High Density Digital Recording by Using New Mapping (7,1) APSK

Abstract

To attain a high recording density, we studied application of APSK (Amplitude Phase Shift Keying) for magnetic recording channel. New mapping (7,1) APSK that has optimum allocation of recording signal points for magnetic recording is developed. By employing (7,1) APSK, a linear packing density as high as 129 kbpi (bit length of 0.2 μm) is accomplished with MP tape.