Matching Block Codes to a Channel with Phase Shifts

We investigate the characteristics of block codes in a phase telegraphy channel with phase shifts. Various known classes of codes are considered, namely, BCH codes, majority codes, and generalized concatenated codes. A transparency and phasability condition is given for code constructions. A new notion of automatic phasability is introduced for majority codes. The use of nonbinary codes in multiposition phase telegraphy channels with phase shifts is described.