Presentations below attached.
Generate gpssim file using gps-sdr-sim (Static Mode)
Built on Ubuntu 18.04, hackrf working with no install in GQRX.
git clone https://github.com/osqzss/gps-sdr-sim.git
cd gps-sdr-sim/
ls
make USER_MOTION_SIZE=4000
Also installed: https://github.com/mossmann/hackrf/tree/master/host
sudo apt-get install build-essential cmake libusb-1.0-0-dev pkg-config libfftw3-dev
git clone https://github.com/mossmann/hackrf.git
cd hackrf/
mkdir host/build
cd host/build
cmake ..
make
sudo make install
sudo ldconfig
Download and extract latest: ftp://cddis.gsfc.nasa.gov/gnss/data/daily/2019/brdc/
Build a static position file, 8bit IQ interleave for 360 seconds in gps-sdr-sim:
wget ftp://cddis.gsfc.nasa.gov/gnss/data/daily/2019/brdc/brdcXXX.19n.Z
uncompress brdcXXX.19n.Z
I have automated this process, run update-gps.sh below in your gps-sdr-sim directory.
./gps-sdr-sim -e brdcXXX.19n -l 21.302019,-157.808833,100 -b 8 -d 360
Using my SDR and GNU Radio I tested on ISM 900mhz band. See the attached GNU Radio file for a setup without using hackrf_transfer, take note the -s <frequency> option in gps-sdr-sim must match the sample rate in the sink.
Run hackrf_info to get the serial number to plug into GNU Radio sink output options. Specify your input file.
I have a RTL-SDR and verified traffic, but I have not run a GPS receiver to test the signal or tested on 1.5Ghz