diff --git a/firmware/baseband/dsp_fir_taps.hpp b/firmware/baseband/dsp_fir_taps.hpp index 94a15760..9839a9de 100644 --- a/firmware/baseband/dsp_fir_taps.hpp +++ b/firmware/baseband/dsp_fir_taps.hpp @@ -27,8 +27,18 @@ #include "complex.hpp" +template +struct fir_taps_real { + float pass_frequency_normalized; + float stop_frequency_normalized; + std::array taps; +}; + /* 3kHz/6.7kHz @ 96kHz. sum(abs(taps)): 89429 */ -constexpr std::array taps_64_lp_031_070_tfilter { { +constexpr fir_taps_real<64> taps_64_lp_031_070_tfilter { + .pass_frequency_normalized = 0.031f, + .stop_frequency_normalized = 0.070f, + .taps = { { 56, 58, 81, 100, 113, 112, 92, 49, -21, -120, -244, -389, -543, -692, -819, -903, -923, -861, -698, -424, -34, 469, 1073, 1756, @@ -37,10 +47,14 @@ constexpr std::array taps_64_lp_031_070_tfilter { { 1073, 469, -34, -424, -698, -861, -923, -903, -819, -692, -543, -389, -244, -120, -21, 49, 92, 112, 113, 100, 81, 58, 56, 0, -} }; + } }, +}; /* 4kHz/7.5kHz @ 96kHz. sum(abs(taps)): 96783 */ -constexpr std::array taps_64_lp_042_078_tfilter { { +constexpr fir_taps_real<64> taps_64_lp_042_078_tfilter { + .pass_frequency_normalized = 0.042f, + .stop_frequency_normalized = 0.078f, + .taps = { { -19, 39, 72, 126, 197, 278, 360, 432, 478, 485, 438, 327, 152, -82, -359, -651, -922, -1132, -1236, -1192, -968, -545, 81, 892, @@ -49,10 +63,14 @@ constexpr std::array taps_64_lp_042_078_tfilter { { 81, -545, -968, -1192, -1236, -1132, -922, -651, -359, -82, 152, 327, 438, 485, 478, 432, 360, 278, 197, 126, 72, 39, -19, 0, -} }; + } }, +}; /* 5kHz/8.5kHz @ 96kHz. sum(abs(taps)): 101312 */ -constexpr std::array taps_64_lp_052_089_tfilter { { +constexpr fir_taps_real<64> taps_64_lp_052_089_tfilter { + .pass_frequency_normalized = 0.052f, + .stop_frequency_normalized = 0.089f, + .taps = { { -65, -88, -129, -163, -178, -160, -100, 9, 160, 340, 523, 675, 758, 738, 591, 313, -76, -533, -987, -1355, -1544, -1472, -1077, -335, @@ -61,10 +79,14 @@ constexpr std::array taps_64_lp_052_089_tfilter { { -1077, -1472, -1544, -1355, -987, -533, -76, 313, 591, 738, 758, 675, 523, 340, 160, 9, -100, -160, -178, -163, -129, -88, -65, 0, -} }; + } }, +}; /* 6kHz/9.6kHz @ 96kHz. sum(abs(taps)): 105088 */ -constexpr std::array taps_64_lp_063_100_tfilter { { +constexpr fir_taps_real<64> taps_64_lp_063_100_tfilter { + .pass_frequency_normalized = 0.063f, + .stop_frequency_normalized = 0.100f, + .taps = { { 43, 21, -2, -54, -138, -245, -360, -453, -493, -451, -309, -73, 227, 535, 776, 876, 773, 443, -86, -730, -1357, -1801, -1898, -1515, @@ -73,10 +95,14 @@ constexpr std::array taps_64_lp_063_100_tfilter { { -1898, -1801, -1357, -730, -86, 443, 773, 876, 776, 535, 227, -73, -309, -451, -493, -453, -360, -245, -138, -54, -2, 21, 43, 0, -} }; + } }, +}; /* 7kHz/10.4kHz @ 96kHz: sum(abs(taps)): 110157 */ -constexpr std::array taps_64_lp_073_108_tfilter { { +constexpr fir_taps_real<64> taps_64_lp_073_108_tfilter { + .pass_frequency_normalized = 0.073f, + .stop_frequency_normalized = 0.108f, + .taps = { { 79, 145, 241, 334, 396, 394, 306, 130, -109, -360, -550, -611, -494, -197, 229, 677, 1011, 1096, 846, 257, -570, -1436, -2078, -2225, @@ -85,10 +111,14 @@ constexpr std::array taps_64_lp_073_108_tfilter { { -2078, -1436, -570, 257, 846, 1096, 1011, 677, 229, -197, -494, -611, -550, -360, -109, 130, 306, 394, 396, 334, 241, 145, 79, 0, -} }; + } }, +}; /* 8kHz/11.5kHz @ 96kHz. sum(abs(taps)): 112092 */ -constexpr std::array taps_64_lp_083_120_tfilter { { +constexpr fir_taps_real<64> taps_64_lp_083_120_tfilter { + .pass_frequency_normalized = 0.083f, + .stop_frequency_normalized = 0.120f, + .taps = { { -63, -72, -71, -21, 89, 248, 417, 537, 548, 407, 124, -237, -563, -723, -621, -238, 337, 919, 1274, 1201, 617, -382, -1514, -2364, @@ -97,10 +127,14 @@ constexpr std::array taps_64_lp_083_120_tfilter { { -1514, -382, 617, 1201, 1274, 919, 337, -238, -621, -723, -563, -237, 124, 407, 548, 537, 417, 248, 89, -21, -71, -72, -63, 0, -} }; + } }, +}; /* 9kHz/12.4kHz @ 96kHz. sum(abs(taps)): 116249 */ -constexpr std::array taps_64_lp_094_129_tfilter { { +constexpr fir_taps_real<64> taps_64_lp_094_129_tfilter { + .pass_frequency_normalized = 0.094f, + .stop_frequency_normalized = 0.129f, + .taps = { { 5, -93, -198, -335, -449, -478, -378, -144, 166, 444, 563, 440, 82, -395, -788, -892, -589, 73, 859, 1421, 1431, 734, -530, -1919, @@ -109,10 +143,14 @@ constexpr std::array taps_64_lp_094_129_tfilter { { -530, 734, 1431, 1421, 859, 73, -589, -892, -788, -395, 82, 440, 563, 444, 166, -144, -378, -478, -449, -335, -198, -93, 5, 0, -} }; + } }, +}; /* 10kHz/13.4kHz @ 96kHz. sum(abs(taps)): 118511 */ -constexpr std::array taps_64_lp_104_140_tfilter { { +constexpr fir_taps_real<64> taps_64_lp_104_140_tfilter { + .pass_frequency_normalized = 0.104f, + .stop_frequency_normalized = 0.140f, + .taps = { { 89, 159, 220, 208, 84, -147, -412, -597, -588, -345, 58, 441, 595, 391, -128, -730, -1080, -914, -198, 793, 1558, 1594, 678, -942, @@ -121,12 +159,16 @@ constexpr std::array taps_64_lp_104_140_tfilter { { 678, 1594, 1558, 793, -198, -914, -1080, -730, -128, 391, 595, 441, 58, -345, -588, -597, -412, -147, 84, 208, 220, 159, 89, 0, -} }; + } }, +}; /* Wideband FM channel filter * 103kHz/128kHz @ 768kHz */ -constexpr std::array taps_64_lp_130_169_tfilter { { +constexpr fir_taps_real<64> taps_64_lp_130_169_tfilter { + .pass_frequency_normalized = 0.130f, + .stop_frequency_normalized = 0.169f, + .taps = { { 100, 127, 62, -157, -470, -707, -678, -332, 165, 494, 400, -85, -610, -729, -253, 535, 1026, 734, -263, -1264, -1398, -332, 1316, 2259, @@ -135,7 +177,8 @@ constexpr std::array taps_64_lp_130_169_tfilter { { 2259, 1316, -332, -1398, -1264, -263, 734, 1026, 535, -253, -729, -610, -85, 400, 494, 165, -332, -678, -707, -470, -157, 62, 127, 100, -} }; + } }, +}; /* Wideband audio filter */ /* 96kHz int16_t input @@ -144,7 +187,10 @@ constexpr std::array taps_64_lp_130_169_tfilter { { * Padded to multiple of four taps for unrolled FIR code. * sum(abs(taps)): 125270 */ -constexpr std::array taps_64_lp_156_198 { { +constexpr fir_taps_real<64> taps_64_lp_156_198 { + .pass_frequency_normalized = 0.156f, + .stop_frequency_normalized = 0.196f, + .