COMBINED EQUALIZATION AND CODING FOR HIGH-DENSITY SATURATION RECORDING CHANNELS

Combined equalization and coding approaches which significantly outperform previous techniques are presented for the binary Lorentzian channel with additive Gaussian noise. We develop a technique based on the concatenation of standard trellis codes with an "equalization code" and a block decision feedback equalizer (BDFE). Signal sets for the trellis code are generated by partitioning BDFE output vectors according to four- and eight-dimensional lattices. We also investigate the combination of a decision feedback equalizer (DFE) and a convolutional code (CC) and find that this system provides theoretical coding gains from 1 to 3 dB in the high linear recording density range of 2 less-than-or-equal-to pw50/T less-than-or-equal-to 3. Although the BDFE with trellis code system does not perform as well as the DFE with CC system at high densities, it does produce substantial coding gains at low linear recording densities.