Blind identification of FIR channels via antenna arrays

We propose a new method for blind identification of possibly nonminimum phase FIR channels using antenna arrays. Based on a frequency domain formulation, we show that even a nonminimum phase channel driven by stationary sequences can be identified from the second-order statistics. Although in the single antenna case it is necessary to use cyclostationary signals or higher order statistics to identify the magnitude and phase of the channel, we circumvent such a requirement by exploiting multichannel properties of the array. We also present necessary and sufficient conditions for channel identifiability, and develop an identification algorithm.