Constellation And Communication Link Design Of Non-geostationary Satellite Communication System

With decades of investment, research and development on the space technology,our country has made great progress on GEO satellite communication technology,reducing the gap with the state of the art in abroad, but the gap level on the research of Non-geostationary(NGEO) orbit satellite communication technology is more and more big due to various reasons. With the arrival of the personal mobile communication age, there are higher requirements for quality of service and the miniaturization hand-held terminal is development trend. This paper focuses on the research of NGEO satellite communication system design, including the NGEO satellite constellation design and the communication link design.First, the design and optimization to common-track satellite constellation of regional coverage is finished in this paper. With the basic principle of the common-track constellation and uniform coverage, the implementation step of common-track satellite constellation meeting one orbit plane with multiple satellites is deduced. The common-track satellite constellation scheme coveraging our country and the surrounding areas is designed based the steps. The coverage performance is optimized and simulated with maximum average elevation when the real time coverage ratio is 100%. Comparing with these suited constellation schemes comprehensively, a eight-satellites scheme with two orbits of four satellites is optimal because its lower orbit altitude and fewer satellites is helpful to reduce system cost and complexity.The satellite communication user link is designed based on the optimal constellation scheme of eight satellites. The mobile users can roam between satellite network and ground network to communication freely with 3G mobile phone oriented satellite communication system. Satellite radio interface G being compatible with WCDMA network is pointed out based on the analysis of IMT-2000 satellite radio interface. The basic parameters of 3G mobile phone is assumed refer to the satellite mobile communication system of satellite radio interface G. The relation between carrier noise ratio(CNR) and system capacity is deduced with the multiple access interference of intra and inter multi-beam.Equipment parameters on board including satellite receiving antenna gain and satellite Equivalent Isotropic Radiated Power(EIRP) value is obtained after the design and simulation of the satellite communication link.