Institute of Electrical & Electronic Engineers
Recently developed adaptive modulation schemes for opportunistic Decode-and-Forward (DF) relaying require knowledge of instantaneous Channel-State-Information (CSI) of all links. This paper aims at reducing signalling overhead of modulation-adaptive opportunistic DF relaying through exploitation of mixed channel knowledge. A novel semi-deterministic approach is proposed for performing joint rate-adaptation and best-relay selection. The selection process employs two criteria using mixed channel knowledge. A new metric namely the Probability of Missing the Best Relay (PMBR) is introduced, as only when the best relay is selected, the full diversity order can be achieved.