Patent ID: 7106801

Claim:
A method for separating at a receiver a desired signal from a combination of signals received from a multitude of sources, each of the sources being located at a different distance from the receiver, the desired signal being contributed by a desired source at a distance, and each of the signals and their combination occupying an original band of frequencies, the method comprising the steps of splitting the received combination of signals into one or more spectral subbands; expanding each of the spectral subbands into a corresponding plurality of component subband spectra, each plurality corresponding to one of the multitude of sources and being shifted in frequency in proportion to the distance from the receiver of the corresponding one of the multitude of sources; selecting in each plurality of component subband spectra a shifted component subband spectrum corresponding to the desired source; down-transforming each selected shifted component subband spectrum back to the original band of frequencies; and recombining the selected shifted component subband spectra to recover the desired signal.