Repetitive Pulse Width Modulation Based Single-RF MIMO System with Compact 4-Port Antenna

A single-RF transmitter based on repetitive pulse width modulation (RPWM) was proposed for an alternative system of multiple-input multiple-output (MIMO) system. However, the RPWM transmitter system has demerits which are to require switch modules with high resolution and twice the number of antenna elements than the conventional system. In the previous works, the relation of the switch resolution and the performance of the RPWM transmitter system has not been analyzed and the practical antenna has not been considered. Also, it has not been also provided how to demodulate the received signal from the RPWM transmitter system. In this paper, we propose a compact 4-port antenna which can be applied for the RPWM transmitter system practically. We provide also a receiver architecture for the RPWM transmitter system. Then we will verify that the RPWM transmitter system achieves similar multiplexing gain compared to the conventional MIMO system practically by considering the proposed antenna, the practical switch modules, and the proposed receiver system.