/* * Copyright (C) 2015 Jared Boone, ShareBrained Technology, Inc. * Copyright (C) 2017 Furrtek * * This file is part of PortaPack. * * This program 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 2, or (at your option) * any later version. * * This program 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 this program; see the file COPYING. If not, write to * the Free Software Foundation, Inc., 51 Franklin Street, * Boston, MA 02110-1301, USA. */ #ifndef __DSP_FIR_TAPS_H__ #define __DSP_FIR_TAPS_H__ #include #include #include "complex.hpp" template struct fir_taps_real { float low_frequency_normalized; float high_frequency_normalized; float transition_normalized; std::array taps; }; template struct fir_taps_complex { float low_frequency_normalized; float high_frequency_normalized; float transition_normalized; std::array taps; }; // NBFM 16K0F3E emission type ///////////////////////////////////////////// // IFIR image-reject filter: fs=3072000, pass=8000, stop=344000, decim=8, fout=384000 constexpr fir_taps_real<24> taps_16k0_decim_0{ .low_frequency_normalized = -8000.0f / 3072000.0f, .high_frequency_normalized = 8000.0f / 3072000.0f, .transition_normalized = 336000.0f / 3072000.0f, .taps = {{ 1, 67, 165, 340, 599, 944, 1361, 1820, 2278, 2684, 2988, 3152, 3152, 2988, 2684, 2278, 1820, 1361, 944, 599, 340, 165, 67, 1, }}, }; // IFIR prototype filter: fs=384000, pass=8000, stop=40000, decim=8, fout=48000 constexpr fir_taps_real<32> taps_16k0_decim_1{ .low_frequency_normalized = -8000.0f / 384000.0f, .high_frequency_normalized = 8000.0f / 384000.0f, .transition_normalized = 32000.0f / 384000.0f, .taps = {{ -26, -125, -180, -275, -342, -359, -286, -90, 250, 733, 1337, 2011, 2688, 3289, 3740, 3982, 3982, 3740, 3289, 2688, 2011, 1337, 733, 250, -90, -286, -359, -342, -275, -180, -125, -26, }}, }; // Channel filter: fs=48000, pass=8000, stop=12400, decim=1, fout=48000 constexpr fir_taps_real<32> taps_16k0_channel{ .low_frequency_normalized = -8000.0f / 48000.0f, .high_frequency_normalized = 8000.0f / 48000.0f, .transition_normalized = 4400.0f / 48000.0f, .taps = {{ -73, -285, -376, -8, 609, 538, -584, -1387, -148, 2173, 1959, -2146, -5267, -297, 12915, 24737, 24737, 12915, -297, -5267, -2146, 1959, 2173, -148, -1387, -584, 538, 609, -8, -376, -285, -73, }}, }; // NBFM 11K0F3E emission type ///////////////////////////////////////////// // IFIR image-reject filter: fs=3072000, pass=5500, stop=341500, decim=8, fout=384000 constexpr fir_taps_real<24> taps_11k0_decim_0{ .low_frequency_normalized = -5500.0f / 3072000.0f, .high_frequency_normalized = 5500.0f / 3072000.0f, .transition_normalized = 336000.0f / 3072000.0f, .taps = {{ 38, 102, 220, 406, 668, 1004, 1397, 1822, 2238, 2603, 2875, 3020, 3020, 2875, 2603, 2238, 1822, 1397, 1004, 668, 406, 220, 102, 38, }}, }; // IFIR prototype filter: fs=384000, pass=5500, stop=42500, decim=8, fout=48000 constexpr