一种新型变步长CMA盲均衡算法

针对传统固定步长CMA盲均衡算法中收敛速度和剩余误差这对矛盾,提出了一种新型变步长恒模盲均衡算法,即由瑞利分布函数实施对其步长的调节,通过调整该步长公式中的两个参数以加快收敛速度和减小剩余误差,并且在此基础上对该算法进行了改进。用4QAM信号,通过典型电话信道对固定步长的CMA算法,基于瑞利步长的CMA和改进后的CMA算法进行计算机仿真。通过对仿真出的算法收敛曲线以及输出星座图进行分析,最终得出在瑞利步长算法的基础上改进后的CMA算法克服了前两种算法的缺点,即具有收敛速度更快,剩余误差更小的优点。

A new variable step-size CMA blind equalization algorithm

A new variable step-size constant modulus algorithm （CMA） blind equalization algorithm based on the Rayleigh distribution has been proposed aiming at the slow convergence rates and residual error of the traditional CMA with fixed step- size. The convergence rate was accelerated and the residual error was reduced by regulating the two parameters in the step-size equation. On this basis, the algorithm was improved. Simulation tests with typical telephone channel using 4QAM are carried out. The simulation results indicate that the improved algorithm based on the Rayleigh distribution step-size CMA algorithm has higher convergence rate and lower residual error.