A complex multiplexer/demultiplexer apparatus which converts input low order group data signals to middle order group data signals and multiplexes them to high order group data signals and converts high order group data signals to middle order group data signals and demultiplexes them to low order group...http://www.google.com/patents/US5001711?utm_source=gb-gplus-sharePatent US5001711 - Complex multiplexer/demultiplexer apparatus
