Galileo E5a acquisition adapter and signal processing

src/algorithms/libs/galileo_e5_signal_processing.cc

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+/*
+ * galileo_e5_signal_processing.cc
+ *
+ *  Created on: May 20, 2014
+ *      Author: marc
+ */
+
+#include "galileo_e5_signal_processing.h"
+
+void galileo_e5_a_code_gen_complex(std::complex<float>* _dest, signed int _prn, bool _pilot)
+{
+	unsigned int prn=_prn-1;
+	unsigned int index=0;
+	//int _code_int[(int)Galileo_E5a_CODE_LENGTH_CHIPS];
+	int a[4];
+
+	if ((_prn < 1) || (_prn > 50))
+	        {
+	            return;
+	        }
+	if (_pilot)
+	    {
+            for (size_t i = 0; i < Galileo_E5a_Q_PRIMARY_CODE[prn].length(); i++)
+                {
+//                hex_to_binary_converter(&_dest[index],
+//                		Galileo_E5a_Q_PRIMARY_CODE[prn].at(i));
+//                hex_to_binary_converter(&_code_int[index],
+//                		Galileo_E5a_Q_PRIMARY_CODE[prn].at(i));
+                    hex_to_binary_converter(&a[0],
+                    		Galileo_E5a_Q_PRIMARY_CODE[prn].at(i));
+                    _dest[index]=std::complex<float>(float(a[0]),0.0);
+                    _dest[index+1]=std::complex<float>(float(a[1]),0.0);
+                    _dest[index+2]=std::complex<float>(float(a[2]),0.0);
+                    _dest[index+3]=std::complex<float>(float(a[3]),0.0);
+                    index = index + 4;
+                }
+	    }
+	else
+	    {
+            for (size_t i = 0; i < Galileo_E5a_I_PRIMARY_CODE[prn].length(); i++)
+                {
+//                hex_to_binary_converter(&_code_int[index],
+//                		Galileo_E5a_I_PRIMARY_CODE[prn].at(i));
+            	    hex_to_binary_converter(&a[0],
+            	           Galileo_E5a_I_PRIMARY_CODE[prn].at(i));
+            	    _dest[index]=std::complex<float>(float(a[0]),0.0);
+            	    _dest[index+1]=std::complex<float>(float(a[1]),0.0);
+            	    _dest[index+2]=std::complex<float>(float(a[2]),0.0);
+            	    _dest[index+3]=std::complex<float>(float(a[3]),0.0);
+                    index = index + 4;
+                }
+	    }
+}
+
+void galileo_e5_a_code_gen_complex_sampled(std::complex<float>* _dest, bool _pilot,
+		unsigned int _prn, signed int _fs, unsigned int _chip_shift,
+        bool _secondary_flag)
+{
+    // This function is based on the GNU software GPS for MATLAB in the Kay Borre book
+
+    std::complex<float> _code[Galileo_E5a_CODE_LENGTH_CHIPS];
+    signed int _samplesPerCode, _codeValueIndex;
+    float _ts;
+    float _tc;
+    const int _codeFreqBasis = Galileo_E5a_CODE_CHIP_RATE_HZ; //Hz
+    unsigned int _codeLength = Galileo_E5a_CODE_LENGTH_CHIPS;
+    std::complex<float> primary_code_E5a_chips[(int)Galileo_E5a_CODE_LENGTH_CHIPS];
+    _samplesPerCode = round(_fs / (_codeFreqBasis / _codeLength));
+    const unsigned int delay = (((int)Galileo_E5a_CODE_LENGTH_CHIPS - _chip_shift)
+                                % (int)Galileo_E5a_CODE_LENGTH_CHIPS)
+                                * _samplesPerCode / Galileo_E5a_CODE_LENGTH_CHIPS;
+
+    galileo_e5_a_code_gen_complex(_code , _prn , _pilot);
+
+    if (_fs != _codeFreqBasis)
+        {
+        	std::complex<float>* _resampled_signal = new std::complex<float>[_codeLength];
+        	resampler(_code, _resampled_signal, _codeFreqBasis, _fs,
+        	                    _codeLength, _samplesPerCode); //resamples code to fs
+        	delete[] _code;
+        	_code = _resampled_signal;
+        }
+    // TODO generar codigo secundario cuando sepamos si se hace aqui o se replica en el tracking
+    // o en una funcion a parte en esta misma clase
+    for (unsigned int i = 0; i < _samplesPerCode; i++)
+        {
+            _dest[(i+delay)%_samplesPerCode] = _code[i];
+        }
+
+    delete[] _code;
+
+}

src/algorithms/libs/galileo_e5_signal_processing.h

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+/*
+ * galileo_e5_signal_processing.h
+ *
+ *  Created on: May 20, 2014
+ *      Author: marc
+ */
+
+#ifndef GALILEO_E5_SIGNAL_PROCESSING_H_
+#define GALILEO_E5_SIGNAL_PROCESSING_H_
+
+#include <complex>
+#include <iostream>
+#include <gnuradio/math.h>
+#include "Galileo_E5a.h"
+#include "gnss_signal_processing.h"
+
+/*!
+ * \brief Generates Galileo E5a code at 1 sample/chip
+ * bool _pilot generates E5aQ code if true and E5aI (data signal) if false.
+ */
+void galileo_e5_a_code_gen_complex(std::complex<float>* _dest, signed int _prn, bool _pilot);
+
+/*!
+ * \brief Generates Galileo E5a complex code, shifted to the desired chip and sampled at a frequency fs
+ * bool _pilot generates E5aQ code if true and E5aI (data signal) if false.
+ */
+void galileo_e5_a_code_gen_complex_sampled(std::complex<float>* _dest,
+        bool _pilot, unsigned int _prn, signed int _fs, unsigned int _chip_shift,
+        bool _secondary_flag);
+
+
+#endif /* GALILEO_E5_SIGNAL_PROCESSING_H_ */