diff options
3 files changed, 33 insertions, 15 deletions
diff --git a/gnuradio-core/src/lib/filter/gr_iir_filter_ffd.h b/gnuradio-core/src/lib/filter/gr_iir_filter_ffd.h index 386d056e5..ba0c78486 100644 --- a/gnuradio-core/src/lib/filter/gr_iir_filter_ffd.h +++ b/gnuradio-core/src/lib/filter/gr_iir_filter_ffd.h @@ -43,16 +43,22 @@ gr_make_iir_filter_ffd (const std::vector<double> &fftaps, * * * The input and output satisfy a difference equation of the form + \f{html}{ + y[n] - \sum_{k=1}^{M} a_k y[n-k] = \sum_{k=0}^{N} b_k x[n-k] + \f} - \f[ + \xmlonly y[n] - \sum_{k=1}^{M} a_k y[n-k] = \sum_{k=0}^{N} b_k x[n-k] - \f] + \endxmlonly * with the corresponding rational system function + \f{html}{ + H(z) = \ frac{\sum_{k=0}^{M} b_k z^{-k}}{1 - \sum_{k=1}^{N} a_k z^{-k}} + \f} - \f[ - H(z) = \frac{\sum_{k=0}^{M} b_k z^{-k}}{1 - \sum_{k=1}^{N} a_k z^{-k}} - \f] + \xmlonly + H(z) = \ frac{\sum_{k=0}^{M} b_k z^{-k}}{1 - \sum_{k=1}^{N} a_k z^{-k}} + \endxmlonly * Note that some texts define the system function with a + in the denominator. * If you're using that convention, you'll need to negate the feedback taps. diff --git a/gnuradio-core/src/lib/filter/gr_single_pole_iir_filter_cc.h b/gnuradio-core/src/lib/filter/gr_single_pole_iir_filter_cc.h index 3ce468db2..c330c2140 100644 --- a/gnuradio-core/src/lib/filter/gr_single_pole_iir_filter_cc.h +++ b/gnuradio-core/src/lib/filter/gr_single_pole_iir_filter_cc.h @@ -40,16 +40,22 @@ gr_make_single_pole_iir_filter_cc (double alpha, unsigned int vlen=1); * \ingroup filter_blk * * The input and output satisfy a difference equation of the form + \f{html}{ + y[n] - (1-alpha) y[n-1] = alpha x[n] + \f} - \f[ + \xmlonly y[n] - (1-alpha) y[n-1] = alpha x[n] - \f] + \endxmlonly * with the corresponding rational system function - - \f[ + \f{html}{ H(z) = \frac{alpha}{1 - (1-alpha) z^{-1}} - \f] + \f} + + \xmlonly + H(z) = \ frac{alpha}{1 - (1-alpha) z^{-1}} + \endxmlonly * Note that some texts define the system function with a + in the denominator. * If you're using that convention, you'll need to negate the feedback tap. diff --git a/gnuradio-core/src/lib/filter/gr_single_pole_iir_filter_ff.h b/gnuradio-core/src/lib/filter/gr_single_pole_iir_filter_ff.h index d376587df..ee6a554bf 100644 --- a/gnuradio-core/src/lib/filter/gr_single_pole_iir_filter_ff.h +++ b/gnuradio-core/src/lib/filter/gr_single_pole_iir_filter_ff.h @@ -39,16 +39,22 @@ gr_make_single_pole_iir_filter_ff (double alpha, unsigned int vlen=1); * \ingroup filter_blk * * The input and output satisfy a difference equation of the form + \f{html}{ + y[n] - (1-alpha) y[n-1] = alpha x[n] + \f} - \f[ + \xmlonly y[n] - (1-alpha) y[n-1] = alpha x[n] - \f] + \endxmlonly * with the corresponding rational system function - - \f[ + \f{html}{ H(z) = \frac{alpha}{1 - (1-alpha) z^{-1}} - \f] + \f} + + \xmlonly +H(z) = \ frac{alpha}{1 - (1-alpha) z^{-1}} + \endxmlonly * Note that some texts define the system function with a + in the denominator. * If you're using that convention, you'll need to negate the feedback tap. |