Blind Adaptive Equalization Method without Channel Order Estimation

In this paper, we propose a new blind minimum mean square error (MMSE) equalization algorithm of noisy single-input multiple-outputs finite impulse response (SIMO-FIR) systems, relying only on second order statistics. This algorithm offers an important advantage, a total independence of the channel order. Exploiting the fact that the equalizer filter belongs both, to the signal subspace and to the kernel of truncated data covariance matrix, the algorithm achieves blindly a direct estimation of the zero-delay MMSE equalizer parameters. The proposed approach has several features that are studied in this work. More precisely, we develop a two-step procedure to further improve the performance gain and to control the equalization delay. We present an efficient adaptive implementation of our equalizer, which reduces the computational complexity from O(n³) to O(n²p), where n is the data vector length and n is the number of sensors. Simulation results are provided to illustrate the effectiveness of the proposed blind equalization algorithm