Performance Analysis and Comparative Studies of Carrierless Amplitude and Phase Modulation for Visible Light Communication

Carrierless Amplitude and Phase (CAP) and multiband CAP (m-CAP) modulations are among the modulation systems that can be used in radio frequency and visible light communication (VLC) systems. In this paper an intensive study for CAP and m-CAP modulations performance for VLC is presented. The study includes the effect of different modulation parameters on both Peak to Average Power Ratio (PAPR) and Bit Error Rate (BER). Also sparse activated sub-band m-CAP (SAS-$m$-CAP) modulation technique was proposed to improve the PAPR. Results indicate that PAPR of SAS-$m$-CAP is reduced by 2 dB and the BER of SAS-$m$-CAP is improved with 3 dB compared with classical m-CAP. A comparison of Spectral Efficiency (SE) and PAPR for SAS-m-CAP and sparse activated subcarriers OFDM Index Modulation (SAS-OFDM-IM) is performed. It is found that there is an improvement in SE about 100% and in PAPR about 7dB for SAS-$m$-CAP.