Adaptive joint frame synchronization and carrier frequency offset estimation in OFDM systems

An adaptive joint frame synchronization and carrier frequency offset estimation scheme in orthogonal frequency division multiplexing (OFDM) systems is proposed in this paper. Compared with conventional algorithm, the proposed one can reduce the Cramer-Rao lower bound (CRLB) to the minimum without changing the total energy consumption. In the proposed scheme, a variable parameter M is introduced in generating training sequence, where M is a function of the maximum multipath delay of the multipath channel. By adaptively adjusting M, the optimum training sequence can be obtained. Accurate frame synchronization and carrier frequency offset acquisition can be performed simultaneously in the proposed scheme. An adaptive tracking algorithm in the proposed scheme is also needed to estimate the remaining carrier frequency offset after acquisition. By using the proposed optimum training sequence, considerable performance improvement in the proposed tracking algorithm over Moose algorithm can be obtained.