Transmission quality improvement by LED back-off optimization for visible light wireless communications

Abstract

This paper proposes an LED back-off optimization method for visible light wireless communications. The method changes the set back-off value and controls LED saturation according to Noise-to-Carrier power ratios (N/C) of a receiver. Signal-to-Noise and Distortion Ratio (SNDR) of a receiver with the proposed method is evaluated by computer simulation. In this evaluation, a wireless system with OFDM signals is assumed and an LED linearization method which uses clipping followed by inband filtering and pre-distortion is employed. The evaluation results show that the back-off optimization can improve transmission quality in a receiver. The result also shows that the linearization method can enhance the improvement.