FIELD: radio communication. SUBSTANCE: invention is intended for communication systems of multiple access with code division of channels having different coefficients of expansion of spectrum. Device of channel expansion for base station of communication system with multiple access with code division of channels intended for expansion of input symbols with use of quasi- orthogonal code includes generator of expansion code to generate second quasi- orthogonal code, channel expansion unit to obtain aggregate of duration by way of division of duration of second quasi-orthogonal code by multiple value of length of first quasi-orthogonal code and expansion of symbols and unit of pseudo-noise expansion. Procedure of channel expansion in base station of communication system with multiple access with code division of channels for expansion of input symbols with the aid of second quasi-orthogonal code whose length is multiple of duration of first orthogonal code includes stages of generation of second quasi-orthogonal code, formation of aggregate of duration. EFFECT: expansion and compression of channel signals with use of expansion codes. 8 cl, 10 dwg
