Digital signal reproducing apparatus using a Viterbi decoder

摘要

A digital signal reproducing apparatus using a Viterbi decoder, reproduces a digital signal without deteriorating the decoding performance even if a DC component is included in recorded data or the optical characteristics such as a reflection index or a refraction factor of an optical recording medium has altered. The digital signal reproducing apparatus converts read signals read from a recording medium to a digital sample value series by means of A/D conversion, extracts specified sample values from the sample value series to use an average of the specified sample values as an offset level, and uniformly adds a value corresponding to this offset level to each estimated sample value in a Viterbi decoder.