一种新的CMA-DFE盲均衡方法

A New Method of ACMA-DFE (Absolute Constant Modulus Algorithm-Decision Feedback Equalizer) Blind Equalization

提出了一种新的常数模 ( CMA)盲均衡方法 ,误差性能表面 ( EPS)分析表明其收敛性优于常用的 CMA2 - 2方法。为进一步减小稳态失调误差 ,采用峰度判决机制 ,一旦检测到眼图张开即转入判决反馈均衡 ( DFE)工作方式。

Constant modulus algorithm (CMA) is one of the most important blind equalization methods to deal with received communication signals distorted by band-limited channels. However, the widely used CMA2-2 method is bothered by slow convergence rate and high noise floor. In this paper we propose a new blind equalization method named ACMA (absolute constant modulus algorithm) to overcome the above shortcomings. In this paper, we give a fairly detailed theoretical analysis based on EPS (Error Performance Surface) that proves that our ACMA method has the advantage of much faster convergence rate. To further reduce the mean square error (MSE), the kurtosis of the output signal of the equalizer is computed and compared with a pre-selected threshold. If the kurtosis is smaller than the threshold, which means the eye-diagram is open, the equalizer turns to the decision feedback equalization (DFE) mode, so as to achieve much lower noise floor. Both theoretical analysis and computer simulations show preliminarily that our method has much better performance than CMA2-2.