The fun and benefits from SDRs are interesting but not of much use unless one can acquire and use the necessary tools to work with SDR technology. This website is oriented to beginners who want to commit to home-brew SDR. The ability to author custom DSP software is key to working effectively with SDR at the level to which amateurs have become accustomed and in effect partially replaces the soldering iron when it comes to home-brew radio projects. GNU Radio, is a popular software development environment for SDR Digital Signal Processing (DSP) software.
The ability to create and work with software for SDR projects is a new skill for many hams. Professional programmers have a number of options to pursue. For hams without a programming background, software packages are now available that simplify programming with graphically based interfaces and useful DSP libraries already packaged in the application.
The ham experimenter has choices of graphically based DSP software packages: the proprietary packages, MatlabR / SimulinkR by Math Works and LabVIEW by National Instruments, or the open source GNU Radio / GNU Radio Companion (GRC) DSP library package. This website will introduce the combination of GNU Radio as a powerful, ‘ham friendly’, open source DSP library and application environment for SDR projects. The material is based on a pair of QEX articles by W7FU (See: QEX Articles.)
The GNU Radio open source DSP software library is a development tool intended for educational programs, industrial product development labs, and for hobbyists. GNU Radio can be used as a simulation tool to study DSP without being connected to an SDR. GNU Radio can also be used to develop practical and operationally satisfying DSP software for both transmitters and receivers.
To make DSP authoring accessible for all levels of users, the GNU Radio developers provided the user option of GNU Radio Companion (GRC). GRC is the graphical DSP library interface, an integral part of GNU Radio. The foundational GNU Radio DSP library is accessed with character-based command line commands. GRC is a graphical overlay to the GNU Radio DSP library. The graphical overlay represents DSP functions as graphical icons with data inputs and outputs.