基于多光束合束发射和SiPM分集接收的长距离高速水下光无线通信技术研究

长距离高速水下光无线通信（UOWC）在水下信息传输中具有巨大的应用前景。由于吸收、散射和湍流等影响，光信号在长距离水下传输时存在严重的损耗和畸变（目前>100米传输距离，速率仅Mbps量级）。鉴此，本项目提出采用多光束合束发射和硅光电倍增管（SiPM）分集接收的系统方案，以提高接收灵敏度、延长传输距离和增强系统可靠性，并通过先进的数字信号处理技术改善UOWC的系统性能，最终在实际的外场环境测试中实现传输距离/速率至少：100米/1.5Gbps、200米/100Mbps的目标。研究内容包括：静态/动态因素影响下的长距离UOWC海水光信道建模；UOWC收发端优化设计；基于奈奎斯特准则的正交波形传输、基于时域/频域压缩的非正交波形传输和概率整形编码等技术对基于SiPM的长距离高速UOWC系统的性能改善。研究成果将大幅提升UOWC的应用前景，满足长距离、高速率和高可靠性的水下通信应用需求。

Long reach and high speed underwater optical wireless communication (UOWC) has a great application prospect in underwater information transmission. Due to the effects of absorption, scattering and turbulence, optical signal suffers from serious attenuation and distortion during long reach underwater transmission, and the data rate is limited to the order of Mbps at a transmission distance large than 100 meters. In this project, a multi-beam combined emission and silicon photomultiplier (SiPM) diversity reception based UOWC system is proposed to improve the receiver sensitivity, extend the transmission distance, and enhance the reliability of the system. Advanced digital signal processing techniques are also employed to improve the performance of the UOWC system, realizing an experimental demonstration of at least 100m/1.5Gbps and 200m/100Mbps in the field test. The main research includes optical channel modeling for long reach UOWC systems under the influence of static/dynamic factors, design of UOWC transceivers, performance improvement exploration to the SiPM-based long reach and high speed UOWC systems using orthogonal waveform transmission based on Nyquist criterion, non-orthogonal waveform transmission based on time/frequency domain compression, and probabilistic shape coding techniques. The research results will forecast well application of UOWC systems and meet the requirements of long reach, high speed, and reliable underwater communication.