Achievable data rate of coordinated multi-point transmission for visible light communications

Abstract

This paper studies the sum data rate that a Visible Light Communication (VLC) system with multiple users can achieve when phosphor-converted white LED panels are used to provide illumination and communication simultaneously. Three different transmission schemes based on Asymmetrically Clipped Optical Orthogonal Frequency Division Multiplexing (ACO-OFDM) are considered to allocate the communication resources in each transmission point: Frequency Reuse (FR), Joint Transmission Coordinated Multi-Point (JT-CoMP), and a Hybrid combination of them. Since phosphor-converted white LEDs have a larger modulation bandwidth for blue optical wavelengths rather than green-yellow-red ones, the performance of each transmission method is also evaluated using a visible and/or blue light optical filter in front of the Photodetector (PD). When the transmission points apply FR, strong inter-cell interference results in high variability of the achievable data rate at different locations. On the other hand, when JT-CoMP is applied, a more homogeneous data rate coverage is achieved, reducing the peak data rate in the inner parts of the cells but improving notably the data rate in cell-edge areas.