Deceptive behavior detection in cooperative diversity

Cooperative diversity is a tool with which resource limited wireless nodes achieve spatial diversity. However, in some cases the cooperating node (also known as relay) is not a trust worthy partner and it may exhibit deceptive behavior. In this paper we have considered an intelligent destination that detects the relay behavior in case of amplify and forward protocol. The detection technique is based on a fact that vagueness in the direct path is only due to the channel, the relay behavior can be judged by comparing the source and relay signals. The destination computes correlation of the received signals from two diversity branches before applying the diversity combining technique. In case the relay is deceptive, the correlation is considerably reduced. We have also given a concept of extending the same correlation based behavior detection strategy to networks where multiple relays are used. At the end we have shown that the detection strategy results in a subsequent Bit Error Rate performance improvement.