Measurement reporting for carrier phase positioning

Abstract

Various aspects of the present disclosure relate to receiving (902) a set of positioning reference signals (PRS) associated with a set of transmission-reception points (TRP) and determining (904) a set of carrier phase measurements based at least in part on the set of PRS, where each PRS in the set of PRSs is associated with a PRS symbol and a subcarrier frequency. Aspects of the present disclosure further relate to indicating (906) the set of carrier phase measurements to a location management function (LMF), where the reported set of carrier phase measurements includes a carrier frequency offset corresponding to the set of PRSs, or a set of carrier phase differences corresponding to the set of PRS, or both.

Description

MEASUREMENT REPORTING FOR CARRIER PHASE POSITIONING TECHNICAL FIELD

[0001] The present disclosure relates to wireless communications, and more specifically to carrier frequency measurement reporting for carrier phase positioning techniques. BACKGROUND

[0002] A wireless communications system may include one or multiple network communication devices, such as base stations, which may be otherwise known as an evolved NodeB (eNB), a next-generation NodeB (gNB), or other suitable terminology. Each network communication device, such as a base station, may support wireless communications for one or multiple user communication devices, which may be otherwise known as user equipment (UE), or other suitable terminology. The wireless communications system may support wireless communications with one or multiple user communication devices by utilizing resources of the wireless communication system (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers). Additionally, the wireless communications system may support wireless communications across various radio access technologies including third generation (3G) radio access technology (RAT), fourth generation (4G) RAT, fifth generation (5G) RAT, among other suitable RATs beyond 5G (e.g., sixth generation (6G)). SUMMARY

[0003] An article “a” before an element is unrestricted and understood to refer to “at least one” of those elements or “one or more” of those elements. The terms “a,” “at least one,” “one or more,” and “at least one of one or more” may be interchangeable. As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of” or “one or both of”) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on. Further, as used herein, including in the claims, a “set” may include one or more elements.

[0004] Some implementations of the method and apparatuses described herein may include means for receiving a set of Positioning Reference Signals (PRSs) associated with a set of Transmission-Reception Points (TRPs), each Positioning Reference Signal (PRS) in the set of PRSs associated with a PRS symbol and a subcarrier frequency. The method and apparatuses described herein may include means for determining a set of carrier phase measurements based at least in part on the set of PRSs, where the set of carrier phase measurements comprises a carrier frequency offset corresponding to the set of PRSs, or a set of carrier phase differences corresponding to the set of PRSs, or both. The method and apparatuses described herein may include means for indicating the set of carrier phase measurements to a Location Management Function (LMF).

[0005] In some implementations, the method and apparatuses described herein may further include means for receiving a first set of carrier phase measurements from a target User Equipment (UE) associated with a set of TRPs, wherein the first set of carrier phase measurements comprises a first carrier frequency offset between the UE and the set of TRPs, or a first set of carrier phase differences corresponding to the set of PRSs, or both. The method and apparatuses described herein may include means for receiving a second set of carrier phase measurements from a Positioning Reference Unit (PRU) associated with the set of TRPs, wherein the PRU is associated with a fixed and known location, wherein the second set of carrier phase measurements comprises a second carrier frequency offset between the PRU and the set of TRPs, or a second set of carrier phase differences corresponding to the set of PRSs, or both. The method and apparatuses described herein may include means for determining initial phase offset information for the set of TRPs based at least in part on the first and second sets of carrier phase measurements. The method and apparatuses described herein may include means for deriving UE positioning data associated with the target UE by performing carrier phase positioning using the initial phase offset information. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 illustrates an example of a wireless communications system in accordance with aspects of the present disclosure.

[0007] Figure 2 illustrates an example of a Third Generation Partnership Project (3GPP) New Radio (NR) downlink (DL) based positioning, in accordance with aspects of the present disclosure.

[0008] Figure 3 an example of maximum phase error as a function of symbol separation and carrier frequency, in accordance with aspects of the present disclosure.

[0009] Figure 4 illustrates an example of a Positioning Reference Signal (PRS) subframe, in accordance with aspects of the present disclosure.

[0010] Figure 5 illustrates an example of a procedure for reporting carrier frequency offset measurements for carrier phase positioning, in accordance with aspects of the present disclosure.

[0011] Figure 6 illustrates an example of a user equipment (UE) 600, in accordance with aspects of the present disclosure.

[0012] Figure 7 illustrates an example of a processor 700, in accordance with aspects of the present disclosure.

[0013] Figure 8 illustrates an example of a network equipment (NE) 800, in accordance with aspects of the present disclosure.

[0014] Figure 9 illustrates a flowchart of a method performed by a UE or PRU, in accordance with aspects of the present disclosure.

[0015] Figure 10 illustrates a flowchart of a method performed by a LMF, in accordance with aspects of the present disclosure. DETAILED DESCRIPTION

[0016] Generally, the present disclosure describes systems, methods, and apparatuses for carrier frequency measurement reporting for carrier phase positioning techniques. In certain embodiments, the methods may be performed using computer-executable code embedded on a computer-readable medium. In certain embodiments, an apparatus or system may include a computer-readable medium containing computer-readable code which, when executed by a processor, causes the apparatus or system to perform at least a portion of the below described solutions.

[0017] Carrier phase positioning techniques have a high resolution, which can improve the positioning accuracy of wireless cellular networks. Carrier phase technology uses the phase- locked loop to measure the phase information of a received signal. Due to the short carrier wavelength, the positioning accuracy of the carrier phase measurement technology is high. However, because the carrier signal is periodic (i.e., a sinusoidal signal), the receiver (e.g., UE) can only measure the fractional part of the phase, or equivalently, the phase modulo 2^.

[0018] Carrier frequency offsets have a negative impact on the accuracy of carrier phase positioning. Fundamentally, the carrier phase positioning techniques have ignored the issue of phase error and / or assumed the initial phase offsets among the PRS transmitters, between the PRS transmitters and the UE receivers, and between the PRS transmitters and the PRU receivers to be static.

[0019] Moreover, there will be frequency offsets among the PRS transmitters which will cause the carrier phase offsets to change relative to each other over time. Similarly, there will be carrier frequency offsets between the PRS transmitters and the UE and PRU receivers which will cause these phase offsets to change over time.

[0020] Further, the carrier frequencies for the UEs, the TRPs (i.e., the PRS transmitters), and the PRUs are not exactly the same. The carrier frequency tolerance which for the base station is defined for the base station (BS) in 3GPP Technical Specification (TS) 38.104, clauses 6.5.1.2 and 9.6.1.3, and is given in the following Tables 1 and 2, where “ppm” denotes parts per million: BS class Accuracy Wide Area BS ±0.05 ppm Medium Range BS ±0.1 ppm Local Area BS ±0.1 ppm Table 1: Frequency error minimum requirement BS class Accuracy Wide Area BS ±0.05 ppm Medium Range BS ±0.1 ppm Local Area BS ±0.1 ppm Table 2: Over-The-Air (OTA) frequency error minimum requirement

[0021] Similarly, the carrier frequency tolerance for the UE is defined in 3GPP TS 38.101-1 for Frequency Range #1 (FR1) (e.g., 410 MHz – 7.125 GHz). In Section 6.4.1 of 3GPP TS 38.101-1, the requirement is defined: “The UE basic measurement interval of modulated carrierfrequency is 1 UL slot. The mean value of basic measurements of UE modulated carrier frequency shall be accurate to within ± 0.1 PPM observed over a period of 1 ms of cumulated measurement intervals compared to the carrier frequency received from the NR Node B.”

[0022] Likewise, in Section 6.4D.1 of 3GPP TS 38.101-1, the carrier frequency tolerance requirement is defined: “For UE(s) supporting UL MIMO, the basic measurement interval of modulated carrier frequency is 1 UL slot. The mean value of basic measurements of UE modulated carrier frequency at each transmit antenna connector shall be accurate to within ± 0.1 PPM observed over a period of 1 ms of cumulated measurement intervals compared to the carrier frequency received from the NR Node B.”

[0023] A requirement of ± 0.1 ppm corresponds to a maximum frequency error of 10-7fc, where fc is the carrier frequency expressed in GHz.

[0024] To solve the problems with frequency error in performing carrier phase positioning discussed herein, the PRS receiving devices, e.g., the UE and the PRU, transmit, e.g., to an LMF, carrier phase information that allows the LMF to derive the initial phase offsets among the PRS transmitters (e.g., the TRPs) and between the PRS transmitters and the PRS receivers (e.g., the UEs and the PRU). In one embodiment, a respective PRS receiving device transmits carrier frequency offset information corresponding to the PRS transmitters. In another embodiment, the respective PRS receiving device transmits a set of carrier phase differences corresponding to the PRS transmitters. The LMF uses the carrier frequency offsets corresponding to the set of PRSs and / or the set of carrier phase differences to derive the initial phase offsets and remove the phase measurement error associated with the carrier phase measurements when performing carrier phase positioning. As used herein, the LMF refers to a location management server in the core network (e.g., 5GC). The LMF receives measurements and assistance information, e.g., from the RAN and / or the UE, and derives a target UE’s position. Various LMF-based positioning methods are described in 3GPP TS 38.305.

