Unified analysis of energy harvesting–based MIMO relay wireless systems over Nakagami‐m fading channels

Abstract

AbstractIn this paper, we consider two‐hop multi‐input multi‐output relay wireless systems with energy harvesting. In each hop, transmit antenna selection/receive antenna selection, transmit antenna selection/maximum ratio combining, or maximum ratio transmission/receive antenna selection is used. Also, an energy‐constrained relay harvests energy from the source via either a time switching–based relaying protocol or a power splitting–based relaying protocol. We perform unified analysis of the systems over Nakagami‐m fading channels. Specifically, we derive exact closed form expressions for ergodic capacity and throughput (for delay‐tolerant transmission mode) and outage probability and throughput (for delay‐limited transmission). Optimal energy‐harvesting time (in time switching–based relaying protocol–based system) and optimal power‐splitting ratio (in power splitting–based relaying protocol–based system) to achieve maximum throughput at high signal‐to‐noise‐ratio are also determined. Moreover, we derive an exact closed form expression for the bit error rate, which facilitates the evaluation of the system performance. Impacts of various multi‐input multi‐output processing schemes, numbers of equipped antennas, energy‐harvesting mechanisms, and transmission modes on the system performance are also examined and discussed. All theoretical analyses are corroborated by simulations.