Symmetric Information Rate of an Ideal Readback Two Dimensional Magnetic Recording (TDMR) Channel with Random Voronoi Grains

Abstract

Two-dimensional magnetic recording (TDMR) is a data storage paradigm that has recently been proposed to record more than one channel bit to one magnetic grain in order to achieve 10 Tbit/in² of user bit density on a magnetic recording medium with 20 Tgrains/in². In addition to conventional noise in magnetic recording, the TDMR channel also suffers from write errors due to the randomness in size and placement of the grains; however aggressive two-dimensional (2D) signal processing schemes may enable reliable data retrieval. In this study, the symmetric information rate (SIR) of a TDMR channel model based on random Voronoi grains, named the ideal readback TDMR channel model, is analyzed. Using numerical simulations, a lower bound of the SIR is evaluated for a half grain per channel bit ideal readback TDMR channel. Although approximately half of the channel bits may not be recorded in this channel, the resulting lower bound of the SIR is 0.46 ~ 0.51 information bits per grain. This result indicates the potential of TDMR to achieve 10 Tbit/in² of user bit density on a magnetic medium with 20 Tgrains/in².