On the performance of a rate 8/10 matched spectral null code for class-4 partial response

The authors present the application and performance of a rate 8/10 matched-spectral null (MSN) trellis code in conjunction with class-4 partial response (PR4) signaling. Details of the encoder and decoder functions are presented, as well as the reduced-complexity trellis structure underlying the Viterbi detector for the coded system. Implementation issues involved in the design of a VLSI chip embodying the encoder, decoder, and Viterbi detector for the trellis-coded system are discussed. Results of experiments using synthesized PR4 waveforms are presented, and it is shown that the rate 8/10 code can provide about a 3-dB advantage relative to the class-4 partial response maximum likelihood detection in the presence of additive white Gaussian noise as well as additive synthesized adjacent track interference