Terrestrial wireless positioning in licensed and unlicensed frequency bands
Disclosed are techniques for positioning a user equipment (UE). In an aspect, a location server receives a first propagation time measurement and a first plurality of OTDOA RSTD measurements from a first UE at a first time, receives a second propagation time measurement and a second plurality of OTDOA RSTD measurements from a second UE at a second time, determines at least one real-time difference between a pair of base stations based on the first and second propagation time measurements and the first and second pluralities of OTDOA RSTD measurements, wherein the pair of base stations is associated with the first and second pluralities of OTDOA RSTD measurements, receives a third plurality of OTDOA RSTD measurements from a third UE at a third time, and determines a position of the third UE based at least in part on the at least one real-time difference between the pair of base stations.
1. A method at a location server for positioning a user equipment (UE), comprising:
receiving a first propagation time measurement and a first plurality of observed time difference of arrival (OTDOA) reference signal time difference (RSTD) measurements from a first UE at a first time;
receiving a second propagation time measurement and a second plurality of OTDOA RSTD measurements from a second UE at a second time, wherein the first propagation time measurement and the second propagation time measurement are for a same base station;
determining at least one real-time difference between a pair of base stations based on the first propagation time measurement, the second propagation time measurement, the first plurality of OTDOA RSTD measurements, and the second plurality of OTDOA RSTD measurements, wherein the pair of base stations is associated with the first plurality of OTDOA RSTD measurements and the second plurality of OTDOA RSTD measurements;
receiving a third plurality of OTDOA RSTD measurements from a third UE at a third time; and
determining a position of the third UE based at least in part on the at least one real-time difference between the pair of base stations.
2. The method of claim 1 , wherein the first propagation time measurement and the second propagation time measurement are for a common serving base station for the first UE and the second UE.
3. The method of claim 1 , wherein the first time and the second time are within a threshold period of time of each other.
4. The method of claim 3 , wherein the second time and the third time are within a threshold period of time of each other.
5. The method of claim 1 , wherein the pair of base stations are not synchronized with each other.
6. The method of claim 1 , wherein the first and second UEs are the same UE.
7. The method of claim 6 , wherein the second and third UEs are the same UE.
8. The method of claim 7 , wherein the first propagation time measurement and the second propagation time measurement and the first plurality of OTDOA RSTD measurements and the second plurality of OTDOA RSTD measurements are previous propagation time measurements and previous OTDOA RSTD measurements performed by the same UE.
9. The method of claim 1 , wherein the first and second propagation time measurements and the first and second pluralities of OTDOA RSTD measurements are measurements for Long Term Evolution (LTE) radio access in unlicensed spectrum.
10. An apparatus for positioning a user equipment (UE), comprising:
a receiver of a location server configured to:
receive a first propagation time measurement and a first plurality of observed time difference of arrival (OTDOA) reference signal time difference (RSTD) measurements from a first UE at a first time; and
receive a second propagation time measurement and a second plurality of OTDOA RSTD measurements from a second UE at a second time, wherein the first propagation time measurement and the second propagation time measurement are for a same base station; and
at least one processor of the location server configured to:
determine at least one real-time difference between a pair of base stations based on the first propagation time measurement, the second propagation time measurement, the first plurality of OTDOA RSTD measurements, and the second plurality of OTDOA RSTD measurements, wherein the pair of base stations is associated with the first plurality of OTDOA RSTD measurements and the second plurality of OTDOA RSTD measurements,
wherein the receiver is further configured to receive a third plurality of OTDOA RSTD measurements from a third UE at a third time, and
wherein the at least one processor is further configured to determine a position of the third UE based at least in part on the at least one real-time difference between the pair of base stations.
11. The apparatus of claim 10 , wherein the first propagation time measurement and the second propagation time measurement are for a common serving base station for the first UE and the second UE.
12. The apparatus of claim 10 , wherein the first time and the second time are within a threshold period of time of each other.
13. The apparatus of claim 12 , wherein the second time and the third time are within a threshold period of time of each other.
