MULTIPLE TRELLIS CODED FREQUENCY AND PHASE MODULATION

Multiple trellis coded modulation of constant envelope frequency and phase modulated signal sets (MTCM/FPM) is investigated for performance on the AWGN channel and on the one-sided normal, Rayleigh- and Rician-fading channels. The Nakagami-m fading model is used as an alternative to the Rician-fading model to calculate the error probability upper bound for trellis coded schemes on the fading channel. The likenesses and the disparity between the upper bounds to the error probability for the two fading models is discussed. The design criteria for the one-sided normal fading channel, modeled by the Nakagami-m distribution, are observed to be the same as those for the Rayleigh-fading channel. For the MTCM/FPM schemes considered in this study, it is demonstrated that the set partitioning designed to maximize symbol diversity (optimum for fading channels) is optimum for performance on the AWGN channel as well. The MTCM/FPM schemes demonstrate improved performance over MTCM/MPSK schemes and TCM/FPM schemes on the AWGN channel and the fading channel. The simultaneous optimization of set partitioning rules for AWGN and fading channels proves to be particularly advantageous for the Rician-fading channels with less severe fading conditions.