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:
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, wherein a first antenna among the at least two antennas or the four or more omnidirectional antennas is displaced in a vertical direction with respect to a second antenna among the at least two antennas or other antennas among the 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 between a baseline of the at least two antennas or the four or more omnidirectional antennas and incident energy 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 signals includes determining start times of the signals using parameters of the signals and the plurality of buffered I/Q samples.
7. The method of claim 1 , 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 plurality of buffered I/Q samples.
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 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.
17. The method of claim 1 , wherein the buffered I/Q samples are digital representations of the signals in time domain.
18. A method for determining one or more of a horizontal position and a vertical 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 a first antenna among the plurality of antennas is displaced in a vertical direction with respect to at least a second antenna 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 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, wherein determining one or more of the horizontal angle of arrival and the vertical 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 four or more omnidirectional antennas among the plurality of antennas, wherein the sub-sample estimation mitigates a minor image of a true line of bearing (LOB) between the UI and the four or more omnidirectional antennas; and
utilizing one or more of the horizontal angle of arrival to calculate a horizontal position of the UE and the vertical angle of arrival to calculate a vertical position of the UE.
19. The method of claim 18 , wherein signal parameters identify a demodulation reference signal as the previously known signals.
20. The method of claim 18 , wherein signal parameters identify a sounding reference signal as the previously known signals.
21. The method of claim 18 , wherein the plurality of antennas are within an antenna array.
22. The method of claim 21 , 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.
23. The method of claim 1 , wherein the four or more omnidirectional antennas are indoor antennas.
24. The method of claim 23 , wherein the wireless system is one of a bluetooth network, a WiFi network and a mobile device network.
25. The method of claim 18 , 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.
26. The method of claim 25 , 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.
27. The method of claim 25 , wherein the plurality of antennas are antenna elements, wherein determining 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 the sub-sample estimation of at least one of the direct line of sight (DLOS) flight time and the direct path flight time from the UE and each antenna element among antenna elements.
28. The method of claim 18 , wherein a first distance between the first antenna and the second antenna is small relative to a second distance to the UE from the first antenna and the second antenna.
29. The method of claim 28 , wherein the second distance is determined from at least one round trip time measurement.
30. 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.
31. The method of claim 18 , wherein the buffered I/Q samples are digital representations of the signals in time domain.