Patent ID: 6608592
Filing Date: 2003-08-19
Classification: G01S

Abstract:
A location system comprising:a plurality of beacon transmitters each positioned at a respective location, each beacon transmitter including a plurality of antennas positioned in a circular arrangement, wherein each beacon transmitter is configured to transmit an identification signal having a plurality of reference data and to transmit a directional signal from said plurality of antennas by selecting one of said antennas at a time in sequence around said circular arrangement to simulate a rotating antenna; and a receiver configured to receive said plurality of identification signals and a plurality of Doppler-shifted directional signals each corresponding to one of said directional signals, wherein said receiver is configured to generate a plurality of time data for each received Doppler-shifted directional signal, and wherein said receiver is configured to determine a location of said receiver using each received Doppler-shifted directional signal, each time data, and each identification signal.