POST COMPENSATION FOR NONLINEAR DISTORTIONS IN PRML RECORDING CHANNEL

The performance of the PRML recording channel is degraded due to nonli near distortions introduced in the recording or reproducing processes for high density recordings. Although the maximum likelihood sequence detector (Viterbi detector) might be applied to the channel including these nonlinearities, the Viterbi detector suffers from hardware compl exity since the interleaved two-state trellis diagram for 1-D partial response channel does not sufficiently describe the PRML channel inclu ding nonlinearities, In this study, a post compensation for the PRML r ecording channel including nonlinearities is presented. The nonlinear effects are compensated for after playback and the interleaved two-sta te trellis for 1-D partial response channel is used to recover data fr om compensated signal. Simulation results indicate that the performanc e can be enhanced with a slight increase in hardware complexity.