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define ht length #227

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define ht length #227

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64b5137
define ht lenght
ik1xpv May 15, 2022
4ad7556
HTLEN
ik1xpv May 16, 2022
746d9ca
Soft tone generator
ik1xpv May 21, 2022
ba50e58
HTLEN tests
ik1xpv May 23, 2022
b8af5c9
Update config.h
ik1xpv May 23, 2022
cc9f320
large FFTN test
ik1xpv Jun 9, 2022
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7 changes: 4 additions & 3 deletions Core/fft_mt_r2iq.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -156,6 +156,7 @@ void fft_mt_r2iq::Init(float gain, ringbuffer<int16_t> *input, ringbuffer<float>

// DbgPrintf((char *) "RandTable generated\n");

#define HTLEN (halfFft / 4 + 1)
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// filters
fftwf_complex *pfilterht; // time filter ht
pfilterht = (fftwf_complex*)fftwf_malloc(sizeof(fftwf_complex)*halfFft); // halfFft
Expand All @@ -166,7 +167,7 @@ void fft_mt_r2iq::Init(float gain, ringbuffer<int16_t> *input, ringbuffer<float>
}

filterplan_t2f_c2c = fftwf_plan_dft_1d(halfFft, pfilterht, filterHw[0], FFTW_FORWARD, FFTW_MEASURE);
float *pht = new float[halfFft / 4 + 1];
float *pht = new float[HTLEN];
const float Astop = 120.0f;
const float relPass = 0.85f; // 85% of Nyquist should be usable
const float relStop = 1.1f; // 'some' alias back into transition band is OK
Expand All @@ -176,7 +177,7 @@ void fft_mt_r2iq::Init(float gain, ringbuffer<int16_t> *input, ringbuffer<float>
// to allow same stopband-attenuation for all decimations
float Bw = 64.0f / mratio[d];
// Bw *= 0.8f; // easily visualize Kaiser filter's response
KaiserWindow(halfFft / 4 + 1, Astop, relPass * Bw / 128.0f, relStop * Bw / 128.0f, pht);
KaiserWindow(HTLEN, Astop, relPass * Bw / 128.0f, relStop * Bw / 128.0f, pht);

float gainadj = gain * 2048.0f / (float)FFTN_R_ADC; // reference is FFTN_R_ADC == 2048

Expand All @@ -185,7 +186,7 @@ void fft_mt_r2iq::Init(float gain, ringbuffer<int16_t> *input, ringbuffer<float>
pfilterht[t][0] = pfilterht[t][1]= 0.0F;
}

for (int t = 0; t < (halfFft/4+1); t++)
for (int t = 0; t < (HTLEN); t++)
{
pfilterht[halfFft-1-t][0] = gainadj * pht[t];
}
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