diff options
Diffstat (limited to 'gr-fft/include/gnuradio/fft/window.h')
| -rw-r--r-- | gr-fft/include/gnuradio/fft/window.h | 554 |
1 files changed, 279 insertions, 275 deletions
diff --git a/gr-fft/include/gnuradio/fft/window.h b/gr-fft/include/gnuradio/fft/window.h index 564753a61c..d6ccf9ff7c 100644 --- a/gr-fft/include/gnuradio/fft/window.h +++ b/gr-fft/include/gnuradio/fft/window.h @@ -29,284 +29,288 @@ #include <gnuradio/gr_complex.h> namespace gr { - namespace fft { - - class FFT_API window { - public: - - enum win_type { - WIN_HAMMING = 0, //!< Hamming window; max attenuation 53 dB - WIN_HANN = 1, //!< Hann window; max attenuation 44 dB - WIN_BLACKMAN = 2, //!< Blackman window; max attenuation 74 dB - WIN_RECTANGULAR = 3, //!< Basic rectangular window; max attenuation 21 dB - WIN_KAISER = 4, //!< Kaiser window; max attenuation see window::max_attenuation +namespace fft { + +class FFT_API window +{ +public: + enum win_type { + WIN_HAMMING = 0, //!< Hamming window; max attenuation 53 dB + WIN_HANN = 1, //!< Hann window; max attenuation 44 dB + WIN_BLACKMAN = 2, //!< Blackman window; max attenuation 74 dB + WIN_RECTANGULAR = 3, //!< Basic rectangular window; max attenuation 21 dB + WIN_KAISER = 4, //!< Kaiser window; max attenuation see window::max_attenuation WIN_BLACKMAN_hARRIS = 5, //!< Blackman-harris window; max attenuation 92 dB - WIN_BLACKMAN_HARRIS = 5, //!< alias to WIN_BLACKMAN_hARRIS for capitalization consistency - WIN_BARTLETT = 6, //!< Barlett (triangular) window; max attenuation 26 dB - WIN_FLATTOP = 7, //!< flat top window; useful in FFTs; max attenuation 93 dB - }; - - /*! - * \brief Given a window::win_type, this tells you the maximum - * attenuation you can expect. - * - * \details - * For most windows, this is a set value. For the Kaiser window, - * the attenuation is based on the value of beta. The actual - * relationship is a piece-wise exponential relationship to - * calculate beta from the desired attenuation and can be found - * on page 542 of Oppenheim and Schafer (Discrete-Time Signal - * Processing, 3rd edition). To simplify this function to solve - * for A given beta, we use a linear form that is exact for - * attenuation >= 50 dB. - * - * For an attenuation of 50 dB, beta = 4.55. - * - * For an attenuation of 70 dB, beta = 6.76. - * - * \param type The window::win_type enumeration of the window type. - * \param beta Beta value only used for the Kaiser window. - */ - static double max_attenuation(win_type type, double beta=6.76); - - /*! - * \brief Helper function to build cosine-based windows. 3-coefficient version. - */ - static std::vector<float> coswindow(int ntaps, float c0, float c1, float c2); - - /*! - * \brief Helper function to build cosine-based windows. 4-coefficient version. - */ - static std::vector<float> coswindow(int ntaps, float c0, float c1, float c2, float c3); - - /*! - * \brief Helper function to build cosine-based windows. 5-coefficient version. - */ - static std::vector<float> coswindow(int ntaps, float c0, float c1, float c2, float c3, float c4); - - /*! - * \brief Build a rectangular window. - * - * Taps are flat across the window. - * - * \param ntaps Number of coefficients in the window. - */ - static std::vector<float> rectangular(int ntaps); - - /*! - * \brief Build a Hamming window. - * - * See: - * <pre> - * A. V. Oppenheim and R. W. Schafer, "Discrete-Time - * Signal Processing," Upper Saddle River, N.J.: Prentice - * Hall, 2010, pp. 535-538. - * </pre> - * - * \param ntaps Number of coefficients in the window. - */ - static std::vector<float> hamming(int ntaps); - - /*! - * \brief Build a Hann window (sometimes known as Hanning). - * - * See: - * <pre> - * A. V. Oppenheim and R. W. Schafer, "Discrete-Time - * Signal Processing," Upper Saddle River, N.J.: Prentice - * Hall, 2010, pp. 535-538. - * </pre> - * - * \param ntaps Number of coefficients in the window. - */ - static std::vector<float> hann(int ntaps); - - /*! - * \brief Alias to build a Hann window. - * - * \param ntaps Number of coefficients in the window. - */ - static std::vector<float> hanning(int ntaps); - - /*! - * \brief