Adaptive spreading factor assignment for VLC-OFDM-IDMA with PIC

Abstract

This letter proposes a signal-to-Noise Ratio (SNR) based spreading factor adaptation for orthogonal frequency division multiple interleave division multiple access (OFDM-IDMA) incorporated with parallel interference cancellation (PIC) on visible light communication (VLC) systems. Orthogonal variable spread factor (OVSF) code is an effective solution to eliminate multiple access interference (MAI) in exchange for spectral resource consumption. Channel ranking based spreading factor optimization can maximize the system throughput performance. The major contribution of this letter is to achieve its adaptive allocation according to the estimated value of SNR. The computer simulation results clarify its effectiveness.