A base station device configured to communicate with a mobile station device by component carrier aggregation using a first component carrier and a second component carrier, the base station device comprising: a data control unit configured to generate a synchronization signal corresponding to a first cell identity for identifying a cell, generate a first transmission signal including the synchronization signal, a first physical channel and a first reference signal, wherein the first physical channel and the first reference signal are generated based on the first cell identity, and generate a second transmission signal including a second physical channel and a second reference signal, wherein the second physical channel and the second reference signal are generated based on a second cell identity different from the first cell identity, and the second transmission signal excludes the synchronization signal; an upper layer unit configured to send information indicating the second cell identity, the information being carried by the first transmission signal; and a transmission unit configured to transmit the first transmission signal using the first component carrier via a first frequency band, and transmit the second transmission signal using the second component carrier via a second frequency band different from the first frequency band, wherein the first component carrier and the second component carrier are aggregated to support a wider transmission bandwidth than the first component carrier. a data control unit configured to generate a synchronization signal corresponding to a first cell identity for identifying a cell, generate a first transmission signal including the synchronization signal, a first physical channel and a first reference signal, wherein the first physical channel and the first reference signal are generated based on the first cell identity, and generate a second transmission signal including a second physical channel and a second reference signal, wherein the second physical channel and the second reference signal are generated based on a second cell identity different from the first cell identity, and the second transmission signal excludes the synchronization signal; generate a synchronization signal corresponding to a first cell identity for identifying a cell, generate a first transmission signal including the synchronization signal, a first physical channel and a first reference signal, wherein the first physical channel and the first reference signal are generated based on the first cell identity, and generate a second transmission signal including a second physical channel and a second reference signal, wherein the second physical channel and the second reference signal are generated based on a second cell identity different from the first cell identity, and the second transmission signal excludes the synchronization signal; an upper layer unit configured to send information indicating the second cell identity, the information being carried by the first transmission signal; and a transmission unit configured to transmit the first transmission signal using the first component carrier via a first frequency band, and transmit the second transmission signal using the second component carrier via a second frequency band different from the first frequency band, wherein transmit the first transmission signal using the first component carrier via a first frequency band, and transmit the second transmission signal using the second component carrier via a second frequency band different from the first frequency band, wherein the first component carrier and the second component carrier are aggregated to support a wider transmission bandwidth than the first component carrier. <EOS>