1 files changed, 85 insertions, 0 deletions
diff --git a/host/utils/usrp_cal_utils.hpp b/host/utils/usrp_cal_utils.hpp
new file mode 100644
index 000000000..3e2aa6ae0
--- /dev/null
+++ b/host/utils/usrp_cal_utils.hpp
@@ -0,0 +1,85 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// 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, either 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 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 <vector>
+#include <complex>
+#include <cmath>
+#include <fstream>
+
+struct result_t{double freq, real_corr, imag_corr, sup;};
+
+/***********************************************************************
+ * Constants
+ **********************************************************************/
+static const double tau = 6.28318531;
+static const double alpha = 0.0001; //very tight iir filter
+static const size_t wave_table_len = 8192;
+static const size_t num_search_steps = 5;
+static const size_t num_search_iters = 7;
+static const size_t skip_initial_samps = 20;
+
+/***********************************************************************
+ * Sinusoid wave table
+ **********************************************************************/
+static inline std::vector<std::complex<float> > gen_table(void){
+    std::vector<std::complex<float> > wave_table(wave_table_len);
+    for (size_t i = 0; i < wave_table_len; i++){
+        wave_table[i] = std::polar<float>(1.0, (tau*i)/wave_table_len);
+    }
+    return wave_table;
+}
+
+static inline std::complex<float> wave_table_lookup(const size_t index){
+    static const std::vector<std::complex<float> > wave_table = gen_table();
+    return wave_table[index % wave_table_len];
+}
+
+/***********************************************************************
+ * Compute power of a tone
+ **********************************************************************/
+static inline double compute_tone_dbrms(
+    const std::vector<std::complex<float> > &samples,
+    const double freq //freq is fractional
+){
+    //shift the samples so the tone at freq is down at DC
+    std::vector<std::complex<double> > shifted(samples.size() - skip_initial_samps);
+    for (size_t i = 0; i < shifted.size(); i++){
+        shifted[i] = std::complex<double>(samples[i+skip_initial_samps]) * std::polar<double>(1.0, -freq*tau*i);
+    }
+
+    //filter the samples with a narrow low pass
+    std::complex<double> iir_output = 0, iir_last = 0;
+    double output = 0;
+    for (size_t i = 0; i < shifted.size(); i++){
+        iir_output = alpha * shifted[i] + (1-alpha)*iir_last;
+        iir_last = iir_output;
+        output += std::abs(iir_output);
+    }
+
+    return 20*std::log10(output/shifted.size());
+}
+
+/***********************************************************************
+ * Write a dat file
+ **********************************************************************/
+static inline void write_samples_to_file(
+    const std::vector<std::complex<float> > &samples, const std::string &file
+){
+    std::ofstream outfile(file.c_str(), std::ofstream::binary);
+    outfile.write((const char*)&samples.front(), samples.size()*sizeof(std::complex<float>));
+    outfile.close();
+}