.Modelica_LinearSystems2.Controllers.Internal.FIR_window

Information

Weighting windows are used for digital filter design or spectrum estimation (e.g. DFT) to increase the quality. In designing FIR-Filter the main role of windowing is to remove non-ideal effects caused by the endless number of filter coefficients (Gibbs phenomenon). Multiplying the coefficients with a window damps the coefficients at the beginning and at the end.

The function outputs a L-point vector for a given kind of window. The parameter "beta" is only needed by the Kaiser window. The types of windows are:

1. Rectangle
2. Bartlett
3. Hann
4. Hamming
5. Blackman
6. Kaiser

Interface

function FIR_window
  extends Modelica.Icons.Function;
  import Modelica_LinearSystems2.Controllers.Types.Window;
  input Integer L "Number of Points";
  input Window window "Type of window";
  input Real beta = 2.12 "Beta-Parameter for Kaiser-window";
  output Real a[L] "output vector";
end FIR_window;