Experimental Evaluation of a Software Defined Visible Light Communication System

Abstract

Visible light communication (VLC) allows the dual use of light-emitting diodes (LEDs) for illumination and communication purposes. With its large bandwidth and immunity to electromagnetic interference, VLC can be used as complementary and/or alternative to radio communications. In this paper, we present a comprehensive experimental evaluation of a softwaredefined VLC system with on-off keying for both line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios. The experimental set-up is based on a pair of modified National Instruments USRPs coupled with a custom design front-end. In the measurement campaign, we vary the distance between 1 to 3 meters with a step size of 0.5 m. For each point in this LOS scenario, we measure signal-to-noise ratio (SNR) and bit error rate (BER) with and without a lens. We also evaluate the effect of the reception angle (i.e, no strict alignment) on system performance. We further evaluate the SNR performance for NLOS scenarios and demonstrate a robust performance due to the wide field-ofview of the front-end.

Experimental Investigation of MISO Vehicular Visible Light Communication Under Mobility Conditions

“…1, the received baseband signal samples from the USRP are first matched-filtered to improve the SNR. Subsequently, symbol synchronization is performed using the maximum output energy method [20], [21] to find the optimal sampling points of the symbols. The beginning of the frame is determined by cross-correlating the received frame with a clean copy of preamble sequence stored in the receiver.…”