To obtain a high frequency diversity effect while suppressing inter-code interference in code multiplexing transmission in an OFDM-based radio access scheme, a transmission apparatus is provided with an orthogonal spreading code generating section (10) that generates different spreading codes based on orthogonal code sequences, a phase rotation giving section (11) and spreading modulation section (12) which provide the information symbols or spreading codes with different phase rotation for each symbol sequence and then, spreads the information symbols with the spreading codes for each symbol sequence, and a multiplexing section (13) that multiplexes spread symbols of different symbol sequences, where the information symbols or the spreading codes are rotated by a phase rotation amount such that overlaps in a signal constellation in polar coordinates of spread symbols for transmitting different information symbols are controlled to within a required range.