Welcome to the Public page for UQ Communication Systems. This page is mainly part of two courses at The University of Queensland: COMS4105 (which is taken by both undergraduate and masters coursework students).

In this wiki we list some instructions for setting up the hardware, and some hints in developing under Matlab/Octave, Gnuradio or software defined radio (SDR) in general.

As part of the course at UQ, students work with the RTL2832U dongles, which also function as low-cost software defined radios. Many of the pitfalls in setting up these devices in a wide variety of environments and operating systems have been solved, and so it is hoped that others (outside of UQ) also find this useful.

Where relevant, information from other Internet references are cited.

Setting up Hardware and Software

See the setup guides page for links to setup RTLSDR, Octave, and Gnuradio.

Processing Captured Data

After capturing samples with RTL SDR (to something like dump.bin), you can use the language of your choice (MATLAB/Octave, GNUradio (Python/C++), Raw C/C++ with a library such as ITPP) to process it. See the guide below for more information:

• Reading in Samples

Converting data

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

General Hints

In this subject you should avoid "screenshots" as a way of adding figures to your assignments. Where possible vector graphics should be used. In MATLAB this is easy by using the "File > Save Figure" menu, or simply "Edit > Copy Figure" and paste in the destination program. In other programs, like Octave (3.8+), use "File > Save Figure".

In the repository you may also find several code snippets used in lectures.

• Plotting Spectrum Using PWelch
• Exporting Figures in Octave
• Making graphs look nice