Asymptotic SER of MIMO beamforming for AF relay selection systems

This paper derives an asymptotic average symbol error rate (SER) expression for multiple-input multiple-output (MIMO) amplify-and-forward (AF) relay selection systems with optimal beamforming. The analysis at high SNR quantifies the diversity order and array gain, which are valid for any antenna numbers of the terminals and arbitrary channel fading models. It is also proved that the system performance is not only dominated by the number of relays and also by the weak hop with the smallest diversity. Our results based on the closed-form expressions provide valuable insights into the performance and practical design considerations of MIMO AF relay networks.