Cutoff Rate Analysis of Amplify-and-Forward Relay System

We derive in this paper the bit error probability and cutoff rate of an Amplify-and-Forward (AF) relay system operating in Rayleigh fast fading. In our model, we consider the relay thermal noise to be non-negligible and derive a closed form expression to approximate the bit error probability. Our approximated closed form expression matches well with simulation result. Using Chernoff bound, we upper bound its pairwise error probability and we also derive the cutoff rate of the AF relay system.