A comparison of trellis coded SSMA systems over fading channels using pragmatic and Ungerboeck encoder structures

This paper compares the performance of a trellis coded spread spectrum multiple access system using two forms of encoder structures. Performance in additive white Gaussian noise and Rician fading channels is investigated. Degradation in the system performance due to interuser interference is modelled using the method of moments, since normal bounding techniques cannot be used. Results are given for eight state, rate 2/3 trellis codes in conjunction with 8-PSK constellations.