Elements of Approximation Theory for Signals and Systems

摘要

The report contains an exposition of the essentials of the theory of linear least square approximation for scientists. Its format is based on the modern methods of functional analysis, namely the projection theory of Hilbert space. The content of the report is best appreciated by the reader who has some knowledge of Hilbert space theory. The unifying concept which prevails throughout the report allows the treatment of the problems of least square approximation in a variety of fields. Applications to problems of linear systems, networks, and communication theory are included. (Author)