1. A multi-input multi-output (MIMO) repeater system comprising a plurality of repeaters, wherein each of the repeaters comprises: a receive (Rx) antenna; a receiver configured to convert a signal received through the Rx antenna into a digital signal; an interference cancellation unit configured to cancel interference from an output signal of the receiver, wherein the interference cancellation unit comprises: an interference signal canceller configured to cancel the prediction signal from the input signal and generate an error signal; a reference signal generator configured to generate a reference signal based on the error signal; and an interference signal detector configured to generate the current filter coefficient vector in response to the input signal, the reference signal vector, and a previous filter coefficient vector, and output the prediction signal by filtering the reference signal vector through the current filter coefficient vector; a transmitter configured to convert an output signal of the interference cancellation unit into an analog signal; and a transmit (Tx) antenna configured to transmit an output signal of the transmitter, and the interference cancellation unit provided in each of the repeaters receives the output signal of the receiver as an input signal, receives reference signals provided from the plurality of repeaters as a reference signal vector, outputs a prediction signal according to a current filter coefficient vector generated in response to the input signal and the reference signal vector, and cancels the prediction signal from the input signal.