Outage minimized relay selection with partial channel information

Selection relaying is a promising technique for practical implementation of cooperative systems with multiple relays. However, to select the best relay, globe channel knowledge is required at the selecting entity. In this paper, we consider the relay selection problem in dual-hop amplify-and-forward (AF) communication systems with partial channel state information (CSI). We present relay selection strategies aiming at minimizing the outage probability with different kinds of channel knowledge available, including perfect, statistical and quantized CSI. Simulation results show that near optimal performance is achievable with a few bits feedback to the selecting entity. Thus the signaling overhead of relay selection can be greatly reduced with quantized CSI feedback.