An improved frequency offset estimator for OFDM applications

Abstract

An efficient algorithm has been proposed by Schmidl and Cox (see IEEE Trans. Commun., vol.45, p.1613-21, 1997) for carrier frequency estimation in orthogonal frequency-division multiplexing systems. The scheme is based on the transmission of a training symbol composed of two identical halves in the time domain. We extend this algorithm by considering a training symbol composed of L>2 identical parts. This makes it possible to achieve a better accuracy at the cost of some increase in computational load. The estimation range can be made as large as desired without the need of a second training symbol, as required by the Schmidl and Cox method.