Regarding an uplink demodulation reference signal to which a cyclic shift and an orthogonal cover code is applied, IFDM is applied to the uplink demodulation reference signal while retaining the number of bits of control information that specifies a cyclic shift and an orthogonal cover code transmitted from a base station apparatus to a mobile station apparatus. A subcarrier offset and a subcarrier interval based on IFDM are uniquely determined in accordance with the cyclic shift and the orthogonal cover code of the uplink demodulation reference signal, reported from the base station apparatus to the mobile station apparatus.