Digital signal processing means

In an amount of inter-symbol corresponds to the insertion of the fixed filter of the residual interference filter adaptive parameters optimized manner. Included in the optical signal receiver includes a digital signal processing means processing the digital signal converted optical signal: a linear adaptive filter, the transfer function of the linear action possible to dynamically control in a digital signal; maximum likelihood sequence decoder by maximum likelihood sequence estimation of the received signal is decoded, the maximum output signal and the control signal likelihood sequence estimation that the effect of the transfer function of the transmission path model in the plurality of signals and generating a plurality of candidate sequence control signals, the evaluation of the linear adaptive filter differential and estimates the most likely sequence of transmission time; a signal reproducer generates a sequence from the maximum likelihood decoder then decodes the data signal corresponding; additional filter feedback distortion, the transmission path used in the maximum likelihood sequence decoder additional equivalent model distortion in the output signal of the reproduction signal; difference between the target signal and the output signal of the adaptation of the filter control block, the additional distortion as a feedback filter and the digital signals as an error signal, updated by the LMS algorithm linear filter tap coefficient adaptation.