Frequency Synchronization Algorithm Based on PN Sequence

In this paper, we propose a new frequency synchronization algorithm for orthogonal frequency division multiplexing (OFDM) system by combining PN sequences with cyclic prefix. It is the improvement of Tufvesson´s algorithm. In the new algorithm, the frequency offset is estimation with two steps. First a small step (span of the correlation) is used to estimate frequency offset which will result in a larger estimation range but less precise. After the frequency offset has been compensated, the second estimation using cyclic prefix is conducted which is a large step. The new algorithm has large estimation range and the estimation is more precise. Performance of the new estimator improved than that of the old one in AWGN channel and multipath fading channel.