[0025] Note that the initial phase of the UE is an unknown phase because the UE is not calibrated to this degree, and thus does not know its initial phase. In a mobile communication system with potentially millions of users, it is not economically feasible to calibrate the UE transceivers to the level of fine calibration required to know, a priori, a UE’s initial phase. Similarly, the PRUs and the TRPs are also not sufficiently calibrated, and thus their initial phases are also unknown.

[0026] Further note that the TRPs are at fixed, known locations and the PRUs are also at fixed, known locations. Therefore, the phase information between the TRPs and the PRUs can be used to solve for the initial phase offsets of the TRPs, thereby compensating for phase measurement error when solving for the UE’s unknown location.

[0027] By compensating for the (i.e., unknown) initial phase offset and removing the phase measurement error, the improved techniques for carrier phase positioning, as described herein, allow the mobile network (i.e., LMF and / or UE) to determine a target UE’s location with enhanced accuracy as compared to conventional positioning techniques.

[0028] Aspects of the present disclosure are described in the context of a wireless communications system.

[0029] Figure 1 illustrates an example of a wireless communications system 100 in accordance with aspects of the present disclosure. The wireless communications system 100 may include one or more NE 102, one or more UE 104, and a core network (CN) 106. The wireless communications system 100 may support various radio access technologies. In some implementations, the wireless communications system 100 may be a 4G network, such as a Long- Term Evolution (LTE) network or an LTE-Advanced (LTE-A) network. In some other implementations, the wireless communications system 100 may be a NR network, such as a 5G network, a 5G-Advanced (5G-A) network, or a 5G ultrawideband (5G-UWB) network. In other implementations, the wireless communications system 100 may be a combination of a 4G network and a 5G network, or other suitable radio access technology including Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20. The wireless communications system 100 may support radio access technologies beyond 5G, for example, 6G. Additionally, the wireless communications system 100 may support technologies, such as time division multiple access (TDMA), frequency division multiple access (FDMA), or code division multiple access (CDMA), etc.

[0030] The one or more NE 102 may be dispersed throughout a geographic region to form the wireless communications system 100. One or more of the NE 102 described herein may be or include or may be referred to as a network node, a base station, a network element, a network function, a network entity, a radio access network (RAN), a NodeB, an eNodeB (eNB), a next- generation NodeB (gNB), or other suitable terminology. An NE 102 and a UE 104 may communicate via a communication link, which may be a wireless or wired connection. For example, an NE 102 and a UE 104 may perform wireless communication (e.g., receive signaling, transmit signaling) over a Uu interface.

[0031] An NE 102 may provide a geographic coverage area for which the NE 102 may support services for one or more UEs 104 within the geographic coverage area. For example, an NE 102 and a UE 104 may support wireless communication of signals related to services (e.g., voice, video, packet data, messaging, broadcast, etc.) according to one or multiple radio access technologies. In some implementations, an NE 102 may be moveable, for example, a satellite associated with a non-terrestrial network (NTN). In some implementations, different geographic coverage areas associated with the same or different radio access technologies may overlap, but the different geographic coverage areas may be associated with different NE 102.

[0032] The one or more UE 104 may be dispersed throughout a geographic region of the wireless communications system 100. A UE 104 may include or may be referred to as a remote unit, a mobile device, a wireless device, a remote device, a subscriber device, a transmitter device, a receiver device, or some other suitable terminology. In some implementations, the UE 104 may be referred to as a unit, a station, a terminal, or a client, among other examples. Additionally, or alternatively, the UE 104 may be referred to as an Internet-of-Things (IoT) device, an Internet- of-Everything (IoE) device, or machine-type communication (MTC) device, among other examples.

[0033] A UE 104 may be able to support wireless communication directly with other UEs 104 over a communication link. For example, a UE 104 may support wireless communication directly with another UE 104 over a device-to-device (D2D) communication link. In some implementations, such as vehicle-to-vehicle (V2V) deployments, vehicle-to-everything (V2X) deployments, or cellular-V2X deployments, the communication link may be referred to as a sidelink. For example, a UE 104 may support wireless communication directly with another UE 104 over a PC5 interface.

[0034] An NE 102 may support communications with the CN 106, or with another NE 102, or both. For example, an NE 102 may interface with other NE 102 or the CN 106 through one or more backhaul links (e.g., S1, N2, N2, or network interface). In some implementations, the NE 102 may communicate with each other directly. In some other implementations, the NE 102 may communicate with each other or indirectly (e.g., via the CN 106). In some implementations, one or more NE 102 may include subcomponents, such as an access network entity, which may be an example of an access node controller (ANC). An ANC may communicate with the one or more UEs 104 through one or more other access network transmission entities, which may be referred to as a radio heads, smart radio heads, or transmission-reception points (TRPs).

[0035] The CN 106 may support user authentication, access authorization, tracking, connectivity, and other access, routing, or mobility functions. The CN 106 may be an evolved packet core (EPC), or a 5G core (5GC), which may include a control plane entity that manages access and mobility (e.g., a mobility management entity (MME), an access and mobility management functions (AMF)) and a user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW), a Packet Data Network (PDN) gateway (P- GW), or a user plane function (UPF)). In some implementations, the control plane entity may manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management (e.g., data bearers, signal bearers, etc.) for the one or more UEs 104 served by the one or more NE 102 associated with the CN 106.

[0036] The CN 106 may communicate with a packet data network over one or more backhaul links (e.g., via an S1, N2, N2, or another network interface). The packet data network may include an application server. In some implementations, one or more UEs 104 may communicate with the application server. A UE 104 may establish a session (e.g., a protocol data unit (PDU) session, or a PDN connection, or the like) with the CN 106 via an NE 102. The CN 106 may route traffic (e.g., control information, data, and the like) between the UE 104 and the application server using the established session (e.g., the established PDU session). The PDU session may be an example of a logical connection between the UE 104 and the CN 106 (e.g., one or more network functions of the CN 106).

[0037] In the wireless communications system 100, the NEs 102 and the UEs 104 may use resources of the wireless communications system 100 (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers)) to perform various operations (e.g., wireless communications). In some implementations, the NEs 102 and the UEs 104 may support different resource structures. For example, the NEs 102 and the UEs 104 may support different frame structures. In some implementations, such as in 4G, the NEs 102 and the UEs 104 may support a single frame structure. In some other implementations, such as in 5G and among other suitable radio access technologies, the NEs 102 and the UEs 104 may support various frame structures (i.e., multiple frame structures). The NEs 102 and the UEs 104 may support various frame structures based on one or more numerologies.

[0038] One or more numerologies may be supported in the wireless communications system 100, and a numerology may include a subcarrier spacing and a cyclic prefix. A first numerology (e.g., ^=0) may be associated with a first subcarrier spacing (e.g., 15 kHz) and a normal cyclic prefix. In some implementations, the first numerology (e.g., ^ =0) associated with the firstsubcarrier spacing (e.g., 15 kHz) may utilize one slot per subframe. A second numerology (e.g.,^=1) may be associated with a second subcarrier spacing (e.g., 30 kHz) and a normal cyclicprefix. A third numerology (e.g., ^=2) may be associated with a third subcarrier spacing (e.g., 60 kHz) and a normal cyclic prefix or an extended cyclic prefix. A fourth numerology (e.g., ^=3) may be associated with a fourth subcarrier spacing (e.g., 120 kHz) and a normal cyclic prefix. A fifth numerology (e.g., ^=4) may be associated with a fifth subcarrier spacing (e.g., 240 kHz) and a normal cyclic prefix.

[0039] A time interval of a resource (e.g., a communication resource) may be organized according to frames (also referred to as radio frames). Each frame may have a duration, for example, a 10 millisecond (ms) duration. In some implementations, each frame may include multiple subframes. For example, each frame may include 10 subframes, and each subframe may have a duration, for example, a 1 ms duration. In some implementations, each frame may have the same duration. In some implementations, each subframe of a frame may have the same duration.

[0040] Additionally, or alternatively, a time interval of a resource (e.g., a communication resource) may be organized according to slots. For example, a subframe may include a number (e.g., quantity) of slots. The number of slots in each subframe may also depend on the one or more numerologies supported in the wireless communications system 100. For instance, the first, second, third, fourth, and fifth numerologies (i.e., ^=0, ^=1, ^=2, ^=3, ^=4) associated with respective subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz may utilize a single slot per subframe, two slots per subframe, four slots per subframe, eight slots per subframe, and 16 slots per subframe, respectively. Each slot may include a number (e.g., quantity) of symbols (e.g., orthogonal frequency domain multiplexing (OFDM) symbols). In some implementations, the number (e.g., quantity) of slots for a subframe may depend on a numerology. For a normal cyclic prefix, a slot may include 14 symbols. For an extended cyclic prefix (e.g., applicable for 60 kHz subcarrier spacing), a slot may include 12 symbols. The relationship between the number of symbols per slot, the number of slots per subframe, and the number of slots per frame for a normal cyclic prefix and an extended cyclic prefix may depend on a numerology. It should be understood that reference to a first numerology (e.g., ^ =0) associated with a first subcarrier spacing (e.g., 15 kHz) may be used interchangeably between subframes and slots.

