New GPS L1 CA tracking module GpsL1CaDllPllOptimTracking optimized for speed:

- The local code replica is pre-initialized and resampled to the nominal PRN code sample rate (no code Doppler correction)

git-svn-id: https://svn.code.sf.net/p/gnss-sdr/code/trunk@242 64b25241-fba3-4117-9849-534c7e92360d

src/algorithms/tracking/adapters/gps_l1_ca_dll_pll_optim_tracking.cc

@@ -0,0 +1,163 @@
+/*!
+ * \file gps_l1_ca_dll_pll_optim_tracking.cc
+ * \brief  Interface of an adapter of a speed optimized DLL+PLL tracking loop block
+ * for GPS L1 C/A to a TrackingInterface
+ * \author Javier Arribas, 2012. jarribas(at)cttc.es
+ *
+ * GPS L1 TRACKING MODULE OPTIMIZED FOR SPEED:
+ * - Code Doppler is not compensated in the local replica
+ * Code DLL + carrier PLL according to the algorithms described in:
+ * K.Borre, D.M.Akos, N.Bertelsen, P.Rinder, and S.H.Jensen,
+ * A Software-Defined GPS and Galileo Receiver. A Single-Frequency
+ * Approach, Birkha user, 2007
+ *
+ * -------------------------------------------------------------------------
+ *
+ * Copyright (C) 2010-2012  (see AUTHORS file for a list of contributors)
+ *
+ * GNSS-SDR is a software defined Global Navigation
+ *          Satellite Systems receiver
+ *
+ * This file is part of GNSS-SDR.
+ *
+ * GNSS-SDR 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.
+ *
+ * GNSS-SDR 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 GNSS-SDR. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * -------------------------------------------------------------------------
+ */
+
+#include "gps_l1_ca_dll_pll_optim_tracking.h"
+#include "GPS_L1_CA.h"
+#include "configuration_interface.h"
+#include <boost/math/special_functions/round.hpp>
+#include <gnuradio/gr_io_signature.h>
+#include <glog/log_severity.h>
+#include <glog/logging.h>
+
+using google::LogMessage;
+
+GpsL1CaDllPllOptimTracking::GpsL1CaDllPllOptimTracking(
+        ConfigurationInterface* configuration, std::string role,
+        unsigned int in_streams, unsigned int out_streams,
+        gr_msg_queue_sptr queue) :
+        role_(role), in_streams_(in_streams), out_streams_(out_streams),
+        queue_(queue)
+{
+
+    DLOG(INFO) << "role " << role;
+
+    //################# CONFIGURATION PARAMETERS ########################
+
+    int fs_in;
+    int vector_length;
+    int f_if;
+    bool dump;
+    std::string dump_filename;
+    std::string item_type;
+    std::string default_item_type = "gr_complex";
+    float pll_bw_hz;
+    float dll_bw_hz;
+    float early_late_space_chips;
+
+    item_type = configuration->property(role + ".item_type",default_item_type);
+    //vector_length = configuration->property(role + ".vector_length", 2048);
+    fs_in = configuration->property("GNSS-SDR.internal_fs_hz", 2048000);
+    f_if = configuration->property(role + ".if", 0);
+    dump = configuration->property(role + ".dump", false);
+    pll_bw_hz = configuration->property(role + ".pll_bw_hz", 50.0);
+    dll_bw_hz = configuration->property(role + ".dll_bw_hz", 2.0);
+    early_late_space_chips = configuration->property(role + ".early_late_space_chips", 0.5);
+
+    std::string default_dump_filename = "./track_ch";
+    dump_filename = configuration->property(role + ".dump_filename",
+            default_dump_filename); //unused!
+
+    vector_length = round(fs_in / (GPS_L1_CA_CODE_RATE_HZ / GPS_L1_CA_CODE_LENGTH_CHIPS));
+    //################# MAKE TRACKING GNURadio object ###################
+    if (item_type.compare("gr_complex") == 0)
+        {
+            item_size_ = sizeof(gr_complex);
+            tracking_ = gps_l1_ca_dll_pll_make_optim_tracking_cc(
+            		f_if,
+                    fs_in,
+                    vector_length,
+                    queue_,
+                    dump,
+                    dump_filename,
+                    pll_bw_hz,
+                    dll_bw_hz,
+                    early_late_space_chips);
+        }
+    else
+        {
+            LOG_AT_LEVEL(WARNING) << item_type << " unknown tracking item type.";
+        }
+
+    DLOG(INFO) << "tracking(" << tracking_->unique_id() << ")";
+}
+
+GpsL1CaDllPllOptimTracking::~GpsL1CaDllPllOptimTracking()
+{
+}
+
+void GpsL1CaDllPllOptimTracking::start_tracking()
+{
+    tracking_->start_tracking();
+}
+
+/*
+ * Set tracking channel unique ID
+ */
+void GpsL1CaDllPllOptimTracking::set_channel(unsigned int channel)
+{
+    channel_ = channel;
+    tracking_->set_channel(channel);
+}
+
+/*
+ * Set tracking channel internal queue
+ */
+void GpsL1CaDllPllOptimTracking::set_channel_queue(
+        concurrent_queue<int> *channel_internal_queue)
+{
+    channel_internal_queue_ = channel_internal_queue;
+
+    tracking_->set_channel_queue(channel_internal_queue_);
+
+}
+
+void GpsL1CaDllPllOptimTracking::set_gnss_synchro(Gnss_Synchro* p_gnss_synchro)
+{
+    tracking_->set_gnss_synchro(p_gnss_synchro);
+}
+
+void GpsL1CaDllPllOptimTracking::connect(gr_top_block_sptr top_block)
+{
+    //nothing to connect, now the tracking uses gr_sync_decimator
+}
+
+void GpsL1CaDllPllOptimTracking::disconnect(gr_top_block_sptr top_block)
+{
+    //nothing to disconnect, now the tracking uses gr_sync_decimator
+}
+
+gr_basic_block_sptr GpsL1CaDllPllOptimTracking::get_left_block()
+{
+    return tracking_;
+}
+
+gr_basic_block_sptr GpsL1CaDllPllOptimTracking::get_right_block()
+{
+    return tracking_;
+}
+

