RADIO COMMUNICATION DEVICE AND CONSTELLATION CONTROL METHOD

摘要

Provided is a radio communication device which can make ACK reception quality and NACK reception quality to be equal to each other. The device includes: a scrambling unit (214) which multiplies a response signal after modulated, by a scrambling code "1" or "ej(p/2)" so as to rotate a constellation for each of response signals on a cyclic shift axis; a spread unit (215) which performs a primary spread of the response signal by using a ZAC sequence set by a control unit (209); and a spread unit (218) which performs a secondary spread of the response signal after subjected to the primary spread, by using a block-wise spread code sequence set by the control unit (209).