On the Quotient Function Employed in the Blind Source Separation Problem

MSC 2010: 42C40, 94A12

On the blind source separation problem, there is a method to use the quotient function of complex valued time-frequency informations of two ob-served signals. By studying the quotient function, we can estimate the number of sources under some assumptions. In our previous papers, we gave a mathematical formulation which is available for the sources with-out time delay. However, in general, we can not ignore the time delay. In this paper, we will reformulate our basic theorems related to the method of estimating the number of sources to be available for more general cases.