A Blind Partially Coherent Multi-H CPM Receiver for Aeronautical Telemetry

Abstract

Multi-H Continuous Phase Modulation is a highly bandwidth efficient constant amplitude modulation scheme. Because of these qualities it was selected as the Advanced Range Telemetry (ARTM) tier II waveform. In the past, two demodulation techniques have widely been proposed, coherent detection and non-coherent detection. This paper presents a receiver design that implements a hybrid, partially coherent detection scheme that takes advantage of the positive aspects of both coherent and non-coherent detection. Because complete phase recovery is not required, the hybrid receiver performs better in environments with fast fading, strong phase noise, and multi path when compared to the traditional coherent receiver. The hybrid receiver can also acquire and reacquire signals much faster than conventional coherent receivers. The hybrid receiver design implements a partial carrier detection scheme that utilizes phase information that performs much better in AWGN environments than typical non-coherent receivers. Simulation results show that the hybrid receiver has low implementation loss compared to the optimal Maximum Likelihood Sequence Estimation (MLSE) receiver.