Resource Allocation for Cooperative Relaying

The delay-limited capacity of the half-duplex relay channel is analyzed for several cooperative protocols under a long-term average total transmit power constraint. It is assumed that the source and the relay have access to partial channel state information in the form of channel amplitudes. Non-orthogonal Amplify-and-Forward (NAF), Compress-and-Forward (CF) and Opportunistic Decode-and-Forward (ODF) protocols are compared with optimal resource allocation, i.e., at each channel state, the source and the relay transmit with the minimum total power allocation required to achieve the target rate. A hybrid opportunistic protocol is proposed in which CF or ODF with optimal resource allocation is chosen at each channel state.