Patent ID: 6801782
Filing Date: 2004-10-05
Classification: G01S,H04W

Abstract:
A mobile communication device capable of determining range to a reference communication device by exchanging ranging signals with the reference communication device, comprising:a transmitter configured to transmit to the reference communication device a sequence of outbound ranging signals at different carrier frequencies; a receiver configured to receive from the reference communication device a sequence of reply ranging signals at the different carrier frequencies in response to the outbound ranging signals; and a processor configured to select from among the reply ranging signals a reply ranging signal at a carrier frequency providing a highest signal timing accuracy, said processor determining a time of arrival of the selected reply ranging signal and the range to the reference communication device from a round-trip signal propagation time of the selected reply ranging signal and a corresponding outbound ranging signal, and wherein said processor performs Doppler compensation on the selected reply ranging signal to reduce errors in estimating the time of arrival of the selected reply ranging signal.