System perspectives for the application of structured LDPC codes to data storage devices

Evaluation of the Concatenation of LDPC and RS Codes in Magnetic Recording Channel Using Field Programmable Gate Arrays

“…The results of this binomial approximation for Code 2 are shown in Fig. 10, which shows similar optimum T values as in [1]. It might be interesting to note that the sector error rates at the optimum T in this figure are so sensitive to SNR value that a small increase in SNR and T values can greatly improve the sector error rate for this error floor case.…”

“…In order to obtain improved coding gains by inner LDPC codes while handling burst errors and obtaining guaranteed error correction performance by outer RS codes, concatenation of LDPC codes and RS codes has been proposed and investigated [1]- [3] for magnetic recording channels. While one research study [1] suggests that combining the two can lead to better performance, another research study [2] indicated that combining LDPC and RS codes does not always improve performance when compared to using LDPC code only. Unfortunately, it is not possible to directly compare those results since many parameters are different.…”

“…To our knowledge, the three papers mentioned [1]- [3] comprise the entire literature to date regarding the concatenation of LDPC and RS codes for magnetic recording channels. These papers have different results about an optimum T of outer RS codes, where T denotes the maximum number of erroneous symbols that an outer RS code can correct in a codeword.…”

“…However, it is not possible to compare directly the optimum T in those papers since the type of inner LDPC code, the code rate, the number of iterations, the type of noise, and the SNR values were different. In [1], it was shown that the optimum T exists and the range was 6 ≤ T ≤ 13 depending on the type of inner LDPC code and the number of global iterations. This suggests that the concatenation of LDPC and RS codes offers better performance than using LDPC code alone in some cases.…”

Modeling, detection, and LDPC codes for bit-patterned media recording

“…Furthermore, in these works, not all the read channel components have been optimized for BPMR. The low-density parity-check (LDPC) codes have been widely explored in conventional magnetic recording systems due to their potential to approach the Shannon limit [10]. However, the coding gains of LDPC codes have not been fully investigated for BPMR channels.…”