Cooperative multiple trellis coded modulation

In this paper, we consider the general design criteria, properties and explicit code design procedures for cooperative multiple trellis coded modulation (CMTCM) schemes over Rayleigh fading channels. The cooperative system of interest utilizes the decode and forward protocol based on orthogonal transmissions from the cooperating terminals to the destination. We design full diversity cooperative multiple trellis codes using asymmetric constellations that at a frame error probability of 10^-3 provide around 10-12 dB gains over non-cooperative coded modulation without sacrificing the data rate and/or bandwidth efficiency. This is achieved by expanding the baseline constellation used in the non-cooperative transmission, designing the signal constellation to be asymmetric, and adopting multiple mappings among users. The consistent performance gains due to coding, asymmetry, and mappings of symbols onto the constellation are evaluated in terms of the frame error probability. We present simulation results that support the theoretical designs and illustrate the viability of the proposed cooperative MTCM technique.