METHOD AND APPARATUS FOR FINE FREQUENCY SYNCHRONIZATION IN MULTI-CARRIER DEMODULATION SYSTEMS

摘要

A method and an apparatus relate to a fine frequency synchronization compensating for a carrier frequency deviation from an oscillator frequency in a multi-carrier demodulation system (130) of the type capable of carrying out a differential phase decoding of multi-carrier modulated signals, the signals comprising a plurality of symbols (200), each symbol being defined by phase differences between simultaneous carriers (202) having different frequencies. A phase difference between phases of the same carrier (202) in different symbols (200) is determined. Thereafter, a frequency offset is determined by eliminating phase shift uncertainties corresponding to codeable phase shifts from the phase difference. Finally, a feedback correction of the carrier frequency deviation is performed based on the determined frequency offset. Alternatively, an averaged frequency offset can be determined by averaging determined frequency offsets of a plurality of carriers (202). Then, the feedback correction of the frequency deviation is performed based on the averaged frequency offset.