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mirror of https://github.com/gnss-sdr/gnss-sdr synced 2024-09-27 22:58:24 +00:00

Bug fix in GPS L1 CA telemetry decoder, increased subframe realiability

This commit is contained in:
Javier Arribas 2019-05-15 17:35:10 +02:00
parent e1d01d3b97
commit 93bea1591b

View File

@ -160,10 +160,10 @@ bool gps_l1_ca_telemetry_decoder_gs::gps_word_parityCheck(uint32_t gpsword)
parity = parity & 0x3F;
if (parity == (gpsword & 0x3F))
{
return (true);
return true;
}
return (false);
return false;
}
@ -215,7 +215,7 @@ bool gps_l1_ca_telemetry_decoder_gs::decode_subframe()
int32_t word_index = 0;
uint32_t GPS_frame_4bytes = 0;
float symbol_accumulator = 0;
bool subframe_synchro_confirmation = false;
bool subframe_synchro_confirmation = true;
for (float subframe_symbol : d_symbol_history)
{
// ******* SYMBOL TO BIT *******
@ -261,9 +261,10 @@ bool gps_l1_ca_telemetry_decoder_gs::decode_subframe()
{
GPS_frame_4bytes ^= 0x3FFFFFC0; // invert the data bits (using XOR)
}
if (gps_l1_ca_telemetry_decoder_gs::gps_word_parityCheck(GPS_frame_4bytes))
//check parity. If ANY word inside the subframe fails the parity, set subframe_synchro_confirmation = false
if (not gps_l1_ca_telemetry_decoder_gs::gps_word_parityCheck(GPS_frame_4bytes))
{
subframe_synchro_confirmation = true;
subframe_synchro_confirmation = false;
}
// add word to subframe
// insert the word in the correct position of the subframe