The how and why of COFDM

Coded Orthogonal Frequency Division Multiplexing (COFDM) is a form of modulation which is particularly well-suited to the needs of the terrestrial broadcasting channel. COFDM can cope with high levels of multipath propagation, with a wide spread of delays between the received signals. This leads to the concept of single-frequency networks in which many transmitters send the same signal on the same frequency, generating “artificial multipath”. COFDM also copes well with co-channel narrowband interference, as may be caused by the carriers of existing analogue services.

This is a very well written explanation of COFDM (as used in both digital terrestrial television and digital radio in the UK) - the workings of the multi-carrier system was something that I never really understood but this opened my eyes (did you realise that every DVB-T mux uses more than 6,000 carriers!). Recently I was explaining to someone how Viterbei decoders work (with particular reference to Digital Betacam VTRs) - again, I didn't realise that COFDM uses a modified Viterbei decoder (the 'soft viterbei decoder').
I wish I hadn't specialised in post-production so early as there are many things the the broadcast chain that I'm rusty/ignorant of.