Editing Single-frequency network (section)

== OFDM and COFDM ==
In wideband [[digital broadcasting]], [[self-interference cancellation]] is facilitated by the [[OFDM]] or [[COFDM]] modulation method. OFDM uses a large number of slow low-bandwidth [[modulator]]s instead of one fast wide-band modulator. Each modulator has its own frequency sub-channel and sub-carrier frequency. Since each modulator is very slow, one can afford to insert a [[guard interval]] between the symbols, and thus eliminate the ISI. Although the fading is frequency-selective over the whole frequency channel, it can be considered as [[flat fading|flat]] within the narrowband sub-channel. Thus, advanced equalization filters can be avoided. A [[forward error correction]] code (FEC) can counteract some of the sub-carriers being exposed to too much fading to be correctly demodulated.

OFDM is utilized in the terrestrial [[digital TV]] broadcasting system  [[DVB-T]] (used in [[Europe]] and other regions), [[ISDB-T]] (used in [[Japan]], [[Brazil]], and the [[Philippines]]) and in [[ATSC 3.0]]. OFDM is also widely used in [[digital radio]] systems, including [[Digital audio broadcasting|DAB]], [[HD Radio]], and [[T-DMB]]. Therefore, these systems are well-suited to SFN operation.