An application of LDPC code and iterative decoding to hard disk drive is studied. Based on the consideration of the LDPC parity check matrix H that is suitable for partial response system, we propose a simple way to construct the parity check matrix H. The effectiveness of this construction is demonstrated by computer simulation. Moreover, the iterative decoding with DAE (Decision Aided Equalizer), which can enable an easy implementation, is also considered and supposed. The computer simulation illustrates that the performance loss caused by replacing SOVA with DAE is sufficiently small, and about 2.5dB improvement over PRML system is achieved by proposed method.
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