- Generated on Thu Aug 29 2013 15:09:26 for GNU Radio 3.7.1 C++ API by
1.7.6.1
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GNU Radio 3.7.1 C++ API
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00001 /* -*- c++ -*- */ 00002 /* 00003 * Copyright 2002,2008,2012 Free Software Foundation, Inc. 00004 * 00005 * This file is part of GNU Radio 00006 * 00007 * GNU Radio is free software; you can redistribute it and/or modify 00008 * it under the terms of the GNU General Public License as published by 00009 * the Free Software Foundation; either version 3, or (at your option) 00010 * any later version. 00011 * 00012 * GNU Radio is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00015 * GNU General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU General Public License 00018 * along with GNU Radio; see the file COPYING. If not, write to 00019 * the Free Software Foundation, Inc., 51 Franklin Street, 00020 * Boston, MA 02110-1301, USA. 00021 */ 00022 00023 #ifndef _FILTER_FIRDES_H_ 00024 #define _FILTER_FIRDES_H_ 00025 00026 #include <gnuradio/filter/api.h> 00027 #include <vector> 00028 #include <cmath> 00029 #include <gnuradio/gr_complex.h> 00030 00031 namespace gr { 00032 namespace filter { 00033 00034 /*! 00035 * \brief Finite Impulse Response (FIR) filter design functions. 00036 * \ingroup filter_design 00037 */ 00038 00039 class FILTER_API firdes { 00040 public: 00041 00042 enum win_type { 00043 WIN_NONE = -1, // don't use a window 00044 WIN_HAMMING = 0, // max attenuation 53 dB 00045 WIN_HANN = 1, // max attenuation 44 dB 00046 WIN_BLACKMAN = 2, // max attenuation 74 dB 00047 WIN_RECTANGULAR = 3, 00048 WIN_KAISER = 4, // max attenuation a function of beta, google it 00049 WIN_BLACKMAN_hARRIS = 5, 00050 WIN_BLACKMAN_HARRIS = 5, // alias for capitalization consistency 00051 }; 00052 00053 00054 // ... class methods ... 00055 00056 /*! 00057 * \brief use "window method" to design a low-pass FIR filter 00058 * 00059 * \p gain: overall gain of filter (typically 1.0) 00060 * \p sampling_freq: sampling freq (Hz) 00061 * \p cutoff_freq: center of transition band (Hz) 00062 * \p transition_width: width of transition band (Hz). 00063 * The normalized width of the transition 00064 * band is what sets the number of taps 00065 * required. Narrow --> more taps 00066 * \p window_type: What kind of window to use. Determines 00067 * maximum attenuation and passband ripple. 00068 * \p beta: parameter for Kaiser window 00069 */ 00070 static std::vector<float> 00071 low_pass(double gain, 00072 double sampling_freq, 00073 double cutoff_freq, // Hz center of transition band 00074 double transition_width, // Hz width of transition band 00075 win_type window = WIN_HAMMING, 00076 double beta = 6.76); // used only with Kaiser 00077 00078 /*! 00079 * \brief use "window method" to design a low-pass FIR filter 00080 * 00081 * \p gain: overall gain of filter (typically 1.0) 00082 * \p sampling_freq: sampling freq (Hz) 00083 * \p cutoff_freq: center of transition band (Hz) 00084 * \p transition_width: width of transition band (Hz). 00085 * \p attenuation_dB required stopband attenuation 00086 * The normalized width of the transition 00087 * band and the required stop band 00088 * attenuation is what sets the number of taps 00089 * required. Narrow --> more taps 00090 * More attenuatin --> more taps 00091 * \p window_type: What kind of window to use. Determines 00092 * maximum attenuation and passband ripple. 00093 * \p beta: parameter for Kaiser window 00094 */ 00095 00096 static std::vector<float> 00097 low_pass_2(double gain, 00098 double sampling_freq, 00099 double cutoff_freq, // Hz beginning transition band 00100 double transition_width, // Hz width of transition band 00101 double attenuation_dB, // out of band attenuation dB 00102 win_type window = WIN_HAMMING, 00103 double beta = 6.76); // used only with Kaiser 00104 00105 /*! 