| 摘要 |
<p>The parameters of an adaptive filter are optimized in such a manner that inter-symbol interference of an amount that corresponds to the inserted fixed filter remains as a residual. A digital signal processing device that is included in an optical signal receiver, and that processes digital signals that have been converted from optical signals, is provided with: a linear adaptive filter that applies a dynamically controllable linear transmission function to a digital signal; a maximum likelihood decoder that generates a plurality of reference signals by applying a transmission function of a transmission path model to a plurality of signal grouping candidates, and decodes received signals using a maximum likelihood estimation that estimates the most likely transmission time sequence by evaluating the difference between the output signal of the linear adaptive filter and the reference signals, a signal regenerator that generates a signal that corresponds to the decoding data from the maximum likelihood decoder, a feedback distortion filter that applies the equivalent distortion to the transmission path model used in the maximum likelihood decoder to the output signal of the signal regenerator; and an adaptive equalizing filter control block that updates the tap coefficient of the linear adaptive filter using an LMS algorithm, with the difference between the digital signal and the target signal which is the output signal of the feedback distortion filter, as an error signal</p> |
