Patent ID: 8351538

Claim:
A radio communication method comprising: spreading an acknowledgement or non-acknowledgement (ACK/NACK) signal with an orthogonal sequence, which is selected from a plurality of orthogonal sequences, the plurality of orthogonal sequences including more orthogonal sequences that render two values respectively corresponding to Nth symbol and Mth symbol of an ACK/NACK signal transmission slot in phase, than orthogonal sequence(s) that render said two values in opposite phases from each other; transmitting the spread ACK/NACK signal in the ACK/NACK signal transmission slot; arranging two reference signals (RS), which are produced by multiplying two reference signal sequences with values having opposite phases from each other, in the Nth symbol and the Mth symbol of a CQI signals transmission slot, and arranging channel quality indicator (CQI) signals in symbols of the CQI signals transmission slot other than the Nth symbol and the Mth symbol; and transmitting the reference signals (RS) and the CQI signals arranged in the CQI signals transmission slot.