Research And Implementation Channel Estimation Algorithm Of MIMO-OFDM System In LTE-A

MIMO technology can improve system capacity and system performance.OFDM technology can save bandwidth and inhibit the effect of multipath time delay.MIMO-OFDM system comlined MIMO and OFDM technology,thus it is applied to the fourth generation mobile communication system.The accuracy results of channel esitmation is very important to the perfomance of system.Therefore,this thesis focuses on channel estimation of LTE/LTE-A system and the main work and innovations are divided into three parts, as follows:(1) Based on Matlab platform to build LTE-A downlink level simuliation systemIn order to study the channel estimation of LTE-A downlink system, this thesis is based on 3GPP protocol to establish the Matlab simulation platform.Currently, this platform support all of the LTE-A’s bandwidth.Antenna configuration supports 4 ?4 and 1?1.Channel can be configured EPA,EVA and ETU.The supported modulaiton mode includes QPSK,16 QAM and 64 QAM,etc.Meanwhile, based on the rayleigh flat channel model to build the LTE-A channel model and simulate.(2) Analyse and compare the channel estimation techiques and MIMO detection technology for LTE-AFor choosing the hardware implementation of the specific algorithm, this thesis analyses and compares the channel estimation techniques and MIMO detection techniques.The channel estimation algorithms of reference signal include LS algorithm, MMSE algorithm and SVD-LMMSE algorithm.The interpolation algorithms include constant interpolation, linear interpolation, gaussian interpolation and based on low-pass filter interpolation method.Transform domain channel estimation algorithm include based on DFT algorithm.Linear MIMO detection algorithm includes ZF algorithm and MMSE algorithm.Finally,the thesis compares the BER, MSE and hardware implementation complexity of the algorithms.(3) Choose the appropriate channel algorithm to design the hardware implementation cheme and imply in the FPGA platformContrast the results for each algorithm, considering the performance of the algorithm and the complexity of implementation, the thesis choose the LS channel estimation algorithm and based on low-pass filter interpolation algorithm as part of channel estimation algorithm and design the hardware implementation architecture of LTE-A’s channel estimation.Also,selecting the K7XC7K330 T chip of Xilinx to imply the FPGA module of channel estimation.Finally,comparing the simuliation of Modelsim and Matlab verifies the functional correctness and feasibility of channel estimation module.