Save and Transmit Scheme for Energy Harvesting MIMO Systems with TAS/MRC

Abstract

In this paper, we propose and analyze a wireless transmitter, for multiple-input multiple-output (MIMO) systems, that relies exclusively on energy harvesting. We consider wireless transceivers where the transmitter harvests the total required energy from its environment through various sources. We assume that both transmitter and receiver are equipped with multiple antennas. At the transmitter, a single transmit antenna that maximizes the signal-to-noise ratio (SNR) at the receiver is selected for transmission. The remaining antennas are used for energy harvesting. At the receiver side, maximal-ratio com- bining (MRC) is used. Furthermore, we assume that all the harvested power is used to power the transmitter immediately. The performance of the proposed scheme is analyzed in terms of outage probability (OP), symbol error rate (SER) and channel capacity. The harvested energy comes from random sources and is considered as a random variable. Assuming that the harvested power follows a gamma distribution and the MIMO channel is a Rayleigh flat fading process, we derive a closed- form expressions for the exact cumulative distribution function (CDF) and probability density function (PDF) of the SNR. Based on this, we analyze the performance of the proposed energy harvesting scheme. The obtained analytical results are validated by comparing them with the results of Monte-Carlo simulations.

Keywords