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Broadcast FM de-emphasis using 75us time constant.

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Jared Boone
2016-01-01 20:56:30 -08:00
parent 2e90edbf39
commit 0e04939439
3 changed files with 11 additions and 0 deletions
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firmware/baseband/dsp_iir_config.hpp
+8
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@@ -48,4 +48,12 @@ constexpr iir_biquad_config_t audio_deemph_300_6_config {
{ 1.00000000f, -0.96148145f, 0.00000000f, },
};
// 75us RC time constant, used in broadcast FM in Americas, South Korea
// scipy.signal.butter(1, 2122 / 24000.0, 'lowpass', analog=False)
// NOTE: Technically, order-1 filter, b[2] = a[2] = 0.
constexpr iir_biquad_config_t audio_deemph_2122_6_config {
{ 0.12264116f, 0.12264116f, 0.00000000f, },
{ 1.00000000f, -0.75471767f, 0.00000000f, },
};
#endif/*__DSP_IIR_CONFIG_H__*/