一种变步长的恒模均衡算法.pdfVIP

2009年第04期，第42卷 通 信 技 术 Vol.42，No.04,2009 总第208期 Communications Technology No.208,Totally 一种变步长的恒模均衡算法 王天雷 （五邑大学 信息学院，广东 江门 529020） 【摘 要】针对时变信道需进行自适应均衡的要求, 介绍了最常用的恒模算法（Constant Modulus Algorithm, CMA）， 并对该算法进行了改进，提出了一种步长因子μ与误差信号的 e (n)之间另一种新的非线性函数，该函数较为简单，且在误 差e(n)接近零处具有缓慢变化的特性，克服了CMA在收敛调整过程中的不足。同时给出了改进算法的仿真结果，计算机仿真 结果与理论分析相一致，表明该算法提高了恒模算法的收敛速度，同时也保留了恒模算法较为稳定的性能。 【关键词】码间干扰; 自适应均衡; 盲均衡; 恒模算法 【中图分类号】TN911 【文献标识码】A 【文章编号】1002-0802(2009)04-0027-03 An Improved CMA with Varying Step-Size WANG Tian-lei (School of information, Wuyi University, Jiangmen Guangdong 529020, China) 【Abstract】In this paper, for adaptive equalization of the time-varying channel, the Constant Modulus Algorithm (CMA) is analyzed, and a new non-linear functional relationship between μ and e(n) is proposed. The functional relationship is simple, and the property of slight change e(n) near to zero. Therefore, it is superior to CMA in the convergence process. On the basis of the functional relationship, the author presents the new algorithm of variable step-size CMA and analyzes the algorithm with various α and β. The algorithm, with good convergence properties, has less computational complexity than the conventional algorithms. Computer simulation results confirm the theoretical analysis and shows that the performance of new algorithm is better than that of conventional algorithms. Simulation re