Mitigation of performance degradation due to dynamic display contents in visible light communication using TV backlight and CMOS image sensor

• Published in: Optics express 2018-08, Vol.26 (17), p.22342-22347
• Main Authors: Chow, Chi-Wai, Shiu, Ruei-Jie, Liu, Yen-Chun, Wang, Wei-Chung, Liao, Xin-Lan, Lin, Kun-Hsien, Wang, Yi-Chang, Chen, Yi-Yuan
• Format: Article
• Language: English
• ISSN: 1094-4087; 1094-4087
• DOI: 10.1364/OE.26.022342

Here, we propose and demonstrate a performance degradation mitigation scheme in TV backlight and smart-phone-based visible light communication (VLC) system when the display content in the light-panel is dynamically changing. In order to evaluate the influence of the dynamic display contents to the VLC performance, we use a noise-ratio (NR) and noise-ratio standard deviation (NRSD) as the figure-of-merits for the bright-and-dark contrast of the display content; and the dispersal of the changing display content regarding the bright-and-dark contrast respectively. Performances of 4 dynamic display contents with different combinations of NR and NRSD are analyzed. They are: low NR and low NRSD (NR = 36.69%; NRSD = 0.0226); low NR and high NRSD (NR = 30.09%; NRSD = 0.2698); high NR and low NRSD (NR = 81.66%; NRSD = 0.0052); high NR and high NRSD (NR = 73.91%; and NRSD = 0.2717). The proposed scheme can work well; that is, even the transmission distance is up to 200 cm in both smart-phones. If the proposed scheme is not used, then high success rate can be observed only at the low NR and low NRSD display content when the transmission distance is < 100 cm.