Two-Dimensional 15/24 Non-Isolated Patterned Modulation Codes With Minimum Hamming Distance 3 in Bit-Patterned Media Recording

Abstract

Reducing the distance between magnetic islands is essential for increasing the areal density in bit-patterned media recording (BPMR). Consequently, significant two-dimensional (2D) interference emerges, encompassing inter-symbol interference (ISI) and inter-track interference (ITI) along the cross- and down-tracks, respectively. To address the 2D interference, modulation with non-isolated patterns can be employed to mitigate the interference from neighboring bits. In previous studies, authors relied on the Hamming code to propose a non-isolated modulation code with a minimum Hamming distance (MHD) of 3. However, for encoding, authors utilized a mapping method with a large look-up table, resulting in prolonged delay for the decoder. Therefore, in this paper, we proposed a generator matrix for creating the Hamming code with an MHD of 3, thereby generating reverse codewords in the look-up table. Consequently, only half of the look-up table needs to be stored, leading to reduced complexity and delay time in the decoder for non-isolated modulation code with an MHD of 3. Simulation results demonstrate that our proposed model can enhance bit error rate performance and decrease delay time compared to previous studies.

Keywords

• Bit-patterned media recording (BPMR)
• error correction codes (ECCs)
• Hamming code
• modulation coding
• non-isolated pattern