fir_taps_real<32> taps_11k0_decim_1{ .low_frequency_normalized = -5500.0f / 384000.0f, .high_frequency_normalized = 5500.0f / 384000.0f, .transition_normalized = 37000.0f / 384000.0f, .taps = {{ -42, -87, -157, -234, -298, -318, -255, -75, 246, 713, 1306, 1976, 2656, 3265, 3724, 3971, 3971, 3724, 3265, 2656, 1976, 1306, 713, 246, -75, -255, -318, -298, -234, -157, -87, -42, }}, }; // Channel filter: fs=48000, pass=5500, stop=8900, decim=1, fout=48000 constexpr fir_taps_real<32> taps_11k0_channel{ .low_frequency_normalized = -5500.0f / 48000.0f, .high_frequency_normalized = 5500.0f / 48000.0f, .transition_normalized = 3400.0f / 48000.0f, .taps = {{ -68, -345, -675, -867, -582, 247, 1222, 1562, 634, -1379, -3219, -3068, 310, 6510, 13331, 17795, 17795, 13331, 6510, 310, -3068, -3219, -1379, 634, 1562, 1222, 247, -582, -867, -675, -345, -68, }}, }; // NBFM 8K50F3E emission type ///////////////////////////////////////////// // IFIR image-reject filter: fs=3072000, pass=4250, stop=340250, decim=8, fout=384000 constexpr fir_taps_real<24> taps_4k25_decim_0{ .low_frequency_normalized = -4250.0f / 3072000.0f, .high_frequency_normalized = 4250.0f / 3072000.0f, .transition_normalized = 33600.0f / 3072000.0f, .taps = {{ 38, 103, 222, 409, 671, 1006, 1399, 1821, 2236, 2599, 2868, 3012, 3012, 2868, 2599, 2236, 1821, 1399, 1006, 671, 409, 222, 103, 38, }}, }; // IFIR prototype filter: fs=384000, pass=4250, stop=43750, decim=8, fout=48000 constexpr fir_taps_real<32> taps_4k25_decim_1{ .low_frequency_normalized = -4250.0f / 384000.0f, .high_frequency_normalized = 4250.0f / 384000.0f, .transition_normalized = 39500.0f / 384000.0f, .taps = {{ -33, -74, -139, -214, -280, -306, -254, -87, 222, 682, 1274, 1951, 2644, 3268, 3741, 3996, 3996, 3741, 3268, 2644, 1951, 1274, 682, 222, -87, -254, -306, -280, -214, -139, -74, -33, }}, }; // Channel filter: fs=48000, pass=4250, stop=7900, decim=1, fout=48000 constexpr fir_taps_real<32> taps_4k25_channel{ .low_frequency_normalized = -4250.0f / 48000.0f, .high_frequency_normalized = 4250.0f / 48000.0f, .transition_normalized = 3650.0f / 48000.0f, .taps = {{ -58, -14, 153, 484, 871, 1063, 770, -141, -1440, -2488, -2435, -614, 3035, 7771, 12226, 14927, 14927, 12226, 7771, 3035, -614, -2435, -2488, -1440, -141, 770, 1063, 871, 484, 153, -14, -58, }}, }; /* CTCSS audio filter */ /* 12kHz int16_t input * -> FIR filter, <300Hz pass, >300Hz stop, gain of 1 * -> 6kHz int16_t output, gain of 1.0 (I think). * Padded to multiple of four taps for unrolled FIR code. * sum(abs(taps)): 125270 */ /*constexpr fir_taps_real<64> taps_64_lp_025_025 { .taps = { { 0, 0, -3, -7, -13, -20, -27, -32, -34, -33, -25, -10, 13, 47, 94, 152, 223, 307, 402, 508, 622, 742, 866, 991, 1113, 1229, 1336, 1430, 1510, 1571, 1614, 1635, 1635, 1614, 1571, 1510, 1430, 1336, 1229, 1113, 991, 866, 742, 622, 508, 402, 307, 223, 152, 94, 47, 13, -10, -25, -33, -34, -32, -27, -20, -13, -7, -3, 