of the T prop,sat_1→sat_2 from the second satellite.

[0337] Aspect 37 is the apparatus according to any one of Aspects 32 to 36, wherein the at least one processor is further configured to: receive the group delay (T GD_BP ) from the LMF via auxiliary data.

[0338] Aspect 38 is the apparatus according to any one of Aspects 32 to 37, wherein the group delay (T GD_BP ) is associated with one or more of the following: satellite ID or TRP ID.

[0339] Aspect 39 is the apparatus according to any one of Aspects 32 to 38, wherein the at least one processor is further configured to: calculate the positioning of the UE at least partially based on the RSTD of the first PRS and the second PRS.

[0340] Aspect 40 is the apparatus according to any one of Aspects 32 to 39, wherein the second PRS is not a regenerated signal of the first PRS.

[0341] Aspect 41 is a wireless communication method for implementing any one of Aspects 32 to 40.

[0342] Aspect 42 is a device for wireless communication, including means for implementing any one of Aspects 32 to 40.

[0343] Aspect 43 is a computer-readable medium storing computer-executable code, wherein the code, when executed by a processor, causes the processor to implement any one of Aspects 32 to 40.

[0344] Aspect 44: A device for wireless communication, comprising: a memory; at least one transceiver; and at least one processor, the at least one processor communicatively connected to the memory and the at least one transceiver, the at least one processor being configured to: transmit a first PRS to a UE at a first transmission time; transmit a second PRS to a second satellite at a second transmission time, the second PRS being relayed to the UE via the second satellite; and transmit to the UE an indication of a time gap (T gap,PRS_2→PRS_1 ) between the first transmission time and the second transmission time.

[0345] Aspect 45 is the device according to aspect 44, wherein the second satellite does not have the ability to provide baseband on-board processing.

[0346] Aspect 46 is the device according to any one of aspects 44 and 45, wherein the at least one processor is further configured to: receive a resource allocation for transmitting the second PRS from a gateway or an LMF.

[0347] Aspect 47 is the device according to any one of aspects 44 to 46, wherein the at least one processor is further configured to: receive a configuration of one or more transmission beams for transmitting the second PRS from a gateway or an LMF.

[0348] Aspect 48 is a wireless communication method for implementing any one of aspects 44 to 47.

[0349] Aspect 49 is a device for wireless communication, comprising means for implementing any one of aspects 44 to 47.

[0350] Aspect 50 is a computer-readable medium storing computer-executable code, wherein the code, when executed by a processor, causes the processor to implement any one of aspects 44 to 47.

[0351] Aspect 51: A device for wireless communication, comprising: a memory; at least one transceiver; and at least one processor, the at least one processor communicatively connected to the memory and the at least one transceiver, the at least one processor being configured to: receive a PRS from a first satellite at a first reception time; and relay the PRS to a UE at a first relay time.

[0352] Aspect 52 is the device according to aspect 51, wherein the at least one processor is further configured to: transmit to the UE an indication of a signal propagation time (T prop,sat_1→sat_2 ) between the first satellite and the second satellite.

[0353] Aspect 53 is the apparatus according to any one of aspects 51 and 52, wherein the second satellite does not have the ability to provide baseband on-board processing.

[0354] Aspect 54 is the apparatus according to any one of aspects 51 to 53, wherein the at least one processor is further configured to: receive a configuration for relaying the PRS from a gateway or an LMF.

[0355] Aspect 55 is a wireless communication method for implementing any one of aspects 51 to 54.

[0356] Aspect 56 is a device for wireless communication, comprising an apparatus for implementing any one of aspects 51 to 54.

[0357] Aspect 57 is a computer-readable medium storing computer-executable code, wherein the code, when executed by a processor, causes the processor to implement any one of aspects 51 to 54.

Claims

1. A device for wireless communication at a 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: At a first reception time T _Rx_sat_1 Receive a first positioning reference signal (PRS) from a first satellite; Receive an indication of T gap,iner-sat_RS_1→PRS_1 from the first satellite, where the T gap,iner-sat_RS_1→PRS_1 is a time gap between the time when the first satellite transmits the first PRS to the UE and the time when the first satellite transmits the RS to the second satellite; At a second reception time T _Rx_sat_2 Receive a second PRS from a second satellite and an indication of a transmit-receive time difference T sat_2_Tx→Rx wherein the transmit-receive time difference T sat_2_Tx→Rx is the difference between the time when the second satellite transmits the second PRS to the UE and the time when the second satellite receives a reference signal RS from the first satellite; and at least in part based on the first reception time T of the first PRS _Rx_sat_1 , the second reception time T of the second PRS _Rx_sat_2 , the transmit-receive time difference T sat_2_Tx→Rx and the time gap T gap,iner-sat_RS_1→PRS_1 to calculate the reference signal time difference RSTD between the first PRS and the second PRS.

2. The device according to claim 1, wherein the RSTD (RSTD _1_2 ) of the first PRS and the second PRS is calculated based on the following formula: RSTD _1_2 = T _Rx_sat_1 - T _Rx_sat_2 -(T gap,iner-sat_RS_1→PRS_1 + T prop,sat_1→sat_2 + T sat_2_Tx→Rx )， wherein the T prop,sat_1→sat_2 is the signal propagation time between the first satellite and the second satellite.

