声学回波消除方法及实现技术

发布时间：2018-03-14 17:54

本文选题：LMS算法　切入点：回声消除　出处：《西安电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：近年来,语音信号处理技术和通信技术发展得越来越快,人们对通信系统的通话质量要求也变得越来越高。免提语音通话系统得到了人们的青睐,例如电话视频会议、车载免提电话等。其中,声学回声是影响这类免提语音通话质量的首要因素。因此,解决免提语音通话系统中的声学回声问题是人们研究和关注的热点问题。很多人对自适应滤波算法做了深入研究,并通过MATLAB进行了仿真,取得了一定的成果。但是,由于实际通信环境的复杂性,致使仿真实验并不能完全模拟出真实的通话环境,仿真结果和实际结果往往存在着比较大的差别。本文在研究自适应滤波器及其相关算法的基础上,致力于构建一个基于DSP的声学回声消除硬件平台,并且模拟出实际通信系统中的真实通话环境,采集实际的语音信号和回声信号进行回声消除处理,为自适应滤波技术的硬件实现与应用做出进一步尝试。本文采取理论分析、软件仿真和硬件设计实现相结合的研究方法。在研究自适应算法的基础上,用软件仿真验证相关参数对自适应算法性能的影响,并通过仿真将自适应算法运用于自适应滤波实验中,通过回声消除结果来对比算法的性能。最后基于DSP构建声学回声消除的硬件平台,完成自适应滤波器的硬件实现。首先,本文通过对声学回声产生原因的分析,研究了回声消除算法的基本原理,重点研究了LMS算法的推导过程和基本原理,并对影响LMS算法性能和指标的因素做了分析。然后,研究了几种变步长算法,并对变步长算法和标准LMS算法做了比较。其次,本文分别对标准LMS算法和变步长LMS算法进行了仿真,并且比较了两者之间存在的差异。最后,本文以德州仪器公司2000系列芯片TMS320F28335为核心,构建了一个模拟真实通信系统的声学回声消除平台,用实际通话语音和回声做了测试,并且把实际测试结果和仿真结果做了对比。同时,由于实际通信系统中存在着单端通话和双端通话的问题,所以本文探讨了实际应用中的双端通话检测技术,并且实现了对该技术的应用。另外,本文探讨了立体声环境中的回声消除问题,分析了当前的研究现状和未来的发展趋势。
[Abstract]:In recent years, the technology of voice signal processing and communication has developed more and more rapidly, and the quality of communication system has become more and more demanding. Among them, acoustic echo is the primary factor that affects the quality of this kind of hands-free voice communication. To solve the acoustic echo problem in hands-free voice communication system is a hot issue that people study and pay close attention to. Many people have done in-depth research on adaptive filtering algorithm and simulated it through MATLAB. However, some achievements have been made. Because of the complexity of the actual communication environment, the simulation experiment can not completely simulate the real communication environment. The simulation results and the actual results are often quite different. Based on the study of adaptive filter and its related algorithms, this paper is devoted to constructing a hardware platform of acoustic echo cancellation based on DSP. And simulate the real communication environment in the actual communication system, collect the actual voice signal and echo signal for echo cancellation processing, and make a further attempt for the hardware implementation and application of adaptive filtering technology. Based on the research of adaptive algorithm, the influence of relevant parameters on the performance of adaptive algorithm is verified by software simulation. Finally, the hardware platform of acoustic echo cancellation is constructed based on DSP, and the hardware implementation of adaptive filter is completed. Based on the analysis of the cause of acoustic echo generation, the basic principle of echo cancellation algorithm is studied, the derivation process and basic principle of LMS algorithm are emphatically studied, and the factors influencing the performance and index of LMS algorithm are analyzed. Several variable step size algorithms are studied and compared with the standard LMS algorithm. Secondly, the standard LMS algorithm and the variable step size LMS algorithm are simulated, and the differences between them are compared. Based on Texas Instruments 2000 series chip TMS320F28335, an acoustic echo cancellation platform for simulating real communication system is constructed, and tested with actual voice and echo. At the same time, because of the problem of single and double end call in the actual communication system, this paper discusses the dual end call detection technology in practical application. In addition, the problem of echo cancellation in stereo environment is discussed, and the present research situation and future development trend are analyzed.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN912.3

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