受机载环境条件和飞机飞行特性的影响 ,对信号的调制解调是设计测控飞机卫星移动通信系统的关键点和难点之一。在详细分析测控飞机卫星移动通信特点的基础上 ,对几种常用的调制解调方式进行了综合比较 ,指出测控飞机的卫星移动通信系统采用差分相干 BPSK调制解调方式较为合理 ,并对调制解调器的构造进行了初步设计 Influenced by airborne environmental conditions and aircraft flight characteristics, the modulation and demodulation of signals is one of the key points and difficulties in designing and monitoring the satellite mobile communication system of an aircraft. Based on the detailed analysis of the characteristics of the satellite mobile communications of the aircraft under test and control, several commonly used methods of modulation and demodulation are comprehensively compared. It is pointed out that it is reasonable to use the differential coherent BPSK modem in the satellite mobile communication system of the aircraft under test and control. Structure was initially designed