Experimental characterization of media noise based on equalized, synchronized drive data

In this paper, we experimentally measure the nonstationary (non-Toeplitz) write noise correlation matrix and fit key portions of the matrix to a simple theoretical correlation matrix which consists of up to seven terms. The seven terms are associated with transition jitter, transition width and width-like variation, DC noise, residual read noise, timing loop jitter, and amplitude variation. We fit the model using equalized synchronized samples collected from a disk drive. Averaging techniques are used to isolate the write noise from the read noise and bias. Exhaustive searches are performed to find the best subset of parameters for each model order.