This paper evaluates the performance of detectors with d = 1 constraint for perpendicular recording systems under assumptions of nonlinear distortion. Nonlinear distortions considered are transition jitter and DC-offset. Detectors used in this study are the partial response maximum likelihood (PRML), noise-predictive maximum likelihood (NPML), fixed delay tree search with decision feedback (FDTS/DF), dual decision feedback equalizer (DDFE) and multilevel decision feedback equalizer (MDFE). Their performances are discussed in terms of mean squared error (MSE) and noise power spectra of equalizer at discrimination point and similarity of frequency response between overall system and partial response (PR) target polynomial.
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