[0041] In the wireless communications system 100, an electromagnetic (EM) spectrum may be split, based on frequency or wavelength, into various classes, frequency bands, frequencychannels, etc. By way of example, the wireless communications system 100 may support one or multiple operating frequency bands, such as frequency range designations FR1 (410 MHz – 7.125 GHz), FR2 (24.25 GHz – 52.6 GHz), FR3 (7.125 GHz – 24.25 GHz), FR4 (52.6 GHz – 114.25 GHz), FR4a or FR4-1 (52.6 GHz – 71 GHz), and FR5 (114.25 GHz – 300 GHz). In some implementations, the NEs 102 and the UEs 104 may perform wireless communications over one or more of the operating frequency bands. In some implementations, FR1 may be used by the NEs 102 and the UEs 104, among other equipment or devices for cellular communications traffic (e.g., control information, data). In some implementations, FR2 may be used by the NEs 102 and the UEs 104, among other equipment or devices for short-range, high data rate capabilities.

[0042] FR1 may be associated with one or multiple numerologies (e.g., at least three numerologies). For example, FR1 may be associated with a first numerology (e.g., ^=0), which includes 15 kHz subcarrier spacing; a second numerology (e.g., ^=1), which includes 30 kHz subcarrier spacing; and a third numerology (e.g., ^=2), which includes 60 kHz subcarrier spacing. FR2 may be associated with one or multiple numerologies (e.g., at least 2 numerologies). For example, FR2 may be associated with a third numerology (e.g., ^=2), which includes 60 kHz subcarrier spacing; and a fourth numerology (e.g., ^=3), which includes 120 kHz subcarrier spacing.

[0043] Wireless communication in unlicensed spectrum (also referred to as “shared spectrum”) in contrast to licensed spectrum offer some obvious cost advantages allowing communication to obviate overlaying operator’s licensed spectrum and rather use license free spectrum according to local regulation in specific geographies. From 3GPP technology perspective, the unlicensed operation can be on the Uu interface (referred to as NR-U) or also on sidelink interface (e.g., SL-U).

[0044] Figure 2 illustrates an example of an architecture 200 for NR DL-based positioning measurements and reference signals (“RS”), in accordance with aspects of the present disclosure. Figure 2 shows the UE 202, the gNBs 204-208, and a LMF 210. In various embodiments, the UE 202 is representative of a set of UEs 104 interacting with a set of NEs 102 (e.g., gNBs 204- 208) and the LMF 210 is representative of a network function (NF) in the CN 106.

[0045] As depicted, the architecture 200 for NR DL-based positioning includes a UE 202 which may receive a DL PRS from a neighboring first gNB / TRP (denoted “gNB1–TRP1”) 204, from a neighboring second gNB (denoted “gNB2–TRP1”) 206, and also from a third gNB / TRP (denoted “gNB3–TRP1”) 208, which is a reference or serving gNB. The DL PRS can betransmitted by different base stations (e.g., serving gNB and neighboring gNB(s)) using narrow beams over Frequency Range #1 Between (“FR1”) (i.e., frequencies from 410 MHz to 7125 MHz) and Frequency Range #2 (“FR2”) (i.e., frequencies from 24.25 GHz to 52.6 GHz), which is relatively different in NR when compared to LTE where the PRS was transmitted across the whole cell.

[0046] Here, the DL PRS can be locally associated with a DL PRS Resource Identifier (“ID”) and Resource Set ID for a base station (i.e., TRP). In the depicted embodiments, each gNB 204, 206, 208 is configured with a first Resource Set ID (depicted as “Resource Set ID#0”) 212 and a second Resource Set ID (depicted as “Resource Set ID#1”) 214. As depicted, the UE 202 receives DL PRS on transmission beams; here, receiving DL PRS from the gNB1–TRP1204 on DL PRS Resource ID #3 from the second Resource Set ID (“Resource Set ID#1”) 214, receiving DL PRS from the gNB2–TRP1206 on DL PRS Resource ID #3 from the first Resource Set ID (“Resource Set ID#0”) 212, and receiving DL PRS from the gNB3–TRP1208 on DL PRS Resource ID #1 from the second Resource Set ID (“Resource Set ID#1”) 214.

[0047] UE positioning measurements, such as Reference Signal Time Difference (RSTD) and PRS Reference Signal Received Power (RSRP) measurements, may be made between different beams (e.g., between a different pair of DL PRS resources or DL PRS resource sets). The LMF 210 uses the UE positioning measurements to determine the location (e.g., absolute position) of the UE 202. In addition, there are additional uplink (UL) positioning methods for the network to exploit in order to compute the location of the target UE 202.

[0048] Carrier frequency offsets between the Transmission-Reception Point (TRP) transmitters and the UE and PRU receivers can results in large phase measurement errors which depend on: 1) the carrier frequency offsets between the TRP transmitters and the UE and PRU receivers; and 2) the time interval between the PRS symbols being used to measure the phase difference. Note that the carrier frequency offsets are independent of the PRS subcarriers used to measure the carrier phase information.

[0049] To examine the effect of carrier frequency offset, consider the simplest case in which two TRPs, TRP l and TRP m, are transmitting PRS and the channel between each of two TRPs and the UE is line-of-sight (no multipath). Further, assume that the carrier transmitted by each TRP has a fixed frequency offset (within the required ± 0.1 ppm frequency tolerance) relative to the frequency of the serving cell of the UE.

[0050] Let ^^,^,^denote the demodulated PRS symbol received from TRP l on the i-th subcarrier and k-th symbol given by ^^ ^^^^^^^^^^ ^^^^^^^ ^,^^ ^^ ^^ ^^,^^ ^ ^^^ ^ ^^ ^^^ ^^^^^ ^^^,^^ ^^^^^^^!= ^ +where(in radians),Δ$ denotes the subcarrier spacing, Δ$)* denotes the frequen -^,'( cy offset of the carrier of the l thTRP relative to that of the UE receiver, +^= ,^⁄ - denotes the propagation delay corresponding to the distance ,^between the l-th TRP and the UE, / '0*(^0^denotes the initial phase of the UEcarrier, / )*^0^denotes the initial phase (for n=0) transmitter carrier for the l-th TRP,# is the additive noise at the output of the for the k-th symbol of the i-th

[0051] The phase increment Δ / ^),'*( denotes the change in the phase of the carrier of the l-thTRP relative to that of the UEover the period of one symbol given byΔ / )* )*^,'( = Δ$^,'( 23where 23is the symbol period. The phase term^^^^^,^^^^^is due to the frequency offset of the subcarrier with the correlator demodulator and isas <=^Δω^>^^ ^^^^.

[0052] It can be noted that(+ frequency offset was previously in 3GPP document R1-2204807, submitted by Intel, but was shown to have little impact.

[0053] Multiplying ^^,^,^by the conjugate ^^∗,^,^of the known positioning reference symbol for the l-th TRP (assumed to have unit amplitude) yields ^^ ^^^^^^^ ^^ ^^^^^^^ ^ ^ ^ B,^^ ^^^^ ^^ ^^ ^^^^^ ^^ ^^^^^^^

[0054] Similarly, for the i-th subcarrier of the k+n-th symbol received from TRP m, results in the expression:A^,^^C,D= ^^,^^C,D^^∗,^^C,DA∗^,^,^ A^,^^C,D^E^^^^^^ ^^^ ^^B^^^^^^^^^ ^^ ^^B^^,^^ ^^^^^,^^B,^^ ^B^^^^,^^ ^^^ ^^ ^^ ^^ ^^ ^^^ ^^ ^ ^ ^ ^^B ^^^^^^ ^^^^ ^ ^^^B,^^ ^^^^,^^ ^^ C ^^B,^^ F= ^^Fwhere the term Δ$)* )*D,'( Δ$− ^,'(+ / D)*^0^ − / ^)*^0^ + H ^Δ / )* − )* ^ + # )*(of the TRP transmitters relative to the UE receiver and is unknown to the UE. The term−Δ$)* )*D,'( +D + Δ$^,'( +^depends on both the carrier frequency offsets and the propagation delays +Dand +^and is also unknown to the UE. The noise term #^G, H, H + #, I, J^ is implicitly defined in the above as the sum of three noise terms.

[0056] The present disclosure defines / D)*,^^0^ as the difference between the initial phase offsets of the m-th and l-th TRPs given by / )* ^ ^ *^ ^ ) ^ ^the term Δ$D)*,^as the difference between the frequency offsets of the m-th and l-th TRP’s relativeto the byΔ$)* )* )*D,^ = Δ$D,'( − Δ$^,'( ,and the term Δ / D)*,^as theof the m-th TRP relative to that ofthe l-th TRP the period of one symbol given byΔ / )* = )* )*D,^ Δ / D,'( − Δ / ^,'( .

