GNSS‐SDR 2

In GNSS-SDR 1 the data from the GNSS-Firehose channel 1 was turned into 8bit IQ data and the processed by GNSS-SDR.

Using the Two_Bit_Packed_File_Signal_Source it is possible to not do any conversion on the data. All that needs to be done is filter out the channel 1 data using the command:

<outfile.pcap ./packet2bitIQ 1 > outfile.bit

GNSS SDR needs to be told to use the Two_Bit_Packed_File_Signal_Source and what order the bits are in. The output of the signal source is gr_complex and so the Data Type Adapter can be set to pass through. The rest of the configuration file is the same as GNSS-SDR 1

;######### SIGNAL_SOURCE CONFIG ############

SignalSource.implementation=Two_Bit_Packed_File_Signal_Source

SignalSource.filename=/home/alan/fpga/GNSS_Firehose/test/outfile.bit

SignalSource.item_type=byte

SignalSource.sampling_frequency=69984000

SignalSource.freq=1584754875

SignalSource.samples=0

SignalSource.sample_type=iq

SignalSource.big_endian_bytes=true

SignalSource.repeat=false

SignalSource.dump=false

SignalSource.dump_filename=../data/signal_source.dat

SignalSource.enable_throttle_control=false

;######### SIGNAL_CONDITIONER CONFIG ############

SignalConditioner.implementation=Signal_Conditioner

DataTypeAdapter.implementation=Pass_Through

The i5-4590/3.3GHz machine took 272sec to process 60sec of data from the GNSS Firehose.