A method for transmitting signals for interference randomization is disclosed. The method for transmitting signals includes spreading the transmission signals using a plurality of orthogonal codes and transmitting the transmission signals spread by the plurality of orthogonal codes by a spatial frequency block coding (SFBC) or spatial time block coding (STBC) scheme. Among the plurality of orthogonal codes, codes of which mutual interferences are equal to or greater than a predetermined threshold are grouped to the same group, and orthogonal codes belonging to different groups are used for the spreading of the signals which are transmitted at the same timing. Accordingly, it is possible to realize interference randomization.