Robust detector for amplify-and-forward with noncoherent frequency-shift keying

In this paper, we develop a simple closed-form generalized likelihood ratio test (GLRT) detector for a multi-relay amplify-and-forward (AF) cooperative network employing noncoherent M-ary frequency-shift keying (M-FSK). The proposed detector is robust in the sense that it does not require any prior knowledge about the channels such as the variance of the additive white Gaussian noise, the fading model, and the channel statistics. To analytically evaluate the proposed detector, focusing on the single-relay case with a direct source-destination link, we derive an exact expression of the bit-error rate (BER) for binary FSK in Rayleigh fading. Finally, simulation results demonstrate the robustness of the proposed detector.