Wide Dynamic Range Signal Detection for Underwater Optical Wireless Communication Using A Pulse Counting Receiver

Typically, a photomultiplier tube (PMT) can be leveraged as the photon detector in the underwater optical wireless communication (UOWC) system to further extend the transmission distance, whose output electric signal can be generally classified into three regimes named discrete-pulse regime, transition regime, and continuous waveform regime according to various received optical power (ROP). In this paper, we experimentally demonstrate a low-power UOWC system that adopted a PMT as the receiver, and a detection method by taking the cumulative sum of the sampled values in a symbol duration is proposed and experimentally evaluated under different ROP and symbol rates. Experimental results show that the proposed detection method outperforms various statistics-based comparison benchmarks. Furthermore, the effectiveness of the proposed method in alleviating strong ambient radiation is experimentally verified.

I. Introduction

With the increasing depletion of land resources and global climate change, ocean exploration gradually emerges as a hot topic. From the communication perspective in underwater scenario, traditional radio frequency (RF) communication fails to meet the requirement of long transmission distance due to its high attenuation in seawater [1]. The matured acoustic communication typically suffers from intolerable latency, high cost, and lower data rate [2]. Thus, underwater optical wireless communication (UOWC) seems to be a natural candidate to maintain high data rate and long transmission distance simultaneously [3].