Angle of arrival (AOA) positioning method and system for positional finding and tracking objects using reduced attenuation RF technology
Systems and methods for determining user equipment (UE) locations within a wireless network using reference signals of the wireless network are described. The disclosed systems and methods utilize a plurality of in-phase and quadrature (I/Q) samples generated from signals provided by receive channels associated with two or more antennas of the wireless system. Based on received reference signal parameters the reference signal within the signals from each receive channel among the receive channels is identified. Based on the identified reference signal from each receive channel, an angle of arrival between a baseline of the two or more antennas and incident energy from the UE to the two or more antennas is determined. That angle of arrival is then used to calculate the location of the UE. The angle of arrival may be a horizontal angle of arrival and/or a vertical angle of arrival.
1. A method for determining a position of a user equipment (UE) in communication with a wireless system, the method comprising:
buffering a plurality of in-phase and quadrature (I/Q) samples generated from signals provided by receive channels associated with a plurality of antennas in at least one antenna enclosure, wherein each antenna among the plurality of antennas is displaced in one or more of a vertical direction and a horizontal direction with respect to other antennas among the plurality of antennas;
identifying the signals from each receive channel among the receive channels as previously known signals based on the buffered I/Q samples;
based on the previously known signals from each receive channel, determining an angle of arrival between a baseline of the plurality of antennas and incident energy from the UE to the plurality of antennas; and
utilizing the angle of arrival to calculate the position of the UE.
2. The method of claim 1 , wherein the antenna enclosure is an antenna array.
3. The method of claim 2 , wherein antenna elements of the antenna enclosure are located in a single antenna enclosure of a sector.
4. The method of claim 2 , wherein antenna elements of the antenna enclosure are located in different antenna enclosures of a sector.
5. The method of claim 1 , wherein the wireless system is one of a bluetooth network, a WiFi network, and a mobile device network.
6. The method of claim 1 , wherein the plurality of antennas are antenna elements, and wherein determining the angle of arrival includes determining a sub-sample estimation of a direct line of sight (DLOS) flight time or a direct path flight time from the UE and each antenna element among the antenna elements.
7. The method of claim 1 , wherein determining the angle of arrival includes determining a sub-sample estimation of a direct line of sight (DLOS) flight time or a direct path flight time from the UE to each antenna among the plurality of antennas.
8. The method of claim 7 , wherein a super-resolution (sub-space) algorithm is utilized to separate a DLOS path or a direct path between the UE and each antenna and any reflected signal paths.
9. The method of claim 7 , wherein the plurality of antennas are antenna elements, and wherein a super-resolution (sub-space) algorithm is utilized to separate a DLOS path or a direct path between the UE and each antenna element among the antenna elements and any reflected signal paths.
10. The method of claim 1 , wherein the previously known signals include a sounding reference signal (SRS) or a demodulation reference signal (DMRS).
11. The method of claim 1 , wherein a first distance between two antennas among the plurality of antennas is small relative to a second distance to the UE from the plurality antennas.
12. The method of claim 11 , wherein the second distance is determined from at least one round trip time measurement.
13. The method of claim 1 , wherein digital representations of the signals in frequency domain are in a form of resource elements and the identification of the previously known signals within the signals from each receive channel among the receive channels is based on the resource elements.
14. The method of claim 1 , wherein the buffered I/Q samples are digital representations of the signals in time domain.
15. A method for determining a position of a user equipment (UE) in communication with a wireless system, the method comprising:
buffering a plurality of in-phase and quadrature (I/Q) samples generated from signals provided by receive channels associated with a plurality of antennas, wherein at least one antenna among the plurality of antennas is displaced in a vertical direction with respect to another antenna among the plurality of antennas;
identifying the signals from each receive channel among the receive channels as previously known based on the buffered I/Q samples;
based on the previously known signals from each receive channel, determining a horizontal angle of arrival between a baseline of the plurality of antennas and incident energy from the UE to the plurality of antennas and a vertical angle of arrival between the baseline of the plurality of antennas and incident energy from the UE to the plurality of antennas; and
utilizing the horizontal angle of arrival and the vertical angle of arrival to calculate the position of the UE.
16. The method of claim 15 , wherein the plurality of antennas are within an antenna array.
17. The method of claim 16 , wherein the plurality of antennas are antenna elements located in a single antenna enclosure of a cell sector or different antenna enclosures of a cell sector.
