Unified theory of digital modulation

A theory of signal quantisation is developed from first principles that describes quantisation using analogue-modulation techniques. The nonlinearities, which are fundamental to digital source encoding, are expressed by two sampling processes, which directly lead to solutions in terms of amplitude and phase modulation. The analysis derives a related set of mathematical models that deter mini stically describe the input/output transfer characteristics of uniform and nonuniform p.c.m., uniform delta modulation (d.m.) and uniform d.p.c.m.