Patent ID: 8897228

Claim:
A mobile communication system in which a mobile station apparatus transmits, to a base station apparatus, a sounding reference signal, the mobile communication system comprising: the base station apparatus configured to: transmit, to the mobile station apparatus, a higher layer signal including first parameters and second parameters, transmit, to the mobile station apparatus, a first downlink control information format including information requesting to transmit the sounding reference signal, the first downlink control information format being used for scheduling of a physical uplink shared channel, transmit, to the mobile station apparatus, a second downlink control information format including the information requesting to transmit the sounding reference signal, the second downlink control information format being used for scheduling of a physical downlink shared channel, the mobile station apparatus configured to transmit, based on a detection of the information requesting to transmit the sounding reference signal, to the base station apparatus, the sounding reference signal based on the first parameters or the second parameters, wherein the first parameters are configured for the transmission of the sounding reference signal based on the information requesting to transmit the sounding reference signal included in the first downlink control information format, and the second parameters are configured for the transmission of the sounding reference signal based on the information requesting to transmit the sounding reference signal included in the second downlink control information format.