ABSTRACT
Coded Orthogonal Frequency Division Multiplexing (COFDM) works by taking the data to be sent from transmitter to receiver and spreading it over a large number of carriers rather than modulating it all onto a single carrier as is done in essentially all other modulation methods. In doing so, COFDM creates a large number of parallel paths, each of which carries data at a much slower rate than that of the overall COFDM signal or of a single-carrier signal. Probably the most compelling argument in favor of COFDM is its potential for handling echoes and multipath signals. This becomes a particular advantage in a system where more than one transmitter is used, as in a so-called single frequency network (SFN) where multiple lower power transmitters are used to cover or extend a service area. Another advantage cited for COFDM is its ability to handle echoes and multipath without the need for an adaptive equalizer.
