Beamforming using FIR Eigenfilter Approach in Cognitive Radio Network

Abstract

Beamforming technique allows the cognitive users to opportunistically access the licensed spectrum without interfering the licensed users by exploiting the spatial domain in the radio transmission for cognitive radio network. In this paper, the eigenfilter approach to solve general least-squares approximation problems is extended. Such extension unifies previous work in eigenfilters and many other filter design problems, including spectral/spatial filtering, one-dimensional or multidimensional filters etc. With this approach, various filter design problems are transformed into problems of finding an eigenvector of a positive definite matrix that is determined by filter design specifications. A number of design examples are presented to show the usefulness and flexibility of the proposed approach.