A Robust Joint Model-Based Demodulator for Continuous Phase Modulation Signals in an Unknown Environment

Cellular communications systems often suffer from co-channel interference, due to signals from adjacent cells interfering with each other. Previous demodulation techniques have relied on interference rejection to extract only the highest power signal; cancellation techniques are required to extract weaker ones. In this paper, the authors describe a Joint Model-Based Demodulator (J-MBD) that extracts two or more co-channel signals using Continuous Phase Modulation (CPM) simultaneously. The technique is based upon a root selection algorithm using Forward-Backward Linear Prediction (FBLP), whereby multiple unequal powered signals are extracted by choosing the highest powered roots.