0, 0 } }, };*/ /* CTCSS audio filter */ /* 24kHz int16_t input * -> FIR filter, <300Hz pass, >300Hz stop, gain of 1 * -> 12kHz int16_t output, gain of 1.0 (I think). * Padded to multiple of four taps for unrolled FIR code. * sum(abs(taps)): 125270 */ constexpr fir_taps_real<64> taps_64_lp_025_025{ .low_frequency_normalized = 0, .high_frequency_normalized = 0, .transition_normalized = 0, .taps = {{0, 0, 2, 6, 12, 20, 32, 46, 64, 85, 110, 138, 169, 204, 241, 281, 323, 367, 412, 457, 502, 547, 590, 631, 669, 704, 735, 762, 784, 801, 812, 818, 818, 812, 801, 784, 762, 735, 704, 669, 631, 590, 547, 502, 457, 412, 367, 323, 281, 241, 204, 169, 138, 110, 85, 64, 46, 32, 20, 12, 6, 2, 0, 0}}, }; // DSB AM 6K00A3E emission type /////////////////////////////////////////// // IFIR image-reject filter: fs=3072000, pass=3000, stop=339000, decim=8, fout=384000 constexpr fir_taps_real<24> taps_6k0_decim_0{ .low_frequency_normalized = -3000.0f / 3072000.0f, .high_frequency_normalized = 3000.0f / 3072000.0f, .transition_normalized = 336000.0f / 3072000.0f, .taps = {{ 39, 104, 224, 412, 674, 1008, 1400, 1821, 2234, 2594, 2863, 3006, 3006, 2863, 2594, 2234, 1821, 1400, 1008, 674, 412, 224, 104, 39, }}, }; // IFIR prototype filter: fs=384000, pass=3000, stop=45000, decim=8, fout=48000 constexpr fir_taps_real<32> taps_6k0_decim_1{ .low_frequency_normalized = -3000.0f / 384000.0f, .high_frequency_normalized = 3000.0f / 384000.0f, .transition_normalized = 43000.0f / 384000.0f, .taps = {{ -26, -63, -123, -195, -263, -295, -253, -99, 199, 651, 1242, 1927, 2633, 3273, 3760, 4023, 4023, 3760, 3273, 2633, 1927, 1242, 651, 199, -99, -253, -295, -263, -195, -123, -63, -26, }}, }; // IFIR prototype filter: fs=48000, pass=3000, stop=6700, decim=4, fout=12000 constexpr fir_taps_real<32> taps_6k0_decim_2{ .low_frequency_normalized = -3000.0f / 48000.0f, .high_frequency_normalized = 3000.0f / 48000.0f, .transition_normalized = 3700.0f / 48000.0f, .taps = {{ 95, 178, 247, 208, -21, -474, -1080, -1640, -1857, -1411, -83, 2134, 4978, 7946, 10413, 11815, 11815, 10413, 7946, 4978, 2134, -83, -1411, -1857, -1640, -1080, -474, -21, 208, 247, 178, 95, }}, }; // IFIR prototype filter fs=48000 ; pass=4500 (cutt off -3dBs) , stop=8000 (<-60dBs), decim=4, fout=12000 // For Europe AM commercial broadcasting stations in LF/MF/HF, Emissions Designator 9K00A3E Bandwidth: 9.00 kHz (derivated from taps_6k0_decim_2 ) // Pre-decimate LPF FIR filter design Created with SciPy Python with the "window method", num_taps = 32, cut_off = 5150. sample_rate = 48000 # Hz, // Created with h = signal.firwin(num_taps, cut_off, nyq=sample_rate/2, window=('chebwin',50)) , achieving good STOP band plot < -60 dB's with some ripple. // post-scaled h taps to avoid decimals , targeting <= similar int values as previous taps_6k0_dsb_channel peak < 32.767 (2 exp 15) and similar H(f)gain constexpr fir_taps_real<32> taps_9k0_decim_2{ .low_frequency_normalized = -4500.0f / 48000.0f, // Negative -cutt off freq -3dB (real achieved data ,in the plot and measurements) .high_frequency_normalized = 4500.0f / 48000.0f, // Positive +cutt off freq -3dB (idem) .transition_normalized = 3500.0f / 48000.0f, // 3500 Hz = (8000 Hz - 4500 Hz) (both from plot H(f) curve plot) .taps = {{-53, -30, 47, 198, 355, 372, 89, -535, -1307, -1771, -1353, 370, 3384, 7109, 10535, 12591, 12591, 10535, 7109, 3384, 370, -1353, -1771, -1307, -535, 89, 372, 355, 198, 47, -30, -53}}, }; // Channel filter: fs=12000, pass=3000, stop=3300, decim=1, fout=12000 /* NOTE: Slightly less than 1.0 gain (normalized to 65536) due to max(taps) being * slightly larger than 32767 (33312). */ constexpr fir_taps_complex<64> taps_6k0_dsb_channel{ .low_frequency_normalized = -3000.0f / 12000.0f, .high_frequency_normalized = 3000.0f / 12000.0f, .transition_normalized = 300.0f / 12000.0f, .taps = {{ {-69, 0}, {-140, 0}, {119, 0}, {89, 0}, {-132, 0}, {-134, 0}, {197, 0}, {167, 0}, {-273, 0}, {-206, 0}, {372, 0}, {247, 0}, {-497, 0}, {-289, 0}, {654, 0}, {331, 0}, {-854, 0}, {-372, 0}, {1112, 0}, {411, 0}, {-1455, 0}, {-446, 0}, {1933, 0}, {476, 0}, {-2654, 0}, {-501, 0}, {3902, 0}, {520, 0}, {-6717, 0}, {-531, 0}, {20478, 0}, {32767, 0}, {20478, 0}, {-531, 0}, {-6717, 0}, {520, 0}, {3902, 0}, {-501, 0}, {-2654, 0}, {476, 0}, {1933, 0}, {-446, 0}, {-1455, 0}, {411, 0}, {1112, 0}, {-372, 0}, {-854, 0}, {331, 0}, {654, 0}, {-289, 0}, {-497, 0}, {247, 0}, {372, 0}, {-206, 0}, {-273, 0}, {167, 0}, {197, 0}, {-134, 0}, {-132, 0}, {89, 0}, {119, 0}, {-140, 0}, {-69, 0}, {0, 0}, }}, }; // Channel filter: fs=12000, pass=4500 (cutt off -3dBs), stop=4940 (<-60dBs), decim=1, fout=12000 (*1) real frec pass / stop , based on plotted H(f) curve) // For Europe AM commercial broadcasting stations in LF/MF/HF, Emissions Designator 9K00A3E Bandwidth: 9.00 kHz (derivative from taps_6k0_dsb_channel) // FIR filter design created with SciPy Python using "window method"; selected design parameters: num_taps = 64, cut_off = 4575. sample_rate = 12000 # Hz, // Created with : h = signal.firwin(num_taps, cut_off, nyq=sample_rate/2, window=('chebwin',50)) , achieving real plot curve (*1) with peak stop band ripple -60dBs. // post-scaled h taps to avoid decimals , targeting <= similar int values as previous taps_6k0_dsb_channel peak < 32.767 (2 exp 15), (29625) and similar H(f)gain constexpr fir_taps_complex<64> taps_9k0_dsb_channel{ .low_frequency_normalized = -4500.0f / 12000.0f, // Negative -cutt off freq -3dB (in the H(f) curve plot) .high_frequency_normalized = 4500.0f / 12000.0f, // Positive +cutt off freq -3dB (in the H(f) curve plot) .transition_normalized = 440.0f / 12000.0f, // 440Hz = (4940 Hz -4500 Hz) cut-3dB's (both data comes from H(f) curve plot and confirmed by measurements ) .taps = {{ {2, 0}, {-18, 0}, {34, 0}, {-33, 0}, {6, 0}, {44, 0}, {-91, 0}, {96, 