Diversity-multiplexing tradeoff analysis for wireless multicast systems with Amplify-and-Forward scheme

In this paper, we consider a Amplify-and-Forward (AF) cooperative multicast system in a Rayleigh-fading environment, where two-sources communicate with two destinations assisted by N relays (2 - N - 2 system). We consider two cooperative schemes, i.e., the conventional Round-Robin (RR) Scheme and the proposed relay selection (RS) scheme in the multicast system. The diversity-multiplexing tradeoff (DMT) analysis is performed over the two cooperative schemes, by which we find both cooperative schemes can provide N order diversity. The simulation not only validates the theoretical prediction, but also shows that RR offers better performance than RS in the sense of system outage probability (SOP). But RS just employs one relay in one time frame. This offers a tradeoff between the outage probability and the number of relays in service during one time frame.