水下自同步激光通信接收机的设计与性能测试

Design and Evaluation of Underwater High Sensitivity Self Synchronous Laser Communication Receiver

为了促进激光通信在水下场景的应用,满足远距离无线光通信的需求,设计了一款基于450 nm蓝色激光二极管的开关键控(OOK)调制水下高灵敏度自同步激光通信发收机。提出一种时钟恢复算法在接收端能自动恢复出与数据同步的时钟信号,解决了水下通信系统发射端与接收端时钟无法同步的问题,实现了水下长距离通信误码率的实时获取。接收端采用FIR滤波、自适应门限判决的数字处理手段提高系统信噪比,并在不同水下环境中搭建通信实验系统。实验结果表明,在水下通信距离20 m、系统通信速率为10 Mbps、误码率为10-6情况下,接收机能有效地恢复基带信号与时钟并测得灵敏度可达到-38.7 dBm。

In order to promote the application of laser communication in underwater scenes and meet the needs of longdistance wireless optical communication,a high-sensitivity underwater self synchronous laser communication transceiver based on switch keying(OOK)modulation of 450 nm blue laser diode is designed.A clock recovery algorithm is proposed to automatically recover the clock signal synchronized with the data at the receiver,which solves the problem that the clock of the transmitter and receiver of the underwater communication system cannot be synchronized,and realizes the real-time acquisition of the bit error rate of the underwater long-distance communication.At the receiver,FIR filtering and adaptive threshold decision are used to improve the signal-to-noise ratio of the system,and communication experimental systems are built in different underwater environments.The experimental results show that the receiver can effectively recover baseband signal and clock,and the measured sensitivity can reach-38.7 dBm under the conditions of 20 m underwater communication distance,10 Mbps system communication rate and the bit error rate about 10^(-6).