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Adding 2 WFM filters more to current Audio App ( bw 180Khz and 40 khz to support rx for weather NOAA APT) (#961)

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* First part new filter 40k for NOAA in Audio App

* Adding a third WFM filter 180Khz general pursose
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Brumi-2021 2023-05-07 16:08:45 +02:00 • committed by GitHub
parent 3cb927c840
commit dfadd38e32
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6 changed files with 105 additions and 4 deletions
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53
firmware/common/dsp_fir_taps.hpp
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@ -450,6 +450,59 @@ constexpr fir_taps_real<64> taps_64_lp_156_198 {
} },
};
// 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