Matched spectral null trellis codes for partial response channels I. Low rate concatenated codes

Abstract

Summary form only given, as follows. The authors obtain expressions for the channel metrics of binary input partial-response channels with transfer polynomials of the form (1 - DN) and (1 + D N). Based on these metrics, they propose a concatenated coding scheme for these channels. The codes here comprise convolutional outer codes and simple nonlinear block inner codes. They show that two of the inner codes given are robust, for there exist nontrivial lower bounds to the minimum Euclidean distance achieved at the output of the partial-response filters in terms of the free Hamming distance of the outer convolutional codes. The authors give tables of performance for these inner codes with several optimum convolutional codes, and exhibit the significant reduction of decoder hardware complexity with respect to previously known trellis codes.