QPSK空间相干激光通信仿真与实验

Simulation and experiment of QPSK spatialcoherent laser communication

相干激光通信因其具有高通信速率、复杂编码格式、极高灵敏度,已成为星间高速数据通信的重要技术之一。本文设计了一种QPSK空间相干激光通信系统链路,给出发射端二进制电信号到激光载波相位的调制映射表,和接收端激光载波相位到二进制电信号的解调映射表。对设计的空间相干激光通信系统链路进行数字化仿真,以星座图的EVM作为核心指标衡量系统性能,仿真分析接收端入射光功率、接收端光放大器噪声系数等因素对EVM的影响。根据仿真结果搭建相应通信链路,在输入光功率为-45 dBm、-48.5 dBm时,经测试得到相应星座图EVM分别为17.8%、24.4%,与仿真结果较符合。

Coherent laser communication has become one of the important technologies of inter satellite high-speed data communication because of its high communication rate,complex coding format and extremely high sensitivity.In this paper,a QPSK spatially coherent laser communication system link is designed to give the modulation mapping table from the binary electrical signal to the laser carrier phase at the transmitter and the demodulation mapping table from the laser carrier phase to the binary electrical signal at the receiver are given.The digital simulation of the designed spatial coherent laser communication system link is carried out,and the EVM of constellation is used as the core index to measure the system performance.The impact of the parameters such as the input power at the receiver and the noise figure of the optical amplifier at the receiver on the EVM are simulated and analyzed.The corresponding communication link is built according to the simulation results.When the input power is-45 dBm and-48.5 dBm,the corresponding EVM of constellation is 17.8%and 24.4%respectively,which is in good agreement with the simulation results.