An integrated circuit includes circuitry, which, in operation, controls transmitting downlink data to a terminal apparatus; receiving a plurality of transport blocks which are transmitted in a same time period using a same frequency band in a spatial multiplexing scheme, wherein a same acknowledgement information (ACK/NACK) relating to an error detection result of the downlink data is scrambled with different scrambling schemes respectively for the plurality of transport blocks and the respectively scrambled ACK/NACK is multiplexed with data on respective ones of the plurality of transport blocks, and channel quality information (CQI) of a downlink channel is multiplexed with the data on only one transport block of the plurality of transport blocks by the terminal apparatus; and extracting the ACK/NACK and the CQI from the received plurality of transport blocks.