Performance optimization of ACO-OFDM-based VLC systems through PAPR reduction and noise cancellation techniques
摘要
Visible Light Communications (VLC) is a promising communication technology designed to serve as a supplemental system to radio frequency communications for many demanding applications. VLC employs optical orthogonal frequency division multiplexing (O-OFDM) techniques to achieve higher data rates and resist intersymbol interference. Among these, asymmetrically clipped O-OFDM (ACO-OFDM) stands out as one of the most power-efficient and high-performing methods for VLC. However, like other O-OFDM techniques, ACO-OFDM encounters the challenge of a high peak-to-average power ratio (PAPR). VLC utilizes light-emitting diodes (LEDs) for data transmission at the transmitter and photodiodes (PDs) for data reception at the receiver. However, the high PAPR issue can drive LEDs to operate in their nonlinear region, reducing system performance and potentially causing LED damage or burnout. The paper aims to alleviate the high PAPR issue by proposing a hybrid combination of precoding technique and various nonlinear companding techniques. Compared to the standard ACO-OFDM, the proposed methodologies can reduce the PAPR issue by 5.5796 dB without a bit error rate (BER) degradation. The paper also aims to improve another aspect of the BER performance of ACO-OFDM. The paper proposes two noise cancellation receiver models to enhance the performance by 2.275 dB compared to standard ACO-OFDM to attain the same BER performance. The proposed PAPR reduction methodology with noise cancellation receiver model can achieve PAPR reduction by 6.0057 dB and enhanced performance by -0.309 dB to achieve the BER performance relative to standard ACO-OFDM. This paper systematically evaluates the proposed PAPR reduction approach by comparing it with established methods from the literature, ensuring a comprehensive assessment of its effectiveness and reliability.