Rancang Bangun Layer Fisik Visible Light Communication Pada Sistem Transmisi Audio

Abstract

Currently, LED functions not only as illumination purpose but also can be used as a communication device. Commonly, this technology is called as "visible light communication (VLC)", which has begun to be applied in areas susceptible to electromagnetic waves, such as hospitals, aircraft cabins, airports, military headquarters and etc. Generally, the media, which is used as object of the data transmission, e.g. digital images, video, audio (music only), texts, and even data packets for internet browsing purposes. This research implements a VLC system that focuses on the physical layer, especially in Analog Front-End (AFE) part. The designed system consists of an AFE transmitter module as a modulator and an AFE receiver as a demodulator. The designing AFE transmitter adopts the Bias-T module principle, it has same the functionality but extremely lower in the cost factor. While in the AFE receiver part, the DC-offset remover module is implemented, it has a function to reduce the DC signal that generated from ambient light. The results of demonstration show that the system, functionally, can be used for transmitting audio signals via visible light and the received data can be displayed to the loudspeaker directly. In this work, the data observation is done by comparing the amplitude of input signal connected to the driver LED against the output signal from the last stage of the AFE receiver. From the test results, it can be shown that the optimum bandwidth of the AFE transceiver is about 50 kHz to 450 kHz (with attenuation at fc = -3 dB as a reference) and the maximum distance for data transmission is 40 cm and angle of reception is 0o