基于模式分集的星地激光通信技术研究

Research on satellite-to-ground laser communication based on mode diversity reception

摘要:

针对星地激光通信的大气湍流导致信号光损伤这一问题，实验搭建了一种能够补偿大气湍流的空间激光通信系统，采用模式分集接收结合最大比合并方法对大气湍流进行补偿，采用相干探测技术对高阶调制信号进行光电探测。在不同湍流强度下进行了传输实验，结果表明：模式分集空间激光通信系统的性能相比较于单模光纤接收系统有较大提升，随着湍流强度的增加，性能提升更加显著。在弱、中、强三种湍流强度以及相同目标误码率情况下，模式分集系统相比单模光纤接收系统分别降低了约4.2 dB、5.1 dB 和 5.5 dB的链路损耗。在弱、中、强三种湍流强度以及相同目标中断概率下，模式分集接收系统相比单模光纤接收系统分别降低了约3 dB、5.9 dB 和 4.3 dB的链路损耗。

Abstract:

Aiming at the problem that atmospheric turbulence causes optical signal damage in satellite-to-ground laser communication, we experimentally set up a kind of space laser communication system which can compensate for atmospheric turbulence. The system uses mode diversity reception combined with maximum ratio combining method to compensate for atmospheric turbulence, the coherent detection technique is adopted to detect high-order modulation signals. Transmission experiments are carried out under different turbulence intensities, and the results show that: Compared with a single-mode fiber receiving system, the performance of the mode diversity receiving system has large improvement, with the increase of turbulence intensity, performance improvement is more significant. Under the weak, moderate, and strong turbulence intensities, in the condition of the same target BER, compared with the single-mode fiber receiving system, the mode diversity receiving system reduces the link loss of about 4.2 dB、5.1 dB, and 5.5 dB, respectively. Under the weak, moderate, and strong turbulence intensities, in the same target interruption probability, compared with the single-mode fiber receiving system, the mode diversity receiving system reduces the link loss of about 4.2 dB, 5.1 dB, and 5.5 dB, respectively.