Performance Analysis of Energy Harvesting Multi-Antenna Relay Networks With Different Antenna Selection Schemes

In this paper, we investigate the performance of three transmit antenna selection (TAS) schemes for an energy harvesting decode-and-forward relay cooperative network. In the network, the energy-limited relay first harvests the energy from the received signal with the power-splitting scheme, and then utilizes the harvested energy to forward the received signal to the destination. Specifically, exact analytical expressions for the outage probability of the considered network with three TAS schemes are derived for evaluating the impact of key parameters on the outage performance. In order to deeply extract insights, we further present tractable asymptotic outage probabilities for three TAS schemes to characterize the diversity order and coding gain in high signal-to-noise ratio regimes, respectively. In addition, we also analyze the impact of feedback delays on the performance of the optimal TAS scheme, which is quantified by the reduction of diversity order and coding gain. Numerical results sustained by Monte Carlo simulations demonstrate that: 1) the second suboptimal TAS schemes achieve a comparable performance as the optimal TAS scheme with the reduced implementation cost; 2) the relay location has a great impact on the outage performance and the optimal power-splitting ratio; and 3) the feedback delay plays a critical role in determining the diversity order achieved by the considered system.