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EP-4165918-B1 - PASSIVE POSITIONING WITH ANALOG BEAMFORMING

EP4165918B1EP 4165918 B1EP4165918 B1EP 4165918B1EP-4165918-B1

Inventors

  • YERRAMALLI, Srinivas
  • ZHANG, XIAOXIA
  • YOO, TAESANG
  • MANOLAKOS, Alexandros
  • FERRARI, LORENZO
  • LIN, YIH-HAO
  • PRAKASH, RAJAT
  • SUN, JING

Dates

Publication Date
20260506
Application Date
20210505

Claims (15)

  1. A method for positioning a user equipment (905, 1005, 1105), the method comprising: receiving (1302) a first positioning reference signal (902b, 1002b, 1102b) from a first wireless node (910, 1010, 1110) at a first time (T3); receiving (1304) a first timing difference value based on two or more positioning reference signals transmitted from the first wireless node, wherein the first timing difference value indicates a difference between a time (X1) of transmission of the first positioning reference signal (902b, 1002b, 1102b) and a time (T1) of transmission of another positioning reference signal (902a, 1002a, 1102a) to a second wireless node (912, 1012, 1103); receiving (1306) a second positioning reference signal (904b, 1004b, 1104b) from the second wireless node at a second time (T6); receiving (1308) a second timing difference value based on two or more positioning reference signals transmitted from the second wireless node, wherein the second timing difference value indicates a difference between a time (X4) of transmission of the second positioning reference signal (904b, 1004b, 1104b) and a time (T4) of transmission of another positioning reference signal (904a, 1004a, 1104a) to the first wireless node; and determining (1310) a time difference of arrival between the first positioning reference signal and the second positioning reference signal based at least in part on the first time, the second time, the received first timing difference value and the received second timing difference value, wherein the determined time difference of arrival is a difference between a time of flight of the first positioning reference signal from the first wireless node to the user equipment and a time of flight of the second positioning reference signal from the second wireless node to the user equipment.
  2. The method of claim 1 wherein the first timing difference value is received from the first wireless node and the second timing difference value is received from the second wireless node.
  3. The method of claim 1 wherein the first timing difference value and the second timing difference value are received from a network server or a serving station.
  4. The method of claim 1 wherein the first timing difference value is included in the first positioning reference signal, and the second timing difference value is included in the second positioning reference signal.
  5. The method of claim 1 wherein the first timing difference value and the second timing difference value are received via a higher layer protocol.
  6. The method of claim 1 wherein the first timing difference value is associated with a beam identification value of the first positioning reference signal.
  7. The method of claim 1 wherein the second wireless node is a second user equipment and the second positioning reference signal is received via a sidelink transmitted from the second user equipment.
  8. The method of claim 1 wherein the first positioning reference signal is transmitted via a beam transmitted from the first wireless node.
  9. The method of claim 1 further comprising determining a position estimate based at least in part on the time difference of arrival.
  10. The method of claim 1 wherein the first positioning reference signal and the second positioning reference signal are from different frequency layers.
  11. The method of any preceding claim wherein: the method further comprises receiving a turn-around time value for the second wireless node and receiving a time of flight value associated with the first positioning reference signal and the second positioning reference signal, the time of flight value indicative of a distance between the first wireless node and the second wireless node.
  12. An apparatus (905, 1005, 1105) for positioning a user equipment, the apparatus comprising: a memory; at least one transceiver; at least one processor communicatively coupled to the memory and the at least one transceiver and configured to: receive (1302) a first positioning reference signal (902b, 1002b, 1102b) from a first wireless node (910, 1010, 1110) at a first time (T3); receive (1304) a first timing difference value based on two or more positioning reference signals transmitted from the first wireless node, wherein the first timing difference value indicates a difference between a time (X1) of transmission of the first positioning reference signal (902b, 1002b, 1102b) and a time (T1) of transmission of another positioning reference signal (902a, 1002a, 1102a) to a second wireless node (912, 1012, 1103); receive (1306) a second positioning reference signal (904b, 1004b, 1104b) from the second wireless node at a second time (T6); receive (1308) a second timing difference value based on two or more positioning reference signals transmitted from the second wireless node, wherein the second timing difference value indicates a difference between a time (X4) of transmission of the second positioning reference signal (904b, 1004b, 1104b) and a time (T4) of transmission of another positioning reference signal (904a, 1004a, 1104a) to the first wireless node; and determine (1310) a time difference of arrival between the first positioning reference signal and the second positioning reference signal based at least in part on the first time, the second time, the received first timing difference value, and the received second timing difference value, wherein the determined time difference of arrival is a difference between a time of flight of the first positioning reference signal from the first wireless node to the apparatus and a time of flight of the second positioning reference signal from the second wireless node to the apparatus.
  13. The apparatus of claim 12 wherein the at least one processor is further configured to determine a position estimate based at least in part on the time difference of arrival.
  14. The apparatus of claim 12 or claim 13 wherein: the at least one processor is further configured to receive a turn-around time value for the second wireless node and receive a time of flight value associated with the first positioning reference signal and the second positioning reference signal, the time of flight value indicative of a distance between the first wireless node and the second wireless node.
  15. A non-transitory processor-readable storage medium comprising processor-readable instructions that when executed in a user equipment cause one or more processors for positioning in the user equipment to perform a method according to any of claims 1 to 11.

