Volterra modeling of digital magnetic saturation recording channels

A Volterra input-output model of a magnetic recording channel that allows the readback signal to be defined precisely in terms of the recorded binary data for situations with significant nonlinear distortion (NLD) is described. An efficient procedure to determine the model characteristics from measurements is introduced. The technique was applied to an experimental channel that has significant nonlinear distortion. A comparison of modeled with measured readback waveforms shows precise agreement. It is concluded that, with Volterra models (VMs), substantially better agreement of modeled and measured waveforms can be achieved compared to that attained with conventional linear techniques. VMs are well suited for the analysis and development of advanced signal-processing techniques that can cope with NLD. Moreover, they can be used to characterize and evaluate head and disk components in terms of the underlying physical effects of the recording process