MEDIA DESIGN FOR USER DENSITY OF UP TO 3 BITS PER PULSE WIDTH

Advances in digital signal processing and the use of sequence detection schemes provide new opportunities for increasing user density, i.e. user bits per pulse width, in rigid disk recording. These new channels use linear equalization and multiple samples per decision to better handle intersymbol interference and detection in the presence or noise. The requirements for linearity and stationary noise will limit the approaches which are suitable for taking advantage of these channel improvements. In this paper, the impact of these improvements on the design and characterization or the recording media is analyzed.