A Simple Decoding Scheme for a Balanced 6/8 Modulation Code

Abstract

Two-dimensional (2D) inter-symbol interference (ISI) and inter-page interference (IPI) are major concerns of holographic data storage (HDS). These problems can be mitigated by modulation code. A 6/8 balanced code is one of the modulation codes that has a 1 : 1 ratio of symbol "1" and symbol "0". It avoids the IPI and has a low-pass filtering effect to reduce the ISI. However, the soft-decision decoding for a 6/8 balanced code needs many multiplications to calculate the Euclidean distances, making the circuit complicated. Hard-decision decoding is much simpler but does not perform as well as soft-decision decoding. Therefore, we propose a simple decoding scheme for a 6/8 balanced code which uses hard-decision decoding but performs almost as well as soft-decision decoding. (C) 2012 The Japan Society of Applied Physics