Unified framework for a class of frequency-offset estimation techniques for OFDM

Due to the high sensitivity of OFDM to carrier frequency-offset, accurate estimation algorithms are required in order to achieve high performance. We show that many of the existing methods share the same underlying approach, which is the exploitation of subcarriers. Based on this, a novel computationally simple estimator, named the approximate nonlinear squares estimator (ANLS), is developed. We show that the performance of the ANLS estimator is very close to that of the computationally more demanding NLS estimator, and superior to existing low-complexity estimators.