Write Failure Analysis for Bit-Patterned-Media Recording and Its Impact on Read Channel Modeling

In this paper, we present a write failure analysis for bit-patterned media recording (BPMR) with formulas derived to calculate its probability for a given set of system parameters. The write failure model derived in this work includes the effect of the recording head and media characteristics and that of a hard disk spindle motor speed variations. Such a model can help assess the performance of the writing strategy for BPMR. It is also found that since the media local parameters associated with each bit directly affect both the write failure rate and read-back signal, the read-back signal actually contains information regarding whether a bit is correctly recorded. This may be exploited by coding and detection schemes to reduce the impact of write failure on bit-error-rate performance.