Interference Reduction in LiFi Using an Optical Receiver with Dynamic FoV

Abstract

In optical wireless communication (OWC) networks, managing interference and enhancing data rates are critical challenges, particularly in environments with multiple users. This paper investigates the impact of the receiver’s field of view (FoV) on interference reduction and signal-to-interference-plus-noise ratio (SINR) improvement in light-fidelity (LiFi), which is a networked OWC system. A narrower FoV can effectively limit the reception of unwanted signals, thereby mitigating inter-user interference and enhancing SINR. This work explores how FoV optimisation contributes to interference suppression while maximising SINR. Additionally, the integration of liquid crystal lenses (LCL) to the receiver permits a dynamic FoV for achieving interference-resistant communication. LCLs adjust the focus by applying an electric field to them, and have faster response time in comparison to the coherence time of LiFi. By incorporating realistic scenarios, including both line-of-sight (LoS) and non- LoS (NLoS) propagation, as well as random device orientations, and formulating an optimisation problem to determine the optimal FoV, this study provides valuable insights for designing interference-resistant and high-performance LiFi systems. The results emphasise that employing a dynamic FoV enhances the average SINR by approximately 4 dB across the entire room, even under random device orientations. Moreover, configuring the receiver with a dynamic FoV range between 40◦ to 55◦ consistently yields high SINR throughout the room.