Abstract
We propose the maximum a posteriori (MAP) detection of the misbehaving relay that injects false data or adds channel errors into the network encoder in multiple access relay networks. The proposed scheme does not require sending extra bits at the source and is optimal in the sense of minimizing the probability of incorrect detection. We derive the probability of false alarm and misdetection, taking into account the lossy nature of wireless links. The side information regarding the presence of relay misbehavior is exploited at the decoder to mitigate the relay misbehavior and enhance the reliability of decoding.