00106 * \brief use "window method" to design a high-pass FIR filter 00107 * 00108 * \p gain: overall gain of filter (typically 1.0) 00109 * \p sampling_freq: sampling freq (Hz) 00110 * \p cutoff_freq: center of transition band (Hz) 00111 * \p transition_width: width of transition band (Hz). 00112 * The normalized width of the transition 00113 * band is what sets the number of taps 00114 * required. Narrow --> more taps 00115 * \p window_type: What kind of window to use. Determines 00116 * maximum attenuation and passband ripple. 00117 * \p beta: parameter for Kaiser window 00118 */ 00119 00120 static std::vector<float> 00121 high_pass(double gain, 00122 double sampling_freq, 00123 double cutoff_freq, // Hz center of transition band 00124 double transition_width, // Hz width of transition band 00125 win_type window = WIN_HAMMING, 00126 double beta = 6.76); // used only with Kaiser 00127 00128 /*! 00129 * \brief use "window method" to design a high-pass FIR filter 00130 * 00131 * \p gain: overall gain of filter (typically 1.0) 00132 * \p sampling_freq: sampling freq (Hz) 00133 * \p cutoff_freq: center of transition band (Hz) 00134 * \p transition_width: width of transition band (Hz). 00135 * \p attenuation_dB out of band attenuation 00136 * The normalized width of the transition 00137 * band and the required stop band 00138 * attenuation is what sets the number of taps 00139 * required. Narrow --> more taps 00140 * More attenuation --> more taps 00141 * \p window_type: What kind of window to use. Determines 00142 * maximum attenuation and passband ripple. 00143 * \p beta: parameter for Kaiser window 00144 */ 00145 00146 static std::vector<float> 00147 high_pass_2(double gain, 00148 double sampling_freq, 00149 double cutoff_freq, // Hz center of transition band 00150 double transition_width, // Hz width of transition band 00151 double attenuation_dB, // out of band attenuation dB 00152 win_type window = WIN_HAMMING, 00153 double beta = 6.76); // used only with Kaiser 00154 00155 /*! 00156 * \brief use "window method" to design a band-pass FIR filter 00157 * 00158 * \p gain: overall gain of filter (typically 1.0) 00159 * \p sampling_freq: sampling freq (Hz) 00160 * \p low_cutoff_freq: center of transition band (Hz) 00161 * \p high_cutoff_freq: center of transition band (Hz) 00162 * \p transition_width: width of transition band (Hz). 00163 * The normalized width of the transition 00164 * band is what sets the number of taps 00165 * required. Narrow --> more taps 00166 * \p window_type: What kind of window to use. Determines 00167 * maximum attenuation and passband ripple. 00168 * \p beta: parameter for Kaiser window 00169 */ 00170 static std::vector<float> 00171 band_pass(double gain, 00172 double sampling_freq, 00173 double low_cutoff_freq, // Hz center of transition band 00174 double high_cutoff_freq, // Hz center of transition band 00175 double transition_width, // Hz width of transition band 00176 win_type window = WIN_HAMMING, 00177 double beta = 6.76); // used only with Kaiser 00178 00179 /*! 00180 * \brief use "window method" to design a band-pass FIR filter 00181 * 00182 * \p gain: overall gain of filter (typically 1.0) 00183 * \p sampling_freq: sampling freq (Hz) 00184 * \p low_cutoff_freq: center of transition band (Hz) 00185 * \p high_cutoff_freq: center of transition band (Hz) 00186 * \p transition_width: width of transition band (Hz). 