Hierarchical transmission and COFDM systems

Draft European terrestrial digital video broadcasting (DVB-T) standard will pose problems for in the selection of the most beneficial and cost effective modes of operation within this flexible standard. This paper describes possible implementations of coded orthogonal frequency division multiplexing (COFDM) transmission schemes. Particular emphasis is placed on practical transmission aspects such as: radio frequency characteristics of the COFDM signal, field trials, and the more common digital television (DTV) measurements. Selection of the best system by broadcasters will involve compromises between costs and system parameters. The unique feature of Hierarchical transmission is described illustrating coverage benefits