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chebwin

Chebyshev window

Syntax

w = chebwin(L,r)

Description

w = chebwin(L,r) returns the column vector w containing the length L Chebyshev window whose Fourier transform sidelobe magnitude is r dB below the mainlobe magnitude. The default value for r is 100.0 dB.

    Note   If you specify a one-point window (set L=1), the value 1 is returned.

Examples

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Chebyshev Window

Create a 64-point Chebyshev window with 100 dB of sidelobe attenuation. Display the result using wvtool.

L = 64;
bw = chebwin(L);
wvtool(bw)

More About

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Algorithms

An artifact of the equiripple design method used in chebwin is the presence of impulses at the endpoints of the time-domain response. This is due to the constant-level sidelobes in the frequency domain. The magnitude of the impulses are on the order of the size of the spectral sidelobes. If the sidelobes are large, the effect at the endpoints may be significant. For more information on this effect, see [2].

The equivalent noise bandwidth of a Chebyshev window does not grow monotonically with increasing sidelobe attenuation when the attenuation is smaller than about 45 dB. For spectral analysis, use larger sidelobe attenuation values, or, if you need to work with small attenuations, use a Kaiser window.

References

[1] Digital Signal Processing Committee of the IEEE Acoustics, Speech, and Signal Processing Society, eds. Programs for Digital Signal Processing. New York: IEEE Press, 1979, program 5.2.

[2] Harris, Fredric J. Multirate Signal Processing for Communication Systems. Upper Saddle River, NJ: Prentice Hall PTR, 2004, pp. 60–64.

See Also

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