00187 * \p attenuation_dB out of band attenuation 00188 * The normalized width of the transition 00189 * band and the required stop band 00190 * attenuation is what sets the number of taps 00191 * required. Narrow --> more taps 00192 * More attenuation --> more taps 00193 * \p window_type: What kind of window to use. Determines 00194 * maximum attenuation and passband ripple. 00195 * \p beta: parameter for Kaiser window 00196 */ 00197 00198 static std::vector<float> 00199 band_pass_2(double gain, 00200 double sampling_freq, 00201 double low_cutoff_freq, // Hz beginning transition band 00202 double high_cutoff_freq, // Hz beginning transition band 00203 double transition_width, // Hz width of transition band 00204 double attenuation_dB, // out of band attenuation dB 00205 win_type window = WIN_HAMMING, 00206 double beta = 6.76); // used only with Kaiser 00207 00208 /*! 00209 * \brief use "window method" to design a complex band-pass FIR filter 00210 * 00211 * \p gain: overall gain of filter (typically 1.0) 00212 * \p sampling_freq: sampling freq (Hz) 00213 * \p low_cutoff_freq: center of transition band (Hz) 00214 * \p high_cutoff_freq: center of transition band (Hz) 00215 * \p transition_width: width of transition band (Hz). 00216 * The normalized width of the transition 00217 * band is what sets the number of taps 00218 * required. Narrow --> more taps 00219 * \p window_type: What kind of window to use. Determines 00220 * maximum attenuation and passband ripple. 00221 * \p beta: parameter for Kaiser window 00222 */ 00223 static std::vector<gr_complex> 00224 complex_band_pass(double gain, 00225 double sampling_freq, 00226 double low_cutoff_freq, // Hz center of transition band 00227 double high_cutoff_freq, // Hz center of transition band 00228 double transition_width, // Hz width of transition band 00229 win_type window = WIN_HAMMING, 00230 double beta = 6.76); // used only with Kaiser 00231 00232 /*! 00233 * \brief use "window method" to design a complex band-pass FIR filter 00234 * 00235 * \p gain: overall gain of filter (typically 1.0) 00236 * \p sampling_freq: sampling freq (Hz) 00237 * \p low_cutoff_freq: center of transition band (Hz) 00238 * \p high_cutoff_freq: center of transition band (Hz) 00239 * \p transition_width: width of transition band (Hz). 00240 * \p attenuation_dB out of band attenuation 00241 * The normalized width of the transition 00242 * band and the required stop band 00243 * attenuation is what sets the number of taps 00244 * required. Narrow --> more taps 00245 * More attenuation --> more taps 00246 * \p window_type: What kind of window to use. Determines 00247 * maximum attenuation and passband ripple. 00248 * \p beta: parameter for Kaiser window 00249 */ 00250 00251 static std::vector<gr_complex> 00252 complex_band_pass_2(double gain, 00253 double sampling_freq, 00254 double low_cutoff_freq, // Hz beginning transition band 00255 double high_cutoff_freq, // Hz beginning transition band 00256 double transition_width, // Hz width of transition band 00257 double attenuation_dB, // out of band attenuation dB 00258 win_type window = WIN_HAMMING, 00259 double beta = 6.76); // used only with Kaiser 00260 00261 /*! 00262 * \brief use "window method" to design a band-reject FIR filter 00263 * 00264 * \p gain: overall gain of filter (typically 1.0) 00265 * \p sampling_freq: sampling freq (Hz) 00266 * \p low_cutoff_freq: center of transition band (Hz) 00267 * \p high_cutoff_freq: center of transition band (Hz) 00268 * \p transition_width: width of transition band (Hz). 00269 * The normalized width of the transition 00270 * band is what sets the number of taps 00271 * required. Narrow --> more taps 00272 * \p window_type: What kind of window to use. Determines 00273 * maximum attenuation and passband ripple. 