14. The apparatus of claim 10 , wherein the pair of base stations are not synchronized with each other.
15. The apparatus of claim 10 , wherein the first and second UEs are the same UE.
16. The apparatus of claim 15 , wherein the second and third UEs are the same UE.
17. The apparatus of claim 16 , wherein the first propagation time measurement, the second propagation time measurement, the first plurality of OTDOA RSTD measurements, and the second plurality of OTDOA RSTD measurements are previous propagation time measurements and previous OTDOA RSTD measurements performed by the same UE.
18. The apparatus of claim 10 , wherein the first and second propagation time measurements and the first and second pluralities of OTDOA RSTD measurements are measurements for Long Term Evolution (LTE) radio access in unlicensed spectrum.
19. A non-transitory computer-readable medium storing computer-executable instructions for positioning a user equipment (UE), the computer-executable instructions comprising:
at least one instruction instructing a location server to receive a first propagation time measurement and a first plurality of observed time difference of arrival (OTDOA) reference signal time difference (RSTD) measurements from a first UE at a first time;
at least one instruction instructing the location server to receive a second propagation time measurement and a second plurality of OTDOA RSTD measurements from a second UE at a second time, wherein the first propagation time measurement and the second propagation time measurement are for a same base station;
at least one instruction instructing the location server to determine at least one real-time difference between a pair of base stations based on the first propagation time measurement, the second propagation time measurement, the first plurality of OTDOA RSTD measurements, and the second plurality of OTDOA RSTD measurements, wherein the pair of base stations is associated with the first plurality of OTDOA RSTD measurements and the second plurality of OTDOA RSTD measurements;
at least one instruction instructing the location server to receive a third plurality of OTDOA RSTD measurements from a third UE at a third time; and
at least one instruction instructing the location server to determine a position of the third UE based at least in part on the at least one real-time difference between the pair of base stations.
20. The non-transitory computer-readable medium of claim 19 , wherein the first propagation time measurement and the second propagation time measurement are for a common serving base station for the first UE and the second UE.
21. The non-transitory computer-readable medium of claim 19 , wherein the first time and the second time are within a threshold period of time of each other.
22. The non-transitory computer-readable medium of claim 21 , wherein the second time and the third time are within a threshold period of time of each other.
23. The non-transitory computer-readable medium of claim 19 , wherein the pair of base stations are not synchronized with each other.
24. The non-transitory computer-readable medium of claim 19 , wherein the first and second UEs are the same UE.
25. The non-transitory computer-readable medium of claim 24 , wherein the second and third UEs are the same UE.
26. The non-transitory computer-readable medium of claim 25 , wherein the first propagation time measurement, the second propagation time measurement, the first plurality of OTDOA RSTD measurements, and the second plurality of OTDOA RSTD measurements are previous propagation time measurements and previous OTDOA RSTD measurements performed by the same UE.
27. The non-transitory computer-readable medium of claim 19 , wherein the first and second propagation time measurements and the first and second pluralities of OTDOA RSTD measurements are measurements for Long Term Evolution (LTE) radio access in unlicensed spectrum.
28. An apparatus for positioning a user equipment (UE), comprising:
receiving means of a location server configured to:
receive a first propagation time measurement and a first plurality of observed time difference of arrival (OTDOA) reference signal time difference (RSTD) measurements from a first UE at a first time; and
receive a second propagation time measurement and a second plurality of OTDOA RSTD measurements from a second UE at a second time, wherein the first propagation time measurement and the second propagation time measurement are for a same base station; and
processing means of the location server configured to:
determine at least one real-time difference between a pair of base stations based on the first propagation time measurement, the second propagation time measurement, the first plurality of OTDOA RSTD measurements, and the second plurality of OTDOA RSTD measurements, wherein the pair of base stations is associated with the first plurality of OTDOA RSTD measurements and the second plurality of OTDOA RSTD measurements,
wherein the receiving means is further configured to receive a third plurality of OTDOA RSTD measurements from a third UE at a third time, and
wherein the processing means is further configured to determine a position of the third UE based at least in part on the at least one real-time difference between the pair of base stations.
29. The apparatus of claim 28 , wherein the first propagation time measurement and the second propagation time measurement are for a common serving base station for the first UE and the second UE.
30. The apparatus of claim 28 , wherein the pair of base stations are not synchronized with each other.