Estimation of channel and Carrier Frequency Offset in OFDM systems using joint statistical framework

Joint estimation of channel and Carrier Frequency Offset (CFO) in Orthogonal Frequency Division Multiplexing (OFDM) systems, using a Statistical framework, is shown in this paper. Hybrid Cramér-RaoLower Bounds (HCRLBs) for the estimation of CFO together with the channel are obtained. The significance of prior information in the formulation of a joint estimator is shown by comparing HCRLB with the corresponding standard CRLB. We propose a Joint Maximum a posteriori (JMAP) algorithm for the estimation of channel and CFO in OFDM, utilizing the prior statistical knowledge of channel. To reduce the complexity of JMAP estimator, a Modified JMAP (MJMAP) algorithm, which has no grid searches, is also proposed. The estimation methods are analyzed by numerical simulations and resultant conclusions validate the better performance of the proposed algorithms when compared with previous algorithms.