[0057] Using this notation yields the expression: ^^^^^E^^^^^^ ^^^ ^^B^^^^^^^^^ ^ ^^^^^ ^ ^ B,^ ^^^^ ^^^^^ ^^^^ ^ C ^^^^ FA∗A = ^B,^^ B ^,^^ ^ ^ ^^ B,^ B,^ B,^^

[0058] It can be noted that the term Δ / D)*,'(depends on the frequency offset of the m-th TRP relative to the carrier frequency of the UE.

[0059] Taking the same measurements on the same subframe at the PRU yields: ^^^E^^^^^^ ^^^ ^^BN ^^N^^^^^^^B,O P ^BN ^^^^^^,O P ^N ^^^^ B,^ ^^^^ ^^^^^ ^^^^ ^ C ^^B^^,O ^ F^^ ^^ B,^ B,^where M^,^,^and M^,^^C,Dare defined in the same manner as the measurements A^,^,^and A^,^^C,Dtaken at the UE, the delays +DQand +^Qbetween the TRPs and the PRU are known. The phase increment Δ / D)*,R0'denotes the change in the phase of the carrier frequency of the m-th TRP relative toPRU receiver over the period of one symbol.

[0060] However, the terms−Δ$)* + )*D,'( D + Δ$^,'( +^ , andare very small both in absolute terms and relative to the other terms. In particularT−Δ$)* )*D,'( +D + Δ$^,'( +^T ≤ VWXXYZ[,\]^^+D + +^^

[0061] For a carrier frequency of 5 GHz with a frequency error of 0.1ppm and a maximum range of 200 meters, the corresponding phase term is given by 2^ ∙ 5 ∙ 10b∙ 10^c∙^200 + 200^3∙ 10e = 0.004 radians = 0.24 degrees ,and as a result, these terms can be ignored.

[0062] With this approximation, we have ^^^^^E^^^^^^ ^^^ ^^B^^ B,^^^^ ^^^^B,^ ^^^^^ ^^^^B,^ ^ C ^^B^^,^^ FA^∗A^,^^C,D≈ ^^ ^^+ #^G, H, H + #, I, J^.^^^^E^^^^^^ ^^^ ^^BN ^^N ^^^ B,^ ^^^^ ^^^^^ ^^^^ ^ C ^^^^B, FM∗M ≈ ^^ ^ ^^ B,^ B,^ O ^+ H + J^ .and the PRU, the LMF can use M^∗,^,^M^,^^C,Dto estimate the phase term as Δ$)*D om,^+ / )* ^0^+ H Δ / )*+ #)*n .

[0064] Note thatthe arg^∙^function to have range in the interval p0, 2^^, thenarg^A∗^,^,^ A^,^^C,D^.

[0065] Because the mean of #^G, H, H + #, I, J^ is zero, the expected value of the “arg” term is zero and E |arg^A^∗,^,^A^,^^C,D^} =^+D− +^^ +^^^^B,^^^^+ / D)*,^^0^ + H Δ / D)*,^+ # Δ / D)*,'(, 2^{ .

[0066] mod EE |arg^A^∗,^,^A^,^^C,D^} − mΔ$)*D,^+ / D)* o,^^0^ + H Δ / D)*,^+ # Δ / D)*,R0'n , 2^F= mod Emod u−^$%+ G Δ$^ ^+D− +^^ +D,^+ / D)*,^^0^ + H Δ / D)*,^+ # Δ / D)*,'(, 2^yΔ$D)*,^ )* ) Δ$D)*,^o+ / ^0^ + H Δ / * + # )* − m + )*^ ^0^ + H Δ / )* + # Δ / )* n

[0067] As a result, moduE|−^^^^^B,^+)*^0^ +oH Δ / D)*+ # Δ / D)*^,≈ mod|^$%+ G Δ$^ ^+^− +D^ + # ^Δ / D)*,'(− Δ / D)*,R0'^, 2^}.

[0068] From the above, it can be observed that the expected value of the estimate has a non-zero error term given by#^Δ / )* )*D,'( − Δ / D,R0' ^where n is the separation in time, measured in symbols, between the PRS symbols transmitted from TRP l and TRP m, and Δ / D)*,'(and Δ / D)*,R0Sdenotes the symbol-to-symbol phase rotationof the m-th TRP transmitter carrier relative to the receiver carriers of the UE and PRS, respectively.

[0069] Given that the frequency error of the TRP, the UE, and the PRS are all limited to ± 0.1 ppm, the maximum frequency difference between the TRP and the UE and between the TRP and the PRS are both limited to 0.2 ppm. In the case that the UE carrier frequency is at the range minimum and the PRS carrier frequency is at the range maximum, this error term can beexpressed in degrees as#^Δ / )* − Δ / )*R0S ^ = # 2 ∙ 2 ∙ ^cD,'( D, 3 10 V% ∙ 360 .

[0070] Theand the number of symbol separation is shown in Figure 3 for the case of subcarrier spacing equal to 15 kHz.

[0071] Figure 3 illustrates a graph 300 that charts the maximum phase error vs. time between PRS symbol from different TRPs (in symbols), in accordance with aspects of the present disclosure. From Figure 3, it is apparent that carrier frequency offsets between the TRP transmitters and the UE and PRS receivers can result in very large measurement errors which depend on both the time distance between the PRS symbols and the carrier frequency.

[0072] If the PRS measurements are taken within the same subframe, then the maximum distance between PRS symbols is 13. Conversely, if the PRS symbols are in different subframes, then the maximum distance can be much larger.

[0073] Figure 4 illustrates an exemplary PRS subframe 400 with the placement of the PRS symbols for three TRPs, in accordance with aspects of the present disclosure. Figure 4 shows a Physical Resource Block (PRB) with a comb-6 positioning reference configuration for three TRPs. As defined in 3GPP NR, a PRB consists of 12 subcarriers in frequency and 14 OFDM symbols in time.

[0074] Each row of the PRB (i.e., each subcarrier over the 14-symbol subframe) represents a subcarrier. As depicted, there are two PRS symbols from each of the three TRPs in each subcarrier. The distance between the PRS for a pair of TRPs depends both on the subcarrier selected and the PRS selected within the subcarrier. A few examples follow:

[0075] Example 1: For TRPs 1 and 2 and the first subcarrier, the phase differences measurements can be based on symbols 2, 6, 8, and 12. If only a single pair of PRS symbols is used to determine the phase difference, then the pairs can be 2 and 6, 6 and 8, 8 and 12, or 2 and 12. Alternatively, more than two PRS symbols can be used to determine the phase difference.

[0076] Example 2: For TRPs 2 and 3 and the first subcarrier, the phase difference measurements can be taken using symbols 2, 3, 8, and 9. If only a single pair of PRS symbols is used to determine the phase differences, then the pairs can be 2 and 3, 3 and 8, 8 and 9, or 2 and 9. Alternatively, more than two PRS symbols can be used to determine the phase difference.

[0077] Example 3: For TRPs 1 and 3 and the first subcarrier, the phase difference measurements can be taken using symbols 3, 6, 9, and 12. If only a single pair of PRS symbols is used to determine the phase differences, then the pairs can be 3 and 6, 6 and 9, 9 and 12, or 3 and 12. Alternatively, more than two PRS symbols can be used to determine the phase difference.

[0078] For the example in Figure 4, it is always possible to find a subcarrier for any pair of TRPs for which the PRS symbols are adjacent and for which the error due to the frequency offsets between the TRP, the UE, and the PRU can be minimized. For TRPs 1 and 2, the PRS symbols 4 and 5 of the second subcarrier can be used. For TRPs 2 and 3, the PRS symbols 2 and 3 of the first subcarrier can be used. For TRPs 1 and 3, the PRS symbols 4 and 5 of resource element 4 can be used.

[0079] The errors due to the carrier frequency offsets are predictable if the carrier frequency offsets between the TRP transmitters and the UE and PRU receivers are known. For this reason, in addition to the carrier phase and / or the carrier phase difference, the UE and the PRU can report the carrier frequency offsets for each of the TRPs for which carrier phase measurements are taken. The carrier frequency offset can be determined by measuring the phase difference between reference symbols transmitted by the same TRP.

[0080] As above, let ^^,^,^denote the demodulated PRS symbol received from TRP l on the i-th subcarrier and k-th symbol. Multiplication by the conjugate of the reference symbol yields: ^^^^^^^^ ^^ ^^ ^^^ ^^^ ^,^^ ^^^^^ ^^^^^ ^^^^ ^^ ^^^^^^!.

[0081] Similarly, the PRS symbol received from TRP l on the i-th subcarrier and the k+m-thsymbol can be represented as:A∗^,^^D,^ = ^^,^^D,^ ^^,^^D,^^^^^^^^^^^ ^^ ^ ^ ^,^^ ^^^^ ^.

[0082] Multiplication of A^,^^D,^by the conjugate of A^,^,^yields^^^^^^^^ ^^^^^^^ ^^^^^,^^ ^ ^ ^,^^^^ ^^^^^ ^^^^^^^D^^^^^^,^^ ^^ ^^^^^^!^^ ^^æ,^.ofA^,^^D,^ A∗^,^,^ is given by^ |arg^A ∗ )*^,^^D,^ A^,^,^ ^} = J Δ / ^,'(and the phase offset per symbol ofto the UE receiver is givenby^ |arg^A^,^^D,^A^∗,^,^^}*( .

