Faz gürültüsünün eşevreli görünür ışık haberleşme sistemlerinin performansına etkisi

Leveraging the inherent data carrying capability of light-emitting diode (LED) based illumination infrastructure, visible light communication (VLC) offers a promising approach for wireless data transmission. The recent advent of commercially available white-light luminaires equipped with laser diodes (LDs) presents a unique opportunity to realize high-performance coherent VLC systems. In contrast to conventional VLC employing intensity modulation, coherent VLC harnesses the superior bandwidth characteristics of lasers and advanced digital signal processing (DSP) techniques to achieve significantly enhanced data rates. Coherent detection schemes rely on a highly stable, monochromatic laser as a local oscillator (LO). However, practical laser implementations exhibit inherent phase noise stemming from spontaneous emission and carrier density fluctuations. This work presents a comprehensive analysis of the detrimental effects of phase noise on the performance of a coherent VLC system. To counteract the detrimental effects of phase noise, we propose the utilization of a phase-locked loop (PLL). By characterizing the statistical distribution of the residual phase error after PLL operation, we derive an approximate closed-form expression for the pairwise error probability (PEP). Subsequently, a union bound is established to quantify the overall bit error rate (BER). The derived analytical framework is validated through extensive simulations, confirming its accuracy and enabling the quantification of phase noise's effect on the system's error rate performance.