Symbol Error Probability Bounds for Coherently Viterbi Detected Continuous Phase Modulated Signals

Recently the minimum Euclidean distance and bandwidth properties of continuous phase modulated (CPM) signals have been considered. It has also been shown that, for rational modulation indexes, a state description of these signals is possible and that the Viterbi algorithm (VA) can be used for demodulation. In this paper the performance analysis of CPM systems is extended to obtain bounds on the symbol error probability when the VA is used. The calculation of these bounds is based on the transfer function technique, which has been generalized. From numerical comparisons of the upper and lower bounds, it is concluded that the minimum Euclidean distance is a good performance measure for a broad class of CPM signals, even when the symbol error probability is as large as 10^-2.