Minimum power based relay selection for orthogonal multiple access relay networks

We analyze the performance of a multi-source multi-helper transmission with lossy forward (LF) relaying. In LF, estimates at the relay are encoded and forwarded to the destination for improving the reliability of the received sequence transmitted from the multiple source nodes. Unlike the conventional decode-and-forward (DF) relaying, LF sends the data even in the case where decoding is not error-free. We extend the results of the channel with multiple sources and a single helper to perform relay selection by utilizing the union of rate regions. A power minimization problem is formulated using the above strategy and solved by exploiting the successive convex approximation (SCA) technique. Numerical results are presented to show that the proposed relay selection method achieves the same performance as the exhaustive search.