A Joint Detected-Directed Carrier Frequency Offset and Channel Estimation Technique for OFDM Systems

A new joint carrier frequency offset (CFO) and channel estimation technique by using the detected data is developed for OFDM systems. The synchronization information contained in the channel estimated results which is gained by LS channel estimation method is extracted based on the maximum likelihood (ML) criterion for synchronization estimation, and then the estimated results of CFO are used to correct the initial estimated channel and make it approach to the real channel more strictly. In order to suppress noise, the closed-loop schemes are described in details. Set appropriate values for the loop factors, the algorithm can be used to tracking the time variable channel.