gps-sdr-sim

To build the hackplayer software for HackRF One, you must first build and install libhackrf following the instructions at https://github.com/mossmann/hackrf/tree/master/host. Once the library is installed, you can build the player using make.

$ make hackplayer

Compile the project using GCC with optimization and the math library:

$ gcc gpssim.c -lm -O3 -o gps-sdr-sim

NMEA2UM is a utility used to generate ECEF (Earth-Centered, Earth-Fixed) user motion files required by GPS-SDR-SIM. It processes NMEA GGA data (typically generated by simulation software like LabSat) and converts it into the specific CSV format used for user motion simulation.

nmea2um <nmea_gga> <user_motion>

To build the plutoplayer software for ADALM-Pluto, you must first install the required libraries libiio (instructions at https://wiki.analog.com/resources/tools-software/linux-software/libiio) and libad9361. After the libraries are installed, you can build the player using make.

# Install libad9361
$ git clone https://github.com/analogdevicesinc/libad9361-iio.git
$ cd libad9361-iio
$ cmake ./
$ make all
$ sudo make install

# Build plutoplayer
$ make plutoplayer

To build the project on Windows, use Visual Studio with the following steps:

1. Start Visual Studio.
2. Create an empty project for a console application.
3. Add gpssim.c and getopt.c to the Source Files folder in the Solution Explorer.
4. Select Release in the Solution Configurations drop-down list.
5. Build the solution.

To build the limeplayer software for LimeSDR, you must first build and install libLimeSuite following the instructions at http://wiki.myriadrf.org/Lime_Suite. Once the library is installed, you can build the player using make.

$ make limeplayer

To build the bladeplayer software for bladeRF, you must first build and install libbladeRF following the instructions at https://github.com/Nuand/bladeRF/wiki/Getting-Started:-Linux. Once the library is installed, you can build the player using make.

$ make bladeplayer

To create a custom user motion file for GPS-SDR-SIM, follow these steps:

1. Route Creation: Sketch a desired route in Google Earth.
2. Export Path: Save the sketched path as a .kml file.
3. Simulate NMEA: Load the .kml file into SatGen.
4. Generate NMEA: Set the output rate to 10Hz and generate an NMEA file.
5. Convert Format: Use nmea2um to convert the generated NMEA data into the required user motion CSV format.

By default, user motion files are limited to 30,000 samples (at 10Hz). To use larger files, set the USER_MOTION_SIZE variable to the maximum duration of the motion file in seconds during compilation or via make.

Using make:

$ make USER_MOTION_SIZE=4000

Using GCC:

$ gcc gpssim.c -lm -O3 -o gps-sdr-sim -DUSER_MOTION_SIZE=4000

For UHD supported devices (tested with USRP2), use gps-sdr-sim-uhd.py or the tx_samples_from_file tool. USRP2 requires a sample rate of 2.5MHz.

Using gps-sdr-sim-uhd.py:

> gps-sdr-sim-uhd.py -t gpssim.bin -s 2500000 -x 0

Using tx_samples_from_file:

> tx_samples_from_file --file gpssim.bin --type short --rate 2500000 --freq 1575420000 --gain 0

HackRF requires 8-bit signed I/Q samples. Generate the file with -b 8 and use hackrf_transfer to transmit.

# Generate 8-bit file
> gps-sdr-sim -e brdc0010.22n -b 8

# Transmit
> hackrf_transfer -t gpssim.bin -f 1575420000 -s 2600000 -a 1 -x 0