Random Access Technology In Satellite Mobile Communication LTE System

With the popularization of satellite mobile communication and the high data speed transmission of terrestrial Long Term Evolution (LTE), the integration of satellite and terrestrial LTE is coming. As the first step, uplink random access makes significant sense to the connection between user terminal and network. Compared with terrestrial system, satellite mobile communication system has particular superiority and channel characteristic, so that the terratrial LTE random access cannot be used to satellite directly.In this paper, the research at home and abroad on satellite communication system is introduced first, and then, the constitution and channel characteristic are analyzed. The terrestrial LTE random access technology is studied deeply. Based on the above achievement, the paper launches the research on the random access which is adapted to satellite mobile communication LTE system.Based on LTE random access, the dissertation starts research through characteristic of Geosynchronous Orbit (GEO) satellite mobile communication system, which refers to the long propagation delay and the large coverage range of satellite beam. The research includes the procedure, the design of preamble style, detection algorithm and threshold setting scheme of random access. Contraposing the particular superiority, the research has further consummated the design principle of random access preamble which adapts to satellite system. A Peak to Average Ratio after Deleting Quasi-users (PAR-DQ) detection algorithm and threshold setting scheme which is independent of noise variance are proposed. Eventually, utilize zero padding method to inprove the precision of timing advance (TA) estimation. Through the simulation and analysis, the proposed detection algorithm and threshold setting acheme can assure the lower error detection probability and satisfying performance, which can be applied to GEO satellite mobile communication system.