| Communication theory was founded on the system
of sine-cosine functions. A more general theory has become known more recently;
it replaces the sine-cosine functions by other systems of orthogonal functions,
and the concept of frequency by that of sequency. Of these systems, the
Walsh functions are of great practical interest since they lead to equipment
that is easily implemented by semiconductor technology. Filters, multiplexing
equipment, and a voice analyzer/synthesizer have been built successfully
for Walsh functions. Some interesting applications of electromagnetic Walsh
waves have been found theoretically. 10 pages. |