Partially synchronized multilateration or trilateration method and system for positional finding using RF
Systems and methods for determining a location of user equipment (UE) in a wireless system can comprise receiving reference signals via a location management unit (LMU) having two or more co-located channels, wherein the two or more co-located channels are tightly synchronized with each other and utilizing the received reference signals to calculate a location of the UE. Some systems may include multichannel synchronization with a standard deviation of less than or equal 10 ns. Some systems may include two LMUs, with each LMU having internal synchronization, or one LMU with tightly synchronized signals.
1. A method for determining a location of a user equipment (UE) in a wireless system, the method comprising:
receiving reference signals via two or more co-located channels;
synchronizing timings of the two or more co-located channels within a standard deviation of less than or equal to a predetermined time based on a distance location accuracy for the wireless system; and
utilizing the received reference signals to calculate the location of the UE.
2. The method of claim 1 , wherein each of the two or more co-located channels comprise a location management unit card or a small cell.
3. The method of claim 1 , wherein the predetermined time is between about 3 nanoseconds (ns) and about 10 ns.
4. The method of claim 1 , wherein the received reference signals are uplink reference signals, downlink reference signals, distributed antennae system references signals, or a combination thereof.
5. The method of claim 1 , wherein the wireless system includes one or more nodes and each node among the one or more nodes includes at least one sector, wherein the at least one sector of each node is configured to communicate with a locate server unit (LSU), and wherein the step of utilizing is performed by the LSU or a combination of the one or more nodes and the LSU.
6. The method of claim 1 , wherein the wireless system includes one or more nodes and each of the one or more nodes includes at least one sector, wherein a sector of each node is configured to communicate with a locate server unit (LSU), and wherein the step of utilizing is performed by the UE, the LSU, the one or more nodes, or a combination thereof.
7. The method of claim 6 , wherein the UE is configured to communicate with the LSU.
8. The method of claim 7 , wherein the UE, the LSU, the one or more nodes, or a combination thereof are configured to support multipath mitigation and reference signals processing to calculate the location the UE.
9. The method of claim 1 , wherein the wireless system is configured to include functionality of a locate server unit (LSU) in a network SUPL server, a E-SMLC server, a LCS (LoCation Services) system, or a combination thereof.
10. The method of claim 1 , wherein the wireless system includes a locate server unit (LSU) and one or more nodes, and wherein the LSU is configured to interface the one or more nodes and network infrastructure of the wireless system.
11. The method of claim 1 , wherein the step of utilizing includes utilizing one or more line of position (LOP).
12. The method of claim 1 , wherein the reference signals are received from geographically distributed antennae.
13. The method of claim 1 , wherein utilizing the received reference signals to calculate the location of the UE includes using a multipath mitigation processor to range the UE based on the received reference signals.
14. The method of claim 13 , wherein the multipath mitigation processor is configured to time-stamp and process the received reference signals to range the UE.
15. The method of claim 13 , wherein the multipath mitigation processor is configured to support a half-duplex, a full duplex or a simplex mode of operation.
16. The method of claim 13 , wherein the multipath mitigation processor ranges the UE by computing a channel response based on the received reference signals.
17. A method for determining a location of a user equipment (UE) in a wireless system, the method comprising:
receiving reference signals via a first location management unit having a first plurality of co-located channels;
synchronizing timings of the first plurality of co-located channels within a first standard deviation of less than or equal to a first predetermined time based on a distance location accuracy for the wireless system;
receiving reference signals via a second location management unit having a second plurality of co-located channels;
synchronizing timings of the second plurality of co-located channels of the second location management unit within a second standard deviation of less than or equal to a second predetermined time based on the distance location accuracy for the wireless system; and
utilizing the received reference signals from the first location management unit and the received reference signals from the second location management unit to calculate the location of the UE.
18. The method of claim 17 , wherein the first predetermined time and the second predetermined time are between about 3 nanoseconds (ns) and about 10 ns.
19. The method of claim 17 , wherein the second predetermined time is between about 3 ns and about 10 ns.
20. The method of claim 17 , wherein the received reference signals are uplink reference signals, downlink reference signals, distributed antennae system references signals, or a combination thereof.
21. The method of claim 17 , wherein the step of utilizing includes utilizing one or more line of position (LOP).
22. The method of claim 17 , wherein the first location management unit receives reference signals from geographically distributed antennae.
23. The method of claim 17 , wherein the second location management unit receives reference signals from geographically distributed antennae.
24. The method of claim 17 , wherein the first predetermined time and the second predetermined time are greater than 10 ns.
25. The method of claim 17 , wherein a multipath mitigation processor is used to calculate the location of the UE.
26. The method of claim 25 , wherein the multipath mitigation processor calculates the location of the UE, in part, by computing a first distance between the UE and the first location management unit based on the received reference signals from the first location management unit.
27. The method of claim 26 , wherein the multipath mitigation processor reduces a multipath mitigation error in the received reference signals from the first location management unit prior to computing the first distance.
28. The method of claim 25 , wherein the multipath mitigation processor calculates the location of the UE, in part, by computing a second distance between the UE and the second location management unit based on the received reference signals from the second location management unit.
29. The method of claim 28 , wherein the multipath mitigation processor computes the second distance, in part, by calculating a channel response based on the received reference signals from the second location management unit.
30. A method for determining a location of a user equipment (UE) in a wireless system, the method comprising:
receiving reference signals via a stationary location management unit having two or more co-located receive channels comprising one or more of software and hardware-implemented signal processing components, wherein the two or more co-located receive channels are tightly time synchronized with each other; and
utilizing the received reference signals to calculate a location of the UE.
31. The method of claim 30 , wherein each of the two or more co-located receive channels comprise a location management unit card or a small cell.
32. The method of claim 30 , wherein each of the two or more co-located receive channels are integrated with a single rack mount system.
33. The method of claim 30 , wherein the co-located receive channels are synchronized within a standard deviation of a predetermined time based on a distance location accuracy for the wireless system.
34. The method of claim 33 , wherein the predetermined time is between about 3 nanoseconds (ns) and about 10 ns.
35. The method of claim 30 , wherein the step of utilizing includes utilizing one or more line of position (LOP).
36. The method of claim 30 , wherein the reference signals are received from distributed antennae connected to the location management unit.
37. The method of claim 30 , wherein the reference signals are received from a shared group of antennae in communication with the two or more co-located receive channels.
38. The method of claim 30 , wherein the location management unit or an antenna servicing the location management unit is co-located with a WiFi access point.
39. The method of claim 38 , wherein the location management unit shares a power source with the WiFi access point.
40. The method of claim 38 , wherein the antenna servicing the location management unit shares a power source with the WiFi access point.
41. The method of claim 30 , wherein utilizing includes a multipath mitigation processor configured to calculate the location of the UE by:
calculating a time different of arrival (TDOA) of the received reference signals, each received reference signal being received from a spatially distributed antenna;
computing an angle of arrival (AOA) of the received reference signals based on the TDOA; and
determining the location of the UE based on the AOA.
42. The method of claim 41 , wherein the each of the received reference signals includes one or more subcarriers, and wherein the multipath mitigation processor is configured to calculate the location of the UE based in part on the one or more subcarriers' phase, amplitude, or a combination thereof.