A carrier synchronization technique for OFDM on the frequency-selective fading environment

This paper proposes a new frequency offset correction technique for OFDM (orthogonal frequency division multiplexing) receivers on a frequency-selective fading channel. In order to combat the frequency offset effectively, the proposed technique consists of two steps: acquisition and tracking. In the acquisition process, the frequency offset is reduced to less than half of the intercarrier spacing. In the tracking process, the frequency offset is corrected to zero by employing an automatic frequency detector (AFD). In addition, this paper proposes a pattern matching algorithm for the acquisition and derives an AFD characteristic curve for the tracking. From the results, it is shown that the proposed algorithm can correct a large frequency offset encountered in a severely frequency-selective fading environment.