Relay search algorithms for coded cooperative systems

Cooperation provides an efficient form of diversity in wireless communications. In this paper we consider a coded cooperative system where the source and the relays may have multiple antennas. We describe two simple algorithms for choosing a good relay: Blind-Selection-Algorithm and Informed-Selection-Algorithm. These algorithms only require the knowledge of average received signal to noise ratios at the destination. Simulation results, carried out for a cellular system, show that both algorithms result in substantial improvement over direct transmission and random choice of relay in the cell and provide error rates close to best relay performance.