Co-channel interference cancellation for HDTV receivers

A new method of co-channel interference rejection for digital television receivers is presented that uses a different rejection filter from the comb filter that was used in the prototype built by Zenith. This filter is optimized for rejection of co-channel NTSC interference in the presence of white noise and hence suffers a penalty of only 0.4 dB in AWGN as compared to 3.5 dB with the comb. The receiver structure with this filter, including required equalizer and trellis decoder modifications is presented, along with simulation results showing the improvement in performance in co-channel-plus-AWGN interference and hence in coverage area.