适用于高阶QAM信号的双模式分数间隔盲均衡

Fractionally-spaced Based Dual-mode Blind Equalization Suitable for High-Order QAM Signals

为了克服常数模算法收敛速度慢稳态误差大的缺点,利用高阶QAM信号分布在多个不同模值上的特点,提出了一种适用于高阶QAM信号的双模式分数间隔盲均衡算法。该算法采用T/2分数间隔结构,并以常数模算法为基础模式,而在第二模式中采用一种多模算法,且通过判决条件对均衡器的输出信号进行判决,使均衡器能在多个模值中自动切换。计算机仿真实验结果表明新方法具有快收敛速度和低稳态误差。

In order to overcome the slow convergence rate and the large steady-state mean square error（MSE） of the constant modulus algorithm（CMA）,a new T/2 Fractional-spaced blind equalization suitable for high-order QAM signals is proposed.This algorithm uses the CMA as the basal mode.And in the second mode it uses the multi-modulus algorithm which means that the equalization for the signals locating in the different modulus is implemented respectively.Furthermore,the two modes operate concurrently,and based on the decision of the equalizer output,the switching for different modulus is automatic.The efficiency of the method is proved by computer simulations.