Pedestrian positioning via vehicle collaboration
Disclosed are techniques for using ranging signals to determine a position of a pedestrian user equipment (P-UE). In an aspect, a UE receives a plurality of ranging signals transmitted by one or more UEs, measures one or more properties of each of the plurality of ranging signals, and calculates an estimate of the position of the P-UE based on the one or more properties of each of the plurality of ranging signals. In an aspect, the P-UE transmits a plurality of ranging signals, receives a first message and a second message from first and second vehicle UEs (V-UEs), the first and second messages including first and second estimated positions of the P-UE and associated first and second confidences, and calculates an estimate of the position of the P-UE based on the first estimated position, the first confidence, the second estimated position, the second confidence, or a combination thereof.
1. A first user equipment (UE), comprising:
a memory;
at least one transceiver; and
at least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor configured to:
receive, via the at least one transceiver, one or more ranging signals transmitted by a second UE;
perform one or more positioning measurements of each of the one or more ranging signals; and
calculate an estimate of a position of the second UE based on the one or more positioning measurements of each of the one or more ranging signals and at least one known position of the first UE, wherein the at least one known position of the first UE comprises at least one satellite positioning system (SPS) position of the first UE.
2. The first UE of claim 1 , wherein the one or more positioning measurements of each of the one or more ranging signals comprise a time of arrival (ToA) of each of the one or more ranging signals, an angle-of-arrival (AoA) of each of the one or more ranging signals, or any combination thereof.
3. The first UE of claim 2 , wherein the ToA of each of the one or more ranging signals is based on a local clock time of the first UE.
4. The first UE of claim 1 , wherein the at least one processor is further configured to:
cause the at least one transceiver to transmit the estimate of the position of the second UE to a third UE.
5. The first UE of claim 4 , wherein the at least one processor is further configured to:
calculate a confidence level in the estimate of the position of the second UE.
6. The first UE of claim 5 , wherein:
the one or more ranging signals comprise a plurality of ranging signals,
the confidence level is based on AoAs of the plurality of ranging signals, and
the confidence level is higher based on larger differences between AoAs of the plurality of ranging signals.
7. The first UE of claim 5 , wherein the at least one processor being configured to cause the at least one transceiver to transmit the estimate of the position of the second UE to the third UE comprises the at least one processor being further configured to cause the at least one transceiver to transmit the confidence level in the estimate of the position of the second UE to the third UE.
8. The first UE of claim 4 , wherein the third UE comprises the second UE.
9. The first UE of claim 4 , wherein the third UE comprises at least one vehicle UE (V-UE).
10. The first UE of claim 9 , wherein the at least one processor causes the at least one transceiver to transmit the estimate of the position of the second UE to the at least one V-UE in a Basic Safety Message (BSM).
11. The first UE of claim 1 , wherein the at least one known position of the first UE comprises a plurality of positions of the first UE.
12. The first UE of claim 1 , wherein:
the first UE is a vehicle UE (V-UE), and
the second UE is a pedestrian UE (P-UE).
13. The first UE of claim 1 , wherein each of the one or more ranging signals encodes an identifier of a UE by which the ranging signal was transmitted.
14. The first UE of claim 1 , wherein the one or more ranging signals is transmitted periodically in consecutive resource pools.
15. The first UE of claim 1 , wherein the position of the second UE is considered to be constant when calculating the estimate of the position of the second UE.
16. A method for using ranging signals to determine a position of a second user equipment (UE), comprising:
receiving, at a first UE, one or more ranging signals transmitted by the second UE;
performing, by the first UE, one or more positioning measurements of each of the one or more ranging signals; and
calculating, by the first UE, an estimate of the position of the second UE based on the one or more positioning measurements of each of the one or more ranging signals and a known position of the first UE, wherein the at least one known position of the first UE comprises at least one satellite positioning system (SPS) position of the first UE.
17. The method of claim 16 , wherein the one or more positioning measurements of each of the one or more ranging signals comprise a time of arrival (ToA) of each of the one or more ranging signals, an angle-of-arrival (AoA) of each of the one or more ranging signals, or any combination thereof.
18. The method of claim 16 , further comprising:
transmitting, by the first UE, the estimate of the position of the second UE to a third UE.
19. The method of claim 18 , further comprising:
calculating, by the first UE, a confidence level in the estimate of the position of the second UE.
20. The method of claim 19 , wherein:
the one or more ranging signals comprise a plurality of ranging signals,
the confidence level is based on AoAs of the plurality of ranging signals, and
the confidence level is higher based on larger differences between AoAs of the plurality of ranging signals.
21. The method of claim 19 , wherein transmitting the estimate of the position of the second UE to the third UE further comprises transmitting, by the first UE, the confidence level in the estimate of the position of the second UE to the third UE.
22. The method of claim 18 , wherein the third UE comprises the second UE.
23. The method of claim 18 , wherein the third UE comprises at least one vehicle UE (V-UE).
24. The method of claim 23 , wherein the first UE transmits the estimate of the position of the second UE to the at least one V-UE in a Basic Safety Message (BSM).
25. The method of claim 16 , wherein the at least one known position of the first UE comprises a plurality of positions of the first UE.
26. The method of claim 16 , wherein:
the first UE is a vehicle UE (V-UE), and
the second UE is a pedestrian UE (P-UE).
27. The method of claim 16 , wherein the one or more ranging signals is transmitted periodically in consecutive resource pools.
28. The method of claim 16 , wherein the position of the second UE is considered to be constant when calculating the estimate of the position of the second UE.
29. A first user equipment (UE), comprising:
means for receiving one or more ranging signals transmitted by a second UE;
means for performing one or more positioning measurements of each of the one or more ranging signals; and
means for calculating an estimate of a position of the second UE based on the one or more positioning measurements of each of the one or more ranging signals and a known position of the first UE, wherein the at least one known position of the first UE comprises at least one satellite positioning system (SPS) position of the first UE.
30. A non-transitory computer-readable medium storing computer-executable instructions that, when executed by a first user equipment (UE), cause the first UE to:
receive one or more ranging signals transmitted by a second UE;
perform one or more positioning measurements of each of the one or more ranging signals; and
calculate an estimate of the position of the second UE based on the one or more positioning measurements of each of the one or more ranging signals and a known position of the first UE, wherein the at least one known position of the first UE comprises at least one satellite positioning system (SPS) position of the first UE.