Effect of transition noise on turbo decoding for optical data storage

We present the results of a simulation study of applying turbo decoding to optical data storage channel in the presence of transition noise. We use an optical recording channel model that captures the storage density effects, the effects of transition noise, the effects of finite equalizer lengths and the noise coloring caused by the equalizers. Our simulator uses the least mean squares (LMS) adaptive algorithm for the partial response (PR) equalizer design and thus captures the effect of a limited training set. We consider three iterative decoding architectures, three different partial response (PR) targets suitable for optical recording, two different precoders, and two different normalized recording densities.