Optimum equalization of multicarrier systems: A unified geometric approach

This paper presents a new iterative equalization algorithm that maximizes c apacity for discrete multitone (DMT) systems. The research modifies a previ ously proposed criterion and applies an appropriate transformation to map t he objective function and the constraint set into a canonical region. The r esulting constraint set exhibits an identifiable geometric characteristic. Using the gradient projection method in conjunction with projection onto co nvex sets (POCS) provides us with an iterative search algorithm that facili tates the gradient descent method. We also generalize the approach to two i mportant subclasses of equalizers, namely linear phase and unit tap filters . We also derive a fundamental limit on the performance of the proposed app roach. In comparison with the previous methods, the proposed equalization a lgorithm is less computationally complex and more geometrically intuitive. Simulation experiments confirm the validity of the proposed method for equa lization of DMT systems.