Distributed Source-Coding, Channel-Coding and Modulation for Cooperative Communications

In this contribution, we propose a novel Distributed Source-coding, Channel-coding and Modulation (DSCM) scheme for cooperative communications. The proposed DSCM scheme is designed for ensuring the decoding convergence of its constituent component codes, namely, the Variable Length Code (VLC) and two Coded Modulation (CM) schemes. The source node encodes the source symbols with the aid of a serially-concatenated VLC and a Turbo Trellis Coded Modulation (TTCM) scheme. The TTCM-VLC encoded symbols are transmitted to both a relay node and to the destination node during the first transmission period. The relay node employs a powerful iterative TTCM-VLC decoder for estimating the VLC-encoded bit sequence. This decoded bit sequence is then re-encoded with the aid of a simple Trellis Coded Modulation (TCM) scheme before it is transmitted to the destination node. At the destination node, a novel four-component iterative decoding arrangement is invoked for recovering the original source symbols. It is shown that the DSCM scheme significantly outperforms the TTCM-VLC benchmarker scheme dispensing with relaying. The proposed power- and bandwidth-efficient DSCM scheme is an ideal candidate for next-generation mobile multimedia systems.