基于QR分解的MIMO-OFDM系统信道估计降噪方法

摘要

MIMO⁃OFDM传输系统的信道估计降噪算法多是基于DFT，如果系统中含有虚载波，该方法将严重影响系统的性能。为使信道估计性能不受系统虚载波影响，提出了基于QR分解的系统信道估计降噪方法，该方法将部分频域变换矩阵经过QR分解，得到酉矩阵，将其与LS频域信道估计矢量相乘后得出信道估计噪声。用Matlab对提出的算法进行了仿真，通过对仿真结果进行分析比较并得出结论，验证了改进算法的优越性。%In MIMO⁃OFDM communications systems,most noise reduction algorithms of channel estimation are based on DFT, which will lead to severe performance degradation of the system if virtual subcarriers are contained in the system.To address this issue,a noise reduction algorithm of channel estimation based on QR decomposition is proposed,in which part of the frequency domain transfer matrix is decomposed by QR,and the unitary matrix is obtained. The channel estimation noises are obtained by multiplying the unitary matrix with the LS channel estimation vectors.Finally,Matlab simulation results show the effectiveness of the improved algorithm.