Throughput improvement in ACO-OFDM-based VLC systems using noise cancellation and precoding techniques

Abstract

One of the primary challenges faced by visible light communication (VLC) systems employing optical orthogonal frequency division multiplexing is the peak-to-average power ratio (PAPR). This study is dedicated to designing, simulating, and evaluating bit error rate (BER) and PAPR reduction methods tailored for the VLC broadcasting system. The asymmetric clipped optical orthogonal frequency division multiplexing (ACO-OFDM) scheme is highlighted in this work for its impressive performance. Therefore, the proposed PAPR mitigation methodologies applied to ACO-OFDM. The proposed PAPR reduction strategy involves 5 distinct precoding methodologies. The PAPR was mitigated by 3.485 dB after applying the DST precoding methodology. Still, the WHT precoding methodology can achieve PAPR reduction by 1.131 dB, without BER performance degradation, with respect to the conventional ACO-OFDM system. Furthermore, the work addresses another challenge in VLC systems: the bit error rate (BER). This is accomplished by introducing approaches to Time Domain Noise Cancelation and Frequency Domain Noise Cancelation (FDNC). The BER performance of these 2 receiver models is nearly the same. The simulation results indicate the system performance enhancement after applying noise cancellation approaches by 1.65 dB at the 4-QAM modulation scheme and 2.97 dB at the 1024-QAM modulation scheme. The 16-QAM modulation scheme, after applying DST and WHT methodologies alongside noise cancellation approaches, can enhance both PAPR by 20.83% and 6.76%, but the E_b/N₀ performance enhancement by 10.10% and 14.64%, respectively. Additionally, the effectiveness and validity of the proposed schemes are verified by comparing them with relevant literature reviews on PAPR reduction techniques and selecting an optimal choice among them.