Performance of trellis coded M-ary 1RC CPM with linear receiver and pre-coding

1RC continuous phase modulation (CPM) has a constant envelope and good spectral containment. It can thus be effectively used over highly non-linear bandlimited channels for high data rates. In this paper the performance of trellis coded 4, 8 and 16 ary 1RC CPM in additive white Gaussian noise (AWGN) channel is investigated. A linear receiver followed by a Viterbi (1989) decoder matched to the trellis code is used for the detection of the waveform. The IF filter is optimized for all the three different waveforms so as to minimize the combined effect of intersymbol interference (ISI) and noise at the sampling instant. In order to use a coherent linear receiver we propose to pre-code the transmitted signal so that the information is in the received phase and not in the phase difference between the two consecutive phase samples. BER performance results for these waveforms are presented