Model Research And Implementation Verification Of Satellite Mobile Communication Channel

To achieve the reliable and efficient information transmission of the satellite mobile communication system, it is necessary to test the communication technology constantly for the satellite mobile communication characteristic. So, establishing effective satellite channel simulator, which can realize real-time, accurate simulation of actual satellite mobile communication channel has great significance.Firstly, this paper studies the transmission characteristics of satellite mobile communication channel, the large scale fading, small scale fading and Doppler effect are analyzed in detail. This paper derives the mathematical model of large scale fading and small scale fading. And analysis the statistical properties of common satellite mobile flat fading channel model. On the basis of above research, this paper proposes “extend Rayleigh channel model”, the extend Rayleigh channel model consists of two real Gaussian random processes which are associated with each other. And based extend Rayleigh channel model,puts forward an extended Corazza satellite mobile communication channel model. This model assumes that the Doppler extension power spectral density which is caused by multipath scattering is double-end truncated, through configure the size of bilateral frequency to simulate different scattering environments. The model can fits the experimental data better, can reflects real channel propagation characteristics accurately.This paper designs a general satellite mobile communication channel model, and analysis the design principle based digital signal processor in detail. And provide realization block diagram of fading module, Doppler module and digital orthogonal upper and lower frequency conversion module. For the implementation algorithm of extend Rayleigh channel model which is used in fading module, this paper gives the detailed derivation process, and simulates the statistical properties, from the perspective of simulation,demonstrates the validity of the implementation algorithm. The general satellite mobile communication channel model which is proposed in this paper can simulate different orbit height and different fading environment.To verify the correctness of the satellite channel simulator, this paper sets up instrument testing platform to verify the delay characteristic and Doppler frequency shift characteristic, sets up data acquisition platform and software simulation platform to verify the fading characteristic from first order statistical property and second order statistical property. Analysis results show that the satellite channel simulator can simulate thedifferent channel propagation characteristics correctly.