Research On Algorithm Of Reducing ICI In LTE System Over High-Speed Mobile Environment

As an effective multi-carrier modulation technology，OFDM（Orthogonal FrequencyDivision Multiplexing）is good to resist frequency-selective fading and has high spectrumefficiency. It has been adopted by3GPP as the physical technology of LTE system. Onerequirement of the LTE system is that the mobile terminal can reach certain QoS level overhigh-speed mobile environment. In this environment, compared with the situation of staticstate or low-speed mobile, communications will be confronted with more problems, Dopplereffect is the most stressed one. The frequency offset caused by Doppler effect impactsinter-carrier synchronization seriously in LTE system, which leads to ICI(Inter-CarrierInterference). This paper researches the algorithms of reducing ICI in LTE system overhigh-speed mobile environment. Author’s main work is showed as following:In Chapter3, two improved schemes are presented respectively, including ICIself-cancellation scheme based on parameter adjustment and ICI self-cancellation schemebased on differential encoding. The first scheme ameliorates CIR and reduces BER of LTEsystem, and the second scheme increases the spectrum efficiency of LTE system. Thesimulation indicates that the improved schemes achieve anticipate purpose.In Chapter4, a new guideline of coding matrix is designed for TD-LTE system intime-varying Rayleigh channels. The new scheme involves classic precoding matrix andDoppler shift matrix. Furthermore, TD-LTE system model combined with precoding andsymbol coding is putted forward. The simulation shows that the performance of TD-LTEsystem is enhanced greatly.