An improved OFDM phase noise cancellation method

Abstract

Phase noise of transceiver local oscillator disturbs the orthogonality among subcarriers and causes inter-subcarrier-interference (ICI), which results in the significant degradation in the performance of wireless communication systems based on orthogonal frequency division multiplexing (OFDM). We observe that the inverse Fourier transform coefficient of the discrete phase noise varies gradually from a subcarrier to the next one in the middle subcarriers and is to be symmetric conjugate for the two end subcarriers. Based on this property, a novel ICI self-cancellation method is proposed in this paper to reduce the phase noise. Every data symbol is mapped onto a pair of adjacent subcarriers for the middle subcarriers and is mapped onto a pair of symmetric subcarriers for the two end subcarriers. As a result, it can be shown that common phase noise (CPE) becomes zero in the OFDM with the proposed method. Compared with other ICI self-cancellation method under the Spatial Channel Model (SCM) proposed by the Third Generation Partnership Project (3GPP), the bit error rate (BER) performance of the proposed method is much better. The simulations results show that it needs less signal-to-noise ratio to achieve the same BER performance in three environments of SCM: urban microcell, urban macrocell and suburban macrocell.