Research On Channel Characteristics And Modeling Of High-speed Mobile Communication Links

The rapidly developing satellite mobile communication has large coverage, wideworking frequency band, high communication efficiency and flexibility. Non-geostationarysatellite travels in low orbit with high speed, which results in its complicated and dynamicchannel characteristics. So the research on its communication links is one of the difficultiesand keys in satellite mobile communication area.Channel characteristics and modeling of two kinds of high-speed mobilecommunication link, land mobile satellite link and inter-satellite link withnon-geostationary orbit satellite, are analyzed in this paper. To study the channelcharacteristics, three satellite orbit estimation algorithms are analyzed and simulated, andthe estimation algorithm based on SGP model is used to calculate the channelcharacteristics of land mobile satellite link, such as path loss, propagation delay, Dopplerfrequency shift and its rate of change. In addition, the channel characteristics ofinter-satellite links between different satellites with the same or different height aresimulated according to the analysis of spatial geometrical relations. To study the channelmodels, two kinds of narrowband channel model, C.Loo and Corazza, are analyzed in detail.Then a six-path channel model is proposed. By adjusting the number of paths andparameters, the model can realize either wideband or narrowband channel model. Besides,parameters of the model under three representative surroundings are collected.On the basis of the analysis and simulations above, the high-speed mobilecommunication system control software is designed and realized. It can calculate thechannel characteristics with parameters of satellite and ground terminal or inter-satelliteparameters. Then, the channel characteristics and parameters of channel model are sent tothe dedicated channel simulator through network to make the channel simulator realize thechannel simulation. In addition, the software can control the communication parameters,like modulation mode and symbol rate, and it can also estimate the system performance. Atthe end of the paper, the main functions of the control software are tested to verify thecompleteness of the function realization.When designing the non-geostationary satellite mobile communication links, studyingchannel characteristics, establishing accurate channel models and exploring efficientchannel estimation algorithm has important significance to realization of mobile satellite communication with high reliability and is also the main problem this paper aims to studyand solve.