3) By the description on the PPM theory of the atmosphere laser emergency communication system and the comparison to the L-PPM, DPPM and multiple pluse PPM, the thesis proposes the scheme of the L-PPM modulator and demodulator.

• 并对L-PPM、DPPM、多脉冲PPM这三种脉冲位置调制进行了比较,给出了大气激光通信系统中单脉冲PPM调制器和解调器的设计方案。