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, @@ -153,133 +199,7 @@ constexpr std::array taps_64_lp_156_198 { { -1121, -1740, -493, 957, 1131, 137, -778, -716, 49, 597, 427, -130, -430, -232, 148, 287, 109, -129, -174, -36, 104, 166, -27, 0, -} }; - -/* Narrowband FM filter */ -/* 96kHz int16_t input - * -> FIR filter, <4kHz (0.042fs) pass, Hamming window. - * -> 48kHz int16_t output, gain of 1.0. - * Padded to multiple of four taps for unrolled FIR code. - * sum(abs(taps)): 81493 - */ -constexpr std::array taps_64_lp_042_hamming { { - 51, 57, 61, 65, 63, 55, 35, 0, - -52, -122, -207, -304, -402, -491, -556, -582, - -552, -453, -271, 0, 363, 815, 1343, 1930, - 2553, 3183, 3788, 4338, 4802, 5154, 5374, 5449, - 5374, 5154, 4802, 4338, 3788, 3183, 2553, 1930, - 1343, 815, 363, 0, -271, -453, -552, -582, - -556, -491, -402, -304, -207, -122, -52, 0, - 35, 55, 63, 65, 61, 57, 51, 0 -} }; - -/* Narrowband FM filter */ -/* 96kHz int16_t input - * -> FIR filter, <6kHz (0.063fs) pass, Hamming window. - * -> 48kHz int16_t output, gain of 1.0. - * Padded to multiple of four taps for unrolled FIR code. - * sum(abs(taps)): 92477 - */ -constexpr std::array taps_64_lp_063_hamming { { - -20, -40, -59, -75, -83, -78, -52, 0, - 77, 173, 272, 352, 386, 348, 221, 0, - -300, -644, -974, -1219, -1304, -1158, -730, 0, - 1016, 2261, 3641, 5034, 6305, 7325, 7985, 8213, - 7985, 7325, 6305, 5034, 3641, 2261, 1016, 0, - -730, -1158, -1304, -1219, -974, -644, -300, 0, - 221, 348, 386, 352, 272, 173, 77, 0, - -52, -78, -83, -75, -59, -40, -20, 0 -} }; - -/* sum(abs(taps)): 85241 */ -constexpr std::array taps_64_lp_063_blackman { { - 0, 0, -2, -6, -11, -14, -11, 0, - 24, 62, 110, 157, 188, 184, 125, 0, - -194, -441, -704, -926, -1035, -957, -626, 0, - 925, 2109, 3466, 4872, 6182, 7249, 7946, 8189, - 7946, 7249, 6182, 4872, 3466, 2109, 925, 0, - -626, -957, -1035, -926, -704, -441, -194, 0, - 125, 184, 188, 157, 110, 62, 24, 0, - -11, -14, -11, -6, -2, 0, 0, 0 -} }; - -/* Narrowband FM filter */ -/* 96kHz int16_t input - * -> FIR filter, <8kHz (0.083fs) pass, Hamming window. - * -> 48kHz int16_t output, gain of 1.0. - * Padded to multiple of four taps for unrolled FIR code. - * sum(abs(taps)): 99180 - */ -constexpr std::array taps_64_lp_083_hamming { { - -26, 0, 32, 65, 90, 95, 67, 0, - -100, -211, -294, -304, -208, 0, 288, 582, - 782, 785, 524, 0, -702, -1412, -1901, -1931, - -1322, 0, 1962, 4340, 6795, 8932, 10388, 10904, - 10388, 8932, 6795, 4340, 1962, 0, -1322, -1931, - -1901, -1412, -702, 0, 524, 785, 782, 582, - 288, 0, -208, -304, -294, -211, -100, 0, - 67, 95, 90, 65, 32, 0, -26, 0 -} }; - -/* sum(abs(taps)): 92568 */ -constexpr std::array taps_64_lp_083_blackman { { - 0, 0, 1, 5, 12, 17, 15, 0, - -32, -77, -119, -136, -101, 0, 164, 355, - 508, 541, 381, 0, -560, -1173, -1636, -1717, - -1209, 0, 1876, 4221, 6695, 8883, 10388, 