src/algorithms/tracking/adapters/gps_l1_ca_dll_pll_optim_tracking.h

@@ -0,0 +1,115 @@
+/*!
+ * \file gps_l1_ca_dll_pll_optim_tracking.h
+ * \brief  Interface of an adapter of a speed optimized DLL+PLL tracking loop block
+ * for GPS L1 C/A to a TrackingInterface
+ * \author Javier Arribas, 2012. jarribas(at)cttc.es
+ *
+ * GPS L1 TRACKING MODULE OPTIMIZED FOR SPEED:
+ * - Code Doppler is not compensated in the local replica
+ * Code DLL + carrier PLL according to the algorithms described in:
+ * K.Borre, D.M.Akos, N.Bertelsen, P.Rinder, and S.H.Jensen,
+ * A Software-Defined GPS and Galileo Receiver. A Single-Frequency
+ * Approach, Birkha user, 2007
+ *
+ * -------------------------------------------------------------------------
+ *
+ * Copyright (C) 2010-2012  (see AUTHORS file for a list of contributors)
+ *
+ * GNSS-SDR is a software defined Global Navigation
+ *          Satellite Systems receiver
+ *
+ * This file is part of GNSS-SDR.
+ *
+ * GNSS-SDR 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.
+ *
+ * GNSS-SDR 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 GNSS-SDR. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * -------------------------------------------------------------------------
+ */
+
+#ifndef GNSS_SDR_GPS_L1_CA_DLL_PLL_OPTIM_TRACKING_H_
+#define GNSS_SDR_GPS_L1_CA_DLL_PLL_OPTIM_TRACKING_H_
+
+#include "tracking_interface.h"
+#include "gps_l1_ca_dll_pll_optim_tracking_cc.h"
+#include <gnuradio/gr_msg_queue.h>
+
+class ConfigurationInterface;
+
+/*!
+ * \brief This class implements a code DLL + carrier PLL tracking loop
+ */
+class GpsL1CaDllPllOptimTracking : public TrackingInterface
+{
+
+public:
+
+  GpsL1CaDllPllOptimTracking(ConfigurationInterface* configuration,
+            std::string role,
+            unsigned int in_streams,
+            unsigned int out_streams,
+            gr_msg_queue_sptr queue);
+
+    virtual ~GpsL1CaDllPllOptimTracking();
+
+    std::string role()
+    {
+        return role_;
+    }
+    std::string implementation()
+    {
+        return "GPS_L1_CA_DLL_PLL_Optim_Tracking";
+    }
+    size_t item_size()
+    {
+        return item_size_;
+    }
+
+    void connect(gr_top_block_sptr top_block);
+    void disconnect(gr_top_block_sptr top_block);
+    gr_basic_block_sptr get_left_block();
+    gr_basic_block_sptr get_right_block();
+
+
+    /*!
+     * \brief Set tracking channel unique ID
+     */
+    void set_channel(unsigned int channel);
+
+    /*!
+     * \brief Set acquisition/tracking common Gnss_Synchro object pointer
+     * to efficiently exchange synchronization data between acquisition and tracking blocks
+     */
+    void set_gnss_synchro(Gnss_Synchro* p_gnss_synchro);
+
+    /*!
+     * \brief Set tracking channel internal queue
+     */
+    void set_channel_queue(concurrent_queue<int> *channel_internal_queue);
+
+    void start_tracking();
+
+private:
+
+    gps_l1_ca_dll_pll_optim_tracking_cc_sptr tracking_;
+    size_t item_size_;
+
+    unsigned int channel_;
+
+    std::string role_;
+    unsigned int in_streams_;
+    unsigned int out_streams_;
+    gr_msg_queue_sptr queue_;
+    concurrent_queue<int> *channel_internal_queue_;
+};
+
+#endif // GNSS_SDR_GPS_L1_CA_DLL_PLL_OPTIM_TRACKING_H_

src/algorithms/tracking/adapters/jamfile.jam

@@ -4,3 +4,4 @@ obj gps_l1_ca_dll_pll_tracking : gps_l1_ca_dll_pll_tracking.cc : <toolset>darwin
 obj gps_l1_ca_dll_fll_pll_tracking : gps_l1_ca_dll_fll_pll_tracking.cc : <toolset>darwin:<define>GNSS_SDR_USE_BOOST_ROUND ;
 obj gps_l1_ca_tcp_connector_tracking : gps_l1_ca_tcp_connector_tracking.cc : <toolset>darwin:<define>GNSS_SDR_USE_BOOST_ROUND ;
 obj galileo_e1_dll_pll_veml_tracking : galileo_e1_dll_pll_veml_tracking.cc : <toolset>darwin:<define>GNSS_SDR_USE_BOOST_ROUND ;
+obj gps_l1_ca_dll_pll_optim_tracking : gps_l1_ca_dll_pll_optim_tracking.cc : <toolset>darwin:<define>GNSS_SDR_USE_BOOST_ROUND ;

