On blind system identification from its output autocorrelation

When the input to a linear time-invariant system is a sequence of equispaced Dirac delta functions with IID. random amplitudes, it has been shown that a time-limited system can be uniquely identified from its output autocorrelation by making use of the cyclostationarity of the output [Tong et al. 1991]. The present authors show that a bandlimited system, however, can not be uniquely identified from its output autocorrelation. A necessary and sufficient condition for a bandlimited system to be uniquely identified from its output autocorrelation is given. Further, simulation results show that the identification method in Tong et al. does not yield satisfactory results for bandlimited systems