Experimental study on SPAD-based VLC systems with an LED status indicator

Abstract

According to our experimental observation, the effect of dead time caused by the quenching circuit of single photon avalanche diode (SPAD) devices could affect the system performance significantly. Hence, we propose a corresponding synchronization scheme and a fast blind union detection (FBUD) algorithm for the received photon-counting pulse waveform by considering the effect of dead time. To verify our proposed theory under the long distance turbulence fading channel, we demonstrate a long distance SPAD-based visible light communication system with a red light-emitting diode status indicator in the practical circuit board. The experimental results indicate that the proposed FBUD algorithm outperforms the conventional dead-time free Poisson multiple-symbol detection method under different conditions. Meanwhile, the bit-to-error ratio gaps of the two algorithms will become more and more larger with the increasing of the data rate.