Thermal asperity suppression in perpendicular recording channels

The "thermal asperity" (TA) defect associated with magnetoresistive (MR) read heads used in high-density magnetic recording systems can distort the readback signal to the extent of causing possible sector read failure. This problem becomes more serious in perpendicular recording channels since these channels pass DC. In this paper, we present a novel and simple threshold-based approach to detect and suppress TA-induced signal distortions in perpendicular channels. The proposed method is shown to give good bit error rate (BER) performance in the presence of a TA while maintaining satisfactory BER in the absence of TAs. We also show that the proposed method is robust with respect to the peak TA amplitude and the mismatch between estimated and actual TA duration.