User terminal, radio communication system and radio communication method

A radio communication system using a system band configurable of a plurality of component carriers, the radio communication system comprising:

• a plurality of base station apparatuses that each form a cell;
• and
• a user terminal that is capable of communicating with one or more of the base station apparatuses via a plurality of component carriers,
• the base station apparatuses each comprising:
• a control section that controls an uplink transmission timing per timing group, one or more component carriers being grouped into timing groups;
• and
• a receiving section that receives an uplink physical channel from the user terminal, and
• the user terminal comprising:
• a transmitting section that transmits the uplink physical channel at the uplink transmission timing controlled per timing group;
• and
• a power control section that, when the uplink transmission timing is controlled per timing group, performs power scaling preferentially on physical channels in a full overlapping period in which the physical channels are of same subframe number and overlap each other across component carriers.

A radio communication method in a radio communication system in which a plurality of cells are formed, the radio communication system having a plurality of base station apparatuses that form the cells respectively;

• and a user terminal that is capable of communicating with one or more of the base station apparatuses via a plurality of component carriers, the radio communication method comprising the steps of:
• transmitting, by the user terminal, an uplink physical channel at an uplink transmission timing controlled per timing group;
• and
• when the uplink transmission timing is controlled per timing group, performing, by the user terminal, power scaling preferentially on physical channels in a full overlapping period in which the physical channels are of same subframe number and overlap each other across component carriers.