Asymptotic Performance of Two-Hop Amplify-and-Forward MIMO Relaying with Transmit Antenna Selection

Abstract

The asymptotic performance of transmit antenna selection (TAS) in a two-hop amplify-and-forward (AF) MIMO relay network over Rayleigh-fading channels is analyzed. Assuming that the source and destination are equipped with $N_{\rm S}$ and $N_{\rm D}$ antennas, respectively, and communicate with each other with the help of an $N_{\rm R}$-antenna relay, we derive closed-form statistics of received signal-to-noise ratio (SNR) around original, and present the asymptotic average symbol error rate (SER). By analyzing the high SNR performance, we show that the diversity order, $\min\{N_{\rm S}N_{\rm R},N_{\rm R}N_{\rm D}\}$, can be achieved for the transmission. The optimal relay selection problem, selecting the relay that minimizes the average SER, is also analyzed which shows that the position of the selected optimal relay depends on the number of antenna of source, relay, and destination. Numerical results that confirm our analysis are also presented in the paper.