General transform filters in perpendicular recording architectures

Unlike longitudinal recording, perpendicular recording (PR) read-back signals have a significant amount of low-frequency content. This constitutes a problem in using the available channel chip architectures designed for longitudinal recording systems. In this paper, we explore the idea of transforming perpendicular read-back signals to longitudinal looking ones. The differentiator and the Hilbert transform are the natural choices for such applications. Here, we generalize this concept of transform filtering and introduce general transform filters. We then evaluate the bit-error-rate performances of those filters in conjunction with various PR targets, preamplifiers and noise characteristics. Although this method allows the use of existing longitudinal channels, it results in performance loss.