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Performance analysis of visible light communication systems over fading channels

The performance of visible light communication (VLC) systems, adopting hybrid modulation techniques, is investigated under dynamic fading channels. Hybrid M-ary quadrature amplitude modulation and multi-pulse pulse-position modulation (hybrid QAM-MPPM) scheme is considered because of its high-power efficiency under constrained spectral efficiency. Expressions for bit-error rate (BER) and outage probability are derived for VLC systems adopting hybrid QAM-MPPM scheme under dynamic channels modeled by Rayleigh distribution. The derived expressions are used to investigate the performance of proposed VLC and compare it to corresponding ordinary QAM and MPPM schemes. Our results reveal that the BER of the proposed hybrid scheme outperforms that of ordinary MPPM by more than 4 dB. In addition, the outage probability of VLC systems is improved when using the hybrid scheme compared to that of ordinary QAM scheme.