Frequency Offset Synchronization for OFDM Systems Based on the Second-Order Feedback Loop

In this paper we discussed a feedback loop for carrier frequency offset synchronization in orthogonal frequency division multiplexing (OFDM) systems. The maximum likelihood (ML) algorithm is introduced, and we present an improved frequency offset synchronization method which uses the ML algorithm and the second-order feedback loop jointly. The result of analysis and computer simulation show that the new method can significantly improve the performance of the ML estimators.