src/algorithms/tracking/gnuradio_blocks/gps_l1_ca_dll_pll_optim_tracking_cc.cc

@@ -0,0 +1,688 @@
+/*!
+ * \file gps_l1_ca_dll_pll_optim_tracking_cc.cc
+ * \brief Implementation of a code DLL + carrier PLL tracking block
+ * \author Javier Arribas, 2012. jarribas(at)cttc.es
+ * GPS L1 TRACKING MODULE OPTIMIZED FOR SPEED:
+ * - Code Doppler is not compensated in the local replica
+ * Code DLL + carrier PLL according to the algorithms described in:
+ * [1] K.Borre, D.M.Akos, N.Bertelsen, P.Rinder, and S.H.Jensen,
+ * A Software-Defined GPS and Galileo Receiver. A Single-Frequency
+ * Approach, Birkha user, 2007
+ *
+ * -------------------------------------------------------------------------
+ *
+ * Copyright (C) 2010-2012  (see AUTHORS file for a list of contributors)
+ *
+ * GNSS-SDR is a software defined Global Navigation
+ *          Satellite Systems receiver
+ *
+ * This file is part of GNSS-SDR.
+ *
+ * GNSS-SDR 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.
+ *
+ * GNSS-SDR 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 GNSS-SDR. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * -------------------------------------------------------------------------
+ */
+
+#include "gnss_synchro.h"
+#include "gps_l1_ca_dll_pll_optim_tracking_cc.h"
+#include "gps_sdr_signal_processing.h"
+#include "tracking_discriminators.h"
+#include "CN_estimators.h"
+#include "GPS_L1_CA.h"
+#include "control_message_factory.h"
+#include <boost/lexical_cast.hpp>
+#include <iostream>
+#include <sstream>
+#include <cmath>
+#include "math.h"
+#include <gnuradio/gr_io_signature.h>
+#include <glog/log_severity.h>
+#include <glog/logging.h>
+#include <gr_fxpt.h>
+
+/*!
+ * \todo Include in definition header file
+ */
+#define CN0_ESTIMATION_SAMPLES 10
+#define MINIMUM_VALID_CN0 25
+#define MAXIMUM_LOCK_FAIL_COUNTER 200
+
+
+using google::LogMessage;
+
+gps_l1_ca_dll_pll_optim_tracking_cc_sptr
+gps_l1_ca_dll_pll_make_optim_tracking_cc(
+        long if_freq,
+        long fs_in,
+        unsigned int vector_length,
+        gr_msg_queue_sptr queue,
+        bool dump,
+        std::string dump_filename,
+        float pll_bw_hz,
+        float dll_bw_hz,
+        float early_late_space_chips)
+{
+    return gps_l1_ca_dll_pll_optim_tracking_cc_sptr(new Gps_L1_Ca_Dll_Pll_Optim_Tracking_cc(if_freq,
+            fs_in, vector_length, queue, dump, dump_filename, pll_bw_hz, dll_bw_hz, early_late_space_chips));
+}
+
+
+
+void Gps_L1_Ca_Dll_Pll_Optim_Tracking_cc::forecast (int noutput_items,
+        gr_vector_int &ninput_items_required)
+{
+    ninput_items_required[0] = (int)d_vector_length*2; //set the required available samples in each call
+}
+
+
+
+Gps_L1_Ca_Dll_Pll_Optim_Tracking_cc::Gps_L1_Ca_Dll_Pll_Optim_Tracking_cc(
+        long if_freq,
+        long fs_in,
+        unsigned int vector_length,
+        gr_msg_queue_sptr queue,
+        bool dump,
+        std::string dump_filename,
+        float pll_bw_hz,
+        float dll_bw_hz,
+        float early_late_space_chips) :
+        gr_block ("Gps_L1_Ca_Dll_Pll_Tracking_cc", gr_make_io_signature (1, 1, sizeof(gr_complex)),
+                gr_make_io_signature(1, 1, sizeof(Gnss_Synchro)))
+{
+
+    //gr_sync_decimator ("Gps_L1_Ca_Dll_Pll_Tracking_cc", gr_make_io_signature (1, 1, sizeof(gr_complex)),
+    //		gr_make_io_signature(3, 3, sizeof(float)),vector_length) {
+    // initialize internal vars
+    d_queue = queue;
+    d_dump = dump;
+    d_if_freq = if_freq;
+    d_fs_in = fs_in;
+    d_vector_length = vector_length;
+    d_dump_filename = dump_filename;
+
+    // Initialize tracking  ==========================================
+
+    d_code_loop_filter.set_DLL_BW(dll_bw_hz);
+    d_carrier_loop_filter.set_PLL_BW(pll_bw_hz);
+
+    //--- DLL variables --------------------------------------------------------
+    d_early_late_spc_chips = early_late_space_chips; // Define early-late offset (in chips)
+
+    // Initialization of local code replica
+    // Get space for a vector with the C/A code replica sampled 1x/chip
+    d_ca_code = new gr_complex[(int)GPS_L1_CA_CODE_LENGTH_CHIPS + 2];
+
+
+
+    d_carr_sign = new gr_complex[d_vector_length*2];
+
+    /* If an array is partitioned for more than one thread to operate on,
+     * having the sub-array boundaries unaligned to cache lines could lead
+     * to performance degradation. Here we allocate memory
+     * (gr_comlex array of size 2*d_vector_length) aligned to cache of 16 bytes
+     */
+    // todo: do something if posix_memalign fails
+    // Get space for the resampled early / prompt / late local replicas
+    if (posix_memalign((void**)&d_early_code, 16, d_vector_length * sizeof(gr_complex) * 2) == 0){};
+    if (posix_memalign((void**)&d_late_code, 16, d_vector_length * sizeof(gr_complex) * 2) == 0){};
+    if (posix_memalign((void**)&d_prompt_code, 16, d_vector_length * sizeof(gr_complex) * 2) == 0){};
+    // space for carrier wipeoff and signal baseband vectors
+    if (posix_memalign((void**)&d_carr_sign, 16, d_vector_length * sizeof(gr_complex) * 2) == 0){};
+    // correlator outputs (scalar)
+    if (posix_memalign((void**)&d_Early, 16, sizeof(gr_complex)) == 0){};
+    if (posix_memalign((void**)&d_Prompt, 16, sizeof(gr_complex)) == 0){};
+    if (posix_memalign((void**)&d_Late, 16, sizeof(gr_complex)) == 0){};
+
+
+    //--- Perform initializations ------------------------------
+    // define initial code frequency basis of NCO
+    d_code_freq_hz = GPS_L1_CA_CODE_RATE_HZ;
+    // define residual code phase (in chips)
+    d_rem_code_phase_samples = 0.0;
+    // define residual carrier phase
+    d_rem_carr_phase_rad = 0.0;
+
+    // sample synchronization
+    d_sample_counter = 0;
+    //d_sample_counter_seconds = 0;
+    d_acq_sample_stamp = 0;
+
+    d_enable_tracking = false;
+    d_pull_in = false;
+    d_last_seg = 0;
+
+    d_current_prn_length_samples = (int)d_vector_length;
+
+    // CN0 estimation and lock detector buffers
+    d_cn0_estimation_counter = 0;
+    d_Prompt_buffer = new gr_complex[CN0_ESTIMATION_SAMPLES];
+    d_carrier_lock_test = 1;
+    d_CN0_SNV_dB_Hz = 0;
+    d_carrier_lock_fail_counter = 0;
+    d_carrier_lock_threshold = 20;
+
+    systemName["G"] = std::string("GPS");
+    systemName["R"] = std::string("GLONASS");
+    systemName["S"] = std::string("SBAS");
+    systemName["E"] = std::string("Galileo");
+    systemName["C"] = std::string("Compass");
+}
+
+void Gps_L1_Ca_Dll_Pll_Optim_Tracking_cc::start_tracking()
+{
+    /*
+     *  correct the code phase according to the delay between acq and trk
+     */
+
+    d_acq_code_phase_samples = d_acquisition_gnss_synchro->Acq_delay_samples;
+    d_acq_carrier_doppler_hz = d_acquisition_gnss_synchro->Acq_doppler_hz;
+    d_acq_sample_stamp =  d_acquisition_gnss_synchro->Acq_samplestamp_samples;
+
+    unsigned long int acq_trk_diff_samples;
+    float acq_trk_diff_seconds;
+    acq_trk_diff_samples = d_sample_counter - d_acq_sample_stamp;//-d_vector_length;
+    std::cout << "acq_trk_diff_samples=" << acq_trk_diff_samples << std::endl;
+    acq_trk_diff_seconds = (float)acq_trk_diff_samples / (float)d_fs_in;
+    //doppler effect
+    // Fd=(C/(C+Vr))*F
+    float radial_velocity;
+    radial_velocity = (GPS_L1_FREQ_HZ + d_acq_carrier_doppler_hz)/GPS_L1_FREQ_HZ;
+    // new chip and prn sequence periods based on acq Doppler
+    float T_chip_mod_seconds;
+    float T_prn_mod_seconds;
+    float T_prn_mod_samples;
+    d_code_freq_hz = radial_velocity * GPS_L1_CA_CODE_RATE_HZ;
+    T_chip_mod_seconds = 1/d_code_freq_hz;
