改进的MIMO系统变步长小波常模盲均衡算法

Improved Wavelet Transformation Variable Step Size Blind Equalization Algorithm of MIMO System

针对传统的多用户MIMO系统常模盲均衡算法收敛速度慢,稳态误差大的缺点,提出来改进的多用户MIMO系统变步长小波常模盲均衡算法,该算法使用变步长代替固定步长来克服收敛速度与剩余误差之间的矛盾,同时利用归一化正交小波变换(WTCMA)和奇异值分解消除时延信号分量,降低接收信号的自相关性,加快收敛速度,减小稳态误差;理论分析和仿真结果表明:新算法可正确恢复出具有信号延时的MIMO系统的源信号,与变步长小波盲均衡算法与CMA算法相比,能获得更快的收敛速度及更小的均方误差。

According to disadvantages of big steady-：-state error, low convergence rate of traditional MIMO system constant modulus blind equalization algorithm, wavelet Transformation variable step size blind equalization algorithm of MIMO System is proposed. This pro- posed algorithm design time-- varying step size instead of the fixed step size to overcome the contradiction between the convergence speed and residual mean square error （MSE）. Meanwhile, we utilize normalized orthogonal wavelet transformation to speed up the convergence rate and reduce the MSE and obtain lower relationship of the received signals. Theoretical analyses and simulation results show that the proposed algorithm can correctly recover the transmitted signals in the MIMO system and can achieve faster convergence speed and smaller MSE com- parison with wavelet blind equalization algorithm with variable step--size and constant modulus algorithm.