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 an elevation of a user equipment (UE) in communication with a wireless system, the method comprising:
identifying a plurality of signals from receive channels associated with at least two antennas or four or more omnidirectional antennas as previously known signals based on buffered I/Q samples associated with each of the signals;
based on the previously known signals from each receive channel determining an angle of arrival from the UE to the at least two antennas or the four or more omnidirectional antennas, wherein determining the angle of arrival includes determining a sub-sample estimation of at least one of a direct line of sight (DLOS) flight time and a direct path flight time from the UE to each antenna among the at least two antennas or the four or more omnidirectional antennas, wherein the sub-sample estimation mitigates a mirror image of a true line of bearing (LOB) between the UI and the at least two antennas or the four or more omnidirectional antennas; and
utilizing the angle of arrival to calculate the elevation of the UE.
2. The method of claim 1 , wherein the at least two antennas are antenna elements of an antenna array located in a single antenna enclosure in a sector or located in different antenna enclosures of the sector.
3. The method of claim 1 , wherein the four or more omnidirectional antennas are indoor antennas.
4. The method of claim 3 , wherein the wireless system is one of a bluetooth network, a WiFi network and a mobile device network.
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 identifying the plurality of signals includes determining start times of each of the signals using parameters of each of the signals and the buffered I/Q samples associated with each of the signals.
7. The method of claim 1 , wherein identifying the plurality of signals includes peak detecting of a matched filter output associated with each receive channel to identify a particular I/Q sample among the buffered I/Q samples associated with each of the signals.
8. The method of claim 1 , wherein the at least two antennas are antenna elements, and wherein the DLOS flight time or the direct path flight time from the UE to each antenna among the least at two antennas is used to determine a time difference of arrival of the previously known signals between the antennas elements.
9. The method of claim 1 , wherein the DLOS flight time or the direct path flight time from the UE to each antenna among the at least two antennas is used to determine a phase shift between individual subcarriers of the previously known signals.
10. The method of claim 1 , wherein the at least two antennas are antenna elements, and wherein the DLOS flight time or the direct path flight time from the UE to each antenna element among the antenna elements is used to determine a phase shift between individual subcarriers of the previously known signals.
11. The method of claim 1 , wherein a super-resolution (sub-space) algorithm is utilized to separate a DLOS path or a direct path between the UE and each antenna among the at least two antennas and any reflected signal paths.
12. The method of claim 1 , wherein the at least two 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.
13. The method of claim 1 , wherein a first distance between the at least two antennas is small relative to a second distance to the UE from the two or more antennas.
14. The method of claim 13 , wherein the second distance from the at least two antennas to the UE is determined from at least one round trip time measurement.
15. The method of claim 1 , wherein the previously known signals include a sounding reference signal (SRS) or a demodulation reference signal (DMRS).
16. The method of claim 1 , wherein digital representations of the plurality of signals in frequency domain are in a form of resource elements and the identification of the previously known signals within the plurality of signals from each receive channel among the receive channels is based on the resource elements.
17. The method of claim 1 , wherein the buffered I/Q samples are digital representations of the plurality of signals in time domain.
18. A method for determining an elevation 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 at least two antennas or four or more omnidirectional 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 from the UE to the at least two antennas or the four or more omnidirectional antennas, wherein determining the angle of arrival includes determining a sub-sample estimation of at least one of a direct line of sight (DLOS) flight time and a direct path flight time from the UE to each antenna among the at least two antennas or the four or more omnidirectional antennas, wherein the sub-sample estimation mitigates a mirror image of a true line of bearing (LOB) between the UI and the at least two antennas or the four or more omnidirectional antennas; and
utilizing the angle of arrival to calculate the elevation of the UE.
19. The method of claim 18 , wherein the at least two antennas are antenna elements of an antenna array located in a single antenna enclosure in a sector or located in different antenna enclosures of the sector.
20. The method of claim 18 , wherein the four or more omnidirectional antennas are indoor antennas.
21. The method of claim 20 , wherein the wireless system is one of a bluetooth network, a WiFi network and a mobile device network.
22. The method of claim 18 , wherein the wireless system is one of a bluetooth network, a WiFi network and a mobile device network.
23. The method of claim 18 , wherein identifying the signals includes determining start times of the signals using parameters of the signals and the buffered I/Q samples.
24. The method of claim 18 , wherein identifying the signals includes peak detecting of a matched filter output associated with each receive channel to identify a particular I/Q sample among the buffered I/Q samples associated with each of the signals.
25. The method of claim 18 , wherein the at least two antennas are antenna elements, and wherein the DLOS flight time or the direct path flight time from the UE to each antenna among the least at two antennas is used to determine a time difference of arrival of the previously known signals between the antennas elements.
26. The method of claim 18 , wherein the DLOS flight time or the direct path flight time from the UE to each antenna among the at least two antennas is used to determine a phase shift between individual subcarriers of the previously known signals.
27. The method of claim 18 , wherein the at least two antennas are antenna elements, and wherein the DLOS flight time or the direct path flight time from the UE to each antenna element among the antenna elements is used to determine a phase shift between individual subcarriers of the previously known signals.
28. The method of claim 18 , wherein a super-resolution (sub-space) algorithm is utilized to separate a DLOS path or a direct path between the UE and each antenna among the at least two antennas and any reflected signal paths.
29. The method of claim 18 , wherein the at least two 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.
30. The method of claim 18 , wherein a first distance between the at least two antennas is small relative to a second distance to the UE from the two or more antennas.
31. The method of claim 30 , wherein the second distance from the at least two antennas to the UE is determined from at least one round trip time measurement.
32. The method of claim 18 , wherein the previously known signals include a sounding reference signal (SRS) or a demodulation reference signal (DMRS).
33. The method of claim 18 , 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.
34. The method of claim 18 , wherein the buffered I/Q samples are digital representations of the signals in time domain.