Ocean observation system that involves multiple underwater vehicles and seafloor nodes plays an important role in better learning the ocean, where underwater wireless communication is mandatory for massive data interaction. Optical communication that has wide bandwidth and comprehensive working distance is the preferred method compared to acoustic and other methods. However, the presence of directionality makes the optical method difficult to use especially when the transceiver is equipped on a motive vehicle. In this study, an underwater free-space optical communication method of transmitting information is proposed. Characteristics of underwater optical transmission, as well as the photoelectric signal processing and modulation and demodulation algorithms, are studied and modeled. New approach for realizing underwater free-space optical communication is proposed and simulated. A prototype including a free-space optical transmitter and a receiver is developed; tests in different scenarios were carried out, and the results were observed: (1) by using the minimum number of LEDs, the effect of uniform lighting in space is achieved, and the transmitter coverage reaches 160°. (2) When the power of the transmitter is 10 W and the communication rate is 1 Mbps, the maximum communication distance reaches 13 m.

涉及多个水下航行器和海底节点的海洋观测系统在更好地学习海洋方面发挥着重要作用，其中水下无线通信对于海量数据交互是必不可少的。与声学和其他方法相比，具有宽带宽和综合工作距离的光通信是首选方法。然而，方向性的存在使得光学方法难以使用，特别是当收发器配备在机动车辆上时。在这项研究中，提出了一种水下自由空间光通信传输信息的方法。对水下光传输特性、光电信号处理和调制解调算法进行了研究和建模。提出并模拟了实现水下自由空间光通信的新方法。开发了包含自由空间光发射器和接收器的原型；进行了不同场景下的测试，观察结果：（1）通过使用最少数量的LED，达到空间均匀照明的效果，发射机覆盖范围达到160°。(2) 当发射机功率为10W，通信速率为1Mbps时，最大通信距离达到13m。