Wireless Mobile Channel Model And Realization

As one of the most powerful means of modern communications, the technique of radio mobile communication has been deeply approached and kept quickly developing. When designing the communication system, the characteristics of radio mobile channel are the most important and fundamental factor, which directly influence the quality of service provided and the stability of the communication system. Therefore, a good learning of the characteristics of radio mobile channel is necessary to research and develop an excellent wireless communication system.The key parameters to describe the characteristics of radio mobile channel include: time delay-spread, geometrical path loss and excess path loss, shadow fading, multipath fading characteristics and operating radio frequency. And the fading of signal and channel time dispersion caused by multipath propagation are the core factors that have great impact on propagation characteristics of radio mobile channel The fading characteristics vary with the propagation environment and its impact on the communication quality (i.e. bit error patterns) is highly dependent on the speed of the mobile terminal. In satellite communication--an important research field of radio mobile communications, to predict the quality of the satellite communication service, or to provide credible proof for the building and testing of the satellite communication system, it is entailed to set up a dynamic real-time model to simulate the propagation characteristics of satellite mobile communication channel.In this project, based on the theory of the characteristics of the satellite mobile communication channel, we select the popular statistical model--Lutz model to design the radio channel emulating system to simulate the entire course of wireless communication between Low Earth Orbit (LEO) satellite and mobile terminal when satellite flying over the earth. All work involves the model simulation in Simulink4.0 of Matlab, the design of fading factor with C Language in software development and the realization of Doppler frequency shift and additive white Gaussian noise(AWGN) in hardware design. The communication between the software and hardware is connected by parallel port.The propagation characteristics of satellite mobile communication channel and the relating statistical models are researched and analyzed in this paper. The design of each module of Lutz model and the relating simulation have been given and explained in details. And in the end, the software and hardware design of this emulating system are briefly refered.