+    T_prn_mod_seconds = T_chip_mod_seconds * GPS_L1_CA_CODE_LENGTH_CHIPS;
+    T_prn_mod_samples = T_prn_mod_seconds * (float)d_fs_in;
+
+    d_next_prn_length_samples = round(T_prn_mod_samples);
+
+    float T_prn_true_seconds = GPS_L1_CA_CODE_LENGTH_CHIPS / GPS_L1_CA_CODE_RATE_HZ;
+    float T_prn_true_samples = T_prn_true_seconds * (float)d_fs_in;
+    float T_prn_diff_seconds;
+    T_prn_diff_seconds = T_prn_true_seconds - T_prn_mod_seconds;
+    float N_prn_diff;
+    N_prn_diff = acq_trk_diff_seconds / T_prn_true_seconds;
+    float corrected_acq_phase_samples, delay_correction_samples;
+    corrected_acq_phase_samples = fmod((d_acq_code_phase_samples + T_prn_diff_seconds * N_prn_diff * (float)d_fs_in), T_prn_true_samples);
+    if (corrected_acq_phase_samples < 0)
+        {
+            corrected_acq_phase_samples = T_prn_mod_samples + corrected_acq_phase_samples;
+        }
+    delay_correction_samples = d_acq_code_phase_samples - corrected_acq_phase_samples;
+
+    d_acq_code_phase_samples = corrected_acq_phase_samples;
+
+    d_carrier_doppler_hz = d_acq_carrier_doppler_hz;
+    // DLL/PLL filter initialization
+    d_carrier_loop_filter.initialize(d_carrier_doppler_hz); //initialize the carrier filter
+    d_code_loop_filter.initialize(d_acq_code_phase_samples); //initialize the code filter
+
+    // generate local reference ALWAYS starting at chip 1 (1 sample per chip)
+    gps_l1_ca_code_gen_complex(&d_ca_code[1], d_acquisition_gnss_synchro->PRN, 0);
+    d_ca_code[0] = d_ca_code[(int)GPS_L1_CA_CODE_LENGTH_CHIPS];
+    d_ca_code[(int)GPS_L1_CA_CODE_LENGTH_CHIPS + 1] = d_ca_code[1];
+
+
+    //******************************************************************************
+    // Experimental: pre-sampled local signal replica at nominal code frequency.
+    // No code doppler correction
+
+    // unified loop for E, P, L code vectors
+    double code_phase_step_chips;
+    code_phase_step_chips = (GPS_L1_CA_CODE_RATE_HZ / (double)d_fs_in);
+    double tcode_chips = 0;
+    // Alternative EPL code generation (40% of speed improvement!)
+    int early_late_spc_samples;
+    early_late_spc_samples=round(d_early_late_spc_chips/code_phase_step_chips);
+    double epl_loop_length_samples;
+    epl_loop_length_samples=d_current_prn_length_samples+early_late_spc_samples*2;
+    int associated_chip_index;
+    int code_length_chips = (int)GPS_L1_CA_CODE_LENGTH_CHIPS;
+    for (int i=0; i<epl_loop_length_samples; i++)
+		{
+    	    associated_chip_index = 1 + round(fmod(tcode_chips - d_early_late_spc_chips, code_length_chips));
+            d_early_code[i] = d_ca_code[associated_chip_index];
+            tcode_chips = tcode_chips + d_code_phase_step_chips;
+		}
+
+    memcpy(d_prompt_code,&d_early_code[early_late_spc_samples],d_current_prn_length_samples* sizeof(gr_complex));
+    memcpy(d_late_code,&d_early_code[early_late_spc_samples*2],d_current_prn_length_samples* sizeof(gr_complex));
+
+    //******************************************************************************
+
+    d_carrier_lock_fail_counter = 0;
+    d_rem_code_phase_samples = 0;
+    d_rem_carr_phase_rad = 0;
+    d_rem_code_phase_samples = 0;
+    d_next_rem_code_phase_samples = 0;
+    d_acc_carrier_phase_rad = 0;
+
+    d_code_phase_samples = d_acq_code_phase_samples;
+
+    std::string sys_ = &d_acquisition_gnss_synchro->System;
+    sys = sys_.substr(0,1);
+
+    // DEBUG OUTPUT
+    std::cout << "Tracking start on channel " << d_channel << " for satellite " << Gnss_Satellite(systemName[sys], d_acquisition_gnss_synchro->PRN) << std::endl;
+    DLOG(INFO) << "Start tracking for satellite " << Gnss_Satellite(systemName[sys], d_acquisition_gnss_synchro->PRN)  << " received" << std::endl;
+
+    // enable tracking
+    d_pull_in = true;
+    d_enable_tracking = true;
+
+    std::cout << "PULL-IN Doppler [Hz]=" << d_carrier_doppler_hz
+            << " Code Phase correction [samples]=" << delay_correction_samples
+            << " PULL-IN Code Phase [samples]=" << d_acq_code_phase_samples << std::endl;
+}
+
+
+void Gps_L1_Ca_Dll_Pll_Optim_Tracking_cc::update_local_code()
+{
+    double tcode_chips;
+    double rem_code_phase_chips;
+    int associated_chip_index;
+    int code_length_chips = (int)GPS_L1_CA_CODE_LENGTH_CHIPS;
+    double code_phase_step_chips;
+	int early_late_spc_samples;
+	int epl_loop_length_samples;
+
+    // unified loop for E, P, L code vectors
+    code_phase_step_chips = ((double)d_code_freq_hz) / ((double)d_fs_in);
+    rem_code_phase_chips = d_rem_code_phase_samples * (d_code_freq_hz / d_fs_in);
+    tcode_chips = -rem_code_phase_chips;
+
+    // Alternative EPL code generation (40% of speed improvement!)
+    early_late_spc_samples=round(d_early_late_spc_chips/code_phase_step_chips);
+    epl_loop_length_samples=d_current_prn_length_samples+early_late_spc_samples*2;
+    for (int i=0; i<epl_loop_length_samples; i++)
+		{
+    	    associated_chip_index = 1 + round(fmod(tcode_chips - d_early_late_spc_chips, code_length_chips));
+            d_early_code[i] = d_ca_code[associated_chip_index];
+            tcode_chips = tcode_chips + d_code_phase_step_chips;
+		}
+
+    memcpy(d_prompt_code,&d_early_code[early_late_spc_samples],d_current_prn_length_samples* sizeof(gr_complex));
+    memcpy(d_late_code,&d_early_code[early_late_spc_samples*2],d_current_prn_length_samples* sizeof(gr_complex));
+}
+
+
+
+
+void Gps_L1_Ca_Dll_Pll_Optim_Tracking_cc::update_local_carrier()
+{
+    float phase_rad, phase_step_rad;
+
+    phase_step_rad = (float)GPS_TWO_PI*d_carrier_doppler_hz / (float)d_fs_in;
+    phase_rad = d_rem_carr_phase_rad;
+
+    int phase_rad_i;
+    phase_rad_i=gr_fxpt::float_to_fixed(phase_rad);
+    int phase_step_rad_i;
+    phase_step_rad_i=gr_fxpt::float_to_fixed(phase_step_rad);
+
+    float sin_f,cos_f;
+
+    for(int i = 0; i < d_current_prn_length_samples; i++)
+        {
+    		//using temp variables
+    		gr_fxpt::sincos(phase_rad_i,&sin_f,&cos_f);
+    	    d_carr_sign[i] = gr_complex(cos_f, sin_f);
+			//using references (may be it can be a problem for c++11 standard
+			//gr_fxpt::sincos(phase_rad_i,&d_carr_sign[i].imag(),&d_carr_sign[i].real());
+
+            phase_rad_i += phase_step_rad_i;
+
+            // Using std::cos and std::sin
+    		//d_carr_sign[i] = gr_complex(cos(phase_rad), sin(phase_rad));
+        }
+
+    d_rem_carr_phase_rad = fmod(gr_fxpt::fixed_to_float(phase_rad_i), GPS_TWO_PI);
+    d_acc_carrier_phase_rad = d_acc_carrier_phase_rad + d_rem_carr_phase_rad;
+}
+
+
+
+
+Gps_L1_Ca_Dll_Pll_Optim_Tracking_cc::~Gps_L1_Ca_Dll_Pll_Optim_Tracking_cc()
+{
+    d_dump_file.close();
+
+    free(d_prompt_code);
+    free(d_late_code);
+    free(d_early_code);
+    free(d_carr_sign);
+    free(d_Early);
+    free(d_Prompt);
+    free(d_Late);
+
+    delete[] d_ca_code;
+    delete[] d_Prompt_buffer;
+}
+
+
+/* Tracking signal processing
+ * Notice that this is a class derived from gr_sync_decimator, so each of the ninput_items has vector_length samples
+ */
+
+int Gps_L1_Ca_Dll_Pll_Optim_Tracking_cc::general_work (int noutput_items, gr_vector_int &ninput_items,
+        gr_vector_const_void_star &input_items, gr_vector_void_star &output_items)
+{
+
+    // process vars
+    float carr_error;
+    float carr_nco;
+    float code_error;
+    float code_nco;
+
+    if (d_enable_tracking == true)
+        {
+            /*
+             * Receiver signal alignment
+             */
+            if (d_pull_in == true)
+                {
+                    int samples_offset;
+
+                    // 28/11/2011 ACQ to TRK transition BUG CORRECTION
