DRM/DRM+ Digital Radio Mondiale
There are some good options in order to receive and transmit DRM30 and DRM+ currently available.
Spark free (but not free software) DRM30/DRM+ (also FM/RDS and AM/AMSS) transmitter that supports direct RF output (possible hardware options include the USRP and Diragen).
Dream free software DRM30 receiver and transmitter (see here to use Dream with USRP). Look for [www.pappradio.de Pappradio] for an affordable receiver hardware to use with Dream.
Sodira free DRM30/DRM+ receiver. To receive DRM+ one option is to use a VHF to HF downconverver (FMC 108-20 is a good option) together with a receiver like Pappradio (remember to turn off all band-pass filters). Other option for DRM+ reception is the USRP, using GRC - examples here - to grab the I/Q channels and output it to a VAC, then to RateMonkey, and then to Sodira.