MOBILE TERMINAL APPARATUS, RADIO COMMUNICATION METHOD AND RADIO COMMUNICATION SYSTEM

摘要

A mobile terminal apparatus that transmits a periodic SRS (Sounding Reference Signal) and an aperiodic SRS that comprises a receiving section configured to receive, in a downlink control channel, specific bit information selected from a bit information piece to indicate not to trigger the aperiodic SRS and a plurality of bit information pieces each to indicate to transmit the aperiodic SRS using a predetermined default SRS parameter; and an SRS transmission setting section configured to control transmission timing of the aperiodic SRS based on the specific bit information and control transmission timing of the periodic SRS in a predetermined period, wherein, when transmission of the aperiodic SRS and transmission of the periodic SRS occur in a same subframe, the SRS transmission setting section transmits the aperiodic SRS preferentially and does not transmit the periodic SRS.