基于Raptor10码的自由空间光通信系统设计

大气湍流是自由空间光通信系统的主要限制因素，会造成光束的强度闪烁和相位起伏。为了应对大气湍流及背景光对无线激光通信的影响，设计并实现了一套无线激光通信系统。该系统采用数字喷泉码Raptor10码来提高通信系统的可靠性及抗干扰能力。此外还使用了巴克码作为帧头以及脉冲位置调制（PPM）方式，并以现场可编程门阵列（FPGA）为核心完成了数据的编码、调制、帧同步、解调及译码。其发射光源为波长532 nm激光，探测器采用Silicon Sensor公司的单点APD。最后在2 km的自由空间对整个无线激光通信系统进行测试，测试结果稳定可靠。

Design of free space optical communication system based on Raptor10 code

Atmospheric turbulence is a major limiting factor in free-space optical communication systems, causing intensity flicker and phase fluctuations in the beam. In order to cope with the influence of atmospheric turbulence and background light on wireless laser communication, a wireless laser communication system was designed and implemented. The system used the digital fountain code Raptor10 code to improve the reliability and anti-interference ability of the communication system. In addition, the Barker code was used as the frame header and pulse position modulation(PPM) mode, and the data coding, modulation, frame synchronization, demodulation and decoding were completed with the field programmable gate array(FPGA) as the core. The emission source was a 532 nm laser and the detector used a single point APD from Silicon Sensor. Finally, the entire wireless laser communication system was tested in 2 km of free space, and the test results were stable and reliable.