10924, - 10388, 8883, 6695, 4221, 1876, 0, -1209, -1717, - -1636, -1173, -560, 0, 381, 541, 508, 355, - 164, 0, -101, -136, -119, -77, -32, 0, - 15, 17, 12, 5, 1, 0, 0, 0 -} }; - -/* Narrowband FM filter */ -/* 96kHz int16_t input - * -> FIR filter, <10kHz (0.104fs) pass, Hamming window. - * -> 48kHz int16_t output, gain of 1.0. - * Padded to multiple of four taps for unrolled FIR code. - * sum(abs(taps)): 106396 - */ -constexpr std::array taps_64_lp_104_hamming { { - 53, 40, 8, -37, -83, -106, -82, 0, - 123, 236, 272, 175, -54, -347, -571, -583, - -299, 235, 833, 1215, 1116, 422, -728, -1934, - -2625, -2254, -512, 2509, 6285, 9975, 12663, 13646, - 12663, 9975, 6285, 2509, -512, -2254, -2625, -1934, - -728, 422, 1116, 1215, 833, 235, -299, -583, - -571, -347, -54, 175, 272, 236, 123, 0, - -82, -106, -83, -37, 8, 40, 53, 0 -} }; - -/* sum(abs(taps)): 99426 */ -constexpr std::array taps_64_lp_104_blackman { { - 0, 0, 0, -3, -11, -19, -18, 0, - 39, 85, 110, 78, -26, -184, -325, -355, - -194, 161, 605, 926, 889, 350, -626, -1717, - -2397, -2109, -489, 2436, 6184, 9906, 12645, 13652, - 12645, 9906, 6184, 2436, -489, -2109, -2397, -1717, - -626, 350, 889, 926, 605, 161, -194, -355, - -325, -184, -26, 78, 110, 85, 39, 0, - -18, -19, -11, -3, 0, 0, 0, 0 -} }; - -/* Narrowband AM audio filter */ -/* 96kHz int16_t input - * -> FIR filter, <3kHz (0.031fs) pass, >6kHz (0.063fs) stop - * -> 48kHz int16_t output, gain of 1.0 (I think). - * Padded to multiple of four taps for unrolled FIR code. - * sum(abs(taps)): 94053 - */ -/* TODO: Review this filter, it's very quick and dirty. */ -constexpr std::array taps_64_lp_031_063 { { - -254, 255, 244, 269, 302, 325, 325, 290, - 215, 99, -56, -241, -442, -643, -820, -950, - -1009, -974, -828, -558, -160, 361, 992, 1707, - 2477, 3264, 4027, 4723, 5312, 5761, 6042, 6203, - 6042, 5761, 5312, 4723, 4027, 3264, 2477, 1707, - 992, 361, -160, -558, -828, -974, -1009, -950, - -820, -643, -442, -241, -56, 99, 215, 290, - 325, 325, 302, 269, 244, 255, -254, 0, -} }; + } }, +}; #endif/*__DSP_FIR_TAPS_H__*/ diff --git a/firmware/baseband/main.cpp b/firmware/baseband/main.cpp index 15fb2392..aa879c65 100755 --- a/firmware/baseband/main.cpp +++ b/firmware/baseband/main.cpp @@ -436,9 +436,8 @@ public: * -> FIR filter, 48kHz int16_t[32] */ auto channel = channel_filter.execute(decimator_out, work_baseband_buffer); - // TODO: Set with information determined from filter taps. - channel_filter_pass_frequency = decimator_out.sampling_rate * 31 / 1000; - channel_filter_stop_frequency = decimator_out.sampling_rate * 70 / 1000; + channel_filter_pass_frequency = decimator_out.sampling_rate * channel_filter_taps.pass_frequency_normalized; + channel_filter_stop_frequency = decimator_out.sampling_rate * channel_filter_taps.stop_frequency_normalized; // TODO: Feed channel_stats post-decimation data? feed_channel_stats(channel); @@ -461,7 +460,8 @@ public: private: ChannelDecimator decimator { ChannelDecimator::DecimationFactor::By32 }; - dsp::decimate::FIRAndDecimateBy2Complex<64> channel_filter { taps_64_lp_031_070_tfilter }; + const fir_taps_real<64>& channel_filter_taps = taps_64_lp_031_070_tfilter; + dsp::decimate::FIRAndDecimateBy2Complex<64> channel_filter { channel_filter_taps.taps }; dsp::demodulate::AM demod; IIRBiquadFilter audio_hpf { { 0.93346032f, -1.86687724f, 0.93346032f }, @@ -485,9 +485,8 @@ public: * -> FIR filter, <6kHz (0.063fs) pass, gain 1.0 * -> 48kHz int16_t[32] */ auto channel = channel_filter.execute(decimator_out, work_baseband_buffer); - // TODO: Set with information determined from filter taps. - channel_filter_pass_frequency = decimator_out.sampling_rate * 42 / 1000; - channel_filter_stop_frequency = decimator_out.sampling_rate * 78 / 1000; + channel_filter_pass_frequency = decimator_out.sampling_rate * channel_filter_taps.pass_frequency_normalized; + channel_filter_stop_frequency = decimator_out.sampling_rate * channel_filter_taps.stop_frequency_normalized; // TODO: Feed channel_stats post-decimation data? feed_channel_stats(channel); @@ -510,7 +509,8 @@ public: private: ChannelDecimator decimator { ChannelDecimator::DecimationFactor::By32 }; - dsp::decimate::FIRAndDecimateBy2Complex<64> channel_filter { taps_64_lp_042_078_tfilter }; + const fir_taps_real<64>& channel_filter_taps = taps_64_lp_042_078_tfilter; + dsp::decimate::FIRAndDecimateBy2Complex<64> channel_filter { channel_filter_taps.taps }; dsp::demodulate::FM demod { 48000, 7500 }; IIRBiquadFilter audio_hpf { @@ -578,7 +578,8 @@ private: dsp::decimate::DecimateBy2CIC4Real audio_dec_1; dsp::decimate::DecimateBy2CIC4Real audio_dec_2; dsp::decimate::DecimateBy2CIC4Real audio_dec_3; - dsp::decimate::FIR64AndDecimateBy2Real audio_filter { taps_64_lp_156_198 }; + const fir_taps_real<64>& audio_filter_taps = taps_64_lp_156_198; + dsp::decimate::FIR64AndDecimateBy2Real audio_filter { audio_filter_taps.taps }; IIRBiquadFilter audio_hpf { { 0.93346032f, -1.86687724f, 0.93346032f }, @@ -628,9 +629,8 @@ public: * -> FIR filter, 76.8kHz int16_t[64] */ auto channel = channel_filter.execute(decimator_out, work_baseband_buffer); - // TODO: Set with information determined from filter taps. - channel_filter_pass_frequency = decimator_out.sampling_rate * 31 / 1000; - channel_filter_stop_frequency = decimator_out.sampling_rate * 70 / 1000; + channel_filter_pass_frequency = decimator_out.sampling_rate * channel_filter_taps.pass_frequency_normalized; + channel_filter_stop_frequency = decimator_out.sampling_rate * channel_filter_taps.stop_frequency_normalized; /* 76.8kHz, 64 samples */ feed_channel_stats(channel); @@ -660,7 +660,8 @@ public: private: ChannelDecimator decimator { ChannelDecimator::DecimationFactor::By16 }; - dsp::decimate::FIRAndDecimateBy2Complex<64> channel_filter { taps_64_lp_031_070_tfilter }; + const fir_taps_real<64>& channel_filter_taps = taps_64_lp_031_070_tfilter; + dsp::decimate::FIRAndDecimateBy2Complex<64> channel_filter { channel_filter_taps.taps }; dsp::demodulate::FM demod { 76800, 9600 * 2 }; ClockRecovery clock_recovery;