Digital frequency conversion technique in HDTV

The paper describes research on the fundamental principle of digital modulation and frequency conversion in broadband digital broadcasting-terrestrial TV ( BDB-T) system. Different from conventional down-conversion techniques, a new digital down-conversion model is proposed which utilizes the Hilbert transform. A method eliminating the A/D DC offset in this model is also proposed. The corresponding FPGA hardware is tested in an HDTV prototype and proves the efficiency and good performance of the model and the new method.