DESIGN OF ERROR-CORRECTION SYSTEMS FOR DISK-DRIVES

Certain models are presented for analysis of Reed-Solomon (R-S) error correction systems in the context of optimizing their use in magnetic and optical disk storage devices. A brief statement of design consider ations is noted with references as to which considerations are address ed by the models. This work is motivated by the desire to achieve the highest possible storage density within the constraints of user requir ements (acceptable error rates, performance, etc.), recording code, re cording channel, read channel, and cost, One pair of models treats con version of soft error rates and burst length distributions from the re ad channel into hard bit error rates for various levels of interleavin g. Another model, using the above models, conservatively estimates und etected bit error rate (miscorrection bit error rate). This model is c loser to simulation examples than the previously published McEliece-Sw anson bound [1], A third model includes effect of TA's (thermal asperi ties) on hard bit error rate. A fourth set of models includes the effe ct of thermal asperities (TA's) on an undetected bit error rate. Colle ctively, these models provide a bridge between read channel portions o f data storage systems and error correction systems. A fifth set of mo dels addresses user-perceived performance. Finally, an example is offe red based upon one set of sample data to show how the models can be ap plied to help select an optimum system.