Improve both carrier to interference power ratio and phase rotation error using ICI cancellation scheme in OFDM

Abstract

In an orthogonal frequency division multiplexing (OFDM) system, the performance is sensitive to the carrier frequency offset (CFO). This CFO will destroy the orthogonality between the subcarriers and cause intercarrier interference (ICI), which not only reduces the carrier to interference power ratio (CIR), but also leads to a phase rotation of the desired signal. In existing ICI cancellation schemes, the discussion is mainly about CIR improvement, leaving the equally important phase rotation error (PRE) not considered. In this paper, ICI mechanism and polynomial cancellation coding (PCC) scheme is studied. We proposed a simple ICI cancellation scheme which can improve both CIR and PRE. Simulations show the proposed algorithm considerably outperforms the PCC scheme in the presence of large CFO. Especially, in lower signal to noise ratio (SNR) environment, the performance degradation using the proposed algorithm could be still within an acceptable range.