0}, {-35, 0}, {-80, 0}, {193, 0}, {-223, 0}, {116, 0}, {112, 0}, {-353, 0}, {452, 0}, {-293, 0}, {-111, 0}, {584, 0}, {-844, 0}, {653, 0}, {22, 0}, {-921, 0}, {1554, 0}, {-1422, 0}, {301, 0}, {1533, 0}, {-3282, 0}, {3804, 0}, {-1819, 0}, {-4605, 0}, {29625, 0}, {29625, 0}, {-4605, 0}, {-1819, 0}, {3804, 0}, {-3282, 0}, {1533, 0}, {301, 0}, {-1422, 0}, {1554, 0}, {-921, 0}, {22, 0}, {653, 0}, {-844, 0}, {584, 0}, {-111, 0}, {-293, 0}, {452, 0}, {-353, 0}, {112, 0}, {116, 0}, {-223, 0}, {193, 0}, {-80, 0}, {-35, 0}, {96, 0}, {-91, 0}, {44, 0}, {6, 0}, {-33, 0}, {34, 0}, {-18, 0}, {2, 0}, }}, }; // USB AM 2K80J3E emission type /////////////////////////////////////////// // IFIR prototype filter: fs=12000, pass=3000, stop=3300, decim=1, fout=12000 constexpr fir_taps_complex<64> taps_2k8_usb_channel{ .low_frequency_normalized = 0, .high_frequency_normalized = 3000.0f / 12000.0f, .transition_normalized = 300.0f / 12000.0f, .taps = {{ {-146, 0}, {-41, -45}, {-1, 10}, {-95, 69}, {-194, -41}, {-91, -158}, {14, -43}, {-150, 67}, {-299, -133}, {-100, -307}, {50, -86}, {-254, 54}, {-453, -329}, {-62, -587}, {170, -189}, {-334, 0}, {-580, -645}, {104, -986}, {418, -304}, {-412, -88}, {-680, -1178}, {527, -1623}, {970, -432}, {-441, -196}, {-698, -2149}, {1617, -2800}, {2384, -507}, {-429, -311}, {-545, -5181}, {6925, -7691}, {14340, 0}, {10601, 11773}, {-1499, 14261}, {-8373, 6083}, {-5095, -1083}, {-265, -459}, {-753, 2318}, {-2954, 1315}, {-2064, -919}, {-149, -459}, {-531, 920}, {-1669, 355}, {-1100, -800}, {-44, -419}, {-346, 384}, {-992, 0}, {-580, -645}, {35, -332}, {-205, 149}, {-577, -123}, {-280, -485}, {80, -247}, {-91, 40}, {-294, -131}, {-101, -312}, {82, -142}, {-44, 9}, {-147, -107}, {-21, -197}, {79, -88}, {10, 0}, {-41, -45}, {15, -145}, {0, 0}, }}, }; // LSB AM 2K80J3E emission type /////////////////////////////////////////// // IFIR prototype filter: fs=12000, pass=3000, stop=3300, decim=1, fout=12000 constexpr fir_taps_complex<64> taps_2k8_lsb_channel{ .low_frequency_normalized = -3000.0f / 12000.0f, .high_frequency_normalized = 0, .transition_normalized = 300.0f / 12000.0f, .taps = {{ {-146, 0}, {-41, 45}, {-1, -10}, {-95, -69}, {-194, 41}, {-91, 158}, {14, 43}, {-150, -67}, {-299, 133}, {-100, 307}, {50, 86}, {-254, -54}, {-453, 329}, {-62, 587}, {170, 189}, {-334, 0}, {-580, 645}, {104, 986}, {418, 304}, {-412, 88}, {-680, 1178}, {527, 1623}, {970, 432}, {-441, 196}, {-698, 2149}, {1617, 2800}, {2384, 507}, {-429, 311}, {-545, 5181}, {6925, 7691}, {14340, 0}, {10601, -11773}, {-1499, -14261}, {-8373, -6083}, {-5095, 1083}, {-265, 459}, {-753, -2318}, {-2954, -1315}, {-2064, 919}, {-149, 459}, {-531, -920}, {-1669, -355}, {-1100, 800}, {-44, 419}, {-346, -384}, {-992, 0}, {-580, 645}, {35, 332}, {-205, -149}, {-577, 123}, {-280, 485}, {80, 247}, {-91, -40}, {-294, 131}, {-101, 312}, {82, 142}, {-44, -9}, {-147, 107}, {-21, 197}, {79, 88}, {10, 