Patent ID: 8145238

Claim:
A receiving system for use in a system for locating wireless transmitters employing an Orthogonal Frequency Division Multiplexing (OFDM) digital modulation scheme, wherein said OFDM scheme comprises transmitting signal components over a plurality of narrowband frequency channels spanning a wideband channel, comprising: means for receiving a fraction of the signal components transmitted by a first wireless transmitter to be located in a fraction of the narrowband frequency channels; means for processing said fraction of the signal components to derive location related measurements; means for communicating said location related measurements to a processing system for use in computing the location of said first wireless transmitter; a first frequency conversion circuit configured to convert a first received radio frequency (RF) signal component to a first digital baseband OFDM signal; a Fast Fourier Transform (FFT) circuit configured to perform an FFT of the first digital baseband OFDM signal provided by the first frequency conversion circuit; a demodulation circuit configured to produce coded bits based on the output of the FFT circuit; a first reconstruction circuit configured to reconstruct the first digital baseband OFDM signal based on the coded bits produced by the demodulation circuit; and a first correlation processing system configured to correlate the first reconstructed digital baseband OFDM signal with the first digital baseband OFDM signal, wherein a correlation function peak is indicative of a first time of arrival for the first received RF signal component.