DVB-T signal over cable TV network and phase noise requirements

We study the quality of terrestrial digital video broadcasting (DVB-T) transmission over a cable TV network. Generally, when terrestrial digital TV signals are distributed by cable TV, a conversion from DVB-T (OFDM) to DVB-C (single carrier) is needed in the head-end. In order to avoid this costly conversion and to transmit the DVB-T signal directly in the existent cable channel, many requirements have to be satisfied. It is known that phase noise represents the main limitation for OFDM based systems. In this contribution, we demonstrate the sensitivity of the OFDM system to phase noise effects by using a dynamic model for the CATV channel. We conclude by giving the specifications for a converter that should allow the DVB-T system to function in the CATV network.