added CRC check and also added the LDPC decoder. It does not do error…

… correction

src/algorithms/PVT/libs/rinex_printer.h

@@ -55,6 +55,7 @@
 #include "gps_cnav_navigation_message.h"
 #include "galileo_navigation_message.h"
 #include "glonass_gnav_navigation_message.h"
+#include "beidou_cnav2_navigation_message.h"
 #include "GPS_L1_CA.h"
 #include "Galileo_E1.h"
 #include "GLONASS_L1_L2_CA.h"

src/algorithms/PVT/libs/rtklib_solver.h

@@ -95,7 +95,7 @@ class rtklib_solver : public Pvt_Solution
     std::map<int, Galileo_Ephemeris> galileo_ephemeris_map;            //!< Map storing new Galileo_Ephemeris
     std::map<int, Gps_Ephemeris> gps_ephemeris_map;                    //!< Map storing new GPS_Ephemeris
     std::map<int, Gps_CNAV_Ephemeris> gps_cnav_ephemeris_map;          //!< Map storing new GPS_CNAV_Ephemeris
-    std::map<int, Glonass_Gnav_Ephemeris> glonass_gnav_ephemeris_map;  //!< Map storing new BEIDOU_CNAV2_Ephemeris
+    std::map<int, Glonass_Gnav_Ephemeris> glonass_gnav_ephemeris_map;  //!< Map storing new GLONASS_GNAV_Ephemeris
     std::map<int, Beidou_Cnav2_Ephemeris> beidou_cnav2_ephemeris_map;  //!< Map storing new BEIDOU_CNAV2_Ephemeris
 
     Galileo_Utc_Model galileo_utc_model;

src/algorithms/telemetry_decoder/gnuradio_blocks/beidou_b2a_telemetry_decoder_cc.cc

@@ -35,7 +35,7 @@
 #include <boost/lexical_cast.hpp>
 #include <gnuradio/io_signature.h>
 #include <glog/logging.h>
-
+//#include <memory>
 
 #define CRC_ERROR_LIMIT 8
 
@@ -132,7 +132,22 @@ void beidou_b2a_telemetry_decoder_cc::decode_string(double *frame_symbols, int f
     // 1. Transform from symbols to bits
     std::string data_bits;
 
-    data_bits = frame_symbols[1:288];
+    // we want data_bits = frame_symbols[24:311]
+    assert(frame_length >= 24+288); // or whatever error checking mechanism exists in this cb
+    for (unsigned ii = 24; ii < (24+288); ++ii) {
+    	char bit_value;
+
+    	if (frame_symbols[ii] > 0)
+    		bit_value = '1';
+    	else
+    		bit_value = '0';
+
+    	data_bits.push_back(bit_value);
+
+    	// "ternary" operator
+    	//data_bits.push_back( (frame_symbols[ii] > 0) ? ('1') : ('0') );
+    }
+
 
     // 2. Call the BEIDOU CNAV2 string decoder
     d_nav.string_decoder(data_bits);

src/algorithms/telemetry_decoder/libs/crc24q.c

@@ -67,7 +67,7 @@ static void crc_init(unsigned table[256])
 	    table[i + j] = table[j] ^ h;
     }
 }
-
+/*
 int main(int argc, char *argv[])
 {
     int i;
@@ -83,7 +83,7 @@ int main(int argc, char *argv[])
     exit(0);
 }
 #endif
-
+*/
 static const unsigned crc24q[256] = {
     0x00000000, 0x01864CFB, 0x028AD50D, 0x030C99F6,
     0x0493E6E1, 0x0515AA1A, 0x061933EC, 0x079F7F17,

src/core/system_parameters/beidou_cnav2_almanac.cc

@@ -55,5 +55,5 @@ Beidou_Cnav2_Almanac::Beidou_Cnav2_Almanac()
 
 	delta_A = 0.0;				//!< Correction of semi-major axis relative to reference value at reference time
 	Phi_0 = 0.0;				//!< Argument of latitude at reference time
-	Health = 0.0;				//!< Satellite health information
+	//Health = 0.0;				//!< Satellite health information
 }

src/core/system_parameters/beidou_cnav2_almanac.h

@@ -63,12 +63,8 @@ class Beidou_Cnav2_Almanac
 
 	// Reduced Almanac Parameters
 
-	unsigned int PRN_a;			//!< PRN number of the corresponding almanac data
-	double SatType;				//!< Satellite orbit type
 	double delta_A;				//!< Correction of semi-major axis relative to reference value at reference time
-	double Omega_0;				//!< Longitude of ascending node of orbital plane at weekly epoch
 	double Phi_0;				//!< Argument of latitude at reference time
-	double Health;				//!< Satellite health information
 
     template <class Archive>
     /*!

