Efficient Frequency Offset Estimation and Tracking for Reuse-1 OFDMA Systems

Orthogonal frequency division multiplexing (OFDM) systems are highly sensitive to frequency synchronization errors which cause inter-carrier interference, leading to degradation in the system performance. In this paper, a pragmatic timing and frequency synchronization scheme for reuse-1 OFDMA systems that is compatible with IEEE 802.16d/e wireless MAN standard is proposed. The algorithm uses cyclic prefix correlation technique to both estimate and track OFDMA frame boundary and fractional frequency offset. Once the preamble is captured, the integral part of the frequency offset and cell-specific preamble code can be estimated. This novel scheme is computationally efficient and robust to co-channel interference and multipath fading. Simulation results show that the proposed algorithm gives excellent performance even at very low signal to interference noise ratios