Digital terrestrial television broadcasting with OFDM-a study on the performance of single frequency networks

OFDM is expected to be a suitable modulation method for digital terrestrial broadcasting systems. One of the reasons is that it makes it possible to construct a single frequency network (SFN) and to make effective use of the frequency bands. In a SFN environment, however, some receivers will obtain their signals from more than one transmitter. This causes two effects, intersymbol interference and degradation of frequency characteristics due to echoes. This paper describes a theoretical study on the latter effect in a variety of signal numbers, D/U ratios and delays arriving at the receiving antenna and the BER (bit error rate) distribution within the coverage area of SFNs in a variety of the transmitter numbers with computer simulations on a virtual plain. Finally we suggest a method to improve the quality in a coverage area.