Decision directed OFDM-CPM systems for wireless communications

A decision directed receiver for detection of orthogonal frequency division multiplexing continuous phase modulation (OFDM-CPM) signals is presented. The receiver exploits the correlated phase states of the CPM signal to achieve lower bit error rates than a conventional low-SNR OFDM-CPM receiver. The proposed receiver is suboptimum, less complex and easy-to-implement. It is shown that, for certain modulation parameters of CPM, the proposed receiver outperforms the conventional low-SNR receiver. Bit error rate analysis of the decision directed receiver is given, with the channel assumed AWGN and frequency selective Rayleigh. Performance comparisons of decision directed OFDM-CPM systems with those of conventional systems are presented.