BLS identification by orthogonal functions with application to immunology

An overview is given of BLS (bilinear system) identification and a method which uses Walsh functions is introduced. Walsh functions, their group properties with respect to binary algebra and their integral approximation in terms of Walsh functions, are used conveniently to identify BLS parameters for a simplified model of the immune system´s generation of antibodies in disease control. The technique is effective for time-variant bilinear systems and quadratic systems as well.