A technique for converting a sequence of binary digits into a sequence of signalling alphabets of a modulated carrier signal for data transmission. By introducing additional redundant signalling alphabets and differentially coding incoming data in a state-dependent sequential manner, enlarged minimum...http://www.google.com/patents/US4483012?utm_source=gb-gplus-sharePatent US4483012 - Differentially convolutional channel coding with expanded set of signalling alphabets
