A base station which transmits a reference signal includes: a first reference signal generation unit for generating a first reference signal sequence in which M types of reference signals are arranged; a second reference signal sequence generation unit for generating a second reference signal sequence in which N types (N > M) of reference signals are arranged; a scheduler for allocating a resource block to a first mobile station and a second mobile station; a signal multiplexing unit for multiplexing the first reference signal sequence on a resource block to be allocated to the first mobile station and the second reference signal sequence on a resource block to be allocated to the second mobile station; and a transmission unit for transmitting the first and the second reference signal sequence.
