Time Reversal Scheme using Multiple Transmit Antennas for SWIPT in Indoor Channel

Abstract

Simultaneous wireless information and power transfer (SWIPT) is a promising technology to transmit both power and information for diverse internet of things (IoT) devices. Indoor communication suffers from the inter symbol interference (ISI) due to multipath propagation, and thus the signal transmission deteriorates achievable rate. Time-reversal (TR) achieves the high received signal power and the signal-to-interference plus noise ratio (SINR) gain compared to the direct transmission (DT) in the multipath channel. We propose to use the multiple antennas at the transmitter based on TR SWIPT systems in the indoor multipath channel and derive the rate-energy (R-E) region performance numerically. The power gain obtained from multi-input single-output (MISO) TR-based SWIPT increases as the number of transmit antennas and the sampling frequency increases. Moreover, the achievable rate gain also improves as the number of transmit antennas increases. The proposed scheme is shown suitable to improve the achievable rate and the harvesting energy for SWIPT system in the indoor multipath channel.