Characterization of dropouts with data read-back errors for digital magnetic-tape recorders

Error-correcting two-dimensional modulation codes

“…Peak shift errors are more characteristic of magnetic recording channels than other channels. Although Seymour [41] states that dropouts-additive errors that change a "1" to a "0"-are the "primary cause of data errors in high-density magnetic recording," other analyses [42] suggest that peak shifts are the most prevalent class of errors for recording channels. A peak shift happens when a "1" in the data, corresponding to a transition in the magnetization pattern and a peak at the read head, is detected in a neighboring bit cell instead of the proper one.…”

“…To this point, the codes we have discussed are optimized to work against a certain class of errors-additive, peak shift, or whatever. We know, though, from experi mental data [41,42] that real magnetic channels contain multiple classes of errors.…”