Maximum-Likelihood Detectors for Full-Rate Cooperative Communication Systems

A key issue in the full-rate two-relay cooperative communication systems is the interference which is caused by the simultaneous transmission of the source and one of the relays at any time. In this paper, we exploit the interference signal at the destination to develop a maximum likelihood (ML) detector for decode and forward full-rate cooperative systems. It is shown that the Viterbi algorithm can be employed to find the ML solution. To reduce the complexity of the proposed ML detector, a sub-optimal detector is also introduced. Further, we propose a ML interference cancellation scheme at the relays. The performance of the proposed schemes is evaluated through Monte Carlo simulations. Results indicate that the proposed schemes outperform direct transmission and conventional relaying schemes in terms of their bit error rate.