Relay Performance Analysis of Mixed RF and Optical MIMO Wireless Links

Abstract

In this paper, we consider a relay system which consists of an optical link followed by a radio frequency (RF) link. The optical link consists of a light-emitting diode (LED) array as a transmitter and a digital camera as a receiver. The relay uses the detect-and-forward strategy. The received pixel values in the optical link are processed using equal gain combining (EGC), best pixel selection (BPS), and maximal ratio combining (MRC). The system’s bit error rate performance is evaluated for different values of received optical power as well as for different values of camera-to-optical source distances. It is found that for a small camera-to-optical source distance EGC outperforms BPS, while BPS outperforms EGC at higher distances.