SNR analysis for non-line-of-sight MIMO optical camera communications

Abstract

In this paper, we experimentally demonstrate the interference analysis of a non-line-of-sight (NLOS) multiple-input multiple-output (MIMO)-based optical camera communications (OCC) link. We propose an NLOS MIMO-OCC using two organic light emitting diodes (OLEDs) and a camera as transmitters (Txs) and the receiver, respectively, as well as reflections from plain wall and paper surfaces. We analyze the performance of the proposed scheme when two OLED Txs are modulated out of phase and at different transmission frequencies f(s). We conduct an experimental investigation of the proposed system in an indoor environment and evaluate its performance in terms of signal-to-noise (SNR) ratio and the reception success rates R-rs with respect to camera exposure time, the analog gain and varying f(s). The initial results show that for a link span of 2 m, the reception success is 100 % for the SNR values of (i) similar to 5 dB at transmission frequencies of 100 and 200 Hz; and (ii) similar to 4 and similar to 6 dB for OLED1 and OLED2 at f(s1) and f(s2) of 100 and 200 Hz, respectively.