FIdWinKaiser

Routine

void FIdWinKaiser (double win[], int N, double alpha)

Purpose

Generate a Kaiser window

Description

A Kaiser window is specified by the following equation in continuous time, 
         0 ,                         x < -1


         I0(a sqrt(1 - x^2)
  w(x) = ------------------ ,  -1 <= x <= 1
               I0(a)


         0                      1 <  x
This window sits on a pedestal of height 1/I0(a). The discrete-time window of length N is obtained by setting x = 2n/(N-1)-1, for 0 <= n < N.

The parameter a (alpha) determines the shape of the window, with increasing a giving a larger mainlobe width. For a=0, the window is a rectangular. For a = 5.4414, the window has the same mainlobe width as a Hamming window.

Reference:
J. F. Kaiser, "Nonrecursive digital filter design using the I0-sinh window function", Proc. 1974 IEEE Int. Symp. on Circuits and Syst., pp. 20-23, April 1974.

Parameters

<- double win[]
Array containing the window values
-> int N
Number of window values
-> double alpha
Window parameter

Author / revision

P. Kabal / Revision 1.1 2005/02/01

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