Improvement of the Decision-Directed Frequency Tracking Algorithm for OFDM Systems

In this paper, we first analyze a kind of decision-directed frequency tracking algorithm for OFDM systems, and the approximation in derivation of the estimation result, and then we propose an iterative algorithm. In most cases, the frequency offset can be estimated and compensated within one OFDM symbol by using the iterative algorithm. This results in a shortened convergence time. The cramer-rao low band for the algorithm is derived too, and the simulation results show that the estimation results are close to the cramer-rao low band.