SPAD-Based Optical Wireless Communication with Signal Pre-Distortion and Noise Normalization

Abstract

In recent years, there has been a growing interest in exploring the application of single-photon avalanche diode (SPAD) in optical wireless communication (OWC). As a photon counting detector, SPAD can provide much higher sensitivity compared to the other commonly used photodetectors. However, SPAD-based receivers suffer from significant dead-time-induced non-linear distortion and signal dependent noise. In this work, we propose a novel SPAD-based OWC system in which the non-linear distortion caused by dead time can be successfully eliminated by the pre-distortion of the signal at the transmitter. In addition, another system with joint pre-distortion and noise normalization functionality is proposed. Thanks to the additional noise normalization process, for the transformed signal at the receiver, the originally signal dependent noise becomes signal independent so that the conventional signal detection techniques designed for AWGN channels can be employed to decode the signal. Our numerical results demonstrate the superiority of the proposed systems compared to the state-of-the-art systems in terms of BER performance and achievable data rate.

Time-Gated Photon Counting Receivers for Optical Wireless Communication

“…Due to the effects of the dead time, the average detected photon count in a symbol duration is non-linearly distorted especially in high incident photon rate regimes [9]. In addition, for high speed data transmission with symbol duration comparable or even less than the SPAD dead time, the dead time started in a symbol can extend to the subsequent symbols introducing photon counting blocking in the following symbols.…”