FIELD: turbo- code for radio communication and digital cellular systems, and integrated-service digital networks. SUBSTANCE: device designed to implement free distance of turbo-code when input data word has Hamming weight of 1 and when data word entered in interleaver is of block type has interleaver wherein free distance reduces when input data word has Hamming weight of 1. Method involves division of frame of input K data bits into plurality of groups followed by saving divided groups in data bit group interleaving memory, and also shifting of data bit residing in last position of last group to position preceding last position and choice of groups according to desired number of choice of one of data bits in chosen group. EFFECT: facilitated setting of turbo-code free distance. 16 cl, 12 dwg
