Enhancement And Implementation Of Channel Estimation Algorithm For IMT-Advanced TDD Platform

With the rapid development of wireless communication services,business applications become the biggest driving force for the development of communication technology.Meanwhile,the demand of high peak rate of wireless communications also grows explosively.Thus,better performance of the test prototype system and the algorithm complexity are enssential.The new generation of high-speed wireless access technologies can be verified by existing IMT-Advanced TDD(Time Division Duplex)test prototype verification platforms with better hardware configuration.However,existing prototype platforms only support point-to-point test and are lack of several key equipment and procedures.These resource shortages and single-user limitations affect the continuous evolvement and enhancement of next generation high-speed wireless access technologies.Therefore,this paper aims to improve the existing platforms and investigates the enhancement and implement of channel estimation algorithms for IMT-Advance TDD platforms.The main contributions are as include:Firstly,basic principles of channel estimation technique for existing IMT-Advanced TDD platforms are analyzed.Then,channel estimation models,multi-antenna pilot patterns and channel estimation algorithms are discussed.We find that LS(Least Squares)channel estimation algorithm in existing IMT-Advanced TDD test prototype verification platforms is too simple and cannot effectively compensate for the channel fading.To continuously evolve and enhance the new generation high-speed wireless access platform,the channel estimation algorithms need to be further strengthened and improve.Secondly,this thesis focuses on the channel estimation technique and algorithm enhancement,at the same time analyzes the impact of the guard bands of the radio channel blank channel estimation.The channel estimation algorithm is improved in the virtual carrier by the FFT(Fast Fourier Transform Algorithm)interpolation and replacement to introduce noise suppression module,and in order to suppress due to the CFR(Channel Frequency Response)missing virtual carrier caused by the time domain energy aliasing,based on self-recursive model,the Schur-recursive algorithm joint DFT algorithm,through to the virtual carriers by CFR domain prediction can eliminate the dispersion corresponding distortion.Simulation results demonstrate that the virtual carriers by CFR prediction can achieve better channel estimation performance.Finally,this thesis studies the IMT-Advanced TDD test prototype verification platform of simulation and hardware platform,tested the ATCA_NODE signal processing board,and analyzes the system and frame structure parameters of prototype verification platform.We build and test the hardware platform,now basically solved the problem of downlink hardware and procedural issues.When the hardware platform works in good condition,traffic transmission platform is experimentally established,making verification to channel estimation algorithm.The experimental results show that by using the enhanced channel estimation algorithm the bit error rate can be reduce,and the channel estimation accuracy is increased.Finally,a summary of the full text is made and future research directions are discussed.