Low-complexity iterative carrier frequency offset estimation with ici elimination for OFDM systems

Abstract

In OFDM systems, carrier frequency offset (CFO) between the transmitter and the receiver destroys the orthogonality among subcarriers and induces strong inter-carrier interference (ICI). For the CFO estimation schemes based on frequency-domain pilot signals, the estimation performance is degraded and bounded by the ICI. In this work we propose a novel CFO estimation scheme - PTA-based with ICI elimination (PTA-IE), to improve the CFO estimation performance. By applying an iterative process, the CFO estimation performance can be progressively enhanced, attaining the best achievable performance without ICI. Our proposed scheme can benefit not only the CFO estimation performance but also the demodulation performance on data subcarriers. Moreover, the proposed scheme has low computational complexity without the need of matrix inversion.