A communication device includes an RF receiver that receives a combined signal including a first signal transmitted from a first node and a second signal transmitted from a second node, a channel estimator that estimates first channel information of the first signal and second channel information of the second signal, respectively, a multiuser detector that detects original signal values of the combined signal using the estimated first and second channel information and an RF transmitter that transmits a signal generated based on the values detected by the multiuser detector to the first node and the second node during a predetermined period.