Method and system for determining a location of a mobile device
Embodiments of methods for determining a location of a mobile device, a mobile device, and a location beacon system are described. In an embodiment, a method for determining a location of a mobile device involves receiving, at a dual-antenna receiver of the mobile device, a plurality of ultra wide band (UWB) signals from a group of unsynchronized beacons having a quadrilateral formation, at the mobile device, determining angle of arrival (AoA) information from the UWB signals, and at the mobile device, calculating the location of the mobile device based on the AoA information. Other embodiments are also described.
1. A method for determining a location of a mobile device, the method comprising:
receiving, at a dual-antenna receiver of the mobile device, a plurality of ultra wide band (UWB) signals from a group of unsynchronized beacons having a quadrilateral formation;
at the mobile device, determining angle of arrival (AoA) information from the UWB signals; and
at the mobile device, calculating the location of the mobile device based on the AoA information, locations of at least two respective beacons of the unsynchronized beacons, and distances between the at least two respective beacons of the unsynchronized beacons, wherein the locations of the at least two respective beacons and the distances between the at least two respective beacons are known to the mobile device.
2. The method of claim 1 , wherein the group of unsynchronized beacons comprises at least four beacons that are not clock synchronized.
3. The method of claim 1 , wherein determining the AoA information from the UWB signals comprises estimating an angle between each of the group of unsynchronized beacons and the mobile device.
4. The method of claim 3 , wherein estimating the angle between each of the group of unsynchronized beacons and the mobile device comprises estimating the angle between each of the group of unsynchronized beacons and the mobile device based on a difference between a time of arrival of the UWB signals at a first antenna of the dual-antenna receiver and a time of arrival of the UWB signals at a second antenna of the dual-antenna receiver.
5. The method of claim 3 , wherein calculating the location of the mobile device based on the AoA information comprises calculating the location of the mobile device based on the angles between the group of unsynchronized beacons and the mobile device.
6. The method of claim 3 , wherein the group of unsynchronized beacons comprises four beacons that are not clock synchronized, and wherein calculating the location of the mobile device based on the AoA information comprises calculating the location of the mobile device based on four angles between the group of unsynchronized beacons and the mobile device.
7. A mobile device, the mobile device comprising:
a dual-antenna ultra wide band (UWB) receiver configured to receive a plurality of UWB signals from a group of unsynchronized beacons having a quadrilateral formation;
a processor operably connected to the dual-antenna UWB receiver, wherein the processor is configured to:
determine angle of arrival (AoA) information from the UWB signals; and
calculate a location of the mobile device based on the AoA information, locations of at least two respective beacons of the unsynchronized beacons, and distances between the at least two respective beacons of the unsynchronized beacons, wherein the locations of the at least two respective beacons and the distances between the at least two respective beacons are known to the mobile device.
8. The mobile device of claim 7 , wherein the group of unsynchronized beacons comprises at least four beacons that are not clock synchronized, and wherein the processor is further configured to estimate an angle between each of the group of unsynchronized beacons and the mobile device.
9. The mobile device of claim 7 , wherein the dual-antenna UWB receiver comprises a first antenna and a second antenna.
10. The mobile device of claim 9 , wherein the processor is further configured to estimate the angle between each of the group of unsynchronized beacons and the mobile device based on a difference between a time of arrival of the UWB signals at the first antenna and a time of arrival of the UWB signals at the second antenna.
11. The mobile device of claim 9 , wherein the processor is further configured to calculate the location of the mobile device based on the angles between the group of unsynchronized beacons and the mobile device.
12. The mobile device of claim 9 , wherein the group of unsynchronized beacons comprises four beacons that are not clock synchronized, and wherein the processor is further configured to calculate the location of the mobile device based on four angles between the group of unsynchronized beacons and the mobile device.
13. A method for determining a location of a mobile device, the method comprising:
receiving, at a group of unsynchronized beacons having a quadrilateral formation, an ultra wide band (UWB) signal from the mobile device;
at the group of unsynchronized beacons, determining angle of arrival (AoA) information from the UWB signal; and
at the group of unsynchronized beacons, calculating the location of the mobile device based on the AoA information, locations of the unsynchronized beacons, and distances between at least two respective beacons of the unsynchronized beacons, wherein the locations of the at least two respective beacons and the distance between the at least two respective beacons are determined by a respective beacon.
14. The method of claim 13 , wherein the group of unsynchronized beacons comprises at least four beacons that are not clock synchronized.
15. The method of claim 13 , wherein determining the AoA information from the UWB signals comprises estimating an angle between each of the group of unsynchronized beacons and the mobile device.
16. The method of claim 15 , wherein calculating the location of the mobile device based on the AoA information comprises calculating the location of the mobile device based on the angles between the group of unsynchronized beacons and the mobile device and geographical information of the group of unsynchronized beacons.
17. The method of claim 13 , wherein the group of unsynchronized beacons determines angles between the at least two respective beacons and collaboratively calculates the location of the mobile device based, at least in part, on the angles.
18. The method of claim 13 , wherein the AoA information is aggregated at a particular beacon of the group of unsynchronized beacons and the location of the mobile device is calculated at the particular beacon based on the AoA information.
19. The method of claim 13 , wherein a first location of the mobile device is determined by a first beacon and a second location of the mobile device is determined by a second beacon, and an average location of the mobile device is calculated based on first and second locations.