Robust joint frequency offset and channel estimation for OFDM systems

We consider the joint carrier frequency offset (CFO) and channel estimation for OFDM systems. A novel frequency offset estimator is derived based on maximum likelihood principles by using the pilot symbols embedded in each OFDM symbol. An iterative joint CFO and channel estimator is proposed to further reduce the estimation error and improve the system performance. The joint estimator is initialized with the first CFO estimate and linearly interpolated channel estimates. The CFO and channel response estimates are updated by maximum likelihood (ML) and least squares (LS) algorithms. Simulation results show that the proposed joint estimator is effective and can achieve excellent bit error rates in just one iteration.