18. The method of claim 15 , wherein the wireless system is one of a bluetooth network, a WiFi network and a mobile device network.
19. The method of claim 15 , wherein the plurality of antennas are antenna elements, and wherein determining the horizontal angle of arrival or the vertical angle of arrival includes determining a sub-sample estimation of a direct line of sight (DLOS) flight time from the UE and each antenna element among antenna elements.
20. The method of claim 15 , wherein determining either the horizontal angle of arrival or the vertical angle of arrival, or both the horizontal angle of arrival and the vertical angle of arrival includes determining a sub-sample estimation of a direct line of sight (DLOS) flight time or a direct path flight time from the UE to each antenna among the plurality of antennas.
21. The method of claim 20 , wherein a super-resolution (sub-space) algorithm is utilized to separate a DLOS path or a direct path between the UE and each antenna and any reflected signal paths.
22. The method of claim 20 , wherein the plurality of antennas are antenna elements, and wherein a super-resolution (sub-space) algorithm is utilized to separate a DLOS path or a direct path between the UE and each antenna element among the antenna elements and any reflected signal paths.
23. The method of claim 15 , wherein the previously known signals include a sounding reference signal (SRS) or a demodulation reference signal (DMRS).
24. The method of claim 15 , wherein a first distance between two antennas among the plurality of antennas is small relative to a second distance to the UE from the plurality antennas.
25. The method of claim 24 , wherein the second distance is determined from at least one round trip time measurement.
26. The method of claim 15 , wherein digital representations of the signals in frequency domain are in a form of resource elements and the identification of the previously known signals within the signals from each receive channel among the receive channels is based on the resource elements.
27. The method of claim 15 , wherein the buffered I/Q samples are digital representations of the signals in time domain.
28. A method for determining a position of a user equipment (UE) in communication with a wireless system, the method comprising, at a plurality of antennas:
buffering a plurality of in-phase and quadrature (I/Q) samples generated from signals provided by receive channels associated with the plurality of antennas, wherein at least one antenna among the plurality of antennas is displaced in one or more of a vertical direction and a horizontal direction with respect to at least one other antenna among the plurality of antennas;
producing first time stamps for each buffered I/Q sample among the plurality of buffered I/Q samples during a time interval;
producing a second time stamp corresponding to an identification of the user equipment during the time interval; and
sending the plurality of buffered I/Q samples, the first time stamps and the second time stamp to a locate server physically remote from the plurality of antennas for determination of the position of the UE.
29. The method of claim 28 , wherein digital representations of the signals in frequency domain are in a form of resource elements and the identification of the previously known signals within the signals from the receive channels is based on the resource elements.
30. The method of claim 28 , further comprising, at the locate server:
receiving the plurality of buffered I/Q samples, first time stamps and second time stamp;
identifying the signals from the receive channels as previously known signals based on the plurality of buffered I/Q samples and the first time stamps;
based on the previously known signals from the receive channels determining one or more of a horizontal angle of arrival and a vertical angle of arrival between a baseline of at least some of the plurality of antennas and incident energy from the UE to the at least some of the plurality of antennas; and
based on the second time stamp, utilizing one or more of the horizontal angle of arrival and the vertical angle of arrival to calculate the position of the UE.
31. The method of claim 28 , wherein the locate server is performing ranging calculations of the UE and determining the position of the UE based on the ranging.
32. The method of claim 28 , wherein sending further includes sending a sound reference signal samples in time domain to the locate server.
33. The method of claim 32 , wherein sending further includes sending resource elements to the locate server.
34. The method of claim 28 , wherein sending further includes sending DMRS signal I/Q time samples to the locate server.
35. The method of claim 28 , wherein sending further includes sending DMRS resource elements to the locate server.
36. The method of claim 28 , wherein sending further includes sending a list of served user equipment identifications to the locate server.
37. The method of claim 36 , wherein sending further includes sending a sound reference signal schedule per served user equipment identification.
38. The method of claim 37 , wherein the sound reference schedule includes configuration information.
39. The method of claim 28 , wherein the plurality of antennas are part of one of a network signal acquisition unit, a distributed antenna system, a macro cell, a mini cell, a femto cell, a pico cell, and a small cell.
40. The method of claim 28 , wherein the wireless system is based on a long-term evolution (LTE) standard.
41. The method of claim 28 , wherein the buffered I/Q samples are digital representations of the signals in time domain.