From ce68bbf0692293f093fa54ed5b7e782c18bf69f4 Mon Sep 17 00:00:00 2001
From: Gastd <gabriel.araujo.5000@gmail.com>
Date: Tue, 18 Jul 2017 17:51:28 -0300
Subject: [PATCH] Add glonass signal acquisition

---
 .../gnuradio_blocks/pcps_acquisition_sc.cc    | 36 +++++++++++++++++++
 .../gnuradio_blocks/pcps_acquisition_sc.h     |  3 ++
 2 files changed, 39 insertions(+)

diff --git a/src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition_sc.cc b/src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition_sc.cc
index c265dee17..c4d20f962 100644
--- a/src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition_sc.cc
+++ b/src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition_sc.cc
@@ -41,6 +41,8 @@
 #include <volk_gnsssdr/volk_gnsssdr.h>
 #include "control_message_factory.h"
 #include "GPS_L1_CA.h" //GPS_TWO_PI
+#include "Glonass_L1_CA.h" //GLONASS_TWO_PI
+
 
 using google::LogMessage;
 
@@ -159,6 +161,11 @@ pcps_acquisition_sc::~pcps_acquisition_sc()
 
 void pcps_acquisition_sc::set_local_code(std::complex<float> * code)
 {
+    // This will check if it's fdma, if yes will update the intermediate frequency and the doppler grid
+    if( is_fdma() )
+        {
+            update_grid_doppler_wipeoffs();
+        }
     // COD
     // Here we want to create a buffer that looks like this:
     // [ 0 0 0 ... 0 c_0 c_1 ... c_L]
@@ -175,6 +182,22 @@ void pcps_acquisition_sc::set_local_code(std::complex<float> * code)
 }
 
 
+bool pcps_acquisition_sc::is_fdma()
+{
+    // Dealing with FDMA system
+    if( strcmp(d_gnss_synchro->Signal,"1G") == 0 )
+        {
+            d_freq += DFRQ1_GLO * GLONASS_PRN.at(d_gnss_synchro->PRN);
+            LOG(INFO) << "Trying to acquire SV PRN " << d_gnss_synchro->PRN << " with freq " << DFRQ1_GLO * GLONASS_PRN.at(d_gnss_synchro->PRN) << " in Channel " << GLONASS_PRN.at(d_gnss_synchro->PRN) << std::endl;
+            return true;
+        }
+    else
+        {
+            return false;
+        }
+}
+
+
 void pcps_acquisition_sc::update_local_carrier(gr_complex* carrier_vector, int correlator_length_samples, float freq)
 {
     float phase_step_rad = GPS_TWO_PI * freq / static_cast<float>(d_fs_in);
@@ -211,6 +234,19 @@ void pcps_acquisition_sc::init()
 }
 
 
+void pcps_acquisition_sc::update_grid_doppler_wipeoffs()
+{
+    // Create the carrier Doppler wipeoff signals
+    d_grid_doppler_wipeoffs = new gr_complex*[d_num_doppler_bins];
+
+    for (unsigned int doppler_index = 0; doppler_index < d_num_doppler_bins; doppler_index++)
+        {
+            d_grid_doppler_wipeoffs[doppler_index] = static_cast<gr_complex*>(volk_gnsssdr_malloc(d_fft_size * sizeof(gr_complex), volk_gnsssdr_get_alignment()));
+            int doppler = -static_cast<int>(d_doppler_max) + d_doppler_step * doppler_index;
+            update_local_carrier(d_grid_doppler_wipeoffs[doppler_index], d_fft_size, d_freq + doppler);
+        }
+}
+
 
 void pcps_acquisition_sc::set_state(int state)
 {
diff --git a/src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition_sc.h b/src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition_sc.h
index 1b3ab7bf6..5f207d8b8 100644
--- a/src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition_sc.h
+++ b/src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition_sc.h
@@ -97,6 +97,9 @@ private:
             int correlator_length_samples,
             float freq);
 
+    void update_grid_doppler_wipeoffs();
+    bool is_fdma();
+
     long d_fs_in;
     long d_freq;
     int d_samples_per_ms;