Modulation And Channel Model Simulation In Deep Space Communication System

Because of the complexity of the transmittal environment of the signal between the transmitter and receiver, the wireless communication channel is thought to be a bad channel in the nature. As one kind of the wireless communication channel, deep space communication channel has some other special characteristics besides the characteristics in common to wireless communication channel. Because the design of the wireless communication system is restricted by the wireless channel, it is very important to study the characteristics of the wireless channel.In this paper, firstly, various factors which affect the performance of the wireless channel are analyzed in detail, including amplitude fading, adding noise, multi-path effect and Doppler effect. Secondly, on the basis of probability density statistic model, common wireless fading channels are analyzed theoretically and simulated by software. Thirdly, a variable parameter adding white gauss noise channel model is proposed and also achieved by C language according to the characteristics of the deep space communication channel. In order to validate the model, the technique of continuous phase modulation is applied to build the simulation system in the paper and the entire simulation system is achieved by C language under VC++6.0 development environment. Finally, according to the simulation results, parameters which affect the performance of the simulation system are analyzed and discussed respectively. This simulation system of the wireless channel is not only good for the construction of the integrated simulation system of the deep space communication, but also the foundation of the further research of the deep space communication.