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sigwin.chebwin Class

Namespace: sigwin

Construct Dolph-Chebyshev window object

Description

Note

The use of sigwin.chebwin is not recommended. Use chebwin instead.

sigwin.chebwin creates a handle to a Dolph-Chebyshev window object for use in spectral analysis and FIR filtering by the window method. Object methods enable workspace import and ASCII file export of the window values.

The Dolph-Chebyshev window is constructed in the frequency domain by taking samples of the window's Fourier transform:

W^(k)=(1)kcos[Ncos1[βcos(πk/N)]]cosh[Ncosh1(β)],0kN1

where

β=cos[1/Ncosh1(10α)]

α determines the level of the sidelobe attenuation. The level of the sidelobe attenuation is equal to 20α. For example, 100 dB of attenuation results from setting α=5

The discrete-time Dolph-Chebyshev window is obtained by taking the inverse DFT of W^(k) and scaling the result to have a peak value of 1.

Construction

H = sigwin.chebwin returns a Dolph-Chebyshev window object H of length 64 with relative sidelobe attenuation of 100 dB.

H = sigwin.chebwin(Length) returns a Dolph-Chebyshev window object H of length Length with relative sidelobe attenuation of 100 dB. Length requires a positive integer. Entering a positive noninteger value for Length rounds the length to the nearest integer. A window length of 1 results in a window with a single value equal to 1.

H = sigwin.chebwin(Length,SidelobeAtten) returns a Dolph-Chebyshev window object with relative sidelobe attenuation of atten_param dB.

Properties

Length

Dolph-Chebyshev window length.

SidelobeAtten

The attenuation parameter in dB. The attenuation parameter is a positive real number that determines the relative sidelobe attenuation of the window.

Methods

generateGenerates Dolph-Chebyshev window
infoDisplay information about Dolph–Chebyshev window object
winwriteSave Dolph-Chebyshev window object values in ASCII file

Copy Semantics

Handle. To learn how copy semantics affect your use of the class, see Copying Objects in the MATLAB® Programming Fundamentals documentation.

Examples

collapse all

Generate a Dolph-Chebyshev window of length N = 16. Specify a relative sidelobe attenuation of 40 dB. Return the window values as a column vector. Show information about the window object. Display the window.

H = sigwin.chebwin(16,40);

win = generate(H)
win = 16×1

    0.1138
    0.1964
    0.3319
    0.4926
    0.6613
    0.8163
    0.9353
    1.0000
    1.0000
    0.9353
      ⋮

wininfo = info(H)
wininfo = 4x26 char array
    'Chebyshev Window          '
    '----------------          '
    'Length                : 16'
    'Sidelobe Attenuation  : 40'

wvtool(H)

References

harris, fredric j. “On the Use of Windows for Harmonic Analysis with the Discrete Fourier Transform.” Proceedings of the IEEE®. Vol. 66, January 1978, pp. 51–83.