Build an exact Blackman window. - * - * See: - * <pre> - * A. V. Oppenheim and R. W. Schafer, "Discrete-Time - * Signal Processing," Upper Saddle River, N.J.: Prentice - * Hall, 2010, pp. 535-538. - * </pre> - * - * \param ntaps Number of coefficients in the window. - */ - static std::vector<float> blackman(int ntaps); - - /*! - * \brief Build Blackman window, variation 1. - */ - static std::vector<float> blackman2(int ntaps); - - /*! - * \brief Build Blackman window, variation 2. - */ - static std::vector<float> blackman3(int ntaps); - - /*! - * \brief Build Blackman window, variation 3. - */ - static std::vector<float> blackman4(int ntaps); - - /*! - * \brief Build a Blackman-harris window with a given attenuation. - * - * <pre> - * f. j. harris, "On the use of windows for harmonic analysis - * with the discrete Fourier transforms," Proc. IEEE, Vol. 66, - * ppg. 51-83, Jan. 1978. - * </pre> - * - * \param ntaps Number of coefficients in the window. - - * \param atten Attenuation factor. Must be [61, 67, 74, 92]. - * See the above paper for details. - */ - static std::vector<float> blackman_harris(int ntaps, int atten=92); - - /*! - * Alias to gr::fft::window::blakcman_harris. - */ - static std::vector<float> blackmanharris(int ntaps, int atten=92); - - /*! - * \brief Build a Nuttall (or Blackman-Nuttall) window. - * - * See: http://en.wikipedia.org/wiki/Window_function#Blackman.E2.80.93Nuttall_window - * - * \param ntaps Number of coefficients in the window. - */ - static std::vector<float> nuttall(int ntaps); - - /*! - * Deprecated: use nuttall window instead. - */ - static std::vector<float> nuttal(int ntaps); - - /*! - * \brief Alias to the Nuttall window. - * - * \param ntaps Number of coefficients in the window. - */ - static std::vector<float> blackman_nuttall(int ntaps); - - /*! - * Deprecated: use blackman_nuttall window instead. - */ - static std::vector<float> blackman_nuttal(int ntaps); - - /*! - * \brief Build a Nuttall continuous first derivative window. - * - * See: http://en.wikipedia.org/wiki/Window_function#Nuttall_window.2C_continuous_first_derivative - * - * \param ntaps Number of coefficients in the window. - */ - static std::vector<float> nuttall_cfd(int ntaps); - - /*! - * Deprecated: use nuttall_cfd window instead. - */ - static std::vector<float> nuttal_cfd(int ntaps); - - /*! - * \brief Build a flat top window. - * - * See: http://en.wikipedia.org/wiki/Window_function#Flat_top_window - * - * \param ntaps Number of coefficients in the window. - */ - static std::vector<float> flattop(int ntaps); - - /*! - * \brief Build a Kaiser window with a given beta. - * - * See: - * <pre> - * A. V. Oppenheim and R. W. Schafer, "Discrete-Time - * Signal Processing," Upper Saddle River, N.J.: Prentice - * Hall, 2010, pp. 541-545. - * </pre> - * - * \param ntaps Number of coefficients in the window. - * \param beta Shaping parameter of the window. See the - * discussion in Oppenheim and Schafer. - */ - static std::vector<float> kaiser(int ntaps, double beta); - - /*! - * \brief Build a Barlett (triangular) window. - * - * See: - * <pre> - * A. V. Oppenheim and R. W. Schafer, "Discrete-Time - * Signal Processing," Upper Saddle River, N.J.: Prentice - * Hall, 2010, pp. 535-538. - * </pre> - * - * \param ntaps Number of coefficients in the window. - */ - static std::vector<float> bartlett(int ntaps); - - static std::vector<float> welch(int ntaps); - - /*! - * \brief Build a Parzen (or de la Valle-Poussin) window. - * - * See: - * <pre> - * A. D. Poularikas, "Handbook of Formulas and Tables for - * Signal Processing," Springer, Oct 28, 1998 - * </pre> - * - * \param ntaps Number of coefficients in the window. - */ - static std::vector<float> parzen(int ntaps); - - /*! - * \brief Build an exponential window with a given decay. - * - * See: http://en.wikipedia.org/wiki/Window_function#Exponential_or_Poisson_window - * - * \param ntaps Number of coefficients in the window. - * \param d Decay of \p d dB over half the window length. - */ - static std::vector<float> exponential(int ntaps, double d); - - /*! - * \brief Build a Riemann