0}, {-41, 45}, {15, 145}, {0, 0}, }}, }; // USB AM 700Hz filter: fs=12000, start=600, end=800, width=200, stop=40db, decim=1, fout=12000 constexpr fir_taps_complex<64> taps_0k7_usb_channel{ .low_frequency_normalized = 600.0f / 12000.0f, .high_frequency_normalized = 800.0f / 12000.0f, .transition_normalized = 200.0f / 12000.0f, .taps = {{ {531, 0}, {192, 73}, {181, 163}, {129, 254}, {34, 328}, {-97, 364}, {-251, 345}, {-403, 261}, {-524, 111}, {-585, -92}, {-564, -326}, {-448, -554}, {-239, -737}, {43, -836}, {366, -822}, {681, -681}, {936, -417}, {1085, -56}, {1090, 354}, {935, 757}, {629, 1090}, {205, 1296}, {-283, 1331}, {-766, 1180}, {-1172, 851}, {-1435, 384}, {-1510, -158}, {-1377, -702}, {-1049, -1165}, {-568, -1480}, {0, -1596}, {574, -1496}, {1072, -1191}, {1422, -724}, {1576, -165}, {1515, 406}, {1251, 908}, {827, 1273}, {309, 1453}, {-226, 1431}, {-703, 1218}, {-1058, 856}, {-1248, 405}, {-1257, -65}, {-1100, -489}, {-810, -810}, {-441, -992}, {-53, -1024}, {297, -916}, {566, -699}, {725, -418}, {765, -121}, {697, 148}, {546, 355}, {348, 479}, {138, 517}, {-50, 477}, {-194, 381}, {-280, 252}, {-308, 118}, {-285, 0}, {-228, -87}, {-153, -138}, {-241, -473}, }}, }; // WFM 200KF8E emission type ////////////////////////////////////////////// // IFIR image-reject filter: fs=3072000, pass=100000, stop=484000, decim=4, fout=768000 constexpr fir_taps_real<24> taps_200k_wfm_decim_0 = { .low_frequency_normalized = -100000.0f / 3072000.0f, .high_frequency_normalized = 100000.0f / 3072000.0f, .transition_normalized = 384000.0f / 3072000.0f, .taps = {{ 48, -18, -151, -364, -557, -548, -139, 789, 2187, 3800, 5230, 6071, 6071, 5230, 3800, 2187, 789, -139, -548, -557, -364, -151, -18, 48, }}, }; // IFIR prototype filter: fs=768000, pass=100000, stop=284000, decim=2, fout=384000 constexpr fir_taps_real<16> taps_200k_wfm_decim_1 = { .low_frequency_normalized = -100000.0f / 768000.0f, .high_frequency_normalized = 100000.0f / 768000.0f, .transition_normalized = 184000.0f / 768000.0f, .taps = {{ -67, -123, 388, 622, -1342, -2185, 4599, 14486, 14486, 4599, -2185, -1342, 622, 388, -123, -67, }}, }; /* Wideband audio filter */ /* 96kHz int16_t input * -> FIR filter, <15kHz (0.156fs) pass, >19kHz (0.198fs) stop * -> 48kHz int16_t output, gain of 1.0 (I think). * Padded to multiple of four taps for unrolled FIR code. * sum(abs(taps)): 125270 */ constexpr fir_taps_real<64> taps_64_lp_156_198{ .low_frequency_normalized = -0.156f, .high_frequency_normalized = 0.156f, .transition_normalized = 0.04f, .taps = {{ -27, 166, 104, -36, -174, -129, 109, 287, 148, -232, -430, -130, 427, 597, 49, -716, -778, 137, 1131, 957, -493, -1740, -1121, 1167, 2733, 1252, -2633, -4899, -1336, 8210, 18660, 23254, 18660, 8210, -1336, -4899, -2633, 1252, 2733, 1167, -1121, -1740, -493, 957, 1131, 137, -778, -716, 49, 597, 427, -130, -430, -232, 148, 287, 109, -129, -174, -36, 104, 166, -27, 