THE PERFORMANCE OF TRELLIS-CODED MDPSK WITH MULTIPLE SYMBOL DETECTION

The idea of using a multiple (more than two) symbol observation interval to improve error probability performance is applied to differential detection of trellis-coded MPSK over an additive white Gaussian noise (AWGN) channel. An “equivalent” Euclidean distance measure per trellis branch is determined for this detection scheme. This is used to define an augmented (larger multiplicity) trellis code whose distance measure is the conventional squared Euclidean distance typical of conventional trellis-coded modulation on the AWGN. Such an augmented multiple trellis code is a convenient mathematical tool for simplifying the analysis. Results are obtained via a combination of analysis (upper Chernoff bounds and asymptotic (large signal-to-noise ratio) approximations) and computer simulation. It is shown that only a slight increase (e.g., one symbol) in the length of the observation interval will provide a significant improvement in bit error probability performance. © 1990 IEEE