Designing a Partial Response Equalizer for a Non-linear Magnetic Recording Channel

The nonlinear distortions, known as transition shift and partial erasure, arise and limit the performance of the detector in a high-density magnetic recording channel. In this article, we obtained the correlation functions of the storage data in the presence of the partial erasure under the assumption that the transition shift has been precompensated. The correlation functions are applied in designing a partial equalizer, and a minimum mean square error (MMSE) equalizer is obtained for a partial response class IV (PR4) channel. Computer simulations are given to verified the proposed method; the mean square error of the proposed equalizer can be improved about 2 dB as compared with the conventional one in the presence of the partial erasure.