ERROR PROPAGATION EVALUATION FOR RLL-CONSTRAINED DFE READ CHANNELS

Decision feedback equalization (DFE) is a promising low-cost solution for signal detection in magnetic recording channels, In terms of the b it error rate after detection, (0,k)-DFE and MDFE (Multilevel Decision Feedback Equalization) [1] are comparable to (0,k)-PR4ML. Error propa gation, however, is one of the major concerns for all DFE approaches, In this paper, an analysis of error propagation for RLL-constrained DF E at all stages of data processing, including RLL decoder and error co rrection, is performed, To evaluate error propagation, a Markov chain is constructed that explicitly models any type of RLL con straints. Fr om this model, a Markov chain, describing the error distribution insid e the bursts, is derived and a relation between these chains and error propagation decay rate is established, Performance of interleaved ECC (Error Correction Code) is also evaluated, The results obtained are c ompared with those from simulation, By using the newly developed model , a special technique of equalizer design, aimed to reduce error propa gation, is analyzed. The comparison between (0,k)-DFE and MDFE in term s of the bit error rate after ECC is also provided.