[0084] More than two PRS reference symbols can be used to estimate the frequency offset and these PRS reference symbols can be in different PRS subframes. Additionally, the frequency offset can be estimated for each subcarrier, and these estimates can be averaged since the carrier frequency offset is independent of the subcarrier. As a result, the carrier frequency offset can be averaged across both frequency and time.

[0085] Each of the PRU’s can also estimate the carrier frequency offset of each of the TRPs relative to the PRU receiver, and these frequency offset estimates can be signaled to the LMF and / or the UE’s. Alternatively, the PRU’s can signal the frequency offsets to the LMF after which the LMF can signal these same frequency offsets to the UE.

[0086] It should be noted that if the UE location is determined at the LMF, then the LMF must know the separation (in symbols) of the PRS that are used to determine the phase differences between two TRPs. Alternatively, if carrier phase is reported rather than carrier phase difference, then any averaging of PRS measurements must be known to the LMF in order to enable the LMF to correctly cancel the carrier frequency offset.

[0087] The phase measurement errors due to frequency offsets can be estimated and removed by the LMF when the following conditions are met: i) the UE measures its frequency offset with each of the TRP transmitters and signals the estimate to the LMF; ii) the PRU measures it frequency offset with each of the TRP transmitters and signals the estimate to the LMF; and iii) the LMF knows which PRS reference symbols are used to determine the carrier phase or the carrier phase difference reported to the LMF.

[0088] Alternatively, if the UE reports carrier phase differences, the UE can remove the error due to the carrier frequency offset between the TRP and the UE receiver using its estimate of the carrier frequency offset. However, the LMF must still remove the phase error due to the carrier frequency offset between the TRP and the PRU receiver. Alternatively, if the LMF signals the carrier frequency offset between the TRP and the PRU to the UE, the UE can also cancel the phase error due to the carrier frequency offset between the TRP and the PRU receiver.

[0089] If the UE reports carrier phases for individual PRS symbols, then the UE cannot remove the error due to the carrier frequency offset between the TRP and the UE receiver before reporting to the LMF as this depends on which PRS symbols will be used by the LMF to compute the phase difference and the time offset between them.

[0090] Figure 5 illustrates an example of a procedure 500 for carrier frequency measurement reporting for carrier phase positioning, in accordance with aspects of the present disclosure. The procedure 500 involves at least two TRPs, depicted here as the l-th TRP 502 and the m-th TRP 504, a target UE 506, at least one PRU 508, and a LMF 510. In certain embodiments, the TRPs 502 and 504 are embodiments of the gNBs 204-208 and are representative of a set of Nes 102. In certain embodiments, the target UE 506 is an embodiment of the UE 202 and is representative of a UEs 104. In certain embodiments, the LMF 510 is an embodiment of the LMF 210 and is representative of an NF in the CN 106.

[0091] The procedure 500 begins at Step 1 as the l-th TRP 502 and the m-th TRP 504 each transmit DL-PRS in one or more PRB over at least one PRS subframe (see block 512). An example of the PRS subframe is depicted in Figure 4. In some embodiments, the l-th TRP 502transmits a first DL-PRS 514 (depicted as DL-PRS-l) and the m-th TRP 502 transmits a second DL-PRS 516 (depicted as DL-PRS-m). Here, the first DL-PRS 514 may correspond to the PRS from TRP 1, as depicted in Figure 4, while the second DL-PRS 516 may correspond to the PRS from TRP 2, as depicted in Figure 4. In certain embodiments, the l-th TRP 502 and the m-th TRP 504 may transmit the DL PRS on different DL beams, as depicted in Figure 2.

[0092] At Step 2, the target UE 506 and the PRU(s) 508 each receive the DL PRS and measure a frequency offset with respect to each TRP (see blocks 518 and 520).

[0093] At Step 3, the target UE 506 and the PRU(s) 508 each report carrier frequency measurements including the respective carrier frequency offsets to the LMF 510 (see messaging 522 and 524).

[0094] At Step 4, the LMF 510 performs carrier phase positioning based on the reported carrier frequency offsets to determine a location of the target UE 506 (see block 526). As described above, the LMF 510 derives the initial phase offsets between the l-th TRP 502 and the m-th TRP 504, and the target UE 506 and the PRU 508. According to aspects of the present disclosure, the LMF 510 uses the initial phase offsets to remove the phase measurement error associated with the carrier phase measurements when performing the carrier phase positioning. As used herein, the term “initial phase offset” refers to the difference between the initial transmitter phase and the initial receiver phase and includes the error due to carrier frequency offset. More specifically, the measurement error associated with the carrier phase measurements includes both an initial phase difference error and another error due to the carrier frequency offsets.

[0095] By compensating for the (i.e., unknown) initial phase offset and removing the phase measurement error due to carrier frequency offset, the improved techniques for carrier phase positioning, as described herein, allow the LMF 510 to determine the location of the target UE 506 with enhanced accuracy as compared to conventional positioning techniques.

[0096] At optional Step 5, the LMF 510 may indicate, to the target UE 506, the initial phase offsets and / or carrier frequency offsets (see messaging 528). Alternatively, the LMF 510 may transmit, to the target UE 506, the UE positioning data (e.g., UE location) resulting from the carrier phase positioning (see messaging 528). Where the LMF 510 indicates the initial phase offsets and / or carrier frequency offsets, the target UE 506 may derive its own location using carrier phase positioning and possibly additional DL positioning techniques.

[0097] Figure 6 illustrates an example of a UE 600 in accordance with aspects of the present disclosure. The UE 600 may include a processor 602, a memory 604, a controller 606, and a transceiver 608. The processor 602, the memory 604, the controller 606, or the transceiver 608, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. These components may be coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces.

[0098] The processor 602, the memory 604, the controller 606, or the transceiver 608, or various combinations or components thereof may be implemented in hardware (e.g., circuitry). The hardware may include a processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), or other programmable logic device, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure.

[0099] The processor 602 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a central processing unit (CPU), an ASIC, a field programmable gate array (FPGA), or any combination thereof). In some implementations, the processor 602 may be configured to operate the memory 604. In some other implementations, the memory 604 may be integrated into the processor 602. The processor 602 may be configured to execute computer- readable instructions stored in the memory 604 to cause the UE 600 to perform various functions of the present disclosure.

[0100] The memory 604 may include volatile or non-volatile memory. The memory 604 may store computer-readable, computer-executable code including instructions that, when executed by the processor 602, cause the UE 600 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such the memory 604 or another type of memory. Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer.

[0101] In some implementations, the processor 602 and the memory 604 coupled with the processor 602 may be configured to cause the UE 600 to perform one or more of the UE functions described herein (e.g., executing, by the processor 602, instructions stored in the memory 604). Alternatively, if the UE 600 has a fixed, known location, then the processor 602 and the memory 604 coupled with the processor 602 may be configured to cause the UE 600 to perform one ormore of the PRU functions described herein (e.g., executing, by the processor 602, instructions stored in the memory 604).

[0102] Accordingly, the processor 602 may support wireless communication at the UE 600 in accordance with examples as disclosed herein. For example, the UE 600 may be configured to support a means for receiving a set of (e.g., at least two) PRSs associated with a set of (e.g., at least two) TRPs, each PRS in the set of PRSs associated with a PRS symbol and a subcarrier frequency.

[0103] The UE 600 may be configured to support a means for determining a set of carrier phase measurements based at least in part on the set of PRSs, where the set of carrier phase measurements includes a carrier frequency offset corresponding to the set of PRSs, or a set of carrier phase differences corresponding to the set of PRSs, or both. In some implementations, the UE 600 may be configured to support a means for indicating the set of carrier phase measurements to an LMF.

[0104] In some implementations, the UE 600 may be configured to estimate, based at least in part on the set of PRSs, a first carrier frequency offset associated with the UE and the set of TRPs. In such implementations, the set of carrier phase measurements indicates the first carrier frequency offset. In certain implementations, the UE 600 may be further configured to receive a second carrier frequency offset associated with a PRU and the set of TRPs and to calculate the UE positioning data by using the first carrier frequency offset and the second carrier frequency offset to remove a phase measurement error associated with the set of carrier phase measurements. In one implementation, the second carrier frequency offset is received from the LMF. In another implementation, the second carrier frequency offset is received from the PRU.

[0105] In some implementations, the UE 600 may be further configured to determine the set of carrier phase differences by determining a set of carrier phase differences on a same subcarrier associated with a plurality of TRP and a symbol separation of a subset of the PRS used to measure the carrier phase differences. In such implementations, the UE 600 may be configured to report the set of carrier phase differences and the symbol separation with the set of carrier phase measurements, e.g., when indicating the set of carrier phase measurements.

[0106] In some implementations, the UE 600 may be further configured to determine the carrier frequency offset corresponding to the set of PRSs by measuring a carrier frequency offset with each TRP in the set of TRPs based at least in part on the set of PRSs, and to estimate a phase measurement error corresponding to each carrier frequency offset. In such implementations, theUE 600 may be configured to report each carrier frequency offset and estimated phase measurement error, e.g., when indicating the set of carrier phase measurements.

