PAPR Reduction in PAM-DMT based WDM VLC

Visible light communication (VLC) can achieve high data rate transmission with discrete multitone (DMT) systems.A DMT variant is pulse-amplitude-modulated discrete multitone modulation (PAM-DMT) which offers an energy-efficient modulation solution for VLC.However, similar to other DMT modulation techniques, PAM-DMT suffers from a high peak-toaverage power ratio (PAPR).In this paper, the efficacy of pilotassisted (PA) PAPR reduction system in PAM-DMT based VLC is demonstrated experimentally.Wavelength division multiplexing (WDM) is applied using three low-cost light emitting diodes (LEDs).The available modulation bandwidth of each light source is utilised by adaptive bit and power loading.PA PAM-DMT is compared in this work to PAM-DMT based on achievable data rate and Bit Error Rate (BER).The proposed system reduces the clipping noise and minimises the nonlinear distortion of the system by reducing the high PAPR of each wavelength.Thus, the PA PAM-DMT has achieved 8% higher data rate than the conventional PAM-DMT with no PAPR reduction.