User terminal, radio base station, and radio communication method

A radio communication method in a user terminal that communicates with a radio base station by means of carrier aggregation using a plurality of component carriers (CCs), the radio communication method comprising the steps of:

• receiving DL signals transmitted from each CC;
• and
• transmitting UL signals,
• wherein, when a plurality of CCs, including at least a first CC, which corresponds to a primary CC of an existing system, and a third CC, which is different from the first CC and a second CC that corresponds to a secondary CC of the existing system, are configured, UL signal transmission operations that are different from those of the second CC are applied to the third CC.

A radio base station that communicates with a user terminal that employs carrier aggregation using a plurality of component carriers (CCs), the radio base station comprising:

• a transmission section that transmits DL signals in each CC;
• and
• a control section that controls allocation of UL signals;
• wherein, when a plurality of CCs, including at least a first CC, which corresponds to a primary CC of an existing system, and a third CC, which is different from the first CC and a second CC that corresponds to a secondary CC of the existing system, are configured in the user terminal, the control section allocates resources for a plurality of third CCs at the same time, from one of the first CC and/or the second CC.