A low-cost Analog Front-End (AFE) transmitter designs for OFDM visible light communications

Abstract

One of major challenges in optical communications based visible light is nonlinearity effects which comes from LEDs as light sources. These challenges are exist when VLC systems use analog modulation such as OFDM. Therefore it needs special requirements to design Analog Front-End (AFE), especially at transmitter side. LED driver must be operated at linear mode. In this paper we propose a low cost and simple linear analog AFE transmitter for VLC. According to these problem, the main topic in this paper is to describe a low complexity of AFE transmitter circuit design based OFDM signal. Describing contents consist of: 1) channels model with 3×3×3 of room sizes and single LED, 2) non-linearity LED model transfer function which cover I-V, P-V, and P-I characteristics, 3) proposed AFE transmitter which cover variable non-inverting amplifier, offset adjuster and current-sink LED driver topology.