Frequency domain correction of residual frequency offset in OFDM and DMT systems

OFDM and DMT systems are sensitive to carrier frequency offset between the receiver and transmitter. Most of the systems employ frequency offset estimation and correction, as a part of synchronizing the receiver to the transmitter. Depending on the availability of training data and/or the computation power, frequency offset may not be corrected exactly. Moreover, some times we may want to do the correction in the frequency domain in order to reduce the latency and complexity in the receiver. This paper discusses the frequency domain modeling of the effect of residual frequency offset as a linear transformation on the sub-carrier symbols. An interesting property is observed that the transformation matrix is Toeplitz and which simplifies the frequency correction circuit complexity. Simulation results are given to validate the algorithm.