Comparison of Hybrid Optical Modulation Schemes for Visible Light Communication

In this paper, three hybrid modulation schemes for visible light communication based on orthogonal frequency division multiplexing (OFDM) are compared, which are asymmetrically clipped dc-biased optical OFDM, hybrid asymmetrically clipped optical OFDM, and layered asymmetrically clipped optical OFDM (LACO-OFDM). The following aspects are analyzed and compared, such as the probability distribution functions, the peak-to-average power ratio, and the bit error ratio performance in terms of optical bit energy to noise power under different conditions. Furthermore, the optimal proportion of the optical power on different layers for LACO-OFDM is also investigated. Simulation results show that LACO-OFDM has better performance than other hybrid schemes in high signal-to-noise ratio (SNR) scenario, and the improvement is slight when more than four layers signals are utilized, while in low SNR condition, LACO-OFDM with two layers performs better than that with more layers.