Optical Filter Bank Modeling and Design for Multi-Color Visible Light Communications

Abstract

Multi-color visible light communication (MC-VLC) can achieve a multi-fold rate by taking advantage of multiple color channels. The optical filters for separating different colors are often designed for the normal incidence case only. However, the center wavelength (CWL) of the optical filter shifts as the angle of incidence (AOI) varies, leading to performance degradation. To address the issue caused by the CWL shift, we propose a novel concept of the optical filter bank that uses a group of narrow-band optical filters and divides the whole visible light spectrum into many narrow bands of wavelengths. The optical filter bank can flexibly combine the useful signal of each monochromatic color and effectively avoid the undesired interference, even if the CWL shifts. Based on the optical filter bank, we establish the channel model and signal model of the MC-VLC system, and then jointly design the linear precoding and equalization for MC-VLC. As illustrated by simulations, the proposed optical filter bank transceiver can achieve a high rate and stable performance at varying AOIs.

Impact of Passband Shift in Optical Wireless Communication Systems based on Wavelength Division

“…Moreover, when using a simple modulation scheme like on-off keying (OOK), the average achievable data rate of 106 Mbps is achieved with adaptive WDMA as opposed to 77 Mbps when using state-of-the-art WDMA [14]. It has to be noted though that for both WDM and WDMA, spectral leakage can lead to severe cross-talk if the receiver design is not carefully considered, especially in terms of choosing the right OFs [15]- [17].…”

Optical Filters Based on Cholesteric, Blue and Sphere Mesophases

“…Wavelength-selective and band-pass filters are fundamental and essential devices in optical communication for satisfying the acute need for massive and high-speed communication. They are the essential components of optical wavelength-division multiplexing and orthogonal frequency-division multiplexing systems in optical fiber communication [1][2][3], visible light communication [4,5], and microwave communication [6]. Liquid crystals (LCs) are promising materials in the optical communication field due to the advantages of low driving power, low power consumption, high birefringence, and large electro-optic effect [7][8][9].…”

Channel Modeling and Signal Processing for Array-Based Visible Light Communication System Under Link Misalignment

“…basis. Early research works have been reported in [5] [6] [7] [8] and the researchers are still working on channel modeling. Reference [9] proposed a modeling method based on ray tracing to characterize the transmission environment more accurately.…”