基于LABVIEW的虚拟滤波器设计.doc

毕 业 设 计（论 文） 题 目 基于LabVIEW的虚拟滤波器设计 姓 名 学 号 所在学院 专业班级 指导教师 日 期 摘 要 电子技术和计算机技术的快速发展促进了硬件软件化，使基于个人计算机的测控仪器——虚拟仪器得到了快速的发展。虚拟仪器利用计算机强大的处理能力，使得其在智能化程度、处理能力和可操作性等方面均具有明显的技术优势，其应用范围也越来越广泛。LabVIEW是一种基于图形化编程语言的开发环境，为虚拟仪器设计者提供了一个便捷、轻松的设计环境。 本文首先用LabVIEW设计一个信号发生器，信号类正弦波、方波、锯齿波等）、幅值、相位、频率等参数均可调，其次，给信号发生器产生的信号加噪（如高斯白噪声、均匀白噪声、随机噪声等），要求噪声的幅值和采样信息等值均可调，然后，用LabVIEW设计一个虚拟数字滤波器要求滤波器的频带类型（如低通、高通、带通、带阻）、最佳特性逼近方式（巴特沃斯、切比雪夫、贝塞尔等）、阶数以及高截止频率和低截止频率等参数均可调，将加噪后的波形通过所设计的虚拟滤波器，将它用波形图显示出来，最后，将原始信号与滤波后的信号进行傅里叶变换，在频域显示幅值和相位。比较加噪后的波形与滤波后的波形，发现噪声很大程度地滤除。 关键词：虚拟仪器；滤波器；LabVIEW Abstract With the rapid development of electronic technology and computer technology, the hardware is oriented to software. The control instruments --- the virtual instruments based on the personal computer are prompted rapidly. The virtual instruments have obvious advantages in the degree of intelligence, processing power and maneuverability because of the computer’s strong processing power. And their application is more wide. LabVIEW is a development environment based on the graphical programming. The convenient and relaxed design environment for virtual instrument designers is provided by using LabVIEW. In this paper, a signal generator is designed by using the LabVIEW at first. The signal generator’s signal type(sine, square, sawtooth, etc.), amplitude, phase, frequency and other parameters can be adjusted. Secondly, a noise(Gaussian white noise, uniform white noiserandom noise, etc.) is added into the signal. The amplitude of the noise and the type of the noise and sampling the information equivalents can be adjusted. Then a digital filter is designed by using the LabVIEW. The frequency band(low pass, high pass, band pass, band stop, etc.), the best characteristics of approximation way(Butterworth, Chebyshev, Bessel, etc.), the number of order as well