Combining cyclostationarity and spatial diversity for blind system identification

Second-order blind system identification problem has become an intense area of research [1, 2, 3, 4]. Recently, it has been shown that, by exploiting space diversity (i.e., multiple receivers) and / or time diversity (i.e., cyclostationarity) of communication signals, system identification using only the second order statistics (SOS) of the system output is possible. In this contribution, we propose to combine cyclostationarity and spatial diversity for the blind identification of p-input, q-output rational system. The basic idea consists in associating with each input signal a specific cycle-frequency as a proper 'signature'. This will permit, in a first step, to separate the p input signals by selecting successively their respective cycle-frequencies. In a second step, and thanks to the spatial diversity, we can estimate the channel transfer function using only the output SOS.