Some Results of Experiments in Co-Channel Signal Separation

We present some results of laboratory experiments in separating and demodulating co-channel voice-modulated signals. The desired signal is being received along with a stronger superposed signal with similar modulation. The pairs of signals used for these tests occupied essentially the same frequency spectrum. Successful results have been achieved for both FM and AM modulation. The technique is one of simultaneous signal estimation in the receiver IF by means of cross-coupled phase-locked loops. Operation in real time has been demonstrated using digital processing. Further studies are continuing using a minicomputer-based and evaluation system. Separation of super-test posed digitally modulated signals is also feasible.