PERFORMANCE COMPARISON OF A CLASS OF (1,7) DFE DETECTORS

At high recording densities, it becomes necessary to use constrained c odes for spacing the transitions further apart on the medium to reduce non-linear distortion. In this paper, we present the performance comp arison of a class of rate 2/3 (1,7) coded DFE (decision feedback equal ization) detectors (conventional DFE, dual DFE, FDTS/DF (fixed delay t ree-search with decision feedback), MDFE (multi-level DFE) and M2DFE). M2DFE is a new detector that is a modified version of MDFE incorporat ing two critical loops for making delayed decisions on marginal sample s. Results show that M2DFE outperforms the other detectors, thereby pr oving to be the best choice for (1,7) coded channels. Further, it (as in MDFE) has the additional advantage of being able to operate at half the user data rate while the other detectors need to operate at 1.5 t imes the user rate.