<?xml version="1.0" encoding="UTF-8"?> <!-- * * This help file was generated from qp_kaiser.sci using help_from_sci(). * --> <refentry version="5.0-subset Scilab" xml:id="qp_kaiser" xml:lang="en" xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:svg="http://www.w3.org/2000/svg" xmlns:ns3="http://www.w3.org/1999/xhtml" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:scilab="http://www.scilab.org" xmlns:db="http://docbook.org/ns/docbook"> <refnamediv> <refname>qp_kaiser</refname> <refpurpose>Computes a finite impulse response (FIR) filter for use with a quasi-perfect reconstruction polyphase-network filter bank.</refpurpose> </refnamediv> <refsynopsisdiv> <title>Calling Sequence</title> <synopsis> qp_kaiser (nb, at, linear) qp_kaiser (nb, at) </synopsis> </refsynopsisdiv> <refsection> <title>Parameters</title> <variablelist> <varlistentry><term>nb:</term> <listitem><para> Number of bands</para></listitem></varlistentry> <varlistentry><term>at:</term> <listitem><para> Attenuation</para></listitem></varlistentry> <varlistentry><term>linear:</term> <listitem><para> When not zero, minimum-phase calculation is omitted.</para></listitem></varlistentry> </variablelist> </refsection> <refsection> <title>Description</title> <para> This is an Octave function. This version utilizes a Kaiser window to shape the frequency response of the designed filter. Tha number nb of bands and the desired attenuation at in the stop-band are given as parameters. </para> <para> The Kaiser window is multiplied by the ideal impulse response h(n)=a.sinc(a.n) and converted to its minimum-phase version by means of a Hilbert transform. </para> </refsection> <refsection> <title>Examples</title> <programlisting role="example"><![CDATA[ qp_kaiser (5, 5, 1) ans = 0.11591 0.25606 0.25606 0.25606 0.11591 ]]></programlisting> </refsection> </refentry>