FIELD: code-division multiple access communication systems. SUBSTANCE: proposed method and device are designed to orthogonally expand signal being transmitted with aid of expanding code that has at least double coefficient of expansion at elementary rate of expansion. To this end pair of characters obtained by repeating single character are expanded by quasi-orthogonal code to transmit expanded characters through first antenna, then mentioned character and inverted character of mentioned character are expanded by mentioned quasi-orthogonal code for transmitting expanded characters through second antenna. Proposed method includes expansion of one character out of pair of characters by part of mentioned quasi-orthogonal code, expansion of other character of mentioned pair of characters by remaining part of mentioned quasi-orthogonal code, expansion of character by part of mentioned quasi-orthogonal code, and expansion of mentioned inverted character by remaining part of mentioned quasiorthogonal code. EFFECT: enhanced reliability of channel data expansion by using quasi-orthogonal code. 12 cl, 30 dwg, 4 tbl
