Blind identification of spatial multiplexing and alamouti space-time block code signals based on order statistics

The identification algorithm for a multiple-input and multiple-output system employing the Spatial Multiplexing (SM) and Alamouti (AL) space-time block codes (STBC) is investigated under the assumption of unknown parameters of the coding scheme, the received signal and noise variance. The order statistic of the cross-correlation spectrum between different received antennas is utilized as a feature to discriminate the coding type, and the tests threshold is selected based on the constant false alarm rate criterion. We proposed two methods to compute the threshold, one is based on the exact cumulative distribution function (CDF) of the maximum of the cross-correlation spectrum, and the other relies on the extreme value distribution. Simulations show that the proposed algorithms are effective and the performances of them are both superior to the convention cyclostationarity-based algorithm.