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Bug fix in L2CM CNAV message decoder. The decoder is still experimental.

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This commit is contained in:
Javier Arribas
2016-04-22 16:49:12 +02:00
parent 4cee7965c4
commit 60b6b98c52
2 changed files with 10 additions and 8 deletions
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5
conf/gnss-sdr_multichannel_GPS_L2_M_Flexiband_bin_file_III_1b.conf
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@@ -268,7 +268,9 @@ Resampler2.implementation=Pass_Through
;######### CHANNELS GLOBAL CONFIG ############ ;######### CHANNELS GLOBAL CONFIG ############
;#count: Number of available GPS satellite channels. ;#count: Number of available GPS satellite channels.
Channels_1C.count=1 Channels_1C.count=1
Channels_2S.count=7 Channels_2S.count=8
;#GPS.prns=7,8
;#in_acquisition: Number of channels simultaneously acquiring for the whole receiver ;#in_acquisition: Number of channels simultaneously acquiring for the whole receiver
Channels.in_acquisition=1 Channels.in_acquisition=1
@@ -289,6 +291,7 @@ Channel4.RF_channel_ID=1
Channel5.RF_channel_ID=1 Channel5.RF_channel_ID=1
Channel6.RF_channel_ID=1 Channel6.RF_channel_ID=1
Channel7.RF_channel_ID=1 Channel7.RF_channel_ID=1
Channel8.RF_channel_ID=1
;######### ACQUISITION GENERIC CONFIG ###### ;######### ACQUISITION GENERIC CONFIG ######

13
src/algorithms/telemetry_decoder/gnuradio_blocks/gps_l2_m_telemetry_decoder_cc.cc
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@@ -116,9 +116,6 @@ int gps_l2_m_telemetry_decoder_cc::general_work (int noutput_items __attribute__
const Gnss_Synchro *in = (const Gnss_Synchro *) input_items[0]; // input const Gnss_Synchro *in = (const Gnss_Synchro *) input_items[0]; // input
Gnss_Synchro *out = (Gnss_Synchro *) output_items[0]; // output Gnss_Synchro *out = (Gnss_Synchro *) output_items[0]; // output
// store the time stamp of the first sample in the processed sample block
//double sample_stamp = in[0].Tracking_timestamp_secs;
bool flag_new_cnav_frame = false; bool flag_new_cnav_frame = false;
int last_frame_preamble_start = 0; int last_frame_preamble_start = 0;
// copy correlation samples into samples vector // copy correlation samples into samples vector
@@ -131,7 +128,7 @@ int gps_l2_m_telemetry_decoder_cc::general_work (int noutput_items __attribute__
{ {
if (in[0].Flag_valid_symbol_output == false) // check if the tracking is locked if (in[0].Flag_valid_symbol_output == false) // check if the tracking is locked
{ {
//LOG(INFO)<< "Discarting channel "<<d_channel<<" tracking not ready!"<<std::endl; LOG(INFO)<< "Discarting channel "<<d_channel<<" tracking not ready!"<<std::endl;
d_flag_valid_word = false; d_flag_valid_word = false;
} }
else else
@@ -152,14 +149,14 @@ int gps_l2_m_telemetry_decoder_cc::general_work (int noutput_items __attribute__
// they can be already aligned or shifted by one position // they can be already aligned or shifted by one position
std::vector<int> bits; std::vector<int> bits;
//bool symbol_alignment = d_symbol_aligner_and_decoder.get_bits(d_sample_buf, bits); d_symbol_aligner_and_decoder.get_bits(d_sample_buf, bits);
//std::stringstream ss; //std::stringstream ss;
//for (std::vector<int>::const_iterator bit_it = bits.begin(); bit_it < bits.end(); ++bit_it) //for (std::vector<int>::const_iterator bit_it = bits.begin(); bit_it < bits.end(); ++bit_it)
// { // {
// ss << *bit_it; // ss << *bit_it;
// } // }
// LOG(INFO) << "get_bits=" << ss.str() << std::endl; //LOG(INFO) << "get_bits=" << ss.str() << std::endl;
// search for preambles // search for preambles
// and extract the corresponding message candidates // and extract the corresponding message candidates
@@ -187,12 +184,14 @@ int gps_l2_m_telemetry_decoder_cc::general_work (int noutput_items __attribute__
d_flag_invert_input_symbols = d_flag_invert_buffer_symbols; d_flag_invert_input_symbols = d_flag_invert_buffer_symbols;
std::vector<int> tmp_msg; std::vector<int> tmp_msg;
std::string msg; std::string msg;
//todo: now the symbol buffer size is two CNAV frames because the preamble is not detected.
// Use the first valid frame to realign the bufer symbols with the preamble start and not miss a frame
LOG(INFO) << valid_msgs.size() << " GOOD L2C CNAV FRAME DETECTED! CH " <<this->d_channel; LOG(INFO) << valid_msgs.size() << " GOOD L2C CNAV FRAME DETECTED! CH " <<this->d_channel;
for (unsigned int i = 0;i < valid_msgs.size(); i++) for (unsigned int i = 0;i < valid_msgs.size(); i++)
{ {
tmp_msg = valid_msgs.at(i).second; tmp_msg = valid_msgs.at(i).second;
d_CNAV_Message.decode_page(tmp_msg); d_CNAV_Message.decode_page(tmp_msg);
//std::cout << "Valid CNAV frame with relative preamble start at " << valid_msgs.at(i).first << std::endl; std::cout << "Valid CNAV frame with relative preamble start at " << valid_msgs.at(i).first << std::endl;
flag_new_cnav_frame = true; flag_new_cnav_frame = true;
d_flag_valid_word = true; d_flag_valid_word = true;
last_frame_preamble_start = valid_msgs.at(i).first; last_frame_preamble_start = valid_msgs.at(i).first;