window. - * - * See: - * <pre> - * A. D. Poularikas, "Handbook of Formulas and Tables for - * Signal Processing," Springer, Oct 28, 1998 - * </pre> - * - * \param ntaps Number of coefficients in the window. - */ - static std::vector<float> riemann(int ntaps); - - /*! - * \brief Build a window using gr::fft::win_type to index the - * type of window desired. - * - * \param type a gr::fft::win_type index for the type of window. - * \param ntaps Number of coefficients in the window. - * \param beta Used only for building Kaiser windows. - */ - static std::vector<float> build(win_type type, int ntaps, double beta); + WIN_BLACKMAN_HARRIS = + 5, //!< alias to WIN_BLACKMAN_hARRIS for capitalization consistency + WIN_BARTLETT = 6, //!< Barlett (triangular) window; max attenuation 26 dB + WIN_FLATTOP = 7, //!< flat top window; useful in FFTs; max attenuation 93 dB }; - } /* namespace fft */ + /*! + * \brief Given a window::win_type, this tells you the maximum + * attenuation you can expect. + * + * \details + * For most windows, this is a set value. For the Kaiser window, + * the attenuation is based on the value of beta. The actual + * relationship is a piece-wise exponential relationship to + * calculate beta from the desired attenuation and can be found + * on page 542 of Oppenheim and Schafer (Discrete-Time Signal + * Processing, 3rd edition). To simplify this function to solve + * for A given beta, we use a linear form that is exact for + * attenuation >= 50 dB. + * + * For an attenuation of 50 dB, beta = 4.55. + * + * For an attenuation of 70 dB, beta = 6.76. + * + * \param type The window::win_type enumeration of the window type. + * \param beta Beta value only used for the Kaiser window. + */ + static double max_attenuation(win_type type, double beta = 6.76); + + /*! + * \brief Helper function to build cosine-based windows. 3-coefficient version. + */ + static std::vector<float> coswindow(int ntaps, float c0, float c1, float c2); + + /*! + * \brief Helper function to build cosine-based windows. 4-coefficient version. + */ + static std::vector<float> + coswindow(int ntaps, float c0, float c1, float c2, float c3); + + /*! + * \brief Helper function to build cosine-based windows. 5-coefficient version. + */ + static std::vector<float> + coswindow(int ntaps, float c0, float c1, float c2, float c3, float c4); + + /*! + * \brief Build a rectangular window. + * + * Taps are flat across the window. + * + * \param ntaps Number of coefficients in the window. + */ + static std::vector<float> rectangular(int ntaps); + + /*! + * \brief Build a Hamming window. + * + * See: + * <pre> + * A. V. Oppenheim and R. W. Schafer, "Discrete-Time + * Signal Processing," Upper Saddle River, N.J.: Prentice + * Hall, 2010, pp. 535-538. + * </pre> + * + * \param ntaps Number of coefficients in the window. + */ + static std::vector<float> hamming(int ntaps); + + /*! + * \brief Build a Hann window (sometimes known as Hanning). + * + * See: + * <pre> + * A. V. Oppenheim and R. W. Schafer, "Discrete-Time + * Signal Processing," Upper Saddle River, N.J.: Prentice + * Hall, 2010, pp. 535-538. + * </pre> + * + * \param ntaps Number of coefficients in the window. + */ + static std::vector<float> hann(int ntaps); + + /*! + * \brief Alias to build a Hann window. + * + * \param ntaps Number of coefficients in the window. + */ + static std::vector<float> hanning(int ntaps); + + /*! + * \brief Build an exact Blackman window. + * + * See: + * <pre> + * A. V. Oppenheim and R. W. Schafer, "Discrete-Time + * Signal Processing," Upper Saddle River, N.J.: Prentice + * Hall, 2010, pp. 535-538. + * </pre> + * + * \param ntaps Number of coefficients in the window. + */ + static std::vector<float> blackman(int ntaps); + + /*! + * \brief Build Blackman window, variation 1. + */ + static std::vector<float> blackman2(int ntaps); + + /*! + * \brief Build Blackman window, variation 2. + */ + static std::vector<float> blackman3(int ntaps); + + /*! + * \brief Build Blackman window, variation 3. + */ + static std::vector<float> blackman4(int ntaps); + + /*! + * \brief Build a Blackman-harris window