A circuit includes a calculation circuit configured to calculate a noise power of a predetermined-training-sequence pattern repeatedly included in a first signal input into an adaptive equalizer, based on a second signal obtained by compensating the first signal by a compensation circuit, a channel-estimation value based on the second signal, and the predetermined-training-sequence pattern; and an average circuit configured to obtain an average value of estimation values of frequency offsets based on the predetermined-training-sequence pattern having the noise power equal to or smaller than a predetermined power, among estimation values of frequency offsets based on the predetermined-training-sequence pattern, wherein the compensation circuit is configured to compensate a frequency offset of the predetermined-training sequence pattern based on the average value and thereby obtain the second signal, and the adaptive equalizer is configured to perform adaptive-equalization processing of the first signal with a setting value based on the second signal.