BASE STATION APPARATUS, MOBILE TERMINAL APPARATUS AND COMMUNICATION CONTROL METHOD

摘要

This invention is directed to provision of a base station apparatus, a mobile terminal apparatus and a communication control method that, when a plurality of mobile communication systems are coexistent, can support each of the mobile communication systems. A base station apparatus (20), in wireless communication systems placed in such a manner that an LTE-A system having a system band constituted by a plurality of component carriers overlaps with an LTE system having a system band constituted by a single component carrier, is configured to: generate ACK/NACK of HARQ for upstream transmissions of the plurality of component carriers; set the offset to zero for the component carrier used in the LTE system; set the offset to a larger value in a cyclic order among the plurality of component carriers with the foregoing component carrier used as a starting point; and add the offset to the allocated resource of the ACK/NACK.