Method of obtaining a phase difference signal

Abstract From the Canadian patent

A method of obtaining a signal representing the phase difference between a local carrier signal and the carrier of an amplitude and/or phase shift keyed received signal wherein: the received signal is divided into two cartesian coordinate signal components which are a function of the phase difference and are in a guadrature relationship to one another; each pair of cartesian coordinate signal components each representing one of a plurality of permitted signal states, is converted into two corresponding polar coordinate signal components, a decision is then made as to which is the permitted, unfalsified polar signal components which the polar signal components of the received signal most …