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updating_comments (#2191)

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Brumi-2021 2024-07-08 11:11:12 +02:00 • committed by GitHub
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commit 9ef58b7763
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4 changed files with 7 additions and 12 deletions
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firmware/baseband/dsp_hilbert.cpp
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@ -33,11 +33,11 @@ HilbertTransform::HilbertTransform() {
}
void HilbertTransform::execute(float in, float& out_i, float& out_q) {
// Synthesized Hilbert Transform, it is implemented based on 1/2 band LPF and later freq shift fs/4, achieving a H.T_BW of transmitted = fs/2 ;
// Half_band LPF means a LP filter with f_cut_off = fs/4; Half band = Half max band = 1/2 * fs_max = 1/2 x f_Nyquist = 1/2 * fs/2 = fs/4
float a = 0, b = 0;
float in_filtered = sos_input.execute(in) * 1.0f; // Anti-aliasing LPF at fs/4 mic audio filter front-end.
// it is exactly matching with the usefull mic BW_cut_off =fs/4 of the following Hilbert Transf. implementation
// Ex. to TX SSB 3khz BW (3KHZ =fs/4) ,we need to run Hiblert_Trf fs = 12khz . And our anti-aliasing filter is also fcut =fs/4 when we use a half_band_LPF .
switch (n) {
case 0: