海洋湍流影响下的NOMA多用户激光通信及其衰落抑制方法研究

水下激光通信具有传输带宽大、功耗低和保密性强等优点，是实现海洋近距离高速通信的关键技术之一。针对当前的水下激光通信多采用正交多址这一频谱利用率低的接入方式，申请者提出了一种基于非正交多址接入（NOMA）的水下多用户激光通信系统。研究中拟结合蒙特卡罗仿真、多层相位屏数值模拟以及水下激光传输实验建立能够准确反映海洋NOMA激光通信系统传输特性的复合海洋信道模型。进而，考虑到多用户链路的差异性，基于孔径平均、中继以及空间分集等技术设计高可靠性的水下NOMA用户配对算法。同时，针对水下NOMA激光通信系统设计合理的功率分配算法以满足通信的有效性需求，为海洋高性能激光通信系统设计提供参考。

Undersea laser communication has the advantages of wide transmission band, low power consumption and strong confidentiality, which is one of the key technologies to achieve high-speed communication at short distance in the ocean. In view of the current underwater laser communication using Orthogonal Multiple Access(OMA), which has low spectrum efficiency, the applicant has proposed a Non-Orthogonal Multiple Access(NOMA) based underwater multi-user laser communication system. In the project, it is planned to combine Monte Carlo simulation, Multi-layer phase screen numerical simulation and underwater laser transmission experiment to establish a composite oceanic channel model that can accurately simulate the transmission characteristics of the oceanic NOMA laser communication system. Furthermore, considering the diversity of multi-user links, a highly reliable user pairing algorithm for the oceanic NOMA-based UWOC system is proposed on the basis of the aperture averaging, relay and spatial diversity technology, etc. At the same time, a reasonable power allocation algorithm is presented for the underwater NOMA laser communication system to meet the effectiveness of communication. The project can provide theoretical reference and technical support for the design of high-performance oceanic laser communication system.