Research Of Simulation On LTE-Advanced MIMO Signal Analysis

As is known to all,LTE-A is considered as the fourth generation mobile communication system.With the promotion of operators,the number of users rises quickly.At the same time,the market demand for communication measuring instruments related 4G has also increased gradually,including LTE-Advanced MIMO vector signal analyzer.Currently,the products on the market are Agilent's 89600 VSA,Rohde & Schwarz's R&S FSW43 spectrum and signal analyzers etc.Compared to these types of advanced measuring instrument and equipment abroad,LTE-Advanced MIMO vector signal analyzers developed in China is not yet competitive in the market.Under these circumstances,one of National Science and Technology major projects in 2015,called “New Generation Broadband Wireless Mobile Communication Network”,is a subject 1-5,named “LTE-Advanced MIMO vector signal analyzers”.The subject aims to research and develop multi-mode signal analyzers supporting LTE-A,thereby developing a versatile,stable,and high-performance signal analyzer platform to support various communication standard signal measurement and radio frequency bands.Therefore,under the support of this project,this thesis focuses on researching LTE-A MIMO signal analysis.Firstly,this thesis introduces the characteristics of LTE-A downlink MIMO signals and analyzes the test requirements for MIMO signals.The measurement standards of LTE-A MIMO signal is highlighted,including measurement methods and measurement accuracy.These modes of downlink transmission and corresponding characteristics are introduced in detail.Then the Matlab simulation of LTE-A MIMO signal analysis is investigated.Based on the downlink signal processing model and the the measurement standards of a signal,the block diagram of LTE-A MIMO signal analysis is established.The simulation flow chart is given according to the characteristics of each transmission mode.The simulation results show that,under all bandwidths and modulation modes,the measurement results of signals for all transmission modes are within the accuracy of the measurement standards.On the basis of the simulation of LTE-A MIMO signal analysis in chapter 3,we study the implementation of the floating-point C and fixed-point C on LTE-A MIMO signal analysis.The corresponding.mex files are called by Matlab to achieve a comparison of simulation results.Simulation between the floating-point C and the fixed point C is basically the same as the simulation results of the original Matlab functions,thus verifying the correctness of the generated C code.Finally,this thesis studies a high-precision frequency offset estimation algorithm suitable for LTE-A MIMO signal analysis system.The variance formula of frequency offset estimation algorithm based on cyclic prefix is deduced,analyzing the factors that affect the accuracy of frequency offset estimation.Combined with the characteristics of Kalman's iterative filtering,the state space model of Kalman filtering is established to analyze the performance of the Kalman filter algorithm.The numerical results show that after a few iterations,the frequency offset estimation error is quickly converged.Compared with the classical signal analyzers,the accuracy of measurement is increased by an order of magnitude.