Apparatus and method for determining the location of a mobile device using multiple wireless access points

A method of determining the location of a mobile device using multiple wireless access points, each wireless access point comprising multiple antennas, said method comprising:

• receiving a communication signal from the mobile device at said multiple antennas of said multiple wireless access points;
• for each wireless access point, determining angle-of-arrival information of the received communication signal at the wireless access point, based on a difference in phase of the received signal between different antennas;
• collecting, from each of the multiple wireless access points, the determined angle-of-arrival information for the received communication signal from the mobile device;
• estimating the location of the mobile device from the collected angle-of-arrival information;
• discriminating against multipath reception of the communication signal at a wireless access point, wherein at least one wireless access point comprises two sets of antennas for discriminating against multipath reception;
• and
• discriminating in favour of a direct path over multipath by:
• determining an angle of arrival for each component of the communication signal at each of said two sets of antennas;
• and
• identifying the direct path as corresponding to the component which is detected by both sets of antennas with only a small change in angle of arrival.

A method of determining the location of a mobile device using multiple wireless access points, each wireless access point comprising multiple antennas, said method comprising:

• receiving a communication signal from the mobile device at said multiple antennas of said multiple wireless access points;
• for each wireless access point, determining angle-of-arrival information of the received communication signal at the wireless access point, based on a difference in phase of the received signal between different antennas;
• collecting, from each of the multiple wireless access points, the determined angle-of-arrival information for the received communication signal from the mobile device;
• estimating the location of the mobile device from the collected angle-of-arrival information;
• discriminating against multipath reception of the communication signal at a wireless access point, wherein discriminating against multipath reception of the communication signal at a wireless access point comprises matching angle-of-arrival spectra by correlating individual lobes from two angle-of-arrival spectra with one another;
• grouping two or more angle-of-arrival spectra for the same mobile device, if available;
• arbitrarily choosing one of the angle-of-arrival spectra as the primary, and removing peaks from the primary that are not paired with corresponding peaks on the one or more other angle-of-arrival spectra;
• and
• outputting the primary angle-of-arrival spectrum.

Apparatus for determining the location of a mobile device using multiple wireless access points, each wireless access point comprising multiple antennas, said apparatus being configured to perform a method comprising:

• receiving a communication signal from the mobile device at said multiple antennas of said multiple wireless access points;
• for each wireless access point, determining angle-of-arrival information of the received communication signal at the wireless access point, based on a difference in phase of the received signal between different antennas;
• collecting, from each of the multiple wireless access points, the determined angle-of-arrival information for the received communication signal from the mobile device;
• and
• estimating the location of the mobile device from the collected angle-of-arrival information;
• discriminating against multipath reception of the communication signal at a wireless access point, wherein discriminating against multipath reception of the communication signal at a wireless access point comprises matching angle-of-arrival spectra by correlating individual lobes from two angle-of-arrival spectra with one another;
• grouping two or more angle-of-arrival spectra for the same mobile device, if available;
• arbitrarily choosing one of the angle-of-arrival spectra as the primary, and removing peaks from the primary that are not paired with corresponding peaks on the one or more other angle-of-arrival spectra;
• and
• outputting the primary angle-of-arrival spectrum.

Apparatus for determining the location of a mobile device using multiple wireless access points, each wireless access point comprising multiple antennas, said apparatus being configured to perform a method comprising:

• receiving a communication signal from the mobile device at said multiple antennas of said multiple wireless access points;
• for each wireless access point, determining angle-of-arrival information of the received communication signal at the wireless access point, based on a difference in phase of the received signal between different antennas;
• collecting, from each of the multiple wireless access points, the determined angle-of-arrival information for the received communication signal from the mobile device;
• and
• estimating the location of the mobile device from the collected angle-of-arrival information;
• discriminating against multipath reception of the communication signal at a wireless access point, wherein at least one wireless access point comprises two sets of antennas for discriminating against multipath reception;
• and
• discriminating in favour of a direct path over a multipath by:
• using the two sets of antennas at the wireless access point to disambiguate a direct path from the wireless access point to the mobile device from a multipath, based on intra-wireless access point triangulation between the two sets of multiple antennas;
• determining a difference in angle of arrival for each component of the received communication signal at each of said two sets of antennas;
• determining a source distance for each component of the received communication signal based on said difference in angle;
• and
• identifying the direct path as corresponding to the component of communication signal having the shortest source distance.

Apparatus for determining the location of a mobile device using multiple wireless access points, each wireless access point comprising multiple antennas, said apparatus being configured to perform a method comprising:

• receiving a communication signal from the mobile device at said multiple antennas of said multiple wireless access points;
• for each wireless access point, determining angle-of-arrival information of the received communication signal at the wireless access point, based on a difference in phase of the received signal between different antennas;
• collecting, from each of the multiple wireless access points, the determined angle-of-arrival information for the received communication signal from the mobile device;
• and
• estimating the location of the mobile device from the collected angle-of-arrival information;
• discriminating against multipath reception of the communication signal at a wireless access point, wherein at least one wireless access point comprises two sets of antennas for discriminating against multipath reception;
• and
• discriminating in favour of a direct path over multipath by:
• determining an angle of arrival for each component of the communication signal at each of said two sets of antennas;
• and
• identifying the direct path as corresponding to the component which is detected by both sets of antennas with only a small change in angle of arrival.