Patent ID: 7970353
Filing Date: 2011-06-28
Classification: G01S,G06K

Abstract:
1. A method of processing a reflected data signal, the method comprising: receiving, at a receiver, an incident radio signal and the reflected data signal, wherein the incident radio signal is received from a transmitter located at a known location and the reflected data signal is received from a wireless communication device that uses the incident radio signal as a communication medium, wherein the incident radio signal has been mixed with a transmitter spread spectrum code that is associated with the transmitter, and wherein the wireless communication device has reflectively modulated the incident radio signal with a data signal having a modulation to form the reflected data signal; analyzing the reflected data signal received from the wireless communication device to identify the transmitter spread spectrum code of the incident radio signal that was reflectively modulated by the wireless communication device; identifying the transmitter that transmitted the incident radio signal based on the identified transmitter spread spectrum code; determining a distance between the wireless communication device and the transmitter that transmitted the incident radio signal based on data that includes a time delay between receipt of the incident radio signal and receipt of the reflected data signal by the receiver; and determining an approximate location of the wireless communication device based on data that includes the known location of the transmitter and the determined distance between the wireless communication device and the transmitter.