FMDT

An IBOC (In-Band-On-Channel) Digital Radio system for FM transmitters.

Purpose

The purpose of FMD (FM-Digital), is to provide an open alternative to Ibiquity's HD Radio system for hobbyists and low-power broadcasters.

Prequisites

I have yet to write DRM30 modulation blocks for the graph and thus, for this implementation we will use Dream. On most Linux systems, the following is all you will need to get started:
- GNURadio 3.7 or later.
- JACK Audio Connection Kit (Jackd2)
- gr-drm https://github.com/kit-cel/gr-drm
- (Optional) Stereo Tool or Breakaway Broadcast Processor

What it does.

FMDT is, simply put: "Kind of like HD Radio, except it uses DRM (Digital Radio Monodale) signals as opposed to Ibiquity's proprietary OFDM scheme and codecs. It is intended to give FM stations digital capabilaties of similar or better qualliy than what current commercial standards allow. Occupying a total bandwidth of ~300khz (150khz deviation), it is both bandwidth-efficient, as well as mindful to traditional analog standards.

Standards used for this system:
- NRSC-5-C (National Radio Standards Commitie)
- ITU-R SM.1268 (FM Composite clipping standards)

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TODO

• Implement a DRM30 (Robustness mode A) transmitter with multi-service capabilaty in GNURadio