+                    float acq_trk_shif_correction_samples;
+                    int acq_to_trk_delay_samples;
+                    acq_to_trk_delay_samples = d_sample_counter - d_acq_sample_stamp;
+                    acq_trk_shif_correction_samples = d_next_prn_length_samples - fmod((float)acq_to_trk_delay_samples, (float)d_next_prn_length_samples);
+                    //std::cout<<"acq_trk_shif_correction="<<acq_trk_shif_correction_samples<<"\r\n";
+                    samples_offset = round(d_acq_code_phase_samples + acq_trk_shif_correction_samples);
+                    // /todo: Check if the sample counter sent to the next block as a time reference should be incremented AFTER sended or BEFORE
+                    //d_sample_counter_seconds = d_sample_counter_seconds + (((double)samples_offset) / (double)d_fs_in);
+                    d_sample_counter = d_sample_counter + samples_offset; //count for the processed samples
+                    d_pull_in = false;
+                    //std::cout<<" samples_offset="<<samples_offset<<"\r\n";
+                    consume_each(samples_offset); //shift input to perform alignement with local replica
+                    return 1;
+                }
+
+            // GNSS_SYNCHRO OBJECT to interchange data between tracking->telemetry_decoder
+            Gnss_Synchro current_synchro_data;
+            // Fill the acquisition data
+            current_synchro_data = *d_acquisition_gnss_synchro;
+
+            const gr_complex* in = (gr_complex*) input_items[0]; //PRN start block alignement
+            Gnss_Synchro **out = (Gnss_Synchro **) &output_items[0];
+
+            // Update the prn length based on code freq (variable) and
+            // sampling frequency (fixed)
+            // variable code PRN sample block size
+            d_current_prn_length_samples = d_next_prn_length_samples;
+
+            //update_local_code();
+            update_local_carrier();
+
+            // perform Early, Prompt and Late correlation
+            d_correlator.Carrier_wipeoff_and_EPL_volk(d_current_prn_length_samples,
+                    in,
+                    d_carr_sign,
+                    d_early_code,
+                    d_prompt_code,
+                    d_late_code,
+                    d_Early,
+                    d_Prompt,
+                    d_Late,
+                    is_unaligned());
+
+            // check for samples consistency (this should be done before in the receiver / here only if the source is a file)
+            if (std::isnan((*d_Prompt).real()) == true or std::isnan((*d_Prompt).imag()) == true )// or std::isinf(in[i].real())==true or std::isinf(in[i].imag())==true)
+			{
+				const int samples_available = ninput_items[0];
+				d_sample_counter = d_sample_counter + samples_available;
+				LOG_AT_LEVEL(WARNING) << "Detected NaN samples at sample number " << d_sample_counter;
+				consume_each(samples_available);
+
+				// make an output to not stop the rest of the processing blocks
+	            current_synchro_data.Prompt_I=0.0;
+	            current_synchro_data.Prompt_Q=0.0;
+	            current_synchro_data.Tracking_timestamp_secs=(double)d_sample_counter/(double)d_fs_in;
+	            current_synchro_data.Carrier_phase_rads=0.0;
+	            current_synchro_data.Code_phase_secs=0.0;
+	            current_synchro_data.CN0_dB_hz=0.0;
+	            current_synchro_data.Flag_valid_tracking=false;
+
+	            *out[0] =current_synchro_data;
+
+				return 1;
+			}
+
+            // Compute PLL error and update carrier NCO -
+            carr_error = pll_cloop_two_quadrant_atan(*d_Prompt) / (float)GPS_TWO_PI;
+            // Implement carrier loop filter and generate NCO command
+            carr_nco = d_carrier_loop_filter.get_carrier_nco(carr_error);
+            // Modify carrier freq based on NCO command
+            d_carrier_doppler_hz = d_acq_carrier_doppler_hz + carr_nco;
+
+            // Compute DLL error and update code NCO
+            code_error = dll_nc_e_minus_l_normalized(*d_Early, *d_Late);
+            // Implement code loop filter and generate NCO command
+            code_nco = d_code_loop_filter.get_code_nco(code_error);
+            // Modify code freq based on NCO command
+            d_code_freq_hz = GPS_L1_CA_CODE_RATE_HZ - code_nco;
+
+            // Update the phasestep based on code freq (variable) and
+            // sampling frequency (fixed)
+            d_code_phase_step_chips = d_code_freq_hz / (float)d_fs_in; //[chips]
+            // variable code PRN sample block size
+            float T_chip_seconds;
+            float T_prn_seconds;
+            float T_prn_samples;
+            float K_blk_samples;
+            T_chip_seconds = 1 / d_code_freq_hz;
+            T_prn_seconds = T_chip_seconds * GPS_L1_CA_CODE_LENGTH_CHIPS;
+            T_prn_samples = T_prn_seconds * d_fs_in;
+            d_rem_code_phase_samples = d_next_rem_code_phase_samples;
+            K_blk_samples = T_prn_samples + d_rem_code_phase_samples;
+            d_next_prn_length_samples = round(K_blk_samples); //round to a discrete samples
+            d_next_rem_code_phase_samples = K_blk_samples - d_next_prn_length_samples; //rounding error
+
+            /*!
+             * \todo Improve the lock detection algorithm!
+             */
+            // ####### CN0 ESTIMATION AND LOCK DETECTORS ######
+            if (d_cn0_estimation_counter < CN0_ESTIMATION_SAMPLES)
+                {
+                    // fill buffer with prompt correlator output values
+                    d_Prompt_buffer[d_cn0_estimation_counter] = *d_Prompt;
+                    d_cn0_estimation_counter++;
+                }
+            else
+                {
+                    d_cn0_estimation_counter = 0;
+                    d_CN0_SNV_dB_Hz = gps_l1_ca_CN0_SNV(d_Prompt_buffer, CN0_ESTIMATION_SAMPLES, d_fs_in);
+                    d_carrier_lock_test = carrier_lock_detector(d_Prompt_buffer, CN0_ESTIMATION_SAMPLES);
+                    // ###### TRACKING UNLOCK NOTIFICATION #####
+                    if (std::abs(d_carrier_lock_test) > d_carrier_lock_threshold or d_CN0_SNV_dB_Hz < MINIMUM_VALID_CN0)
+                        {
+                            d_carrier_lock_fail_counter++;
+                        }
+                    else
+                        {
+                            if (d_carrier_lock_fail_counter > 0) d_carrier_lock_fail_counter--;
+                        }
+                    if (d_carrier_lock_fail_counter > MAXIMUM_LOCK_FAIL_COUNTER)
+                        {
+                            std::cout << "Channel " << d_channel << " loss of lock!" << std::endl ;
+                            //tracking_message = 3; //loss of lock
+                            //d_channel_internal_queue->push(tracking_message);
+                        	ControlMessageFactory* cmf = new ControlMessageFactory();
+                        	if (d_queue != gr_msg_queue_sptr()) {
+                        		d_queue->handle(cmf->GetQueueMessage(d_channel, 2));
+                        	}
+                        	delete cmf;
+                            d_carrier_lock_fail_counter = 0;
+                            d_enable_tracking = false; // TODO: check if disabling tracking is consistent with the channel state machine
+
+                        }
+                    //std::cout<<"d_carrier_lock_fail_counter"<<d_carrier_lock_fail_counter<<"\r\n";
+                }
+
+            // ########### Output the tracking data to navigation and PVT ##########
+
