An MMSE Infinite Impulse Response Equalizer for Perpendicular Recording Channels with Jitter Noise

A finite impulse response (FIR) equalizer is practically employed in conjunction with the Viterbi detector for data detection process in magnetic recording channels. However, the FIR equalizer with a large number of taps is required at high density storage channels. It is well-known that an infinite impulse response (IIR) filter with a small number of taps can closely approximate such an FIR filter. In this paper, we propose the IIR filter for perpendicular recording channels, based on a minimum mean-squared error approach, and compare its performance with the FIR equalizer in the presence and in the absence of media jitter noise. Results indicate that the IIR equalizer performs better than the FIR equalizer for all jitter noise levels, especially when the number of equalizer taps is small (e.g., 3 taps) and the normalized recording density is high.