Means of configuring a reference signal unique to a mobile station apparatus is provided. There is provided a control station apparatus notifying a first mobile station apparatus of a parameter group generating a reference signal. The control station apparatus includes: an RRC layer to configure a parameter set including a plurality of parameter groups generating the reference signal; and a physical layer to select one of the parameter groups and notify the mobile station apparatus. It is preferred that the parameter set is configured with a plurality of parameter groups that respectively configure a sequence number and a cyclic shift hopping pattern of the reference signal and includes a parameter group generating a reference signal the same as in a second mobile station apparatus different from the first mobile station apparatus.