+            current_synchro_data.Prompt_I = (double)(*d_Prompt).imag();
+            current_synchro_data.Prompt_Q = (double)(*d_Prompt).real();
+            // Tracking_timestamp_secs is aligned with the PRN start sample
+            current_synchro_data.Tracking_timestamp_secs=((double)d_sample_counter+(double)d_next_prn_length_samples+(double)d_next_rem_code_phase_samples)/(double)d_fs_in;
+            // This tracking block aligns the Tracking_timestamp_secs with the start sample of the PRN, thus, Code_phase_secs=0
+            current_synchro_data.Code_phase_secs=0;
+            current_synchro_data.Carrier_phase_rads = (double)d_acc_carrier_phase_rad;
+            current_synchro_data.CN0_dB_hz = (double)d_CN0_SNV_dB_Hz;
+            *out[0] = current_synchro_data;
+
+            // ########## DEBUG OUTPUT
+            /*!
+             *  \todo The stop timer has to be moved to the signal source!
+             */
+            // debug: Second counter in channel 0
+            if (d_channel == 0)
+                {
+                    if (floor(d_sample_counter / d_fs_in) != d_last_seg)
+                        {
+                            d_last_seg = floor(d_sample_counter / d_fs_in);
+                            std::cout << "Current input signal time = " << d_last_seg << " [s]" << std::endl;
+                            std::cout << "Tracking CH " << d_channel <<  ": Satellite " << Gnss_Satellite(systemName[sys], d_acquisition_gnss_synchro->PRN)
+                                                    << ", CN0 = " << d_CN0_SNV_dB_Hz << " [dB-Hz]" << std::endl;
+                            //std::cout<<"TRK CH "<<d_channel<<" Carrier_lock_test="<<d_carrier_lock_test<< std::endl;
+                            //if (d_last_seg==5) d_carrier_lock_fail_counter=500; //DEBUG: force unlock!
+                        }
+                }
+            else
+                {
+                    if (floor(d_sample_counter / d_fs_in) != d_last_seg)
+                        {
+                            d_last_seg = floor(d_sample_counter / d_fs_in);
+                            std::cout << "Tracking CH " << d_channel <<  ": Satellite " << Gnss_Satellite(systemName[sys], d_acquisition_gnss_synchro->PRN)
+                                                    << ", CN0 = " << d_CN0_SNV_dB_Hz << " [dB-Hz]" << std::endl;
+                            //std::cout<<"TRK CH "<<d_channel<<" Carrier_lock_test="<<d_carrier_lock_test<< std::endl;
+                        }
+                }
+        }
+    else
+        {
+            *d_Early = gr_complex(0,0);
+            *d_Prompt = gr_complex(0,0);
+            *d_Late = gr_complex(0,0);
+            Gnss_Synchro **out = (Gnss_Synchro **) &output_items[0]; //block output streams pointer
+            //std::cout<<output_items.size()<<std::endl;
+            // GNSS_SYNCHRO OBJECT to interchange data between tracking->telemetry_decoder
+            Gnss_Synchro current_synchro_data;
+            *out[0] = current_synchro_data;
+        }
+
+    if(d_dump)
+        {
+            // MULTIPLEXED FILE RECORDING - Record results to file
+            float prompt_I;
+            float prompt_Q;
+            float tmp_E, tmp_P, tmp_L;
+            float tmp_float;
+            double tmp_double;
+            prompt_I = (*d_Prompt).imag();
+            prompt_Q = (*d_Prompt).real();
+            tmp_E = std::abs<float>(*d_Early);
+            tmp_P = std::abs<float>(*d_Prompt);
+            tmp_L = std::abs<float>(*d_Late);
+            try
+            {
+                    // EPR
+                    d_dump_file.write((char*)&tmp_E, sizeof(float));
+                    d_dump_file.write((char*)&tmp_P, sizeof(float));
+                    d_dump_file.write((char*)&tmp_L, sizeof(float));
+                    // PROMPT I and Q (to analyze navigation symbols)
+                    d_dump_file.write((char*)&prompt_I, sizeof(float));
+                    d_dump_file.write((char*)&prompt_Q, sizeof(float));
+                    // PRN start sample stamp
+                    //tmp_float=(float)d_sample_counter;
+                    d_dump_file.write((char*)&d_sample_counter, sizeof(unsigned long int));
+                    // accumulated carrier phase
+                    d_dump_file.write((char*)&d_acc_carrier_phase_rad, sizeof(float));
+
+                    // carrier and code frequency
+                    d_dump_file.write((char*)&d_carrier_doppler_hz, sizeof(float));
+                    d_dump_file.write((char*)&d_code_freq_hz, sizeof(float));
+
+                    //PLL commands
+                    d_dump_file.write((char*)&carr_error, sizeof(float));
+                    d_dump_file.write((char*)&carr_nco, sizeof(float));
+
+                    //DLL commands
+                    d_dump_file.write((char*)&code_error, sizeof(float));
+                    d_dump_file.write((char*)&code_nco, sizeof(float));
+
+                    // CN0 and carrier lock test
+                    d_dump_file.write((char*)&d_CN0_SNV_dB_Hz, sizeof(float));
+                    d_dump_file.write((char*)&d_carrier_lock_test, sizeof(float));
+
+                    // AUX vars (for debug purposes)
+                    tmp_float = d_rem_code_phase_samples;
+                    d_dump_file.write((char*)&tmp_float, sizeof(float));
+                    tmp_double=(double)(d_sample_counter+d_current_prn_length_samples);
+                    d_dump_file.write((char*)&tmp_double, sizeof(double));
+            }
+            catch (std::ifstream::failure e)
+            {
+                    std::cout << "Exception writing trk dump file " << e.what() << std::endl;
+            }
+        }
+
+    consume_each(d_current_prn_length_samples); // this is necesary in gr_block derivates
+    //d_sample_counter_seconds = d_sample_counter_seconds + ( ((double)d_current_prn_length_samples) / (double)d_fs_in );
+    d_sample_counter += d_current_prn_length_samples; //count for the processed samples
+    return 1; //output tracking result ALWAYS even in the case of d_enable_tracking==false
+}
+
+
+
+void Gps_L1_Ca_Dll_Pll_Optim_Tracking_cc::set_channel(unsigned int channel)
+{
+    d_channel = channel;
+    LOG_AT_LEVEL(INFO) << "Tracking Channel set to " << d_channel;
+    // ############# ENABLE DATA FILE LOG #################
+    if (d_dump==true)
+        {
+            if (d_dump_file.is_open() == false)
+                {
+                    try
+                    {
+                            d_dump_filename.append(boost::lexical_cast<std::string>(d_channel));
+                            d_dump_filename.append(".dat");
+                            d_dump_file.exceptions (std::ifstream::failbit | std::ifstream::badbit);
+                            d_dump_file.open(d_dump_filename.c_str(), std::ios::out | std::ios::binary);
+                            std::cout << "Tracking dump enabled on channel " << d_channel << " Log file: " << d_dump_filename.c_str() << std::endl;
+                    }
+                    catch (std::ifstream::failure e)
+                    {
+                            std::cout << "channel " << d_channel << " Exception opening trk dump file " << e.what() << std::endl;
+                    }
+                }
+        }
+}
+
+
+
+void Gps_L1_Ca_Dll_Pll_Optim_Tracking_cc::set_channel_queue(concurrent_queue<int> *channel_internal_queue)
+{
+    d_channel_internal_queue = channel_internal_queue;
+}
+
+void Gps_L1_Ca_Dll_Pll_Optim_Tracking_cc::set_gnss_synchro(Gnss_Synchro* p_gnss_synchro)
+{
+    d_acquisition_gnss_synchro = p_gnss_synchro;
+
+}

