Noise suppression using wave digital filter banks

Some properties of wave digital filter banks are discussed. A wave digital (WD) filter is usually a two-port or, in other words, a two-input two-output system. The two transfer functions which are available if, e.g., one input and two outputs are used are complementary i.e., the WD filter actually represents a so-called directional filter. Due to this fact, WD filters, especially symmetric ones, are very well suited for the design of filter banks. It is shown that these filter banks can be used to find attractive solutions to the problem of extracting a desired signal from two or more input signals each originating from the same source but corrupted by noise of unknown spectrum