Convolutional coding for parallel decision-feedback equalization

A decision-feedback equalizer (DFE) is one of the simplest detectors for use in a magnetic recording channel. An extension of DFE, termed parallel DFE (PDFE), will be shown to offer significant performance improvements with a relatively minor complexity increase. To offer still greater performance gains, a convolutional code will be added to the system. Although PDFE suffers less error propagation than conventional DFE, the error bursts remain problematic when codes are part of the overall system. Therefore, a convolutional interleaver will be added to randomize the error bursts. Simulation results for a Lorentzian channel will be presented for various PDFE structures, with and without convolutional codes, with various levels of interleaving, for both hard and soft sequence detection.