Detection of OFDM-CPM signals over multipath channels

Abstract

A class of orthogonal frequency division multiplexing-continuous phase modulation (OFDM-CPM) signals is introduced in which binary data sequence is mapped to complex symbols using the concept of correlated phase states of a CPM signal. Canonical optimum and suboptimum multiple-symbol-observation OFDM-CPM receivers are derived. Multipath channel with AWGN is assumed. The receivers are analyzed for bit-error-rate (BER) performance in terms of highand low-SNR bounds. These bounds are illustrated as a function of parameter h, time delay and attenuation level. It is shown through numerical computation that the OFDM-CPM system outperforms a similar OFDM-PSK system in a two-ray multipath model. Moreover, an OFDM-CPM system gives the best error performance when the parameter h is 0.5 with an observation interval of 2.