Performance Analysis Framework for Transmit Antenna Selection Strategies of Cooperative MIMO AF Relay Networks

Abstract

The performance of three transmit antenna selection (TAS) strategies for dual-hop multiple-input-multiple-output (MIMO) ideal channel-assisted amplify-and-forward (AF) relay networks is analyzed. All channel fades are assumed to be Nakagami-m (integer m) fading. The source, relay, and destination are MIMO terminals. The optimal TAS and two suboptimal TAS strategies are considered. Since direct analysis of the end-to-end signal-to-noise ratio (e2e SNR) of the optimal TAS is intractable, a lower bound of the e2e SNR is derived. Its cumulative distribution function and the moment generating function (mgf) are derived and used to obtain the upper bounds of the outage probability and the average symbol error rate (SER). For the two suboptimal TAS strategies, we derive the exact mgfs of the e2e SNR and obtain accurate and efficient closed-form approximations for the outage probability and the average SER. The asymptotic outage probability and the average SER, which are exact in high SNR, are also derived, and they provide valuable insights into the system design parameters, such as diversity order and array gain. The exact outage probability, average SER, and their high SNR approximations are also derived for the optimal TAS when the direct path is ignored. The impact of outdated channel state information (CSI) on the performance of TAS is also studied. Specifically, the amount of performance degradation due to feedback delays is studied by deriving the asymptotic outage probability and the average SER and thereby quantifying the reduction of diversity order and array gain. Numerical and Monte Carlo simulation results are provided to analyze the system performance and verify the accuracy of our analysis.