gnuradio : Toolkit that provides signal processing blocks to implement software radios ( https://www.gnuradio.org/ )
gqrx : Software defined radio receiver powered by GNU Radio and Qt ( https://gqrx.dk/ )
gr-iqbal : gnuradio I/Q balancing ( http://git.osmocom.org/gr-iqbal/ )
gr-osmosdr : GNU Radio source block for OsmoSDR and rtlsdr and hackrf ( http://sdr.osmocom.org/trac/wiki/GrOsmoSDR )
uhd : Universal Software Radio Peripheral (USRP) Hardware Driver ( https://kb.ettus.com )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a vowstar
For Paludis use this rsync : rsync://gentoo.zugaina.org/vowstar-portage
If you have a problem : ycarus(-at-)zugaina.org