[0107] In some implementations, the set of carrier phase measurements indicates a set of PRSs symbols associated with the set of carrier phase measurements. In some implementations, the UE 600 may be configured to receive UE positioning data from the LMF.

[0108] In some implementations, the UE 600 may be further configured to receive, from the LMF, initial phase offset information for the set of TRPs. In such implementations, the UE 600 may derive UE positioning data by performing carrier phase positioning using the initial phase offset information. Note that to perform carrier phase positioning, the UE 600 must have knowledge of the TRP locations for the set of TRPs.

[0109] The controller 606 may manage input and output signals for the UE 600. The controller 606 may also manage peripherals not integrated into the UE 600. In some implementations, the controller 606 may utilize an operating system (OS) such as iOS®, ANDROID®, WINDOWS®, or other operating systems. In some implementations, the controller 606 may be implemented as part of the processor 602.

[0110] In some implementations, the UE 600 may include at least one transceiver 608. In some other implementations, the UE 600 may have more than one transceiver 608. The transceiver 608 may represent a wireless transceiver. The transceiver 608 may include one or more receiver chains 610, one or more transmitter chains 612, or a combination thereof.

[0111] A receiver chain 610 may be configured to receive signals (e.g., control information, data, packets) over a wireless medium. For example, the receiver chain 610 may include one or more antennas for receiving the signal over the air or wireless medium. The receiver chain 610 may include at least one amplifier (e.g., a low-noise amplifier (LNA)) configured to amplify the received signal. The receiver chain 610 may include at least one demodulator configured to demodulate the received signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receiver chain 610 may include at least one decoder for decoding / processing the demodulated signal to receive the transmitted data.

[0112] A transmitter chain 612 may be configured to generate and transmit signals (e.g., control information, data, packets). The transmitter chain 612 may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as amplitude modulation (AM), frequency modulation (FM), or digital modulation schemes likephase-shift keying (PSK) or quadrature amplitude modulation (QAM). The transmitter chain 612 may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmitter chain 612 may also include one or more antennas for transmitting the amplified signal into the air or wireless medium.

[0113] Figure 7 illustrates an example of a processor 700 in accordance with aspects of the present disclosure. The processor 700 may be an example of a processor configured to perform various operations in accordance with examples as described herein. The processor 700 may include a controller 702 configured to perform various operations in accordance with examples as described herein. The processor 700 may optionally include at least one memory 704, which may be, for example, an L1 / L2 / L3 cache. Additionally, or alternatively, the processor 700 may optionally include one or more arithmetic-logic units (ALUs) 706. One or more of these components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses).

[0114] The processor 700 may be a processor chipset and include a protocol stack (e.g., a software stack) executed by the processor chipset to perform various operations (e.g., receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) in accordance with examples as described herein. The processor chipset may include one or more cores, one or more caches (e.g., memory local to or included in the processor chipset (e.g., the processor 700) or other memory (e.g., random access memory (RAM), read-only memory (ROM), dynamic RAM (DRAM), synchronous dynamic RAM (SDRAM), static RAM (SRAM), ferroelectric RAM (FeRAM), magnetic RAM (MRAM), resistive RAM (RRAM), flash memory, phase change memory (PCM), and others).

[0115] The controller 702 may be configured to manage and coordinate various operations (e.g., signaling, receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) of the processor 700 to cause the processor 700 to support various operations in accordance with examples as described herein. For example, the controller 702 may operate as a control unit of the processor 700, generating control signals that manage the operation of various components of the processor 700. These control signals include enabling or disabling functional units, selecting data paths, initiating memory access, and coordinating timing of operations.

[0116] The controller 702 may be configured to fetch (e.g., obtain, retrieve, receive) instructions from the memory 704 and determine subsequent instruction(s) to be executed to cause the processor 700 to support various operations in accordance with examples as described herein. The controller 702 may be configured to track memory address of instructions associated with the memory 704. The controller 702 may be configured to decode instructions to determine the operation to be performed and the operands involved. For example, the controller 702 may be configured to interpret the instruction and determine control signals to be output to other components of the processor 700 to cause the processor 700 to support various operations in accordance with examples as described herein. Additionally, or alternatively, the controller 702 may be configured to manage flow of data within the processor 700. The controller 702 may be configured to control transfer of data between registers, arithmetic logic units (ALUs), and other functional units of the processor 700.

[0117] The memory 704 may include one or more caches (e.g., memory local to or included in the processor 700 or other memory, such RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc. In some implementations, the memory 704 may reside within or on a processor chipset (e.g., local to the processor 700). In some other implementations, the memory 704 may reside external to the processor chipset (e.g., remote to the processor 700).

[0118] The memory 704 may store computer-readable, computer-executable code including instructions that, when executed by the processor 700, cause the processor 700 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. The controller 702 and / or the processor 700 may be configured to execute computer-readable instructions stored in the memory 704 to cause the processor 700 to perform various functions. For example, the processor 700 and / or the controller 702 may be coupled with or to the memory 704, the processor 700, the controller 702, and the memory 704 may be configured to perform various functions described herein. In some examples, the processor 700 may include multiple processors and the memory 704 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiple memories, which may, individually or collectively, be configured to perform various functions herein.

[0119] The one or more ALUs 706 may be configured to support various operations in accordance with examples as described herein. In some implementations, the one or more ALUs 706 may reside within or on a processor chipset (e.g., the processor 700). In some other implementations, the one or more ALUs 706 may reside external to the processor chipset (e.g.,the processor 700). One or more ALUs 706 may perform one or more computations such as addition, subtraction, multiplication, and division on data. For example, one or more ALUs 706 may receive input operands and an operation code, which determines an operation to be executed. One or more ALUs 706 be configured with a variety of logical and arithmetic circuits, including adders, subtractors, shifters, and logic gates, to process and manipulate the data according to the operation. Additionally, or alternatively, the one or more ALUs 706 may support logical operations such as AND, OR, exclusive-OR (XOR), not-OR (NOR), and not-AND (NAND), enabling the one or more ALUs 706 to handle conditional operations, comparisons, and bitwise operations.

[0120] In various embodiments, the processor 700 may support wireless communication of a UE, in accordance with examples as disclosed herein. In other embodiments, the processor 700 may support wireless communication of a PRU, in accordance with examples as disclosed herein. For example, the processor 700 may be configured to support a means for receiving a set of (e.g., at least two) PRSs associated with a set of (e.g., at least two) TRPs, each PRS in the set of PRSs associated with a PRS symbol and a subcarrier frequency.

[0121] The processor 700 may be configured to support a means for determining a set of carrier phase measurements based at least in part on the set of PRSs, where the set of carrier phase measurements includes a carrier frequency offset corresponding to the set of PRSs, or a set of carrier phase differences corresponding to the set of PRSs, or both. In some implementations, the processor 700 may be configured to support a means for indicating the set of carrier phase measurements to an LMF. In some implementations, the set of carrier phase measurements indicates a set of PRSs symbols associated with the set of carrier phase measurements.

[0122] In some implementations, the processor 700 may be configured to estimate, based at least in part on the set of PRSs, a first carrier frequency offset associated with the UE and the set of TRPs. In such implementations, the set of carrier phase measurements indicates the first carrier frequency offset. In certain implementations, the processor 700 may be further configured to receive a second carrier frequency offset associated with a PRU and the set of TRPs and to calculate the UE positioning data by using the first carrier frequency offset and the second carrier frequency offset to remove a phase measurement error associated with the set of carrier phase measurements. In one implementation, the second carrier frequency offset is received from the LMF. In another implementation, the second carrier frequency offset is received from the PRU.

[0123] In some implementations, the processor 700 may be further configured to determine the set of carrier phase differences by determining a set of carrier phase differences on a samesubcarrier associated with a plurality of TRP and a symbol separation of a subset of the PRS used to measure the carrier phase differences. In such implementations, the processor 700 may be configured to report the set of carrier phase differences and the symbol separation with the set of carrier phase measurements, e.g., when indicating the set of carrier phase measurements.

[0124] In some implementations, the processor 700 may be further configured to determine the carrier frequency offset corresponding to the set of PRSs by measuring a carrier frequency offset with each TRP in the set of TRPs based at least in part on the set of PRSs, and to estimate a phase measurement error corresponding to each carrier frequency offset. In such implementations, the processor 700 may be configured to report each carrier frequency offset and estimated phase measurement error, e.g., when indicating the set of carrier phase measurements.

[0125] In some implementations, the processor 700 may be further configured to receive, from the LMF, initial phase offset information for the set of TRPs. In such implementations, the processor 700 may derive UE positioning data by performing carrier phase positioning using the initial phase offset information. Note that to perform carrier phase positioning, the processor 700 must have knowledge of the TRP locations for the set of TRPs. In some implementations, the processor 700 may be configured to receive UE positioning data from the LMF.

