Digital Audio Broadcast is a digital radio standard reaching back to 1986. It has been superseded by DAB+ in 2006.
sdrdab's aim is to decode DAB signal efficiently and accurately.
DAB uses transmission frames featuring a NULL symbol, which marks frame beginning (Figure 1).
NULL symbol is followed by a number of OFDM symbols (Figure 2), which varies with each transmission mode. First symbol is always the same and is called Phase Reference Symbol. Each symbol begins with a Cyclic Prefix (also called Guard Interval), which is the same as symbol ending (Figure 3).
DAB+ standard is backward compatible with DAB. General frame structure remains the same, so it is possible to encounter both DAB and DAB+ services in one multiplex .
Difference between DAB+ and DAB can be observed in Figure 7.
- Wikipedia: Digital Audio Broadcasting
- ETSI TS 102 563
- ETSI EN 300 401