THE RELATIONSHIP OF MEDIUM NOISE TO SYSTEM ERROR RATE IN A PRML CHANNEL

High density disk drive systems utilize fine grain polycrystalline thi n films as a storage medium. These films exhibit noise that is pattern dependent and has appreciable magnitude near the center of each recor ded transition. A model for error rates in a PRML channel is presented to explore how variations in medium noise parameters effect system pe rformance. The channel is assumed to be characterized by both pattern dependent nonstationary medium noise and white Gaussian electronic and /or head noise. Results are presented in terms of both error rate and sensitivity of error rate to changes in medium parameters.