Results of the first digital terrestrial television broadcasting field-tests in Germany

Field trials have been carried out on the digital transmission of color TV signals in a standard European terrestrial channel of 8 MHz bandwidth. The goal was to obtain first practical results on the general properties of OFDM modulated digital TV signals under real transmission and reception conditions. A comparison of digitally modulated broadcast TV signals and VSB (vestigial sideband) modulated PAL signals was carried out in a UHF channel under normal and severe reception conditions. The field trials were carried out in September 1992 in a hilly region. The results of measurements for normal reception at a distance of 12 km from the transmitter are shown. For OFDM transmission the presentation of absolutely noise-free and interference-free pictures is possible down to a transmitter output power of 2 dBW (1.6 W) and a SNR in the received signal of 29 dB. To achieve the minimum requirements needed for analog PAL transmission (field strength 69 dBV/m and SNR of 38 dB) a peak power of 13 dBW (20 W) in the synch-pulse has to be used