A low-complexity frame synchronization and frequency offset compensation scheme for OFDM systems over fading channels

dThis paper presents a fast low-complexity synchronization scheme for ortho gonal frequency division multiplexing (OFDM) systems over fading channels. By utilizing the guard interval in OFDM signals, the Frame synchronization and the frequency offset estimation are considered simultaneously. The Impl ementation can be simplified by only using the sign bits of the in-phase an d the quadrature components of the received OFDM signal for frame synchroni zation and frequency offset compensation. A frequency-offset independent fr ame synchronization algorithm is derived, and a low-complexity frequency of fset estimator based on the synchronized correlator output is presented in this paper. Due to the subcarrier ambiguity in the guard-interval-based (GI B) frequency detector, the maximum correctable frequency range is limited t o +/- 1/2 of the subcarrier spacing. In this paper, we also present a new f requency acquisition scheme that can solve the subcarrier ambiguity problem and extend the frequency acquisition range to nearly a half of the useful OFDM signal bandwidth.