0, }}, }; // WFM 180kHZ General purpose filter with sharp transition , it improves Commercial WFM S/N in weak signals ////////////////////////////////////////////// // IFIR image-reject filter: fs=3072000, pass=90000, stop=250000, decim=4, fout=768000 constexpr fir_taps_real<24> taps_180k_wfm_decim_0 = { .low_frequency_normalized = -90000.0f / 3072000.0f, .high_frequency_normalized = 90000.0f / 3072000.0f, .transition_normalized = 160000.0f / 3072000.0f, .taps = {{ 55, 122, 244, 424, 666, 965, 1308, 1669, 2019, 2321, 2544, 2663, 2663, 2544, 2321, 2019, 1669, 1308, 965, 666, 424, 244, 122, 55, }}, }; // IFIR prototype filter: fs=768000, pass=90000, stop=110000, decim=2, fout=384000 constexpr fir_taps_real<16> taps_180k_wfm_decim_1 = { .low_frequency_normalized = -90000.0f / 768000.0f, .high_frequency_normalized = 90000.0f / 768000.0f, .transition_normalized = 20000.0f / 768000.0f, .taps = {{ 55, 19, -356, -916, -529, 2139, 6695, 10392, 10392, 6695, 2139, -529, -916, -356, 19, 55, }}, }; // WFM 40kHZ filter for NOAA APT reception in 137Mhz band with sharp transition ////////////////////////////////////////////// // IFIR image-reject filter: fs=3072000, pass=20000, stop=97000, decim=4, fout=768000 constexpr fir_taps_real<24> taps_40k_wfm_decim_0 = { .low_frequency_normalized = -20000.0f / 3072000.0f, .high_frequency_normalized = 20000.0f / 3072000.0f, .transition_normalized = 67000.0f / 3072000.0f, .taps = {{ 46, 112, 230, 408, 650, 953, 1301, 1671, 2029, 2340, 2570, 2692, 2692, 2570, 2340, 2029, 1671, 1301, 953, 650, 408, 230, 112, 46, }}, }; // IFIR prototype filter: fs=768000, pass=20000, stop=55000, decim=2, fout=384000 constexpr fir_taps_real<16> taps_40k_wfm_decim_1 = { .low_frequency_normalized = -20000.0f / 768000.0f, .high_frequency_normalized = 20000.0f / 768000.0f, .transition_normalized = 35000.0f / 768000.0f, .taps = {{ 83, 299, 743, 1456, 2396, 3418, 4297, 4808, 4808, 4297, 3418, 2396, 1456, 743, 299, 83, }}, }; // TPMS decimation filters //////////////////////////////////////////////// // IFIR image-reject filter: fs=2457600, pass=100000, stop=407200, decim=4, fout=614400 static constexpr fir_taps_real<24> taps_200k_decim_0 = { .low_frequency_normalized = -100000.0f / 2457600.0f, .high_frequency_normalized = 100000.0f / 2457600.0f, .transition_normalized = 307200.0f / 2457600.0f, .taps = {{ 90, 94, 4, -240, -570, -776, -563, 309, 1861, 3808, 5618, 6710, 6710, 5618, 3808, 1861, 309, -563, -776, -570, -240, 4, 94, 90, }}, }; // IFIR prototype filter: fs=614400, pass=100000, stop=207200, decim=2, fout=307200 static constexpr fir_taps_real<16> taps_200k_decim_1 = { .low_frequency_normalized = -100000.0f / 614400.0f, .high_frequency_normalized = 100000.0f / 614400.0f, .transition_normalized = 107200.0f / 614400.0f, .taps = {{ -132, -256, 545, 834, -1507, -2401, 4666, 14583, 14583, 4666, -2401, -1507, 834, 545, -256, -132, }}, }; #endif /*__DSP_FIR_TAPS_H__*/