VLC system performance using Dicode Pulse Position Modulation over an indoor diffuse link

Abstract

Dicode Pulse Position Modulation (DiPPM) has been proposed as an alternative modulation scheme to digital PPM over optical fibre channels. This paper, for the first time, analyses the receiver sensitivity of the DiPPM system on a diffuse indoor Visible Light Communication (VLC). The system operates at a bit rate of 1Gbit/s and = 0.65 m. A mathematical model of the VLC using DiPPM is presented. The results show the degradation in sensitivity as normalized delay spreads increase. It is shown that with a typical delay spread of 5 ns, the DiPPM system can achieve a sensitivity of -36.47 dBm and -37.5 dBm for the error rates of 10 -9 and 10 -6 , respectively. This represents a sensitivity improvement over a comparable digital PPM system by 3.47 dB and 3.5 dB.

Visible light communication based system using high power LED and dicode pulse position modulation technique

“…It was found that DiPPM can be considered as an alternative modulation technique for free space links as it outperforms PCM [15,17]. In order to improve the sensitivity of DiPPM, Reed Solomon (RS) codes or maximum likelihood sequence detection (MLSD) technique can be implemented [18,19].…”

“…Power efficiency of OOK is improved with the method of PPM modulation but it requires higher bandwidth and is more complex [4]. For the improvement and mitigation of transmission quality and the effects of inter symbol interference (ISI) respectively an investigation was conducted with dicode pulse position modulation technique (DiPPM) [15]. In previous experiments by the others, offset pulse position modulation technique has been implemented using a 30 W LED based VLC equipment achieving a data rate of 11 Mbps [16].…”

Visible light communication based on offset pulse position modulation (Offset-PPM) using high power LED

“…The highest achieved bit rate was 190 Mb/s at high illuminance [12]. For the improvement and mitigation of transmission quality and the effects of inter symbol interference (ISI) respectively investigation was conducted using Dicode pulse position modulation technique (DiPPM) [13]. This paper proposes a novel modulation scheme (Offset-PPM) based on visible light communication using a commercial high power LED.…”