A high efficiency carrier estimator for OFDM communications

In OFDM communications, the loss of orthogonality due to carrier offset must be compensated before DFT-based demodulation can be performed. We present two blind carrier offset estimation algorithms by exploiting the intrinsic structure information of OFDM signals. Both algorithms offer the accuracy of super resolution subspace methods, viz., MUSIC and ESPRIT, without involving computationally intensive subspace decompositions. Adaptation rules for implementation of one of the proposed algorithm are provided. Also derived is the Cramer-Rao bound of the carrier offset estimates with which the performance of the new algorithms is evaluated.