SNR Degradation due to Carrier Frequency Offset in Amplify-and-Forward Relay System for Fading Channels

In this paper, we analyze signal-to-noise ratio (SNR) performance of amplify-and-forward (AF) relay system in the presence of carrier frequency offset (CFO) for fading channels. The expression for the average SNR is derived under one-relay-node scenario, and is further extended to multiple-relay-node scenario. It is shown that the SNR is very sensitive to CFO and the sensitivity of SNR to CFO is mainly determined by the power of the corresponding link channel and gain factor. The analytical results are validated through Monte Carlo simulations for both flat and frequency-selective fading channels.