Patent ID: 6385255
Filing Date: 2002-05-07
Classification: G11B,H04L

Abstract:
A system for writing data to and reading data from a multi-level partial response channel, comprising:a trellis coder configured to encode a digital input data stream into a stream of multi-level M-ary data symbols, where M&gE;3; a laser light source modulated with said data symbols to write said stream of multi-level data symbols to said multi-level partial response channel; an optical detector configured to read said written data symbols from said partial response channel, wherein said symbols read differ from said symbols written as a result of a modulation transfer function of said partial response channel, wherein said modulation transfer function includes effects of inter-symbol interference; and a symbol decoder configured to decode said symbols read from the partial response channel and to predict a maximum likelihood sequence of said digital data stream, wherein said symbol decoder considers combined effects of said trellis coder and said partial response channel.