After successful installation of gr-drm, open the MLC flow graphs in
with GNU Radio Companion and execute them in order to generate the appropriate
XML and Python files that are used by the transmitter flow graphs.
You are now ready to transmit!
There are various, fully configured flow graphs under
that can be used pretty much as-is. The DRM+ flow graph does not crash but is
Of course you have to set the path to your USRP (or leave it blank for autodetection) and a source wav-file (either 12 or 24 kHz). There are also several other parameters you can change (see section Features). It is also possible to record a wav-file that can be decoded with DREAM.
As wav files usually aren't sampled with 12 or 24 kHz, I use sox for convenient
sox <mysong.wav> -r <new_sample_rate> <mysongresampled.wav> resample
This project features a DRM/DRM+ software transmitter fully integrated into GNU Radio Companion.
You are also free to play around with several robustness modes (RM) and spectrum occupancies (SO, signal bandwidth) ranging from 4.5 to 20 kHz. The corresponding bit rates vary from below 5 kbps to about 55 kbps. A configuration that is widely used is RM B (==1) and 10 kHz bandwidth (SO 3). Among other parameters, the station label and a text message can also be set by simply adapting the correspondant blocks' values.
As this project is still under development, there are some features of the DRM standard that are not (yet) available. The most important are:
Known Bugs: - text message corrupted for SO 5 / RM A (and possibly other modes)
If you find any bugs or have great ideas you think the project could benefit from, just write me: uncnr[at]student.kit.edu
last updated on: 2015/04/09