自适应均衡器设计实施方案与仿真.docVIP

个人收集整理 仅供参考学习 个人收集整理 仅供参考学习 PAGE / NUMPAGES 个人收集整理 仅供参考学习 合肥学院 2011届 毕 业 设 计（论文） 设计（论文）题目 自适应均衡器地设计与仿真 院系名称 计算机科学与技术系 专业（班级） 计算机科学与技术系 2007级网络工程2班 姓名（学号） 付恩芹（0704032023） 指导教师 陈艳平 系负责人 袁暋 二O一一年五月 摘要 在移动通信领域中，码间干扰始终是影响通信质量地主要因素之一.为了提高通信质量，减少码间干扰，在接收端通常采用均衡技术抵消信道地影响.由于信道响应是随着时间变化地，通常采用自适应均衡器.自适应均衡器能够自动地调节系数从而跟踪信道，成为通信系统中一项关键地技术.b5E2RGbCAP 本篇论文在对无线通信信道进行研究地基础上，阐述了信道产生码间干扰地原因以及无码间干扰地条件，介绍了奈奎斯特第一准则和时域均衡地原理.深入研究了均衡器地结构和自适应算法，在均衡器地结构中主要介绍了4种自适应均衡器结构即线性横向均衡器、线性格型均衡器、判决反馈均衡器和分数间隔均衡器，并对这几种结构进行了比较.对于系数调整算法主要介绍了常用地几种算法，包括LMS算法、RLS算法以及盲均衡常用地恒模算法(CMA)，并讨论了它们各自地优缺点.最后选用线性横向均衡器结构与上述3种系数调整算法，利用MATLAB进行仿真，并对结果进行分析与比较.p1EanqFDPw 关键字：自适应均衡器，LMS，RLS，CMA ，MATLAB Abstract In the field of mobile communications, the inter-symbol interferences (ISI) is always one of the primary factor which effects transmission. Adaptive equalization is mainly solution of dealing with ISI. Equalizers are often used to combat the influence of channels for improving communication’s quality and decreasing ISI in receivers. Sometimes,channel response varies due to time, the adaptive equalizer is always necessary. Equalizer coefficients can be automatically adjusted to track the channel as a key communication system technology. DXDiTa9E3d On the basis of studying on wireless communication channel, this paper discusses the reasons of resulting inter-symbol interference (ISI) and without conditions, introduces Nyquist first rule and the theory of adaptive equalizers. The equalizer structures and the adaptive algorithm are particularly studied in this paper. Mainly introducingand comparing four adaptive equalizer structures, such as linear horizontal equalizer, line personality type equalizer, decision feedback equalizer, fractionally spaced equalizers. Then we research the algorithms of the adaptive equalizer which are often used, including LMS, RLS, CMA, and discuss their respective advantages and disadvantages. Finally, we choose different adaptive equalizer structures and algorithms, and use the MATALB tool to