James Wilson Rae

Improved trellis-coding for partial-response channels

New code design methods and Viterbi detector architectures are presented for high-rate trellis-coded partial-response (TCPR) systems. The methods, which extend the matched-spectral-null (MSN) coding technique, use novel code constraints and time-varying detector trellis structures to reduce path memory requirements by as much as a factor of two, relative to previously reported codes, while retaining the other attractive features of MSN codes. The design methods and corresponding time-varying trellis structures are illustrated with several examples. >

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. >

Real-time recording results for a trellis-coded partial response (TCPR) system

The results of an experimental performance comparison between a trellis-coded partial response (TCPR) system and a partial response maximum likelihood (PRML) channel are described, using magnetoresistive (MR) recording heads and metal film disks. Measured data confirm that the TCPR method provides substantial performance advantage in terms of ontrack error rate, offtrack capability, and areal density. >

Improved Trellis-coding For Partial Response Channels

New code design methods and Viterbi detector architectures are presented for high-rate trelliscoded partialresponse (TCPR) systems. The methods, which extend the matched-spectral-null (MSN) coding technique, use novel code constraints and time-varying detector trellis structures to reduce path memory requirements by as much as a factor of two, relative to previously reported codes, while retaining the other attractive features of MSN codes. The design methods and corresponding time-varying trellis structures are illustrated with