00274 * \p beta: parameter for Kaiser window 00275 */ 00276 00277 static std::vector<float> 00278 band_reject(double gain, 00279 double sampling_freq, 00280 double low_cutoff_freq, // Hz center of transition band 00281 double high_cutoff_freq, // Hz center of transition band 00282 double transition_width, // Hz width of transition band 00283 win_type window = WIN_HAMMING, 00284 double beta = 6.76); // used only with Kaiser 00285 00286 /*! 00287 * \brief use "window method" to design a band-reject FIR filter 00288 * 00289 * \p gain: overall gain of filter (typically 1.0) 00290 * \p sampling_freq: sampling freq (Hz) 00291 * \p low_cutoff_freq: center of transition band (Hz) 00292 * \p high_cutoff_freq: center of transition band (Hz) 00293 * \p transition_width: width of transition band (Hz). 00294 * \p attenuation_dB out of band attenuation 00295 * The normalized width of the transition 00296 * band and the required stop band 00297 * attenuation is what sets the number of taps 00298 * required. Narrow --> more taps 00299 * More attenuation --> more taps 00300 * \p window_type: What kind of window to use. Determines 00301 * maximum attenuation and passband ripple. 00302 * \p beta: parameter for Kaiser window 00303 */ 00304 00305 static std::vector<float> 00306 band_reject_2(double gain, 00307 double sampling_freq, 00308 double low_cutoff_freq, // Hz beginning transition band 00309 double high_cutoff_freq, // Hz beginning transition band 00310 double transition_width, // Hz width of transition band 00311 double attenuation_dB, // out of band attenuation dB 00312 win_type window = WIN_HAMMING, 00313 double beta = 6.76); // used only with Kaiser 00314 00315 /*!\brief design a Hilbert Transform Filter 00316 * 00317 * \p ntaps: Number of taps, must be odd 00318 * \p window_type: What kind of window to use 00319 * \p beta: Only used for Kaiser 00320 */ 00321 static std::vector<float> 00322 hilbert(unsigned int ntaps = 19, 00323 win_type windowtype = WIN_RECTANGULAR, 00324 double beta = 6.76); 00325 00326 /*! 00327 * \brief design a Root Cosine FIR Filter (do we need a window?) 00328 * 00329 * \p gain: overall gain of filter (typically 1.0) 00330 * \p sampling_freq: sampling freq (Hz) 00331 * \p symbol rate: symbol rate, must be a factor of sample rate 00332 * \p alpha: excess bandwidth factor 00333 * \p ntaps: number of taps 00334 */ 00335 static std::vector<float> 00336 root_raised_cosine(double gain, 00337 double sampling_freq, 00338 double symbol_rate, // Symbol rate, NOT bitrate (unless BPSK) 00339 double alpha, // Excess Bandwidth Factor 00340 int ntaps); 00341 00342 /*! 00343 * \brief design a Gaussian filter 00344 * 00345 * \p gain: overall gain of filter (typically 1.0) 00346 * \p symbols per bit: symbol rate, must be a factor of sample rate 00347 * \p ntaps: number of taps 00348 */ 00349 static std::vector<float> 00350 gaussian(double gain, 00351 double spb, 00352 double bt, // Bandwidth to bitrate ratio 00353 int ntaps); 00354 00355 // window functions ... 00356 static std::vector<float> window (win_type type, int ntaps, double beta); 00357 00358 private: 00359 static double bessi0(double x); 00360 static void sanity_check_1f(double sampling_freq, double f1, 00361 double transition_width); 00362 static void sanity_check_2f(double sampling_freq, double f1, double f2, 00363 double transition_width); 00364 static void sanity_check_2f_c(double sampling_freq, double f1, double f2, 00365 double transition_width); 00366 00367 static int compute_ntaps(double sampling_freq, 00368 double transition_width, 00369 win_type window_type, double beta); 00370 00371 static int compute_ntaps_windes(double sampling_freq, 00372 double transition_width, 00373 double attenuation_dB); 00374 }; 00375 00376 } /* namespace filter */ 00377 } /* namespace gr */ 00378 00379 #endif /* _FILTER_FIRDES_H_ */
1.7.6.1