DVB-T: the COFDM-based system for terrestrial television

In early 1996, the European DVB (Digital Video Broadcasting) Project finalised what is now called the `common 2k/8k specification´ for terrestrial television transmission. This specification is an important cornerstone of digital video broadcasting in Europe and numerous other countries in the world. Called DVB-T, it is based on the channel-coding algorithms the DVB Project had earlier devised for digital television on cable and satellite. The modulation scheme that is used for DVB-T is OFDM (orthogonal frequency division multiplexing), which when used in conjunction with channel coding is known as COFDM. Two variants are described, one employing 1705 individual carriers in an 8 MHz channel (`2k variant´), the other employing 6817 carriers (`8k variant´). Each individual carrier can be modulated either by QPSK, 16-QAM, 64-QAM or hierarchical modulation