The use of frequency-orthogonal pseudo-noise (FOPN) sounding signals for identifying transmissions from different transmit antennas
A method is described for identifying simultaneous signals from different transmit antennas in multiantenna sounders. Multiple-orthogonal signals are produced from one pseudonoise code by using it to modulate RF carriers at precalculated offset frequencies. Although their frequency spectra are interleaved and they occupy the same band, the spectral lines from different transmitters are separable a
