Blind iterative carrier frequency offset estimation in orthogonal frequency division multiplexing system with non-constant modulus signalling

Abstract

This paper introduces a blind carrier frequency offset (CFO) estimation scheme for orthogonal frequency division multiplexing (OFDM) systems. The proposed estimator is blind and can be used with non-constant modulus subcarrier modulations such as quadrature amplitude modulation (QAM). The proposed method is a novel technique to estimate CFO in orthogonal frequency division multiplexing systems involving both magnitude and angular methods of offset estimation. A major drawback for several CFO estimation techniques is the constant modulus constraint. The proposed estimate involve angular method where estimation depends only on the argument of the frequency domain signals. Hence, the modulus of the received symbols have no effect on the performance of the proposed algorithm. The estimation range is enhanced using magnitude method of offset estimation.