OFDM for digital terrestrial television

The author reports on the past two years´ OFDM field trial with emphasis on broadcasting in so-called UHF `taboo´ channels to rooftop antennas. To prevent interference the OFDM signal must be transmitted at very low power, typically 30 dB down on neighbouring PAL services, but measurements indicate that coverage from main stations similar to that of existing PAL services is possible. Other scenarios such as transmitting with high power to portable receivers are also under consideration, although in the UK these would require significant changes to the existing UHF frequency plan. OFDM can offer the flexibility to meet many diverse requirements