Abstract: Asynchronous sampling digital detection (ASDD) methods and apparatus are described. In one embodiment, noise-corrupted information is received and comprises a plurality of information-carrying events which encode binary information which is desired to be retrieved. A plurality of values are extracted from the noise-corrupted information-carrying events which are representative of the encoded binary information. An amount of noise corruption carried by one of these plurality of values is estimated by considering an amount of noise corruption carried by another of the plurality of values. Responsive to the estimation of the noise corruption, the one value is then modified. In another embodiment, noise-corrupted information is received comprising a plurality of information-carrying events which encode binary information which is desired to be retrieved. A plurality of values from the noise-corrupted information-carrying events are determined which are representative of the encoded binary information.

Abstract: A method of predictive failure detection for a data storage system comprises (a) determining a first mean squared error (MSE) value for a read operation wherein the MSE value is indicative of a signal to noise ratio of the read operation, (b) determining a second MSE value for a read operation, and (c) comparing the first and second MSE values wherein a difference in the MSE values indicates a change in the data storage system. The MSE values are directly related to the distance between the storage medium and the read head element used in the read operation. A significant change in MSE values or a trend of increasing MSE values over time indicates a probable impending failure of the data storage system.