Performance of trellis-coded synchronous DS/CDMA over frequency-selective multipath Rayleigh fading channels

This paper considers the application of trellis coded modulation (TCM) techniques to synchronous direct-sequence code-division multiple-access (S-DS/CDMA) communication over frequency-selective fading mobile radio channels. The effect of an optimum adaptive coherent RAKE receiver structure is studied and an exact analytical expression for the pairwise error probability is obtained. This expression is used to evaluate the average BER upper bound through the transfer function bounding technique. The influence over the average BER of various system parameters like the number of active users, receiver complexity, set of sequences or sequence length are considered.