To make an analog filter for antialiasing in common without using a rate conversion by a complex operation in a sampling device.Using: an anti-aliasing filter which has a fixed cut-off frequency fc; an AD converter and a DA converter which have a clock signal input and change the sampling frequency; and a PLL circuit which changes a clock signal frequency. The software radio receiver makes sampling by setting a sampling frequency to be integral multiple of signal bands and to double a cut-off frequency or more.