Dimming controlled multi header hybrid PPM (MH-HPPM) for visible light communication

摘要

Visible Light Communication (VLC), which gives communication alongside illumination, has increased a great deal of enthusiasm amongst researchers. VLC system needs to consider dimming control to offer effective communication while illuminating. In this paper, a dimming control scheme based on pulse position modulaton (PPM) and inverse PPM is proposed, which supports different dimming levels. PPM supports low dimming value whereas inverse-PPM has an inherent property of supporting higher dimming value for the same block length. Hence, the proposed scheme utilizes both PPM and inverse-PPM to achieve different dimming target values. This paper presents the algorithm for encoding and decoding of multi-header hybrid pulse position modulation (MH-HPPM) scheme and also shows the NI Labview SubⅥ code for generating the MH-HPPM frame under dimming values of 0.25, 0.33, 0.5, 0.67 and 0.75. Simulations are executed in MATLAB 2017a to simulate random input bits using the proposed scheme in the VLC system for different dimming values and evaluate the BER performance of the scheme. The simulation result shows that the proposed scheme performs better for dimming value α = 0.25, block length K = 4, is bandwidth efficient and hence can be considered as an alternate dimming control scheme.