TDOA-based positioning system using terrestrial wireless signal sources
A positioning system is provided in which a client device samples a transmission from any suitable terrestrial wireless source. The resulting samples are correlated with replica samples to determine a position of the client device using time-difference-of-arrival-based calculations.
1. A system, comprising:
a correlator configured to correlate a first set of samples taken by a first receiver of a terrestrial wireless communication from a terrestrial wireless source with a second set of samples of a replica of the terrestrial wireless transmission to determine a correlation peak, wherein the first set of samples are time-stamped with a time of receipt according to a first clock in the first receiver, and wherein the second set of samples are time-stamped with a time of receipt according to a GPS clock in a second receiver that is remote from the first receiver; and
a time-difference-of-arrival (TDOA) generator configured to determine a first pseudorange between the first receiver and the terrestrial wireless source based upon the correlation peak and a time of transmission for the terrestrial wireless communication, wherein the terrestrial wireless source is selected from the group consisting of a cellular base station, a WiFi source, a Bluetooth source, and a wireless drone.
2. The system of claim 1 , wherein the TDOA generator is further configured to determine the time of transmission for the terrestrial wireless communication from the replica of the terrestrial wireless communication.
3. The system of claim 1 , wherein the TDOA generator is further configured to determine a plurality of additional pseudoranges between the first receiver and a plurality of corresponding additional terrestrial wireless sources.
4. The system of claim 1 , further comprising a server configured to upload the first set of samples taken by the first receiver to the correlator.
5. The system of claim 4 , wherein the server is a cloud-based server.
6. The system of claim 3 , wherein the TDOA generator is further configured to determine a position for the first receiver using the first pseudorange and the plurality of additional pseudoranges.