>On Oct 25, 6:31 am, "boon" <boon-chun_...@agilent.com> wrote:
>> Hi,
>> I'm looking for the method to get the Rife vincent window or other
>> windows constant value. Take for example Blackman window which has
below
>> equation:
>> w(n)=0.42-0.5cos(2*pi*n/N)+0.08cos(4*pi*n/N), 0<=n<=N
>> where the constant a0=0.42,a1=0.5,a2=0.08 -> How actually these
constant
>> being define for this type of window or other type of windows.
>>
>> Thanks.
>
>boon
>
>Two classic papers that discuss the design of such cosine-summed
>windows are:
>
>On the use of windows for harmonic analysis with the discrete Fourier
>transform
>Harris, F.J. Proceedings of the IEEE
>Publication Date: Jan. 1978
>Volume: 66, Issue: 1
>On page(s): 51- 83
>
>Some windows with very good sidelobe behavior
>IEEE Trans. Acoust., Speech, Signal Processing, vol. 29, pp. 84 - 91,
>February 1981
>Albert H. Nuttall
>
>The Nuttall paper includes some corrections to the Harris paper.
>
>The example you give is the "two digit rounded" version of "three-term
>Blackman". Unfortunately, Harris gives the sidelobe rejection of the
>exact version (unrounded) as -51 dB which Nuttall corrects as -68.24
>dB. Blackman and Tukey published the rounded version as "R. Blackman's
>not very serious proposal". Unfortunately, Harris and others have
>maligned Blackman by applying his name to the rounded version as a
>common usage, If you find the rounded version preferable in
>performance to the exact, you will probably find Nuttall's "3-term
>with continuous 1st derivative" is a few dB better as it is an
>optimized version.
>
>Good Luck!
>
>Dale B. Dalrymple
>http://dbdimages.com
>http://stores.lulu.com/dbd
>
>Hi Dale,
Thanks for your information. The reason of wanted to know how is the
four item cosine constant being defined is because inside the paper named
ANALYSIS BASED ON INTERPOLATING WINDOWED FFT ALGORITHM mentioned
Rife–Vincent (III) type 4 window is a four item cosine window, the four
item cosine constant are a0=1;a1=1.43596;a2=0.49754;a3=0.06158. If I would
like to get the type 5 class III Rife vincent then I must know how those
constant being defined. As I know but putting the proper zero in the sinc
response you will get those constant. But I have no idea how to properly
select the zero location for higher type of Rife vincent windows.
>
Reply by dbd●October 25, 20072007-10-25
On Oct 25, 6:31 am, "boon" <boon-chun_...@agilent.com> wrote:
> Hi,
> I'm looking for the method to get the Rife vincent window or other
> windows constant value. Take for example Blackman window which has below
> equation:
> w(n)=0.42-0.5cos(2*pi*n/N)+0.08cos(4*pi*n/N), 0<=n<=N
> where the constant a0=0.42,a1=0.5,a2=0.08 -> How actually these constant
> being define for this type of window or other type of windows.
>
> Thanks.
boon
Two classic papers that discuss the design of such cosine-summed
windows are:
On the use of windows for harmonic analysis with the discrete Fourier
transform
Harris, F.J. Proceedings of the IEEE
Publication Date: Jan. 1978
Volume: 66, Issue: 1
On page(s): 51- 83
Some windows with very good sidelobe behavior
IEEE Trans. Acoust., Speech, Signal Processing, vol. 29, pp. 84 - 91,
February 1981
Albert H. Nuttall
The Nuttall paper includes some corrections to the Harris paper.
The example you give is the "two digit rounded" version of "three-term
Blackman". Unfortunately, Harris gives the sidelobe rejection of the
exact version (unrounded) as -51 dB which Nuttall corrects as -68.24
dB. Blackman and Tukey published the rounded version as "R. Blackman's
not very serious proposal". Unfortunately, Harris and others have
maligned Blackman by applying his name to the rounded version as a
common usage, If you find the rounded version preferable in
performance to the exact, you will probably find Nuttall's "3-term
with continuous 1st derivative" is a few dB better as it is an
optimized version.
Good Luck!
Dale B. Dalrymple
http://dbdimages.comhttp://stores.lulu.com/dbd
Reply by boon●October 25, 20072007-10-25
Hi,
I'm looking for the method to get the Rife vincent window or other
windows constant value. Take for example Blackman window which has below
equation:
w(n)=0.42-0.5cos(2*pi*n/N)+0.08cos(4*pi*n/N), 0<=n<=N
where the constant a0=0.42,a1=0.5,a2=0.08 -> How actually these constant
being define for this type of window or other type of windows.
Thanks.