src/algorithms/tracking/gnuradio_blocks/gps_l1_ca_dll_pll_optim_tracking_cc.h

@@ -0,0 +1,202 @@
+/*!
+ * \file gps_l1_ca_dll_pll_optim_tracking_cc.h
+ * \brief Implementation of a code DLL + carrier PLL tracking block
+ * \author Javier Arribas, 2012. jarribas(at)cttc.es
+ * GPS L1 TRACKING MODULE OPTIMIZED FOR SPEED:
+ * - Code Doppler is not compensated in the local replica
+ * Code DLL + carrier PLL according to the algorithms described in:
+ * [1] K.Borre, D.M.Akos, N.Bertelsen, P.Rinder, and S.H.Jensen,
+ * A Software-Defined GPS and Galileo Receiver. A Single-Frequency
+ * Approach, Birkha user, 2007
+ *
+ * -------------------------------------------------------------------------
+ *
+ * Copyright (C) 2010-2012  (see AUTHORS file for a list of contributors)
+ *
+ * GNSS-SDR is a software defined Global Navigation
+ *          Satellite Systems receiver
+ *
+ * This file is part of GNSS-SDR.
+ *
+ * GNSS-SDR 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.
+ *
+ * GNSS-SDR 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 GNSS-SDR. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * -------------------------------------------------------------------------
+ */
+
+#ifndef GNSS_SDR_GPS_L1_CA_DLL_PLL_OPTIM_TRACKING_CC_H
+#define	GNSS_SDR_GPS_L1_CA_DLL_PLL_TRACKING_CC_H
+
+#include <fstream>
+#include <queue>
+#include <boost/thread/mutex.hpp>
+#include <boost/thread/thread.hpp>
+#include <gnuradio/gr_block.h>
+#include <gnuradio/gr_msg_queue.h>
+//#include <gnuradio/gr_sync_decimator.h>
+#include "concurrent_queue.h"
+#include "gps_sdr_signal_processing.h"
+#include "gnss_synchro.h"
+#include "tracking_2nd_DLL_filter.h"
+#include "tracking_2nd_PLL_filter.h"
+
+#include "correlator.h"
+
+
+
+class Gps_L1_Ca_Dll_Pll_Optim_Tracking_cc;
+typedef boost::shared_ptr<Gps_L1_Ca_Dll_Pll_Optim_Tracking_cc>
+        gps_l1_ca_dll_pll_optim_tracking_cc_sptr;
+
+gps_l1_ca_dll_pll_optim_tracking_cc_sptr
+gps_l1_ca_dll_pll_make_optim_tracking_cc(long if_freq,
+                                   long fs_in, unsigned
+                                   int vector_length,
+                                   gr_msg_queue_sptr queue,
+                                   bool dump,
+                                   std::string dump_filename,
+                                   float pll_bw_hz,
+                                   float dll_bw_hz,
+                                   float early_late_space_chips);
+
+//class gps_l1_ca_dll_pll_tracking_cc: public gr_sync_decimator
+
+/*!
+ * \brief This class implements a DLL + PLL tracking loop block
+ */
+class Gps_L1_Ca_Dll_Pll_Optim_Tracking_cc: public gr_block
+{
+public:
+
+    ~Gps_L1_Ca_Dll_Pll_Optim_Tracking_cc();
+
+    void set_channel(unsigned int channel);
+    void set_gnss_synchro(Gnss_Synchro* p_gnss_synchro);
+    void start_tracking();
+    void set_channel_queue(concurrent_queue<int> *channel_internal_queue);
+
+    /*
+     * \brief just like gr_block::general_work, only this arranges to call consume_each for you
+     *
+     * The user must override work to define the signal processing code
+     */
+
+    int general_work (int noutput_items, gr_vector_int &ninput_items,
+            gr_vector_const_void_star &input_items, gr_vector_void_star &output_items);
+
+    void forecast (int noutput_items, gr_vector_int &ninput_items_required);
+
+
+private:
+
+    friend gps_l1_ca_dll_pll_optim_tracking_cc_sptr
+    gps_l1_ca_dll_pll_make_optim_tracking_cc(long if_freq,
+            long fs_in, unsigned
+            int vector_length,
+            gr_msg_queue_sptr queue,
+            bool dump,
+            std::string dump_filename,
+            float pll_bw_hz,
+            float dll_bw_hz,
+            float early_late_space_chips);
+
+    Gps_L1_Ca_Dll_Pll_Optim_Tracking_cc(long if_freq,
+            long fs_in, unsigned
+            int vector_length,
+            gr_msg_queue_sptr queue,
+            bool dump,
+            std::string dump_filename,
+            float pll_bw_hz,
+            float dll_bw_hz,
+            float early_late_space_chips);
+    void update_local_code();
+    void update_local_carrier();
+
+    // tracking configuration vars
+    gr_msg_queue_sptr d_queue;
+    concurrent_queue<int> *d_channel_internal_queue;
+    unsigned int d_vector_length;
+    bool d_dump;
+
+    Gnss_Synchro* d_acquisition_gnss_synchro;
+    unsigned int d_channel;
+    int d_last_seg;
+    long d_if_freq;
+    long d_fs_in;
+
+    double d_early_late_spc_chips;
+
+    double d_code_phase_step_chips;
+
+    gr_complex* d_ca_code;
+
+    gr_complex* d_early_code;
+    gr_complex* d_late_code;
+    gr_complex* d_prompt_code;
+    gr_complex* d_carr_sign;
+
+    gr_complex *d_Early;
+    gr_complex *d_Prompt;
+    gr_complex *d_Late;
+
+    // remaining code phase and carrier phase between tracking loops
+    float d_rem_code_phase_samples;
+    float d_next_rem_code_phase_samples;
+    float d_rem_carr_phase_rad;
+
+    // PLL and DLL filter library
+    Tracking_2nd_DLL_filter d_code_loop_filter;
+    Tracking_2nd_PLL_filter d_carrier_loop_filter;
+
+    // acquisition
+    float d_acq_code_phase_samples;
+    float d_acq_carrier_doppler_hz;
+    // correlator
+    Correlator d_correlator;
+
+    // tracking vars
+    float d_code_freq_hz;
+    float d_carrier_doppler_hz;
+    float d_acc_carrier_phase_rad;
+    float d_code_phase_samples;
+
+    //PRN period in samples
+    int d_current_prn_length_samples;
+    int d_next_prn_length_samples;
+    //double d_sample_counter_seconds;
+
+    //processing samples counters
+    unsigned long int d_sample_counter;
+    unsigned long int d_acq_sample_stamp;
+
+    // CN0 estimation and lock detector
+    int d_cn0_estimation_counter;
+    gr_complex* d_Prompt_buffer;
+    float d_carrier_lock_test;
+    float d_CN0_SNV_dB_Hz;
+    float d_carrier_lock_threshold;
+    int d_carrier_lock_fail_counter;
+
+    // control vars
+    bool d_enable_tracking;
+    bool d_pull_in;
+
+    // file dump
+    std::string d_dump_filename;
+    std::ofstream d_dump_file;
+
+    std::map<std::string, std::string> systemName;
+    std::string sys;
+};
+
+#endif //GNSS_SDR_GPS_L1_CA_DLL_PLL_OPTIM_TRACKING_CC_H

