mayhem-firmware/firmware/common/dsp_fir_taps.hpp

/*
 * 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 <cstdint>
#include <array>

#include "complex.hpp"

template<size_t N>
struct fir_taps_real {
	float low_frequency_normalized;
	float high_frequency_normalized;
	float transition_normalized;
	std::array<int16_t, N> taps;
};

template<size_t N>
struct fir_taps_complex {
	float low_frequency_normalized;
	float high_frequency_normalized;
	float transition_normalized;
	std::array<complex16_t, N> 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__*/