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论文编号 ZXX394 论文字数:13398,页数:33
摘 要
随着无线通信技术的不断发展和日益成熟，如何在复杂的通信环境下有效的解调信号并利于数字实现是近年研究的新课题。在通信领域，自适应算法在自适应均衡、自适应频率跟踪与检测等方面的应用比较成熟。随着研究的深入，发现利用自适应滤波器的抗干扰性能和对信号的跟踪能力，可以更加简单的提取基带信息，取得比常用相干解调更理想的性能。
本文通过对各种自适应算法进行了研究和分析，并且利用Matlab对各种算法进行了仿真。本文主要包括以下几个内容：讨论了基本最小均方算法的性能和步长因子对算法性能的影响。自适应滤波器的应用越来越广泛，其LMS算法的性能与滤波器阶数、自适应步长的大小密切相关，这两个参数影响着系统的收敛速度、计算量和稳态误差。系统分析LMS自适应滤波器的工作原理，研究阶数和步长两个参数对滤波效果的影响。对LMS自适应滤波器在系统辨识、自回归过程的自适应预估器、噪声抵消、回声抵消以及在直扩系统中实现伪码同步的应用，利用Matlab进行了编程仿真和分析。
关键词： LMS算法 自适应滤波器 Matlab 应用仿真
ABSTRACT
As wireless communications technology and the continuous development of increasingly mature, how in the complex environment of effective communication signal demodulator and is conducive to achieving figures in recent years on a new topic. In the field of communications, adaptive algorithm in the adaptive equalization, adaptive frequency tracking and detection, such as the application of more mature. With the in-depth study and found that the use of adaptive filter performance and anti-jamming signals on the tracking capability, could be more simple with the extraction of information, a coherent demodulation more common than ideal performance. Through the adaptive algorithm for a variety of research and analysis and use of various algorithms Matlab a simulation.In this paper, include the following elements: Discussed the basic minimum square algorithm performance and step factor on the performance of algorithm. The adaptive filter is widely used nowadays．Based on the LMS adaptive algorithm，the performance of adaptive filter is determined by its order and self-adaptive step size，which influence the convergence rate，calculation complexity and steady state error of the system．This paper analyzes the principle of LMS adaptive filter，studies the two parameters efect on the filtering perform ance separatelyLMS adaptive filter in the system identification, since the reunification process of adaptive predictor, noise cancellation, echo cancellation and the DS system to achieve the application of pseudo-synchronous code, using a Matlab programming simulation and analysis.
Keywords：LMS algorithm; adaptive filter; Matlab; Application Simulation
目录
目录 1
摘 要 I
ABSTRACT II
1 绪论 3
1.1课题背景 3
1.2 自适应滤波应用发展趋势及课题意义 3
1.3本论文研究的主要内容 4
1.3.1LMS算法步骤 4
1.3.2MATLAB相关内容 5
2 基于LMS的自适应滤波器 7
2.1自适应滤波的基本原理 7
2.2 LMS算法原理 7
2.3 针对LMS算法各参数的讨论 8
2.4 LMS算法推导 9
3 LMS自适应滤波器的应用及仿真 11
3.1引言 11
3.2系统辨识与Maltab仿真 11
3.2.1系统和模型 11
3.2.2辨识建模的定义 12
3.2.3系统辨识原理 13
3.2.3 Matlab仿真 13
3.3自回归过程的自适应预估器 15
3.3.1自回归模型 15
3.3.2 Matlab仿真 15
3.4噪声抵消与Maltab仿真 18
3.4.1 自适应噪声抵消基本理论 18
3.4.2 Matlab仿真与结果分析 21
3.5回声抵消与Maltab仿真 25
3.5.1线路回声 25
3.5.2 线路回声抵消器 25
3.5.3 Matlab仿真 26
3.6本章小结 29
4 实验分析和总结 30
4.1总结 30
参考文献 31 |
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发表于 20:39