| 摘要 |
A mobile station apparatus (1) determines an uplink carrier component to which a physical downlink control channel instructing to start random access procedure corresponds. Provided is a wireless communication system in which a base station apparatus (3) and a mobile station apparatus (1) communicate with each other using a plurality of component carriers, wherein the base station apparatus (3) includes a random access controller (1012) that preliminarily allocates random access resources corresponding to a specific downlink component carrier, by means of which the mobile station apparatus (1) can start a random access communication, and a transmission processor (111) that transmits control information instructing to start the random access procedure, and wherein the mobile station apparatus (1) includes a random access processor (2012) that, upon receipt of the control information instructing to start the random access procedure, starts the random access procedure by means of the random access resource corresponding to a specific downlink component carrier preliminarily allocated by the base station apparatus (3). |
