A robust metric for coarse frame and carrier synchronization of OFDM systems

The paper proposes a fast and reduced complexity frame and carrier acquisition scheme for OFDM systems which assume either a continuous or a burst mode operation in additive white Gaussian noise (AWGN) and frequency-selective channels. By exploiting the repetitive structure of a training symbol, a robust frame synchronizer is obtained and shown to resume to finding the peak of a certain correlation metric that is obtained by invoking maximum likelihood principles. A new carrier estimator that can correct frequency offsets by up to two subcarrier spacings is also proposed and achieves the lowest mean-square error among the existing estimators that exploit a similarly structured signaling set-up. The efficiency of the proposed synchronization algorithms is illustrated by both theoretical performance analysis and computer simulations.