Patent ID: 7031090

Claim:
An information recording and reproducing apparatus comprising: a noise correlation arithmetic operating unit which calculates a deviation of noises and a correlation of the noises for a present state which depend on input signal patterns of the present state and past or future states by training; a storing unit which stores said correlation and deviation of said noises; a white noise arithmetic operating unit which obtains white noise values for said input signal patterns in which colored noises are converted into white noises by using said correlation and deviation of the noises which were stored in said storing unit; and an input signal arithmetic operating unit which calculates an input signal of a decoder from said white noise values and a deviation of the white noises, the present state referencing an input signal being processed at present, the past state denoting a first input signal series which is time-precedent to the present state input signal pattern, the future state denoting a second input signal series which is time-subsequent to the present state input signal pattern.