大气激光通信中光PPM偏振调制方案及其关键技术

大气中的雨、雪、雾等对大气激光通信的质量和可靠性影响很大.提出了一种光PPM偏振调制方式,采用改变水平和垂直偏振光束的强度,检测接收到的激光的偏振角进行编码.由于水平偏振和垂直偏振光通过的是同一条光路,在求解光偏振角时大气中的衰减可以相互抵消,因此光PPM偏振调制可以减少甚至消除大气信道对大气激光通信的影响.仿真结果表明:这种方法不但可以消除大气信道对激光通信质量的影响,而且可以成倍提高大气激光通信的码速率.

Light Polarization Modulation with PPM and Its Key Technique in Atmospheric Laser Communication

The rain, snow, and fog in the atmosphere significantly affect the quality and reliability of atmospheric laser communication. The light polarization modulation with PPM is introduced. With this modulation method, we can control the intensity of the horizontally polarized light and vertically polarized light, and detect the polarizing angle of the received laser to encode. As the horizontally polarized light and vertically polarized light pass the same path, the attenuation effects of them can be counteracted while calculating the polarizing angle. Consequently,by using the light polarization modulation with PPM,it can reduce or eliminate the negative effects caused by atmospheric channels on atmospheric laser communication. The simulation results show that this method can not only eliminate the negative effects caused by atmospheric channels on the laser communication quality, but also increase the atmospheric laser communication code rate many times.