A study on multilevel decision feedback viterbi equalizer to (1,7) code at the optical disk recorder

We examined an algorithm for a multilevel adaptive decision feedback (DF) Viterbi equalizer that combines PR(1,1), PR(1,2,1), PR(2,3,2), or PR(1,2,2,1) preequalization, RAM‐DFE (Decision Feedback Equalizer), and Viterbi decoding with the (1,7) code as an ideal recording code and equalization detection scheme in optical disk recorders and evaluated its performance by simulations. The results showed that the minimum bit length of 0.24 µm could be realized in current recording and playback systems by applying PR(1,2,2,1) and 7‐level decision feedback Viterbi equalization. We also verified that the proposed equalization decision scheme is also suited to recorded codes that are not DC free in order to improve the error rate reduction when a DC offset is generated and is effective in shortening the convergence time at low bit rates due to the fast recovery speed from burst errors. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(7): 51–63, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10087