Superposition Coding Based Cooperative Communication with Relay Selection

We study the layered transmission of a Gaussian source over multiple relays using superposition coding. First, we analyze the outage probability and performance in terms of average throughput and distortion for decode-and-forward protocols with single layer and superposed two-layer coding. For the superposition coding approach, we consider different power allocations to the base and enhancement layers. Then, we propose a simple protocol which assigns a pre-determined number of relays to individual layers instead of repeating the superposition coded source packet at the relay. Finally, we present numerical results based on the analysis to compare the performance.