Assessment of the Illumination and Communication Performance of a Visible Light System in an Indoor Scenario

Abstract

Visible-light communication (VLC) is a technique that employs light-emitting diodes (LEDs) and photodiodes to enable communication in indoor scenarios. VLC has gathered increasing attention due to its potential for data transmission across a broad unregulated spectrum (430-790 THz). One of VLC’s primary objectives is to utilize pre-existing LED infrastructures as access points. In this investigation, we assess the performance of an indoor VLC link by measuring the illumination characteristics of commercial LED luminaire. The results are utilized to design an electronic transmission and reception circuit. An analysis was conducted to identify the optimal operating point that ensures adequate lighting and reliable communication. The designed circuits exhibited a bandwidth of 50 MHz at -3 dB. Characterization of the luminaire demonstrated that a single luminaire provided the illumination (486 lx) within the recommended range at 1.6 m. For data transmission, the variable pulse position modulation (VPPM) and the orthogonal frequency-division multiplexing (OFDM) were employed in different configurations. The bit error rate (BER) results, with a threshold of ≤ 10-3, revealed that VPPM performed best at a distance of 1.9 m with a rate of 12.5 Mbps. Conversely, OFDM modulation achieved optimal performance at 1.75 m, providing a transmission rate of 30 Mbps.