Thank you to Adrian Musceac for writing and sharing his article detailing how he implemented an open-source DMR (Digital Mobile Radio) transceiver modem with his LimeSDR Mini and GNU Radio.
DMR is a digital voice communications protocol often used by commercial business band radios, as well as by amateur radio hobbyists.
Adrian explains:
I wrote an article about the implementation of an open-source DMR transceiver using the LimeSDR-mini, GNU Radio and Codec2, which could be used for SDR experiments.
The DMR modem was designed to work both in repeater and direct (DMO) mode, and supports voice and other basic features of the ETSI TS 102 361-1 standard.
In the article there is discussion about aspects of the TDMA transmission, time synchronization, as well as how David Rowe's Codec2 can be used to replace the default vocoder.
The work builds upon Jonathan Naylor's extensive DMR implementation which a large number of amateur radio operators are using as part of MMDVM.