[0126] Figure 8 illustrates an example of a NE 800 in accordance with aspects of the present disclosure. The NE 800 may include a processor 802, a memory 804, a controller 806, and a transceiver 808. The processor 802, the memory 804, the controller 806, or the transceiver 808, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. These components may be coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces.

[0127] The processor 802, the memory 804, the controller 806, or the transceiver 808, or various combinations or components thereof may be implemented in hardware (e.g., circuitry). The hardware may include a processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), or other programmable logic device, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure.

[0128] The processor 802 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, an ASIC, an FPGA, or any combination thereof). In some implementations, the processor 802 may be configured to operate the memory 804. In some otherimplementations, the memory 804 may be integrated into the processor 802. The processor 802 may be configured to execute computer-readable instructions stored in the memory 804 to cause the NE 800 to perform various functions of the present disclosure.

[0129] The memory 804 may include volatile or non-volatile memory. The memory 804 may store computer-readable, computer-executable code including instructions when executed by the processor 802 cause the NE 800 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such the memory 804 or another type of memory. Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer.

[0130] In some implementations, the processor 802 and the memory 804 coupled with the processor 802 may be configured to cause the NE 800 to perform one or more of the LMF functions described herein (e.g., executing, by the processor 802, instructions stored in the memory 804). For example, the processor 802 may support wireless communication at the NE 800 in accordance with examples as disclosed herein.

[0131] The NE 800 may be configured to support a means for receiving, from a target UE, a first set of carrier phase measurements associated with a set of (e.g., at least two) TRP. In such implementations, the first set of carrier phase measurements includes a first carrier frequency offset between the UE and the set of TRPs, or a first set of carrier phase differences corresponding to the set of PRSs, or both. In certain implementations, the first set of carrier phase measurements corresponds to a set of (e.g., at least two) PRS and is associated with the set of TRPs, each PRS in the set of PRSs associated with a PRS symbol and a subcarrier frequency. In certain implementations, the first set of carrier phase measurements includes a first set of carrier phase differences measured on a same subcarrier associated with at least two TRP of the set TRP. In such implementations, the first set of carrier phase measurements further indicates a symbol separation of a subset of the PRS used to measure the first set of carrier phase differences.

[0132] In some implementations, the NE 800 may be configured to support a means for receiving, from a PRU associated with a fixed and known location, a second set of carrier phase measurements associated with the set of TRPs. In such implementations, the second set of carrier phase measurements includes a second carrier frequency offset between the PRU and the set of TRPs, or a second set of carrier phase differences corresponding to the set of PRSs, or both. In certain implementations, the second set of carrier phase measurements corresponds to the set ofPRSs and is associated with the set of TRPs. In certain implementations, the second set of carrier phase measurements includes a second set of carrier phase differences measured on the same subcarrier associated with at least two TRP of the set of TRPs. In such implementations, the second set of carrier phase measurements further indicates a symbol separation of a subset of the PRS used to measure the second set of carrier phase differences.

[0133] The NE 800 may be configured to support a means for determining initial phase offset information for the set of TRPs based at least in part on the first and second sets of carrier phase measurements. In some implementations, the NE 800 is further configured to receive, from the UE and the PRU, an indication of a set of PRSs symbols associated with the first and second sets of carrier phase measurements.

[0134] The NE 800 may be configured to support a means for deriving UE positioning data associated with the target UE by performing carrier phase positioning using the initial phase offset information. In some implementations, to derive the UE positioning data, the NE 800 may be configured to use the initial phase offset information to remove a phase measurement error associated with the first and second sets of carrier phase measurements.

[0135] In certain implementations, the NE 800 may be further configured to transmit, to the UE, the initial phase offset information. In certain implementations, the NE 800 may be configured to transmit, to the UE, the UE positioning data.

[0136] In some implementations, if the NE 800 has a fixed, known location, then the processor 802 and the memory 804 coupled with the processor 802 may be configured to cause the NE 800 to perform one or more of the PRU functions described herein (e.g., executing, by the processor 802, instructions stored in the memory 804). For example, the processor 802 may support wireless communication at the NE 800 in accordance with examples as disclosed herein. The NE 800 may be configured to support a means for receiving a set of (e.g., at least two) PRSs associated with a set of (e.g., at least two) TRPs, each PRS in the set of PRSs associated with a PRS symbol and a subcarrier frequency.

[0137] The NE 800 may be configured to support a means for determining a set of carrier phase measurements based at least in part on the set of PRSs, where the set of carrier phase measurements includes a carrier frequency offset corresponding to the set of PRSs, or a set of carrier phase differences corresponding to the set of PRSs, or both. In some implementations, the NE 800 may be configured to support a means for indicating the set of carrier phase measurements to an LMF.

[0138] In some implementations, to determine the carrier frequency offset corresponding to the PRS, the NE 800 may be configured to estimate, based at least in part on the set of PRSs, a carrier frequency offset associated with the PRU and the set of TRPs. In such implementations, the NE 800 may be configured to report the first carrier frequency offset, e.g., when indicating the ser of carrier phase measurements.

[0139] In some implementations, the NE 800 may be further configured to determine the set of carrier phase differences by determining a set of carrier phase differences on a same subcarrier associated with a plurality of TRP and a symbol separation of a subset of the PRS used to measure the carrier phase differences. In such implementations, the NE 800 may be configured to report the set of carrier phase differences and the symbol separation with the set of carrier phase measurements, e.g., when indicating the set of carrier phase measurements.

[0140] In some implementations, the NE 800 may be further configured to determine the carrier frequency offset corresponding to the set of PRSs by measuring a carrier frequency offset with each TRP in the set of TRPs based at least in part on the set of PRSs, and to estimate a phase measurement error corresponding to each carrier frequency offset. In such implementations, the NE 800 may be configured to report each carrier frequency offset and estimated phase measurement error, e.g., when indicating the set of carrier phase measurements.

[0141] In some implementations, the NE 800 may be further configured to report a set of PRSs symbols associated with the set of carrier phase measurements, e.g., when indicating the set of carrier phase measurements.

[0142] The controller 806 may manage input and output signals for the NE 800. The controller 806 may also manage peripherals not integrated into the NE 800. In some implementations, the controller 806 may utilize an operating system such as iOS®, ANDROID®, WINDOWS®, or other operating systems. In some implementations, the controller 806 may be implemented as part of the processor 802.

[0143] In some implementations, the NE 800 may include at least one transceiver 808. In some other implementations, the NE 800 may have more than one transceiver 808. The transceiver 808 may represent a wireless transceiver. The transceiver 808 may include one or more receiver chains 810, one or more transmitter chains 812, or a combination thereof.

[0144] A receiver chain 810 may be configured to receive signals (e.g., control information, data, packets) over a wireless medium. For example, the receiver chain 810 may include one or more antennas for receiving the signal over the air or wireless medium. The receiver chain 810may include at least one amplifier (e.g., a low-noise amplifier (LNA)) configured to amplify the received signal. The receiver chain 810 may include at least one demodulator configured to demodulate the received signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receiver chain 810 may include at least one decoder for decoding / processing the demodulated signal to receive the transmitted data.

[0145] A transmitter chain 812 may be configured to generate and transmit signals (e.g., control information, data, packets). The transmitter chain 812 may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as amplitude modulation (AM), frequency modulation (FM), or digital modulation schemes like phase-shift keying (PSK) or quadrature amplitude modulation (QAM). The transmitter chain 812 may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmitter chain 812 may also include one or more antennas for transmitting the amplified signal into the air or wireless medium.

[0146] Figure 9 depicts one embodiment of a method 900 in accordance with aspects of the present disclosure. In various embodiments, the operations of the method 900 may be implemented by a UE as described herein. In other embodiments, the operations of the method 900 may be implemented by a PRU as described herein. In some implementations, the UE or PRU may execute a set of instructions to control the function elements of the UE or PRU to perform the described functions.

[0147] At step 902, the method 900 may include receiving a set of PRSs associated with a set of TRPs, each PRS in the set of PRSs associated with a PRS symbol and a subcarrier frequency. The operations of step 902 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of step 902 may be performed by a UE as described with reference to Figure 6. In other embodiments, aspects of the operation of step 902 may be performed by a PRU implemented by a UE, as described with reference to Figure 6, or implemented by a NE, as described with reference to Figure 8.

[0148] At step 904, the method 900 may include determining a set of carrier phase measurements based at least in part on the set of PRSs, where the set of carrier phase measurements comprises a carrier frequency offset corresponding to the set of PRSs, or a set of carrier phase differences corresponding to the set of PRSs, or both. The operations of step 904 may be performed in accordance with examples as described herein. In some implementations,aspects of the operations of step 904 may be performed by a UE as described with reference to Figure 6. In other embodiments, aspects of the operation of step 904 may be performed by a PRU implemented by a UE, as described with reference to Figure 6, or implemented by a NE, as described with reference to Figure 8.

[0149] At step 906, the method 900 may include indicating (e.g., transmitting) the set of carrier phase measurements to an LMF. The operations of step 906 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of step 906 may be performed a UE as described with reference to Figure 6. In other embodiments, aspects of the operation of step 906 may be performed by a PRU implemented by a UE, as described with reference to Figure 6, or implemented by a NE, as described with reference to Figure 8.

