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AssigneeInternational Business Machines Corporation
InventorsGlen G. Langdon, Jr., Paul H. Siegel
Estimating the term…
A class of ternary square wave signals is detectable by peak polarity detection alone without need for amplitude discrimination. The ternary codes are used to increase data density recording at the same clock rate as binary codes. This is satisfied by selective direction-constrained run length limited (RLL) signals. The direction constraint is that the half-step transitions can only occur in pairs of the same polarity. Alternate half-step pairs of opposite polarity are forbidden. This avoids the need for amplitude discrimination. The RLL (d,k) constraint includes "d" number of clock times when a transition is forbidden and "k>d" clock times within which consecutive transitions must occur. The latter determines a minimum frequency for clocking purposes. This eases peak shift detection.
A method for coding binary symbol strings into ternary symbol strings and for synchronously recording said ternary symbol strings onto a magnetic medium such that clocked recovery of the recorded signal may be subsequently made using peak position and polarity detection, comprising the steps of:
In a high-density, high-data rate, nonsaturated magnetic recording environment of signals consisting of (d,k) run length limited, directionconstrained, ternary symbol encodings of binaray symbol strings using peak position and polarity detection for the readback thereof, a method for binary symbol string recovery comprising the steps of:
Dependencies are inferred from the claim text.