3. The device according to claim 2, wherein the at least one processor is further configured to: Receive an indication of the T from the second satellite prop,sat_1→sat_2 .

4. The apparatus according to claim 1, wherein the transmit-receive time difference T sat_2_Tx→Rx is associated with one or more of the following: satellite identifier ID, transmit-receive point TRPID, PRS ID, or timestamp.

5. The device according to claim 1, wherein the at least one processor is further configured to: calculate a location of the UE based at least in part on the RSTD of the first PRS and the second PRS.

6. The device according to claim 1, wherein the second satellite is configured to: receive a reference signal (RS) from the first satellite at a first reception time; transmit a positioning reference signal (PRS) to the UE at a first transmission time; and Transmit an indication of the transmit-receive time difference T between the first reception time and the first transmission time to the UE sat_2_Tx→Rx .

7. The device according to claim 6, wherein the second satellite has the ability to provide baseband on-board processing.

8. The apparatus according to claim 6, wherein the second satellite is further configured to transmit an indication of a signal propagation time T between the first satellite and the second satellite to the UE. prop,sat_1→sat_2 to the UE.

9. The device according to claim 6, wherein the transmit-receive time difference Tsat_2_Tx→Rx is associated with one or more of the following: satellite identifier ID, transmit-receive point TRPID, PRS ID, or timestamp.

10. The device according to claim 6, wherein the second satellite is further configured to: receive a configuration for transmitting the PRS based on the RS from a gateway or a location management function (LMF).

11. The device according to claim 6, receive a measurement gap for receiving the RS from a gateway or a location management function (LMF).

12. The device according to claim 6, wherein the RS is a second PRS.

13. The device according to claim 6, wherein the second satellite is further configured to: receive a resource allocation for receiving the RS from a gateway or a location management function (LMF).

14. The device according to claim 6, wherein the second satellite is further configured to: receive a configuration for one or more receive beams for receiving the RS from a gateway or a location management function (LMF).

15. A device for wireless communication at a first satellite, 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: transmit a reference signal (RS) to a second satellite at a first transmission time; transmit a positioning reference signal (PRS) to a user equipment (UE) at a second transmission time; and Transmit an indication of the time gap T between the first transmission time and the second transmission time to the UE gap,iner-sat_RS_1→PRS_1 to.

16. The device according to claim 15, wherein the second satellite has the ability to provide baseband on-board processing.

17. The device according to claim 15, wherein the RS is a second PRS.

18. The device according to claim 15, wherein the at least one processor is further configured to: receive a resource allocation for transmitting the RS from a gateway or a location management function (LMF).

19. The device according to claim 15, wherein the at least one processor is further configured to: Receive resource allocation for transmitting the RS from a gateway or a Location Management Function (LMF).

20. The apparatus according to claim 15, wherein the at least one processor is further configured to: Receive configuration of one or more transmission beams for transmitting the RS from a gateway or a Location Management Function (LMF).

21. An apparatus for wireless communication at a 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: At a first reception time T _Rx_sat_1 Receive a first positioning reference signal (PRS) from a first satellite; Receive an indication of T from the first satellite, where T gap,PRS_2→PRS_1 is a time gap between a time when the first satellite transmits the first PRS to the UE and a time when the first satellite transmits a second PRS to a second satellite; gap,PRS_2→PRS_1 ​ At a second reception time T _Rx_sat_2 Receive a second PRS from a second satellite, the second PRS being transmitted from the first satellite and relayed to the UE via the second satellite; And at least in part based on the first reception time T of the first PRS _Rx_sat_1 the second reception time T of the second PRS _Rx_sat_2 the group delay T associated with the second satellite GD_BP and the time gap T gap,PRS_2→PRS_1 to calculate the reference signal time difference RSTD between the first PRS and the second PRS.

22. The apparatus according to claim 21, wherein the second satellite does not have the ability to provide baseband on-board processing.

23. The apparatus according to claim 21, wherein the RSTD of the first PRS and the second PRS _1_2 is calculated based on the following formula: RSTD _1_2 = T _Rx_sat_1 - T _Rx_sat_2 -(T gap,PRS_2→PRS_1 + T prop,sat_1→sat_2 + T GD_BP ) wherein said T prop,sat_1→sat_2 is the signal propagation time between the first satellite and the second satellite.

24. The apparatus according to claim 23, wherein the at least one processor is further configured to: Receive an indication of the T from the second satellite prop,sat_1→sat_2 thereof.

25. The apparatus according to claim 21, wherein the at least one processor is further configured to: Receiving the group delay T from a location management function LMF via auxiliary data AD GD_BP .

26. The apparatus according to claim 21, wherein the group delay T GD_BP is associated with one or more of the following: a satellite identifier ID or a transmit-receive point TRPID.

27. The apparatus according to claim 21, wherein the at least one processor is further configured to: Calculate a location of the UE based at least in part on the RSTD of the first PRS and the second PRS.

28. The apparatus according to claim 21, wherein the second PRS is not a regenerated signal of the first PRS.

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