[0150] It should be noted that the method 900 described herein describes one possible implementation, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible.

[0151] Figure 10 depicts one embodiment of a method 1000 in accordance with aspects of the present disclosure. The operations of the method 1000 may be implemented by a LMF as described herein. In some implementations, the LMF may execute a set of instructions to control the function elements of the LMF to perform the described functions.

[0152] At step 1002, the method 1000 may include receiving a first set of carrier phase measurements from a target UE associated with a set of TRPs. Here, the first set of carrier phase measurements may include a first carrier frequency offset between the UE and the set of TRPs, or a first set of carrier phase differences corresponding to the set of PRSs, or both. The operations of step 1002 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of step 1002 may be performed by a LMF implemented by a NE, as described with reference to Figure 8.

[0153] At step 1004, the method 1000 may include receiving, from a PRU associated with a fixed and known location, a second set of carrier phase measurements associated with the set of TRPs. Here, the second set of carrier phase measurements includes a second carrier frequency offset between the PRU and the set of TRPs, or a second set of carrier phase differences corresponding to the set of PRSs, or both. The operations of step 1004 may be performed in accordance with examples as described herein. In some implementations, aspects of theoperations of step 1004 may be performed by a LMF implemented by a NE, as described with reference to Figure 8.

[0154] At step 1006, the method 1000 may include determining initial phase offset information for the set of TRPs based at least in part on the first and second sets of carrier phase measurements. The operations of step 1006 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of step 1006 may be performed by a LMF implemented by a NE, as described with reference to Figure 8.

[0155] At step 1008, the method 1000 may include deriving UE positioning data associated with the target UE by performing carrier phase positioning using the initial phase offset information. The operations of step 1008 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of step 1008 may be performed by a LMF implemented by a NE, as described with reference to Figure 8.

[0156] It should be noted that the method 1000 described herein describes one possible implementation, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible.

[0157] The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

CLAIMS What is claimed is:

1. A user equipment (UE) for wireless communication, comprising: at least one memory; and at least one processor coupled with the at least one memory and configured to cause the UE to: receive a set of positioning reference signals (PRS) associated with a set of transmission-reception points (TRP), each PRS in the set of PRS associated with a PRS symbol and a subcarrier frequency; determine a set of carrier phase measurements based at least in part on the set of PRS, wherein the set of carrier phase measurements comprises a carrier frequency offset corresponding to the set of PRS, or a set of carrier phase differences corresponding to the set of PRS, or both; and indicate the set of carrier phase measurements to a location management function (LMF).

2. The UE of claim 1, wherein the at least one processor is further configured to cause the UE to estimate, based at least in part on the set of PRS, a first carrier frequency offset associated with the UE and the set of TRP, and wherein the set of carrier phase measurements indicates the first carrier frequency offset.

3. The UE of claim 2, wherein the at least one processor is further configured to cause the UE to: receive a second carrier frequency offset associated with a positioning reference unit (PRU) and the set of TRP; and calculate UE positioning data by using the first carrier frequency offset and the second carrier frequency offset to remove a phase measurement error associated with the set of carrier phase measurements.

4. The UE of claim 3, wherein the second carrier frequency offset is received from the LMF or from the PRU.

5. The UE of claim 1, wherein to determine the set of carrier phase differences, the at least one processor is configured to cause the UE to determine a set of carrier phasedifferences on a same subcarrier associated with a plurality of TRP and a symbol separation of a subset of the PRS used to measure the carrier phase differences, and wherein to indicate the set of carrier phase measurements, the at least one processor is configured to cause the UE to report the set of carrier phase differences and the symbol separation.

6. The UE of claim 1, wherein to determine the carrier frequency offset corresponding to the set of PRS, the at least one processor is configured to cause the UE to: measure a carrier frequency offset with each TRP in the set of TRP based at least in part on the set of PRS, and estimate a phase measurement error corresponding to each carrier frequency offset, and wherein to indicate the set of carrier phase measurements, the at least one processor is configured to cause the UE to report each carrier frequency offset and estimated phase measurement error.

7. The UE of claim 1, wherein the set of carrier phase measurements indicates a set of PRS symbols associated with the set of carrier phase measurements.

8. The UE of claim 1, wherein the at least one processor is further configured to cause the UE to: receive, from the LMF, initial phase offset information for the set of TRP; and derive UE positioning data by performing carrier phase positioning using the initial phase offset information.

9. A processor for wireless communication, comprising: at least one controller coupled with at least one memory and configured to cause the processor to: receive a set of positioning reference signals (PRS) associated with a set of transmission-reception points (TRP), each PRS in the set of PRS associated with a PRS symbol and a subcarrier frequency; determine a set of carrier phase measurements based at least in part on the set of PRS, wherein the set of carrier phase measurements comprises a carrierfrequency offset corresponding to the set of PRS, or a set of carrier phase differences corresponding to the set of PRS, or both; and indicate the set of carrier phase measurements to a location management function (LMF).

10. An apparatus for wireless communication at a location management function, comprising: at least one memory; and at least one processor coupled with the at least one memory and configured to cause the location management function to: receive a first set of carrier phase measurements from a target user equipment (UE) associated with a set of transmission-reception points (TRP), wherein the first set of carrier phase measurements comprises a first carrier frequency offset between the UE and the set of TRP, or a first set of carrier phase differences corresponding to the set of PRS, or both; receive a second set of carrier phase measurements from a positioning reference unit (PRU) associated with the set of TRP, wherein the PRU is associated with a fixed and known location, wherein the second set of carrier phase measurements comprises a second carrier frequency offset between the PRU and the set of TRP, or a second set of carrier phase differences corresponding to the set of PRS, or both; determine initial phase offset information for the set of TRP based at least in part on the first and second sets of carrier phase measurements; and derive UE positioning data associated with the target UE by performing carrier phase positioning using the initial phase offset information.

11. The apparatus of claim 10, wherein to derive the UE positioning data, the at least one processor is configured to cause the location management function to use the initial phase offset information to remove a phase measurement error associated with the first and second sets of carrier phase measurements.

12. The apparatus of claim 10, wherein the first set of carrier phase measurements corresponds to a set of positioning reference signals (PRS) and is associated with the set of TRP, each PRS in the set of PRS associated with a PRS symbol and a subcarrier frequency.

13. The apparatus of claim 10, wherein the first set of carrier phase measurements comprises a set of carrier phase differences measured on a same subcarrier associated with a plurality of TRP, and wherein the first set of carrier phase measurements further indicates a symbol separation of a set of positioning reference signals (PRS) used to measure the set of carrier phase differences.

14. The apparatus of claim 10, wherein the second set of carrier phase measurements comprises a set of carrier phase differences measured on a same subcarrier associated with a plurality of TRP, and wherein the second set of carrier phase measurements further indicates a symbol separation of a set of positioning reference signals (PRS) used to measure the set of carrier phase differences.

15. The apparatus of claim 10, wherein the at least one processor is further configured to cause the location management function to transmit, to the UE, the initial phase offset information or the UE positioning data, or both.

16. An apparatus for wireless communication at a positioning reference unit (PRU), comprising: at least one memory; and at least one processor coupled with the at least one memory and configured to cause the PRU to: receive a set of positioning reference signals (PRS) associated with a set of transmission-reception points (TRP), each PRS in the set of PRS associated with a PRS symbol and a subcarrier frequency; determine a set of carrier phase measurements based at least in part on the set of PRS, wherein the set of carrier phase measurements comprises a carrier frequency offset corresponding to the set of PRS, or a set of carrier phase differences corresponding to the set of PRS, or both; and indicate the set of carrier phase measurements to a location management function (LMF).

17. The apparatus of claim 16, wherein to determine the carrier frequency offset corresponding to the set of PRS, the at least one processor is further configured to cause the PRU to estimate, based at least in part on the set of PRS, a carrier frequency offset associated with the apparatus and the set of TRP, and wherein to indicate the set ofcarrier phase measurements, the at least one processor is configured to cause the PRU to report the carrier frequency offset.

18. The apparatus of claim 16, wherein to determine the set of carrier phase differences, the at least one processor is configured to cause the PRU to determine a set of carrier phase differences on a same subcarrier associated with a plurality of TRP and a symbol separation of a subset of the PRS used to measure the carrier phase differences, and wherein to indicate the set of carrier phase measurements, the at least one processor is configured to cause the PRU to report the set of carrier phase differences and the symbol separation.

19. The apparatus of claim 16, wherein to determine the carrier frequency offset corresponding to the set of PRS, the at least one processor is configured to cause the PRU to: measure a carrier frequency offset with each TRP in the set of TRP based at least in part on the set of PRS, and estimate a phase measurement error corresponding to each carrier frequency offset, and wherein to indicate the set of carrier phase measurements, the at least one processor is configured to cause the PRU to report each carrier frequency offset and estimated phase measurement error.

20. The apparatus of claim 16, wherein the at least one processor is further configured to cause the PRU to indicate, to the LMF, the set of PRS symbols associated with the set of carrier phase measurements.

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