Multivariate-KLMS based Post-Distorter for Nonlinear RGB-LEDs for Color-Shift Keying VLC

Abstract

Color-shift keying (CSK) has emerged as an efficient modulation scheme for visible light communication (VLC) to enhance the data rate, which transmits data imperceptibly by variation of the color emitted by red, green and blue (RGB) light emitting diodes (LEDs). However, performance of the CSK-VLC systems is limited by the crosstalk between the adjacent color channels, which arises due to mismatch between the spectra of the RGB-LEDs and the filters at the receiver. Additionally, the RGB-LEDs’ nonlinearity also degrades the overall symbol error rate (SER). In this paper, we propose a novel multivariate kernel least mean square based adaptive nonlinear equalizer for joint mitigation of crosstalk and RGB-LEDs’ nonlinearity for CSK modulation scheme based VLC systems. Simulation results indicate that the proposed algorithm exhibits better SER performance as compared to the existing techniques. Analytical expression for SER is also derived for the proposed algorithm and validated by simulations.