Coded Orthogonal Frequency Division Multiplexing – a modulation scheme which is used by the DVB digital television system. It allows for the use of either 1705 carriers (usually known as ‘2k’), or 6817 carriers (‘8k’). Concatenated error correction is used. The ‘2k’ mode is suitable for single transmitter operation and for relatively small single-frequency networks with limited transmitter power. The ‘8k’ mode can be used both for single transmitter operation and for large area single-frequency networks. The guard interval is selectable. The ‘8k’ system is compatible with the ‘2k’ system.

There has been much discussion about the relative merits of COFDM vs the 8-VSB scheme used in the ATSC standard. The Japanese ISDB system uses a similar scheme, OFDM.