Návrh a realizace post-ekvalizačního obvodu pro VLC komunikační systém

Abstract

Diploma thesis describes the visible light technology, constructing methods of the detectors for optical communications and technology of pre- and post-equalization. The main goal of the thesis is design and implementation of post-equalization circuit for VLC communication system. VLC uses blue emitter in combination with phosphor to emit yellow light. However, this phosphor-based emitters limit bandwidth of LED to approximately 2 MHz. The thesis describes a proposal of post-equalizing circuit consisting of two passive and one active equalizer that compensates for attenuation of signal. We achieved six-time increase in bandwidth with the constructed circuit and this was done without using a blue filter. Improved bandwidth enabled the deployment of the modulation technique Orthogonal Frequency Division Multiplexing, OFDM, at a higher carrier frequency.