Performance Improvement of PRML System for (1, 7) RLL Code

Hisashi OSAWA, Makoto OKADA, Kohei WAKAMIYA, Yoshihiro OKAMOTO

Summary :

The performance improvement of the partial response maximum-likelihood (PRML) system for (1, 7) run-length limited (RLL) code is studied. As a new PRML system, PR (1, 1, 0, 1, 1) system called modified E²PR4 (ME²PR4 ) followed by Viterbi detector for (1, 7) RLL code is proposed. At first, a determination method of the tap weights in transversal filter to equalize to PR (1, 1, 0, 1, 1) characteristic taking account of a noise correlation is described. And the equalization characteristics of the transversal filter are evaluated. Then, a Viterbi detector for ME²PR4 utilizing the constraint of run-length of (1, 7) RLL code is presented. Finally, the bit-error rate is obtained by computer simulation and the performance is compared with that of the conventional PRML systems called PR4, EPR4 and E²PR4 systems with Viterbi detector. The results show that among these systems our system exhibits the best performance and the SNR improvement increases with the increase in the linear density.

• Publication: IEICE TRANSACTIONS on Electronics Vol.E79-C No.10 pp.1455-1461
• Publication Date: 1996/10/25
• Type of Manuscript: PAPER
• Category: Recording and Memory Technologies

Authors

Hisashi OSAWA
Makoto OKADA
Kohei WAKAMIYA
Yoshihiro OKAMOTO

Keyword

digital magnetic recording,  PRML system,  (1,7) RLL code,  Viterbi detection,  bit-error rate