ABSTRACT
Orthogonal frequency division multiplexing (OFDM) is, with substantial progress in digital signal processing, becoming an important part of the telecommunications arena. The most appealing feature of OFDM is the simplicity of the receiver design due to the efficiency with which OFDM can cope with the effects of frequency-selective multipath channels. Multicarrier systems such as OFDM are, however, more sensitive to carrier frequency offset (CFO) than are single-carrier systems. We first review the basics of OFDM communications systems and then address the CFO estimation problem. Both pilot-based and blind estimation techniques are presented. The Crame´r-Rao bound is established, and an optimal null carrier placement scheme is derived.
