An interpolation-based frequency-synchronization scheme for OFDM systems

The mismatch of the oscillators in the transmitter and receiver, or Doppler shift, introduces an offset in the expected carrier frequency. In orthogonal frequency-division multiplexing (OFDM) systems, this frequency offset causes large errors in the signal values and therefore it is important to minimize this offset. In this paper, we propose an interpolation-based scheme for carrier frequency offset synchronization in OFDM systems. The scheme is based on maximum-likelihood estimation and it is applicable for acquisition purposes as only one OFDM training symbol block is required, the algorithm has no inherent limit for the carrier frequency offset being estimated, and it is independent of any carrier phase offset that may occur. Its performance is compared against a method in the literature that also can estimate the carrier frequency offset using the received samples of only one OFDM training symbol block.