| Satellite mobile communication systems are parts of realizing global personal communications. Recently, multimedia mobile satellite communication systems become one of the main research fields of satellite communication technologies. According to the key techniques of the new generation mobile satellite communications and the development status of multimedia satellite communication systems, several fields are researched in this dissertation. They are mobile satellite communications channel modeling and simulation technologies, resource management strategies in a satellite/terrestrial hybrid system, the development and validation of Wideband-CDMA IMT-2000 applications for satellite communication systems, the strategies of mobility management and IP Quality of Services (QoS) guarantee in multimedia satellite communication systems, and military satellite communications with IP technlogies.Chapter 2 proposes a generalized mobile satellite communications channel model. Based on analysis of propagation characteristics about mobile satellite communication channels, the Lognormal-Rice-Rayleigh (LR2) model includes as many classical narrowband models such as Loo's et al. The LR2 model suits well with the features of frequency-bands used by MSS including UHF/L/Ka. The paper provides statistical description of envelope and phase about the LR2 model, and analyses in detail all kinds of parameters related with channel model such as LCR, AFD, BER, block error rate. Finally, the paper describes the procedure to extract model parameters from experimental data.Chapter 3 describes an algorithm to model the characteristics of slow fading in mobile communications. As a part of propagation characteristics about mobile communication channels, slow fading caused by shadowing not only obeys the lognormal probability density distribution (PDF), but also has an exponential autocorrelation function. Cross-correlation of shadowing process between uplink and downlink also should be included. Generally only probability distribution of slow fading is considered in modeling of mobile communication channels, but power spectral density (PSD) or cross-power spectrum is not modeled. An accurate correlation/probability model for shadow fading is of vital importance for both analytical and simulation based evaluation of any power control and handover scheme. The paper proposed a method to realize bi-shaping of PDF/PSD of the slow fadingrandom process for the first time. Theoretic analysis has been given to prove the validation of the method of bi-shaping. Simulation results show the validity of the method.Chapter 4 deals with resource management strategies in a LEO (Low Earth Orbit mobile satellite) satellite/terrestrial hybrid system. A terrestrial cellular mobile network enhanced by a LEO system is given out with the consideration of traditional handoff requests. Moreover, we model inter-beam handoff requests. We also discuss the difference about handoff procedures and mobility-models between terrestrial cellular cells and LEO umbrella cells. An analytical approach has been developed to compare the terrestrial cellular system with hybrid system. The results have been given out in figures.Chapter 5 points out multimedia LEO satellite networks will play an important role in providing truly global coverage required by mobile personal communication services. Due to the high mobility inherent to LEO systems, a number of challenging technical problems arise. The first contribution of this work is to propose a connection admission control (CAC) algorithm differentiating voice and data services based on store-and-forward LEO systems. Our second contribution is a realistic environment simulation method. We uses real mobility model, taking into account the theoretic satellite system and the actual satellite system to open out the difference of performance between numerical analysis, theoretic system simulation and actual system simulation. Finally, we propose a novel numerical analysis method to give the capacity of LEO satellite network...
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