Improved codes for synchronization error correction on the bpmr channel

We study the data recovery problem for bit-patterned media recording (BPMR) with written-in errors, in particular, bit insertions and deletions. The Davey-MacKay (DM) concatenated code construction is applied to combat written-in errors with a twist by dropping the watermark string. This is made possible through the proposed inner code design procedure. The overall system performance with the proposed inner codes on a staggered BPMR channel corresponding to an areal density of 10 Tb/in is presented.