diff options
| author | Martin Braun <martin.braun@kit.edu> | 2010-12-10 10:44:08 +0100 |
|---|---|---|
| committer | Martin Braun <martin.braun@kit.edu> | 2010-12-10 10:44:08 +0100 |
| commit | c96ea6723a3e7ce6dc5bbccb4386647a088186aa (patch) | |
| tree | 0ea3e5df30d8a78edf5f7d909fece285d546a340 /gnuradio-core/src/lib/general/gr_cpm.h | |
| parent | 144ef2dbe12de3f1f784fb2e76771b1e174deb41 (diff) | |
updated doxygen blocks, changed param order for gmsk
Diffstat (limited to 'gnuradio-core/src/lib/general/gr_cpm.h')
| -rw-r--r-- | gnuradio-core/src/lib/general/gr_cpm.h | 81 |
1 files changed, 42 insertions, 39 deletions
diff --git a/gnuradio-core/src/lib/general/gr_cpm.h b/gnuradio-core/src/lib/general/gr_cpm.h index f9b97f7ea7..09598024a2 100644 --- a/gnuradio-core/src/lib/general/gr_cpm.h +++ b/gnuradio-core/src/lib/general/gr_cpm.h @@ -1,17 +1,17 @@ /* -*- c++ -*- */ /* * Copyright 2010 Free Software Foundation, Inc. - * + * * GNU Radio is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 3, or (at your option) * any later version. - * + * * GNU Radio is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. - * + * * You should have received a copy of the GNU General Public License * along with GNU Radio; see the file COPYING. If not, write to * the Free Software Foundation, Inc., 51 Franklin Street, @@ -24,7 +24,9 @@ #include <vector> -#define M_TWOPI (2*M_PI) +#ifndef M_TWOPI +# define M_TWOPI (2*M_PI) +#endif class gr_cpm { @@ -38,41 +40,42 @@ class gr_cpm GENERIC = 999 }; - //! Return the taps for an interpolating FIR filter (gr_fir_filter_fff). - // - // These taps represent the phase response for use in a CPM modulator. - // - // Parameters: - // \p type: The CPM type (Rectangular, Raised Cosine, Spectral Raised Cosine, - // Tamed FM or Gaussian). - // \p samples_per_sym: Samples per symbol. - // \p L: The length of the phase response in symbols. - // \p beta: For Spectral Raised Cosine, this is the rolloff factor. For Gaussian - // phase responses, this the 3dB-time-bandwidth product. For all other - // cases, it is ignored. - // - // Output: returns a vector of length \p L * \p samples_per_sym. This can be used - // directly in an interpolating FIR filter such as gr_interp_fir_filter_fff - // with interpolation factor \p samples_per_sym. - // - // All taps are normalised s.t. \sum taps = 1; this causes a maximum phase change - // of h*pi between two symbols, where h is the modulation index. - // - // The following phase responses can be generated: - // * LREC: Rectangular phase response. - // * LRC: Raised cosine phase response, looks like 1 - cos(x). - // * LSRC: Spectral raised cosine. This requires a rolloff factor beta. - // The phase response is the Fourier transform of raised cosine - // function. - // * TFM: Tamed frequency modulation. This scheme minimizes phase change for - // rapidly varying input symbols. - // * GAUSSIAN: A Gaussian phase response. For a modulation index h = 1/2, this - // results in GMSK. - // - // A short description of all these phase responses can be found in [1]. - // - // - // [1]: Anderson, Aulin and Sundberg; Digital Phase Modulation + /*! \brief Return the taps for an interpolating FIR filter (gr_interp_fir_filter_fff). + * + * These taps represent the phase response \f$g(k)\f$ for use in a CPM modulator, + * see also gr_cpmmod_bc. + * + * \param type The CPM type (Rectangular, Raised Cosine, Spectral Raised Cosine, + * Tamed FM or Gaussian). + * \param samples_per_sym Samples per symbol. + * \param L The length of the phase response in symbols. + * \param beta For Spectral Raised Cosine, this is the rolloff factor. For Gaussian + * phase responses, this the 3dB-time-bandwidth product. For all other + * cases, it is ignored. + * + * Output: returns a vector of length \a K = \p samples_per_sym x \p L. + * This can be used directly in an interpolating FIR filter such as + * gr_interp_fir_filter_fff with interpolation factor \p samples_per_sym. + * + * All phase responses are normalised s.t. \f$ \sum_{k=0}^{K-1} g(k) = 1\f$; this will cause + * a maximum phase change of \f$ h \cdot \pi\f$ between two symbols, where \a h is the + * modulation index. + * + * The following phase responses can be generated: + * - LREC: Rectangular phase response. + * - LRC: Raised cosine phase response, looks like 1 - cos(x). + * - LSRC: Spectral raised cosine. This requires a rolloff factor beta. + * The phase response is the Fourier transform of raised cosine + * function. + * - TFM: Tamed frequency modulation. This scheme minimizes phase change for + * rapidly varying input symbols. + * - GAUSSIAN: A Gaussian phase response. For a modulation index h = 1/2, this + * results in GMSK. + * + * A short description of all these phase responses can be found in [1]. + * + * [1]: Anderson, Aulin and Sundberg; Digital Phase Modulation + */ static std::vector<float> phase_response(cpm_type type, unsigned samples_per_sym, unsigned L, double beta=0.3); }; |