1. A signal estimation loop for generating an estimated signal from an input signal in each symbol period, the input signal being received through a channel having an impulse response including a postcursor component for a plurality of symbols, the signal estimation loop comprising: a subtracter for subtracting a postcursor estimation signal from the input signal to produce a difference signal which is used to generate the estimated signal; a postcursor estimator for generating all possible postcursor estimation signals in a first past symbol period which is one symbol earlier based on a post estimated signal in a second past symbol period which is at least two symbols earlier; and a selector for selecting one of the possible postcursor estimation signals based on the estimated signal to output a selected one as the postcursor estimation signal to the subtracter in the symbol period.