A New Four-Ary Run-Length-Limited (2,12) Code for Multilevel Optical Recording Channels

Abstract

In this paper, we introduce a new four-ary run-length-limited (d,k)=(2,12) code for multilevel optical recording channels. This code has a simple one-codeword look-ahead encoder and a sliding block decoder. The code rate is 4/5 (bits/symbol), and the density ratio is 2.4 bits/T min, which is larger than that of binary codes used for typical optical recording systems. The encoding and decoding rules of the proposed code are simple and easy for implementation. With the bit error rate (BER) performance evaluation, this code shows feasible to be applied in high-density multilevel optical storage systems.

DC-Free Four-Ary (2,8) Run-Length Limited Code for Multi-level Recording Channels

“…2.1 Four-ary ð2; 8ÞRLL code By extending the Immink's code design method, 9) we construct a new 93.25% efficient four-ary ð2; 8ÞRLL code, which is shown in Table II. The proposed code has higher (4.2%) code rate and density ratio than the previous four-ary ð2; 12ÞRLL code, 7) and smaller parameter k (¼ 8), which can facilitate the timing recovery. A comparison of several existing modulation codes and the proposed code is illustrated in Table I.…”

“…For these reasons, researchers tried to use PRML technology to compensate the lost SNR and to handle the ISI effect. 6,7) In a sense, M-ary ðd; kÞRLL achieves a good tradeoff between SNR and recording density, since the reduction of SNR in a multi-level system is rewarded by the increase in recording density. 2.1 Four-ary ð2; 8ÞRLL code By extending the Immink's code design method, 9) we construct a new 93.25% efficient four-ary ð2; 8ÞRLL code, which is shown in Table II.…”

“…Although the coding procedures of the codes shown in Table I are not the same, they all have a basic conversion circuit which is essentially a FSSM, and a RDS controller which is used to suppress the DC content. 5) For the case of four-ary ð2; 12Þ code, 7) two substitution rules should be performed to ensure the ð2; 12Þ constraints, so an additional circuit is needed. Similarly, for the proposed code, an additional circuit is also needed to determine the value of KCS.…”

PRML Detection of Multi-Level DVD Channels with Run-Length-Limited Modulation

“…However, most of these codes have large value of M > 4, and exceed the requirements of practical ML-RLL modulation systems. For ML-RLL modulation with M = 3 and 4, some new codes are constructed with different methods [19], [20], [21], [22]. Table I 0 1 0 1 1 1 0 1 1 0 0 1 1 1 0 1 0 0 2 0 0 0 0 1 0 0 0 2 0 0 0 3 0 0 1 0 0 0 2 2 2 2 2 3 3 3 3 1 1 1 1 0 0 0 1 DR values of M -ary RLL (d, k) codes are much higher than that of binary RLL codes.…”

New Efficient Run-Length Limited Code for Multilevel Read-Only Optical Disc

“…PRML detection has been proposed for high density ML-RLL optical recording channels. 13,14) The PRML detection scheme shown in Fig. 6 is used to evaluate the SER performance of the proposed code.…”