B70-2 Transmission of Information by Orthogonal Functions

The book provides a new and interesting approach to the field of information and communication theory and is a welcome and thought- provoking exposition on a subject too often reviewed by conventional Fourier methods. Dr. Harmuth develops a generalized theory of signal transmission based on the concepts of orthogonal functions, the subject of his first chapter. His presentation is soon directed to the particular class of orthogonal functions known as the system of Walsh functions which have the convenient property of taking on only plus and minus unity values. Thus his subject becomes particularly relevant to the transistor and integrated circuit technology of today. The mathematical theories expounded in the text are unique in that experimental implementation is not far away. The first chapter develops the analytic tools necessary for applying the generalized orthogonal function theory to Walsh function applications in various phases of the communication process. The chapter is exemplary of Dr. Harmuth´s historical accuracy and scholarly style in his exacting references of authors of both published and unpublished works contributing to this area. The fifteen pages of references at the end of the text attest to this fact.