kopia lustrzana https://github.com/AlexandreRouma/SDRPlusPlus
35 wiersze
1.2 KiB
C++
35 wiersze
1.2 KiB
C++
#pragma once
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#include <math.h>
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#include "tap.h"
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#include "../math/constants.h"
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namespace dsp {
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template<class T>
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inline tap<T> rootRaisedCosine(int count, double beta, double Ts) {
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// Allocate taps
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tap<T> taps = taps::alloc<T>(count);
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// Generate taps
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double half = (double)count / 2.0;
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double limit = Ts / (4.0 * beta);
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for (int i = 0; i < count; i++) {
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double t = (double)i - half + 0.5;
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if (t == 0.0) {
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taps.taps[i] = (1.0 + beta*(4.0/DB_M_PI - 1.0)) / Ts;
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}
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else if (t == limit || t == -limit) {
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taps.taps[i] = ((1.0 + 2.0/DB_M_PI)*sin(DB_M_PI/(4.0*beta)) + (1.0 - 2.0/DB_M_PI)*cos(DB_M_PI/(4.0*beta))) * beta/(Ts*DB_M_SQRT2);
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}
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else {
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taps.taps[i] = ((sin((1.0 - beta)*DB_M_PI*t/Ts) + cos((1.0 + beta)*DB_M_PI*t/Ts)*4.0*beta*t/Ts) / ((1.0 - (4.0*beta*t/Ts)*(4.0*beta*t/Ts))*DB_M_PI*t/Ts)) / Ts;
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}
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}
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return taps;
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}
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template<class T>
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inline tap<T> rootRaisedCosine(int count, double beta, double symbolrate, double samplerate) {
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return rootRaisedCosine<T>(count, beta, samplerate / symbolrate);
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}
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} |