| 摘要 |
In one embodiment, irregular electronic disturbance signals in a partial-response read channel are detected by a disturbance detector using state metrics generated by maximum-likelihood sequence detector. For example, a thermal asperity (TA) detector detects the occurrence of TAs in the read channel of perpendicularly recorded magnetic media by using the state metrics generated by a Viterbi detector. Changes in state metrics (e.g., magnitudes of the branch metrics of the trellis diagram) used by the Viterbi detector are tracked. If the magnitude of the rise of the path metric increases above a set threshold, then a TA is detected. Alternatively, or additionally, the rate of change of the magnitude of the path metrics is tracked. If the rate of change within a set time window is above a specified threshold, then a TA is detected. |
