Design Parameter Optimization for Perpendicular Magnetic Recording Systems

In a perpendicular magnetic recording system, advanced read/write transducers, magnetic media, and signal processing techniques are combined to achieve the highest possible storage density, subject to severe constraints on reliability. This paper proposes a quasi-analytic methodology for exploring the complex design tradeoffs among these system components. We use a simple channel model, characterized by three parameters: isolated voltage pulse width, transition jitter noise variance, and additive electronic/replay head noise power. The system incorporates generalized partial-response equalization and maximum-likelihood detection, along with a Reed-Solomon error-correcting code characterized by its code rate. We calculate a family of "design curves" from which we can determine, for a given set of channel parameters, the maximum user density that can be achieved with a specified codeword error rate, along with the corresponding code rate. The design curves can also be used to determine the acceptable range of channel parameters consistent with a target user density and codeword error rate