src/core/system_parameters/beidou_cnav2_navigation_message.cc

@@ -33,7 +33,7 @@
 #include "beidou_cnav2_navigation_message.h"
 #include "gnss_satellite.h"
 #include <glog/logging.h>
-#include "crc24q.c"
+#include "crc24q.h"
 
 void Beidou_Cnav2_Navigation_Message::reset()
 {
@@ -90,10 +90,12 @@ Beidou_Cnav2_Navigation_Message::Beidou_Cnav2_Navigation_Message()
 }
 
 
-bool Beidou_Cnav2_Navigation_Message::read_navigation_bool(std::bitset<BEIDOU_CNAV2_STRING_BITS> bits, const std::vector<std::pair<int, int>> parameter)
+bool Beidou_Cnav2_Navigation_Message::read_navigation_bool(std::bitset<BEIDOU_CNAV2_STRING_BITS> const &bits, const std::vector<std::pair<int, int>> &parameter)
 {
     bool value;
 
+    // bitset::any() (bits.any())
+
     if (bits[BEIDOU_CNAV2_STRING_BITS - parameter[0].first] == 1)
         {
             value = true;
@@ -106,7 +108,7 @@ bool Beidou_Cnav2_Navigation_Message::read_navigation_bool(std::bitset<BEIDOU_CN
 }
 
 
-unsigned long int Beidou_Cnav2_Navigation_Message::read_navigation_unsigned(std::bitset<BEIDOU_CNAV2_STRING_BITS> bits, const std::vector<std::pair<int, int>> parameter)
+unsigned long int Beidou_Cnav2_Navigation_Message::read_navigation_unsigned(std::bitset<BEIDOU_CNAV2_STRING_BITS> const &bits, const std::vector<std::pair<int, int>> &parameter)
 {
     unsigned long int value = 0;
     int num_of_slices = parameter.size();
@@ -117,15 +119,15 @@ unsigned long int Beidou_Cnav2_Navigation_Message::read_navigation_unsigned(std:
                     value <<= 1;  //shift left
                     if (bits[BEIDOU_CNAV2_STRING_BITS - parameter[i].first - j] == 1)
                         {
-                            value += 1;  // insert the bit
+                            value |= 1;  // insert the bit
                         }
                 }
         }
     return value;
 }
 
 
-signed long int Beidou_Cnav2_Navigation_Message::read_navigation_signed(std::bitset<BEIDOU_CNAV2_STRING_BITS> bits, const std::vector<std::pair<int, int>> parameter)
+signed long int Beidou_Cnav2_Navigation_Message::read_navigation_signed(std::bitset<BEIDOU_CNAV2_STRING_BITS> const &bits, const std::vector<std::pair<int, int>> &parameter)
 {
     signed long int value = 0;
     signed long int sign = 0;
@@ -146,52 +148,48 @@ signed long int Beidou_Cnav2_Navigation_Message::read_navigation_signed(std::bit
                     value <<= 1;  //shift left
                     if (bits[BEIDOU_CNAV2_STRING_BITS - parameter[i].first - j] == 1)
                         {
-                            value += 1;  // insert the bit
+                            value |= 1;  // insert the bit
                         }
                 }
         }
     return (sign * value);
 }
 
 
-bool Beidou_Cnav2_Navigation_Message::CRC_test(std::bitset<BEIDOU_CNAV2_STRING_BITS> string_bits)
+bool Beidou_Cnav2_Navigation_Message::CRC_test(std::bitset<BEIDOU_CNAV2_STRING_BITS> const &string_bits)
 {
-    crc_compute = crc24q_check(string_bits({1,264});
+	std::vector<unsigned char> rawBits(0, string_bits.size() / 8);
 
-    if (crc_compute == static_cast<double>(read_navigation_unsigned(string_bits, CRC)))
-        {
-            return true;
-        }
-    else
-        // All other conditions are assumed errors.
-        {
-            return false;
-        }
-	return true;
+	for (unsigned i = 0; i < rawBits.size(); ++i) {
+		for (int j = 0; j < 8; ++j) {
+			rawBits[i] |= (string_bits[8*i + j] << (7 - j));
+		}
+	}
+
+    crc_compute = crc24q_check(rawBits.data(), rawBits.size());
+
+    return crc_compute;
 }
 
