《lms算法研究》》-毕业论文.doc

PAGE PAGE 3 lms算法毕业论文 LMS算法研究 专 业：通信工程 摘 要 因LMS算法具有低计算复杂度、在平稳环境中的收敛性好、其均值无偏地收敛到wiener解和利用有限精度实现算法时的稳定性等特性，使LMS算法成为自适应算法中应用最广泛的算法。对LMS算法及其改进算法进行了研究，探讨了步长因子对各种算法收敛性、稳定性的影响。并用MATLAB对其学习曲线、收敛速度等进行了仿真分析。结果表明，变步长的取值尤为重要，如果μ（n）取较大值则具有较快的收敛速度，如果μ（n）取值很小，则MLMS算法近似等效于LMS算法。它们的自适应过程较快，性能有了很大改进。 Abstract Because of low computational complexity, stable environment in the convergence of good, unbiased and its mean converges to the wiener solution and implementation algorithms using finite precision stability and other characteristics, LMS algorithm as adaptive algorithm in the application of the most a wide range of algorithms.We have a detailed study on LMS algotithm and its complementary algotithm,disscused the step-size’s influent for the algorithm’s convergence speed and stability. And using MATLAB simulated the learning curve, convergence speed of LMS algotithm.The result observed that the value of variable step-size μ（n）is very important,if it is a bigger may have a fast convergence speed,but if not ,the NLMS algotithm can instead the LMS algotithm in the characteristics. In addition , they have a fast adaptive course and greatly progress in performance. Keywords：LMS algorithm，Adaptive，NLMS algorithm，Variable step，MATLAB simulation. 目 录 TOC \o 1-3 \h \z \u HYPERLINK \l _Toc264361485 第一章 绪论 PAGEREF _Toc264361485 \h 5 HYPERLINK \l _Toc264361486 1.1 自适应滤波理论的发展 PAGEREF _Toc264361486 \h 5 HYPERLINK \l _Toc264361487 1.2 自适应LMS算法的发展 PAGEREF _Toc264361487 \h 6 HYPERLINK \l _Toc264361488 1.2.1 LMS算法历史 PAGEREF _Toc264361488 \h 6 HYPERLINK \l _Toc264361489 1.2.2 LMS算法的现状 PAGEREF _Toc264361489 \h 6 HYPERLINK \l _Toc264361490 1.2.3 LMS算法的发展前景 PAGEREF _Toc264361490 \h 6 HYPERLINK \l _Toc264361491 第二章 自适应LMS算法的研究 PAGEREF _Toc264361491 \h 8 HYPERLINK \l _Toc264361492 2.1 概述 PAGEREF _Toc264361492 \h 8 HYPERLINK \l _Toc264361493 2.2 LMS算法 PAGEREF _Toc264361493 \h 8 HYPERLINK \l _Toc264361494 2.2.1自适应收敛性 PAGEREF _Toc264361494 \h 10 HYPERLINK \l _Toc2