an antenna to receive a signal including a holding period, the holding period including part of a period ranging from a leading portion of a delayed wave of a maximum delay time to a trailing portion of a preceding wave;

an estimation unit configured to estimate a channel response of the signal received by the antenna;

a holding unit configured to hold, based on the channel response, a first signal component contained in the holding period, the first signal component including a second signal component which is contained in a period of a preset length which is included in the holding period;

an acquisition unit configured to acquire a set of filter bank outputs by subjecting the second signal component to frequency conversion;

a generation unit configured to generate a plurality of replicas for each of the filter bank outputs, based on the estimated channel response, a frequency response of each of the filter bank outputs, and candidates for a modulation signal corresponding to a subcarrier included in each of the filter bank outputs;

a selection unit configured to select one of the replicas which minimizes a quantity corresponding to differences between components of each of the filter bank outputs and components of the replicas; and

a determination unit configured to determine the modulation signal based on the replica selected for each of the filter bank outputs.