Performance comparison of a class of (1,7) DFE detectors

At high recording densities, it becomes necessary to use constrained codes for spacing the transitions further apart on the medium to reduce non-linear distortion. In this paper, we present the performance comparison of a class of rate 2/3 (1,7) coded DFE (decision feedback equalization) detectors (conventional DFE, dual DFE, FDTS/DF (fixed delay tree-search with decision feedback), MDFE (multi-level DFE) and M2DFE). M2DFE is a new detector that is a modified version of MDFE incorporating two critical loops for making delayed decisions on marginal samples. Results show that MSDFE outperforms the other detectors, thereby proving 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 times the user rate.