with a given attenuation. + * + * <pre> + * f. j. harris, "On the use of windows for harmonic analysis + * with the discrete Fourier transforms," Proc. IEEE, Vol. 66, + * ppg. 51-83, Jan. 1978. + * </pre> + * + * \param ntaps Number of coefficients in the window. + + * \param atten Attenuation factor. Must be [61, 67, 74, 92]. + * See the above paper for details. + */ + static std::vector<float> blackman_harris(int ntaps, int atten = 92); + + /*! + * Alias to gr::fft::window::blakcman_harris. + */ + static std::vector<float> blackmanharris(int ntaps, int atten = 92); + + /*! + * \brief Build a Nuttall (or Blackman-Nuttall) window. + * + * See: http://en.wikipedia.org/wiki/Window_function#Blackman.E2.80.93Nuttall_window + * + * \param ntaps Number of coefficients in the window. + */ + static std::vector<float> nuttall(int ntaps); + + /*! + * Deprecated: use nuttall window instead. + */ + static std::vector<float> nuttal(int ntaps); + + /*! + * \brief Alias to the Nuttall window. + * + * \param ntaps Number of coefficients in the window. + */ + static std::vector<float> blackman_nuttall(int ntaps); + + /*! + * Deprecated: use blackman_nuttall window instead. + */ + static std::vector<float> blackman_nuttal(int ntaps); + + /*! + * \brief Build a Nuttall continuous first derivative window. + * + * See: + * http://en.wikipedia.org/wiki/Window_function#Nuttall_window.2C_continuous_first_derivative + * + * \param ntaps Number of coefficients in the window. + */ + static std::vector<float> nuttall_cfd(int ntaps); + + /*! + * Deprecated: use nuttall_cfd window instead. + */ + static std::vector<float> nuttal_cfd(int ntaps); + + /*! + * \brief Build a flat top window. + * + * See: http://en.wikipedia.org/wiki/Window_function#Flat_top_window + * + * \param ntaps Number of coefficients in the window. + */ + static std::vector<float> flattop(int ntaps); + + /*! + * \brief Build a Kaiser window with a given beta. + * + * See: + * <pre> + * A. V. Oppenheim and R. W. Schafer, "Discrete-Time + * Signal Processing," Upper Saddle River, N.J.: Prentice + * Hall, 2010, pp. 541-545. + * </pre> + * + * \param ntaps Number of coefficients in the window. + * \param beta Shaping parameter of the window. See the + * discussion in Oppenheim and Schafer. + */ + static std::vector<float> kaiser(int ntaps, double beta); + + /*! + * \brief Build a Barlett (triangular) window. + * + * See: + * <pre> + * A. V. Oppenheim and R. W. Schafer, "Discrete-Time + * Signal Processing," Upper Saddle River, N.J.: Prentice + * Hall, 2010, pp. 535-538. + * </pre> + * + * \param ntaps Number of coefficients in the window. + */ + static std::vector<float> bartlett(int ntaps); + + static std::vector<float> welch(int ntaps); + + /*! + * \brief Build a Parzen (or de la Valle-Poussin) window. + * + * See: + * <pre> + * A. D. Poularikas, "Handbook of Formulas and Tables for + * Signal Processing," Springer, Oct 28, 1998 + * </pre> + * + * \param ntaps Number of coefficients in the window. + */ + static std::vector<float> parzen(int ntaps); + + /*! + * \brief Build an exponential window with a given decay. + * + * See: http://en.wikipedia.org/wiki/Window_function#Exponential_or_Poisson_window + * + * \param ntaps Number of coefficients in the window. + * \param d Decay of \p d dB over half the window length. + */ + static std::vector<float> exponential(int ntaps, double d); + + /*! + * \brief Build a Riemann window. + * + * See: + * <pre> + * A. D. Poularikas, "Handbook of Formulas and Tables for + * Signal Processing," Springer, Oct 28, 1998 + * </pre> + * + * \param ntaps Number of coefficients in the window. + */ + static std::vector<float> riemann(int ntaps); + + /*! + * \brief Build a window using gr::fft::win_type to index the + * type of window desired. + * + * \param type a gr::fft::win_type index for the type of window. + * \param ntaps Number of coefficients in the window. + * \param beta Used only for building Kaiser windows. + */ + static std::vector<float> build(win_type type, int ntaps, double beta); +}; + +} /* namespace fft */ } /* namespace gr */ #endif /* INCLUDED_FFT_WINDOW_H */ |