Patent ID: 9084217
Filing Date: 2015-07-14
Classification: G01S,H04W

Abstract:
1. A method implemented by a base station for determining a location of a wireless transmitter, the method comprising: in an off-line phase, pre-collecting and storing by the base station in a database fingerprints and corresponding locations, wherein the fingerprints are extracted from wireless signals received by the base station at a given location from wireless transmitters at known locations in a geographical coverage region; in an on-line phase, receiving by the base station a signal from the wireless transmitter, extracting a fingerprint from the signal, matching the fingerprint with fingerprints in the database to identify a matching fingerprint having a best match, and selecting as an estimated location of the wireless transmitter a location corresponding to the matching fingerprint; wherein the base station uses an antenna array and multi-channel receiver to receive the signal; wherein the fingerprint extracted from the received signal is a single coherent entity implicitly including a directions-of-arrival and differential-delays information of multipath components of the signal and wherein the fingerprint is extracted from a spatio-temporal covariance matrix of the received signal; wherein the matching of the fingerprints comprises searching the fingerprints in the database for a spatio-temporal signal subspace that maximizes a projection of a received signal sample spatio-temporal covariance matrix onto a subspace.