 
-int Beidou_Cnav2_Navigation_Message::string_decoder(std::string frame_string)
+int Beidou_Cnav2_Navigation_Message::string_decoder(std::string const &frame_string)
 {
     int J = 0;
-    d_string_ID = 0;
-    d_frame_ID = 0;
 
     // Unpack bytes to bits
     std::bitset<BEIDOU_CNAV2_STRING_BITS> string_bits(frame_string);
 
-
-    d_string_ID = static_cast<unsigned int>(read_navigation_unsigned(string_bits, MesType));
-
     // Perform data verification and exit code if error in bit sequence
 	flag_CRC_test = CRC_test(string_bits);
 
 
 	if (flag_CRC_test == false)
 		return 0;
 
+    i_string_MesType = static_cast<unsigned int>(read_navigation_unsigned(string_bits, MesType));
+
 	// Decode all 8 string messages
-	switch (d_string_ID)
+	switch (i_string_MesType)
         {
         case 10:
             //--- It is Type 10 -----------------------------------------------

src/core/system_parameters/beidou_cnav2_navigation_message.h

@@ -50,14 +50,13 @@
 class Beidou_Cnav2_Navigation_Message
 {
 private:
-    unsigned long int read_navigation_unsigned(std::bitset<BEIDOU_CNAV2_STRING_BITS> bits, const std::vector<std::pair<int, int>> parameter);
-    signed long int read_navigation_signed(std::bitset<BEIDOU_CNAV2_STRING_BITS> bits, const std::vector<std::pair<int, int>> parameter);
-    bool read_navigation_bool(std::bitset<BEIDOU_CNAV2_STRING_BITS> bits, const std::vector<std::pair<int, int>> parameter);
+    unsigned long int read_navigation_unsigned(std::bitset<BEIDOU_CNAV2_STRING_BITS> const &bits, const std::vector<std::pair<int, int>> &parameter);
+    signed long int read_navigation_signed(std::bitset<BEIDOU_CNAV2_STRING_BITS> const &bits, const std::vector<std::pair<int, int>> &parameter);
+    bool read_navigation_bool(std::bitset<BEIDOU_CNAV2_STRING_BITS> const &bits, const std::vector<std::pair<int, int>> &parameter);
 
 public:
     bool flag_CRC_test;
-    unsigned int d_frame_ID;
-    unsigned int d_string_ID;
+    unsigned int i_string_MesType;
     bool flag_update_slot_number;
 
     int i_channel_ID;
@@ -110,7 +109,7 @@ class Beidou_Cnav2_Navigation_Message
      * \brief Compute CRC for BEIDOU CNAV2 strings
      * \param bits Bits of the string message where to compute CRC
      */
-    bool CRC_test(std::bitset<BEIDOU_CNAV2_STRING_BITS> bits);
+    bool CRC_test(std::bitset<BEIDOU_CNAV2_STRING_BITS> const &bits);
 
     /*!
      * \brief Computes the frame number being decoded given the satellite slot number
@@ -161,7 +160,7 @@ class Beidou_Cnav2_Navigation_Message
      * \param frame_string [in] is the string message within the parsed frame
      * \returns Returns the ID of the decoded string
      */
-    int string_decoder(std::string frame_string);
+    int string_decoder(std::string const &frame_string);
 
     /*!
      * Default constructor

src/core/system_parameters/beidou_cnav2_utc_model.cc

@@ -90,10 +90,12 @@ boost::posix_time::ptime Beidou_Cnav2_Utc_Model::beidt_to_utc(const double offse
      */
 }
 
+template < typename t >
+t square(t x) { return x * x; }
 
 void Beidou_Cnav2_Utc_Model::beidt_to_gpst(double tod_offset, double beidt2utc_corr, double beidt2gpst_corr, double* wn, double* tow) const
 {
-	/*
-	 * dT_systems = t_BD - t_GNSS = A_0BGTO + A_1BGTO*[t_BD - t_0BGTO + 604800*(WN - WN_BGTO)] + A_2BGTO*[t_BD - t_0BGTO +604800*(WN - WN_BGTO)]^2
-	 */
+
+	 dT_systems = t_BD - t_GNSS = A_0BGTO + A_1BGTO*[t_BD - t_0BGTO + 604800*(WN - WN_BGTO)] + A_2BGTO*square(t_BD - t_0BGTO +604800*(WN - WN_BGTO))
+
 }