Turbo decoding for partial response channels with media noise

Abstract

Previous work on the application of turbo decoding techniques to partial response channels has focused on additive white Gaussian noise channel models. Simulations using these ideal partial response channel models show gains exceeding 5 dB over uncoded systems at bit error rates of 10/sup -5/. Since the APP detectors of the turbo decoder assume uncorrelated Gaussian noise, the performance on more realistic channel models, using correlated and media-dependent noise, was unknown. In this work, we replace the white noise partial response channel model with more realistic channel models. First, the effects of colored noise are investigated with an equalized Lorentzian channel model. Then, media noise is added by incorporating the microtrack model into the system. Simulation results of the turbo decoding system with the various channel models are presented. Additionally, since the use of an outer Reed-Solomon code is anticipated in an actual system, the burst statistics at the error floor are investigated.