Norbert Wiener the development of the digital theory. Wiener originated cybernetics, a formalization of the notion of feedback, with many implications for engineering, systems control, computer science, biology, philosophy, and the organization of society. Wiener's work with cybernetics influenced Gregory Bateson and Margaret Mead, and through them, anthropology, sociology, and education. A simple mathematical representation of Brownian motion, the Wiener equation, named after Wiener, assumes the current velocity of a fluid particle fluctuates randomly. For signal processing, the Wiener filter is a filter proposed by Wiener during the 1940s and published in 1942 as a classified document. Its purpose is to reduce
Wiener filter criterion of the latter does not rely on cross-correlations or auto-correlations. Its solution converges to the Wiener filter solution. For complex signals, the derivation of the complex Wiener filter is performed by minimizing formula_55 =formula_56. This involves computing partial derivatives with respect to both the real and imaginary parts of formula_32, and requiring them both to be zero. The resulting Wiener-Hopf equations are: which can be rewritten in matrix form: Note here that:formula_60 The Wiener coefficient vector is then computed as:formula_61 The Wiener filter has a variety of applications in signal processing, image processing, control systems, and digital communications. These