Experimental study on SPAD-based VLC systems after low-pass filtering

Abstract

Abstract The practical output waveforms of single photon avalanche diode (SPAD) devices are some photon-counting pulse sequences during one symbol interval. The adaptive system and the well-known channel information are needed for the practical SPAD-based visible light communication (VLC) system. In this paper, we first study the performance of practical SPAD device after a low-pass filter. After low-pass filtering (LPF), the output of SPAD receiver transforms to be the continuous waveforms which is same as the traditional photodiode (PD)-based receiver. Then we put forward the fast blind union detection (FBUD) theory for the SPAD-based VLC system after LPF. In addition, we design a weak light communication experimental system with a red light-emitting diode (LED) status indicator and a practical SPAD device. After passing a 3 m free space transmission distance, the experimental results indicate that the performance of the proposed scheme is better than the well-established Poisson communication method and is worse than the practical output model under the dead time limit.