Abstract: A universal demodulator programmable for any digitally modulated carrier signal having a known constellation format which can be characterized by a unique constellation pattern of phase-amplitude states. The demodulator also generates phase and gain-error signals for locking onto the phase and amplitude of the digitally modulated carrier. The demodulator splits the received digitally modulated carrier signal into an inphase component, D.sub.x, and a quadrature-phase component, D.sub.y. Using a preprogrammed memory device keyed to the identified modulation format, each D.sub.x signal is mapped into one of a plurality of one-dimensional zones each having R.sub.x center values. Using a second preprogrammed memory device also keyed to the identified modulation format, each D.sub.y signal is similarly mapped into a plurality of orthogonal one-dimensional zones having R.sub.y centers. Each pair of R.sub.x and R.sub.