AM and DRM broadcasts in the HF bands
Traditionally, AM modulation is used in the LW/MW/SW bands for broadcasting purposes. It is very easy to identify these the AM broadcast stations based on their Dual Side Band (DSB) shape in the spectrum. The spectrum and waterfall displays of the Quadrus SDR show such a modulation on the following pictures.
However, digital waveforms, i.e., DRM, have started to populate the HF bands, which can provide high quality content. The modulation format is optimized to the propagation behavior, and is based on the multi-carrier scheme. It is also very easy to recognize them in the band using the Quadrus SDR for DRM, because these stations have a distinct rectangular shape in the spectrum.
DRM in the telecommunication curriculum of universities
As DRM represents a significant part of broadcasting systems nowadays, most universities around the world have included this standard, or parts of it, into their curriculum on telecommunications. It is also an important part of the telecommunications program at the Budapest University of Technology and Economics as well, where we have recently introduced the Quadrus SDR for DRM by showcasing its DRM reception capability.