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Welcome to UQ Communication Systems's Public WIKI. This page is part of the COMS4105 course at the University of Queensland in Australia. It is taken by both undergraduate and masters coursework students, from the Electrical Engineering, Mechatronic Engineering, and Computer Science disciplines.

In this wiki includes some hardware and software guides relating to Communication Systems. In COMS4105 we provide instructions for MATLAB/Octave and Python, and students work with a simple software defined radio (SDR) -- the RTL2832U or RTLSDR.

The RTL2832U dongle is a low-cost software defined radio. This WIKI includes links to instructions online, as well as a list of troubleshooting comments contributed by the staff and students in the course. It is provided online to help save time for those (inside and outside UQ) who are starting their journey of experimenting with SDRs.

Where relevant, information from other Internet references are cited.

Getting Started: Hardware & Software Setup

See the setup guides page for detailed instructinos and links to setup and install RTLSDR Drivers, Octave/Python, and Gnuradio.

Working with Captured Data

After capturing raw samples with am RTL-SDR receiver (often saved as a file like dump.bin), you can process this data using your preferred programming environment. Common choices include MATLAB/Octave, GNUradio (Python/C++), Raw C/C++ with a library such as ITPP. See the guide below for more information:

Preparing data for transmission

Text data, bytes, words may need to be prepared for transmission into the right groups of bits.

  • For guides on how to convert ASCII to bits for modulation see Converting Data for code in Python or MATLAB/Octave.
    • In Gnuradio, there is a repack bits block which does the same process.

Tips and Best Practices

High quality figures and plots

  • Avoid "screenshots" as a way of exporting figures. For documents (word, latex, powerpoint) use vector graphics.
    • To export a figure in MATLAB use the "File > Save Figure" menu, or simply "Edit > Copy Figure" and paste in the destination program.
    • To export a figure in Octave use "File > Save Figure".
  • To do this in code, see the High Quality Figures for code in Python or MATLAB/Octave.

Calculating a signals spectrum