Hu Siqi, Mi Le, Zhou Tianhua, Chen Weibiao
Opt Express. 2018 Aug 20;26(17):21685-21699. doi: 10.1364/OE.26.021685.
We designed a photon-counting receiver system for long-distance underwater wireless laser communication at different code rate Reed-Solomon (RS) and low-density parity check (LDPC) codes. The symbol error rate (SER) performance of the LDPC and RS codes with different signal-to-noise ratios was analyzed. The effects of the background noise, pulse stretching, and frame synchronization were considered in our receiver system. A water tank experiment confirmed that the 1/2-code-rate RS (255,127) is an excellent coding strategy for communication distances in the range of 90-130 m in Jerlov II water. We constructed a communication link with a SER of 6.31 × 10 in a distance of 120-m distance in Jerlov II water for RS (255,127) with 256-pulse-position modulation (PPM) at bandwidth of 13.7 MHz. The maximum link loss was -136.8 dB at λ = 532 nm. The attenuation lengths Natt were 35.88, which were equal at link distances up to 249.2 m in clear ocean water (Jerlov IB water type). The photon counting receiver system can achieve a receiving performance of 3.32 bits/photon. To the best of our knowledge, this is the longest communication attenuation length ever reported under 1 mJ single pulse energy for a narrow field-of-view photon-counting receiver system.
我们设计了一种用于不同码率里德 - 所罗门（RS）码和低密度奇偶校验（LDPC）码的长距离水下无线激光通信的光子计数接收系统。分析了不同信噪比下LDPC码和RS码的误符号率（SER）性能。在我们的接收系统中考虑了背景噪声、脉冲展宽和帧同步的影响。水槽实验证实，对于耶尔洛夫II类水中90 - 130米范围内的通信距离，1/2码率的RS（255,127）是一种出色的编码策略。对于在13.7 MHz带宽下采用256脉冲位置调制（PPM）的RS（255,127），我们在耶尔洛夫II类水中120米的距离上构建了一个误符号率为6.31×10的通信链路。在λ = 532 nm时，最大链路损耗为 - 136.8 dB。衰减长度Natt为35.88，在清澈海水中（耶尔洛夫IB类水型），链路距离达249.2米时该值相等。该光子计数接收系统可实现3.32比特/光子的接收性能。据我们所知，这是窄视场光子计数接收系统在单脉冲能量为1 mJ以下时所报道的最长通信衰减长度。
