Abstract
Visible Light Communication (VLC) uses an Intensity-Modulation and Direct-Detection (IM/DD) scheme to transmit data. However, the light source used in VLC systems is continuously switched on and off quickly, resulting in flickering. In addition, recent illumination systems include dimming support to allow users to dim the light sources to the desired level. Therefore, the modulation scheme for data transmission in VLC system must include flicker mitigation and dimming control capabilities. In this paper, the authors propose a Double Inverse Pulse Position Modulation (DIPPM) scheme that minimizes flickering and supports a high level of dimming for the illumination sources in VLC systems. To form DIPPM, some changes are made in the symbol structure of the IPPM scheme, and a detailed explanation and mathematical model of DIPPM are given in this paper. Furthermore, both analytical and simulation results for the error performance of 2-DIPPM are compared with the performance of VPPM. Also, the communication performance of DIPPM is analyzed in terms of the normalized required power.
Highlights
The demand for additional bandwidth in mobile communications is growing day by day due to the significant increase in the number of mobile users, and the radio capacity of current systems is almost fully occupied
To show the effectiveness of the proposed scheme, we present analytical and simulation results for 2DIPPM where a nondirected LOS channel is considered, that is, number of channel clusters C = 1 with a symbol duration Ts = 0.01 μs
The error performance is described as the bit error rate with respect to the reference Signal-to-Noise Ratio (SNR)
Summary
The demand for additional bandwidth in mobile communications is growing day by day due to the significant increase in the number of mobile users, and the radio capacity of current systems is almost fully occupied. The dual use of both illumination and data transmission involves two main challenges for VLC: flicker mitigation and dimming control. Modern lighting systems provide dimming support to allow users to control the average brightness level of the light source. Flicker mitigation and dimming control can be achieved through an appropriate modulation scheme. Oh proposed a Pulse Dual Slope Modulation (PDSM) scheme to mitigate flicker by changing the slope of the rising and falling edges of the pulse to represent 1 and 0 bits, respectively. In [5], Choi et al merged CSK and VPPM schemes to change the ratio of the colors (red, green, and blue), which changes the perceivable color of light, while the pulse width controls dimming. The authors propose a Double Inverse Pulse Position Modulation (DIPPM) scheme that allows for both flicker mitigation and dimming control.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
