Blind wideband spatio-temporal filtering based on higher-order cyclostationarity properties

In this paper, a new method for blind minimum mean-square error (MMSE) spatio-temporal signal filtering is proposed. To obtain a blind version of the MMSE filter, the proposed method utilizes the signal selectivity property of the higher order cyclostationary statistics (HOCS) exhibited by the signal of interest. An accurate estimate of the transfer function of the MMSE filter is obtained also in the presence of strong frequency-overlapped interfering signals, which would render standard stationarity-based techniques ineffective. The method is useful when the desired signal cannot be accurately extracted by exploiting its second-order cyclostationarity properties because they are too weak and/or they are shared by the interference and noise signals as well. The performance analysis, which is carried out by computer simulations in the case of quadrature amplitude modulated (QAM)-modulated signals with partially overlapping bands, substantiates the effectiveness of the proposed method.