A signal separator for separating multiple signals contained in a received signal from each other based on a replica of the received signal is provided. The signal separator comprises a sampling unit configured to sample the received signal at a prescribed sampling timing; an index output unit configured to monitor sampling counts of the sampling unit and output an index signal representing a remainder of a division dividing the sampling counts by a sampling number per a prescribed time period to group the sampled signals; a coefficient-variable filter configured to generate and output a replica of the received signal based on a channel estimation value and a signal point candidate, at least one of the channel estimation value and the signal point candidate being generated according to the index signal; a subtractor configured to subtract the replica from the sampled signal and output a subtraction result as a residual signal; and a maximum likelihood sequence estimator configured to estimate a sequence for each of the multiple signals based on the residual signal, taking into account signal state transition, and output the estimation result at a signal output timing determined by the index signal.