Description

BACKGROUND Wireless communication systems have developed through various generations, including a first-generation analog wireless phone service (1G), a second-generation (2G) digital wireless phone service (including interim 2.5G and 2.75G networks), a third-generation (3G) high speed data, Internet-capable wireless service, a fourth-generation (4G) service (e.g., Long Term Evolution (LTE) or WiMax), and a fifth generation (5G) service (e.g., 5G New Radio (NR)). There are presently many different types of wireless communication systems in use, including Cellular and Personal Communications Service (PCS) systems. Examples of known cellular systems include the cellular Analog Advanced Mobile Phone System (AMPS), and digital cellular systems based on Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), the Global System for Mobile access (GSM) variation of TDMA, etc. It is often desirable to know the location of a user equipment (UE), e.g., a cellular phone, with the terms "location" and "position" being synonymous and used interchangeably herein. A location services (LCS) client may desire to know the location of the UE and may communicate with a location center in order to request the location of the UE. The location center and the UE may exchange messages, as appropriate, to obtain a location estimate for the UE. The location center may return the location estimate to the LCS client, e.g., for use in one or more applications. Obtaining the location of a mobile device that is accessing a wireless network may be useful for many applications including, for example, emergency calls, personal navigation, asset tracking, locating a friend or family member, etc. Existing positioning methods include methods based on measuring radio signals transmitted from a variety of devices including satellite vehicles and terrestrial radio sources in a wireless network such as base stations and access points. In WO 2020/069083 A1, systems, methods, and circuitries are disclosed for determining a position of a wireless device. In one example, an apparatus for a first wireless communication device including baseband circuitry having a radio frequency (RF) interface configured to transmit and receive RF signals is provided. The apparatus includes one or more processors configured to process a signal received from a second wireless communication device to identify at least first arrival path and a different arrival path between the first wireless communication device and the second wireless communication device; and determine a location of the second wireless communication device based on the first arrival path and the different arrival path. It is stated therein that the positioning accuracy of timing-based techniques depends on synchronization accuracy of gNBs involved in positioning procedure. When the coordinates of base stations are not known, base stations (e.g., gNBs/TRPs) can perform a ranging procedure to estimate round-trip time or time of flight. The distance between nodes can be estimated based on these estimations to improve the accuracy of synchronization. The DL PRS transmissions transmitted by gNBs/TRPs can be re used for that purpose. It is further stated that, when the coordinates of base stations are known, this information can be used for over-the air synchronization. The"known" RTT (round trip time) and ToF (time of flight) between based stations can be determined based on the coordinates of the base stations. This known distance can be compared with the estimated distance derived from the measured RTT/ToF and used to estimate a synchronization error or offset between base stations. The submission document titled "Summary of UE and gNB measurements for NR Positioning" of CATT (3GPP TSG RAN WG1 Meeting #98, Prague, Czech Republic, August 26th to 30th, 2019, document no. R1-1908574) discusses a number of proposals for additional gNB measurements for NR positioning. SUMMARY The invention is defined by the independent claims. Features of some embodiments are recited in dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a simplified diagram of an example wireless communications system.FIG. 2 is a block diagram of components of an example user equipment shown in FIG. 1.FIG. 3 is a block diagram of components of an example transmission/reception point shown in FIG. 1.FIG. 4 is a block diagram of components of an example server shown in FIG. 1.FIGS. 5A and 5B illustrate example downlink positioning reference signal resource sets.FIG. 5C illustrates an example beam sweeping configuration with the positioning reference signal resource sets of FIGS. 5A and 5B.FIG. 6 is an illustration of example subframe formats for positioning reference signal transmission.FIG. 7 is an example round trip time message flow between a user equipment and a base station.FIG. 8 is an example message flow for passive positioning of a user equipment.FIG. 9 is an exampl