盲信道均衡中的一种修正恒模算法  

Modified constant modulus algorithm for blind channel equalization

作　　者：孙守宇[1] 郑君里[1] 张琪[1] 

机构地区：[1]清华大学电子工程系

出　　处：《清华大学学报（自然科学版）》2003年第7期923-926,共4页Journal of Tsinghua University(Science and Technology)

基　　金：国家自然科学基金资助项目(60072001)

摘　　要：用于数字通信盲信道均衡的恒模算法(CMA)存在收敛速度慢和相位旋转等缺点。该文提出了一种修正的恒模算法(MCMA),该算法能使被修正的误差函数最小化,并且自适应学习率可由接收序列即时调整。用正交振幅调制(QAM)信号对两种算法进行了性能比较,广泛的模拟结果显示提出的修正恒模算法比普通恒模算法的收敛速度快,均衡输出符号间干扰(ISI)小。该算法收敛后均衡器输出既无相位旋转也无延迟等特点。与普通恒模算法相比该文提出的修正恒模算法的盲均衡性能更优。In digital communications, t he constant modulus algorithm (CMA) for blind channel equalization has some disa dvantages such as slow convergence speed and phase rotation. Therefore, a modifi ed constant modulus algorithm (MCMA) was developed for blind channel equalizatio n. The algorithm minimizes a modified error function and the learning-rate is m ultiplied by the received sequences. The performance of the two algorithms was c ompared for a QAM signal. Extensive simulation results demonstrated that the MCM A has faster convergence and smaller intersymbol interference than the CMA. The equalizer output has neither phase rotation nor delay. 

关 键 词：数字通信 盲信道均衡 修正恒模算法 误差函数 自适应学习率 正交振幅调制 符号间干扰 

分 类 号：TN911.5[电子电信—通信与信息系统]