FIELD: transmission and/or storage of digital signals from several dependent channels. SUBSTANCE: method involves conversion of input signals from time range to spectral values of frequency range which are encoded, transmitted and/or stored, decoded, and returned over channels in time range. Method is characterized in that value indicating spectral difference between signals of different channels is determined from spectral values of data blocks connecting these channels and this value is compared with desired threshold value; at spectral difference lower than threshold value, signals from different channels are jointly encoded. Joint encoding takes place only when signals in both channels are sufficiently identical. EFFECT: improved noise immunity. 14 cl, 1 dwg