src/algorithms/tracking/gnuradio_blocks/jamfile.jam

@@ -4,3 +4,4 @@ obj gps_l1_ca_dll_pll_tracking_cc : gps_l1_ca_dll_pll_tracking_cc.cc : <toolset>
 obj gps_l1_ca_dll_fll_pll_tracking_cc : gps_l1_ca_dll_fll_pll_tracking_cc.cc : <toolset>darwin:<define>GNSS_SDR_USE_BOOST_ROUND ;
 obj gps_l1_ca_tcp_connector_tracking_cc : gps_l1_ca_tcp_connector_tracking_cc.cc : <toolset>darwin:<define>GNSS_SDR_USE_BOOST_ROUND ;
 obj galileo_e1_dll_pll_veml_tracking_cc : galileo_e1_dll_pll_veml_tracking_cc.cc : <toolset>darwin:<define>GNSS_SDR_USE_BOOST_ROUND ;
+obj gps_l1_ca_dll_pll_optim_tracking_cc : gps_l1_ca_dll_pll_optim_tracking_cc.cc : <toolset>darwin:<define>GNSS_SDR_USE_BOOST_ROUND ;

src/core/receiver/gnss_block_factory.cc

@@ -56,6 +56,7 @@
 #include "gps_l1_ca_pcps_acquisition.h"
 #include "galileo_e1_pcps_ambiguous_acquisition.h"
 #include "gps_l1_ca_dll_pll_tracking.h"
+#include "gps_l1_ca_dll_pll_optim_tracking.h"
 #include "gps_l1_ca_dll_fll_pll_tracking.h"
 #include "gps_l1_ca_tcp_connector_tracking.h"
 #include "galileo_e1_dll_pll_veml_tracking.h"
@@ -352,6 +353,11 @@ GNSSBlockInterface* GNSSBlockFactory::GetBlock(
             block = new GpsL1CaDllPllTracking(configuration, role, in_streams,
                     out_streams, queue);
         }
+    else if (implementation.compare("GPS_L1_CA_DLL_PLL_Optim_Tracking") == 0)
+        {
+            block = new GpsL1CaDllPllOptimTracking(configuration, role, in_streams,
+                    out_streams, queue);
+        }
     else if (implementation.compare("GPS_L1_CA_DLL_FLL_PLL_Tracking") == 0)
         {
             block = new GpsL1CaDllFllPllTracking(configuration, role, in_streams,

src/main/jamfile.jam

@@ -51,10 +51,12 @@ exe gnss-sdr : main.cc
 ../algorithms/PVT/adapters//gps_l1_ca_pvt
 ../algorithms/PVT/gnuradio_blocks//gps_l1_ca_pvt_cc
 ../algorithms/tracking/adapters//gps_l1_ca_dll_pll_tracking
+../algorithms/tracking/adapters//gps_l1_ca_dll_pll_optim_tracking
 ../algorithms/tracking/adapters//gps_l1_ca_dll_fll_pll_tracking
 ../algorithms/tracking/adapters//gps_l1_ca_tcp_connector_tracking
 ../algorithms/tracking/adapters//galileo_e1_dll_pll_veml_tracking
 ../algorithms/tracking/gnuradio_blocks//gps_l1_ca_dll_pll_tracking_cc
+../algorithms/tracking/gnuradio_blocks//gps_l1_ca_dll_pll_optim_tracking_cc
 ../algorithms/tracking/gnuradio_blocks//gps_l1_ca_dll_fll_pll_tracking_cc
 ../algorithms/tracking/gnuradio_blocks//gps_l1_ca_tcp_connector_tracking_cc
 ../algorithms/tracking/gnuradio_blocks//galileo_e1_dll_pll_veml_tracking_cc

src/tests/jamfile.jam

@@ -48,10 +48,12 @@ exe run_tests : test_main.cc
 ../algorithms/PVT/adapters//gps_l1_ca_pvt
 ../algorithms/PVT/gnuradio_blocks//gps_l1_ca_pvt_cc
 ../algorithms/tracking/adapters//gps_l1_ca_dll_pll_tracking
+../algorithms/tracking/adapters//gps_l1_ca_dll_pll_optim_tracking
 ../algorithms/tracking/adapters//gps_l1_ca_dll_fll_pll_tracking
 ../algorithms/tracking/adapters//gps_l1_ca_tcp_connector_tracking
 ../algorithms/tracking/adapters//galileo_e1_dll_pll_veml_tracking
 ../algorithms/tracking/gnuradio_blocks//gps_l1_ca_dll_pll_tracking_cc
+../algorithms/tracking/gnuradio_blocks//gps_l1_ca_dll_pll_optim_tracking_cc
 ../algorithms/tracking/gnuradio_blocks//gps_l1_ca_dll_fll_pll_tracking_cc
 ../algorithms/tracking/gnuradio_blocks//gps_l1_ca_tcp_connector_tracking_cc
 ../algorithms/tracking/gnuradio_blocks//galileo_e1_dll_pll_veml_tracking_cc