Fractional Weight Moving Average Based Thresholding Scheme for VLC with Mobile-Phone Camera

Abstract

In this paper, we propose and demonstrate three weight moving average based thresholding schemes for mobile-phone camera based visible light communication, including equal weight moving average (EWMA) based thresholding scheme, fractional weight moving average (FWMA) based thresholding scheme and equal ratio weight moving average (ERWMA) based thresholding scheme. The conventional third order polynomial fitting (OPF) based thresholding scheme and three proposed thresholding schemes are evaluated and compared. The experimental results show that compared with the third OPF based scheme, our proposed schemes better resist the grayscale value fluctuation and have lower computational complexity. For 2 Kb/s data rate, thresholding schemes based on the third OPF, EWMA, FWMA, and ERWMA can achieve the transmission distances of 50 cm, 175 cm, 200 cm, and 175 cm, respectively. Moreover, we measure the average running time of these thresholding schemes, which are 1051.957 ms, 2.773 ms, 14.372 ms, and 88.271 ms, respectively. Considering the system performance and computational complexity comprehensively, FWMA-based thresholding scheme is optimal, which has great potential in practical applications.