Elimination of two-dimensional intersymbol interference through the use of a 9/12 two-dimensional modulation code

This study presents a 9/12 two-dimensional (2D) modulation code as a way to overcome 2D intersymbol interference (ISI) in high-density storage systems. The next generation of data-storage systems is being continually developed to satisfy a massive demand for reliable storage regarding enormous amounts of data. Holographic data storage, bit-patterned media recording (BPMR), and 2D magnetic recording are promising candidates for the attainment of area-density increases that are beyond the capacities of conventional storage systems. One of the main challenges for these systems is a 2D ISI problem consisting of 1D ISI from neighbour bits and intertrack interference from adjacent tracks. The proposed modulation code maps every 9 bit sequence of user data into a 2D output array of a 3-by-4 size so that the fatal 2D ISI patterns are avoided in every output array. For the assessment of the quality of the proposed modulation code, a simulation model is carried out in a BPMR system. The results show that the proposed modulation code offers a gain of ∼2 dB over that of a system without encoding. In particular, a gain of ∼1 dB is obtained over that of a 6/8 modulation code regarding the same code rate.