GNU Radio is a free & open-source software development toolkit
that provides signal processing blocks to implement software radios.
It can be used with readily-available low-cost external RF hardware
to create software-defined radios, or without hardware in a
simulation-like environment. It is widely used in hobbyist, academic
and commercial environments to support both wireless communications
research and real-world radio systems.

If you want to enable gnuradio-companion (GNU Radio Companion *GRC*
is a graphical tool for creating signal flow graphs and generating
flow-graph source code), you must install at least:
lxml and numpy and then qwt for qtgui or wxPython for wxgui.

Optional dependencies: uhd, cppunit, gsl, orc, jack-audio-connection-kit,
portaudio, SDL2, and Sphinx (the last is to generate additional docs).