File:Window function (Kaiser; alpha = 3 pi).png

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Original file ‎(1,785 × 607 pixels, file size: 84 KB, MIME type: image/png)

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Description
English: Kaiser window and frequency response for alpha = 3 pi.
Date
Source Own work
Author Bob K
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(Reusing this file)
Public domain I, the copyright holder of this work, release this work into the public domain. This applies worldwide.
In some countries this may not be legally possible; if so:
I grant anyone the right to use this work for any purpose, without any conditions, unless such conditions are required by law.
Other versions Derivative works of this file:  Window function (Kaiser; alpha = 3).png
Source code
InfoField
Matlab script 
N=128;
k=0:N-1;

dr = 120;
alpha = 3*pi;
w = besseli(0,alpha*sqrt(1-(2*k/(N-1) -1).^2))/besseli(0,alpha);

B = N*sum(w.^2)/sum(w)^2    % noise bandwidth (bins)

H = abs(fft([w zeros(1,7*N)]));
H = fftshift(H);
H = H/max(H);
H = 20*log10(H);
H = max(-dr,H);

figure
area(k,w,'FaceColor', [0 .4 .6])
xlim([0 N-1])
set(gca,'XTick', [0 : 1/8 : 1]*(N-1))
set(gca,'XTickLabel','0| | | | | | | |N-1')
grid on
ylabel('amplitude')
xlabel('samples')
title('Window function (Kaiser, \alpha = 3\pi)')

figure
h = stem(([1:(8*N)]-1-4*N)/8,H,'-');
set(h,'BaseValue',-dr)
ylim([-dr 0])
set(findobj('Type','line'),'Marker','none','Color',[.871 .49 0])
xlim([-4*N 4*N]/8)
grid on
ylabel('decibels')
xlabel('DFT bins')
title('Frequency response (Kaiser, \alpha = 3\pi)')

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Date/TimeThumbnailDimensionsUserComment
current13:42, 22 October 2008Thumbnail for version as of 13:42, 22 October 20081,785 × 607 (84 KB)Bob K (talk | contribs)Reverted to version as of 22:44, 20 September 2007
15:25, 19 October 2008Thumbnail for version as of 15:25, 19 October 20081,720 × 618 (35 KB)Bob K (talk | contribs){{Information |Description=Kaiser window and frequency response for alpha = 3 pi. Updated for symmetric window samples. |Source=self-made |Date=19-Oct-2008 |Author= Bob K }}
22:44, 20 September 2007Thumbnail for version as of 22:44, 20 September 20071,785 × 607 (84 KB)Bob K (talk | contribs){{Information |Description=Kaiser window and frequency response for alpha = 3 pi. |Source=self-made |Date=20-Sep-2007 |Author= Bob K }}

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