FIR RRC filter

2026-06-12 18:58:48 -04:00 · 2026-02-10 23:25:06 +01:00
parent 26455261ee
commit 649312d7ba
13 changed files with 432 additions and 23 deletions
@@ -0,0 +1,50 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2026 Edouard Griffiths, F4EXB <f4exb06@gmail.com>               //
+//                                                                               //
+// This program is free software; you can redistribute it and/or modify          //
+// it under the terms of the GNU General Public License as published by          //
+// the Free Software Foundation as version 3 of the License, or                  //
+// (at your option) any later version.                                           //
+//                                                                               //
+// This program is distributed in the hope that it will be useful,               //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of                //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
+// GNU General Public License V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#include "mainbench.h"
+#include "dsp/firfilterrrc.h"
+#include <QDebug>
+
+void MainBench::testFIRRRCFilter()
+{
+    qDebug() << "MainBench::testFIRRRCFilter";
+    FIRFilterRRC filter;
+    filter.create(0.05f, 0.35f, 8, FIRFilterRRC::Normalization::Gain);  // 2400 baud, 0.35 rolloff
+
+    qDebug() << "MainBench::testFIRRRCFilter: filter created";
+    FILE *fd_filter = fopen("test_rrc_filter.txt", "w");
+    const std::vector<float>& taps = filter.getTaps();
+    for (auto tap : taps) {
+        fprintf(fd_filter, "%f\n", std::abs(tap));
+    }
+    qDebug() << "MainBench::testFIRRRCFilter: filter coefficients written to test_rrc_filter.txt";
+    fclose(fd_filter);
+
+    qDebug() << "MainBench::testFIRRRCFilter: running filter";
+    FILE *fd = fopen("test_rrc.txt", "w");
+
+    for (int i = 0; i < 1000; i++)
+    {
+        Real phi = i * (1200.0 / 48000.0) * (2*3.141);
+        Real x = sin(phi) > 0.0 ? 1.0f : -1.0f;  // Simulate a BPSK signal at 1200 baud
+        Complex rrc = filter.filter(Complex(x, 0.0f));
+        fprintf(fd, "%f\n", rrc.real());
+    }
+
+    qDebug() << "MainBench::testFIRRRCFilter: output samples written to test_firrrc.txt";
+    fclose(fd);
+}