Description: The Window Design Method
The basic idea behind the design of linear-phase FIR filters using the window
method is to choose a proper ideal frequency-selective filter [which always has
a noncausal, infinite duration impulse response] and then truncate its impulse
response hd[n] to obtain a linear-phase and causal FIR filter h[n]. To truncate the
impulse response of the ideal filter a time window w[n] is used. Available windows
in Matlab are rectangular [or boxcar in Matlab], bartlett, hamming, hanning Platform: |
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Author:Rizwan |
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Description: matlab实现的各种数字滤波器，包括矩形窗，汉明窗，汉宁窗，kaiser窗等。-matlab digital filter to achieve a variety of, including the rectangular window, Hamming window, Hanning window, kaiser windows. Platform: |
Size: 1024 |
Author:袁晓光 |
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Description: N=15, 。用Hanning窗设计一线性相位带通滤波器，观察它的实际3dB和20dB带宽。N=45，重复这一设计，观察幅频和相位特性的变化，注意长度N变化的影响。-N = 15,. Hanning window design with a linear-phase band-pass filter, observe its actual 3dB and 20dB bandwidth. N = 45, repeat the design, observe the amplitude-frequency and phase characteristics of the change, pay attention to the length of N changes. Platform: |
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Author:lm |
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Description: A filter is a system which modifies some special frequencies reletive to the others. As a result i s applicable in some applications when it is necessary to have different gains & phase shifts at different frequencies to perform specific filtering tasks. For example in an audio file which is corrupted by noise it is convinient to use a filter to cancel those frequencies which are affected by noise and consequently having a better sound quality. During this MATLAB experiment we are trying to cancel the noise frequencies out of the original signal frequencies to get the original signal. Due to do this task, different types of filters such as FIR and IIR filters are used. In FIR filters, we use two type of common windows such as fixed window like Hanning and adjustable window like Kaiser. In IIR filters four different types of filter such as Butterworth, Chebyshev I, Chebyshev II, Elliptic are used.-A filter is a system which modifies some special frequencies reletive to the others. As a result it is applicable in some applications when it is necessary to have different gains & phase shifts at different frequencies to perform specific filtering tasks. For example in an audio file which is corrupted by noise it is convinient to use a filter to cancel those frequencies which are affected by noise and consequently having a better sound quality. During this MATLAB experiment we are trying to cancel the noise frequencies out of the original signal frequencies to get the original signal. Due to do this task, different types of filters such as FIR and IIR filters are used. In FIR filters, we use two type of common windows such as fixed window like Hanning and adjustable window like Kaiser. In IIR filters four different types of filter such as Butterworth, Chebyshev I, Chebyshev II, Elliptic are used. Platform: |
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Author:Paria Shahabi |
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Description: 1、验证窗函数 N 变化时，验证其频谱主瓣副瓣比、主瓣宽度的变化。
a)矩形窗函数的 N 变化时，验证其其频谱主瓣副瓣幅度比基本不会发生变化，
而主瓣宽度将会变窄。这说明，当用矩形窗函数设计滤波器时，增大 N 不能使
得阻带衰减减小，但能够减小过渡带。
b)再选取其他的窗如 hamming/hanning 窗，验证当 N 变化时，其频谱主瓣宽
度变化、主瓣副瓣比值变化情况。
2、用窗函数法设计线性相位 FIR 低通，通带截止频率 wp=0.5PI, 阻带截止频率 ws=0.6PI,
阻带衰减不小于 40dB,通带衰减不大于 3dB.
a)选取 Hanning,Hamming 窗查看设计出来的 FIR 的过渡带宽和阻带衰减是否
满足要求，二者有什么不同。
b)使用 hamming 窗，将窗长增大 1 倍，设计 FIR。验证同样的窗函数类型
(hamming)，不同窗长度时，设计出来的 FIR 的过渡带宽和阻带衰减都有什么变
化。
3、不使用 Matlab 系统函数得到上一项指标的低通，并与上一项结果比较。
4 用窗函数法设计线性相位 FIR 高通，通带截止频率 wp=0.8PI, 阻带截止频率
ws=0.7PI, 阻带衰减不小于 30dB,通带衰减不大于 3dB.(An actual filter is implemented using the truncated unit impulse response sequence of the ideal filter.
For the ideal low pass filter, the unit impulse response h, N, D () is intercepted by a length of N, and the length is
The N sequence H (n), when intercepted, guarantees causality and linear phase requirements for the filter.
In order to reduce the Gibbs effect, the H (n) window is added, and the appropriate window function is selected to ensure the stopband attenuation and
Transition zone requirement. Note that the sidelobe of the window function affects the stopband attenuation of the filter, and the main lobe width affects the filter
Transition bandwidth.) Platform: |
Size: 3072 |
Author:花祭嘉音
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Search - Hanning Filter in matlab