A carrier frequency offset and timing offset detection scheme for OFDM systems utilizing pilot sub-carriers

A novel carrier frequency offset and timing off-set detection scheme for or thogonal frequency division multiplexing (OFDM) is proposed. The carrier fr equency offset is detected by utilizing a certain a-priori known pattern of power differences along the sub-carrier index. The power difference is cau sed by the collapse of the orthogonal condition. In order that the power di fferences are effectively influenced by the frequency offset, time-domain w indowing is employed. Timing offset is detected by utilizing average phase rotation according to the sub-carrier index. Moreover, by applying the cycl ically mapped sequence as a pilot sequence, the computational complexity fo r reference signal generation is reduced. Additionally, a simplified burst frame searcher is possible if the sliding correlator is applied as a buret frame searcher. The proposed scheme is advantageous for designing the air-f rame format, because the operation for synchronization is done using only o ne pilot symbol. The simulation results of the offset detection performance are shown, and the validity of the proposed offset detection scheme is pre sented.