Research For Channel Equalization Techniques Of Satellite Mobile Communication System

Satellite mobile communication system came into being because of the limited coverageand natural geographic barriers of terrestrial mobile communications systems. TraditionalTDMA, FDMA and CDMA transmission system does not meet the needs of high-speedtransmission of data of next satellite communications system. For this reason, the orthogonalfrequency division multiplexing (OFDM) is used to study the transmission link of satellitemobile communication system in this paper. OFDM, based on multi-carrier transmissiontechnology, can effectively be against interference caused by multipath channel, which is thehotspot of research in recent years.In satellite communication system, multipath fading and Doppler shift are the biggestfactors affecting the data transmission. Despite the use of OFDM technology, inter-symbolinterference (ISI) and inter-carrier interference (ICI) will still appear in the data transferprocess. In this case, channel equalization techniques are often used to recover the originalsignal much better.Firstly, the current development of mobile satellite communications systems, OFDMtransmission system and balancing techniques is briefly discussed in this article. Then thearticle narrates satellite channel propagation characteristics and makes specific analysis aboutmultipath fading and Doppler shift. The basic principles of OFDM technology and thegeneration mechanism of ISI and ICI are introduced next. Then the classifications, structureof equalization are briefly introduced, and several channel equalization algorithms areanalyzed and derived. Finally, the algorithm of the MMSE and LS is innovated. By adding afrequency offset estimation, elimination, equilibrium, the signal can be compensated well; bycomparing the MATLAB simulation and performance, it can be concluded that LSequalization is simple, but the effect is not good; MMSE equalization is complicated, but theeffect is more ideal.The content of this article provides a theoretical foundation for the practical applicationof satellite mobile communication system and has reference for the designs of channel equalization projects of other multi-carrier systems.