Performance of MMSE-LE in 2 Gbaud/s Single Carrier Visible Light Communication using PAM-2

Abstract

A Visible Light Communication system (VLC) based on Pulse Amplitude Modulation (PAM-2) with equalisation of low-complexity is presented. The VLC system consists of a transmission chain with an off-the-shelf 520 nm Laser Diode (LD), whose distance from the photodiode at the receiver is 1. 8m. A Minimum Mean Square Linear Equalisation (MMSE-LE) with 16 taps enables communication to be performed at a baud rate of 2 Gbaud/s with a measured Bit Error Rate (BER) above the VLC Forward Error Correction (FEC) threshold. Digital Signal Processing (DSP) was performed in offline mode with MATLAB algorithm. Through the study carried out, it is possible to verify how much linear equalisation can compensate for the distortions of the transmission channel through the measured eye diagrams as well as the number of MMSE-LE taps to obtain optimised MMSE-LE performances and increase the capacity of the VLC channel with PAM-2.