Adaptive Modulation Technique for cooperative diversity in Wireless Fading Channels

In recent years, cooperative diversity techniques have gained increased attention as a new way to combat degrading effects of fading. Cooperation among two or more single antenna users generates a virtual diverse multiple-antenna transmission system in the wireless network. In this paper, we investigate the application of adaptive modulation concept to the performance of cooperative techniques. We consider the adaptation of rate and power allocation with M-QAM modulation, and study the performance of amplify & forward scenarios in Rayleigh fading channels. We compare these systems with their comparable adaptive non-cooperative scenario and evaluate the energy saving achieved through cooperation