Robert C. Davis

A nonalgorithmic maximum likelihood decoder for trellis codes

A new decoder for trellis codes is presented. The decoder is based on a graph model consisting of diodes and switches. Such decoders may prove to be well suited for VLSI. >

Two Recent Applications of Error-Correction Coding to Communications Systems Design

This paper describes two communication systems in which convolutional coding with Viterbi maximum likelihood decoding plays a major role. The paper contains a functional description of the system, presents some of the thinking that contributed to the design, and gives some performance curves based on computer simulation and laboratory measurements.

A More General Approach to the Interpolation of Sampled Data by Realizable Filters

This paper derives an expression for root-mean-square (rms) interpolation error in a sampled data system employing lumpedparameter presampling and postsampling filters. The derivation for rms error employs basically a time-domain approach rather than the more usual frequency-domain approach. Plots of rms error versus sampling rate are given for first- through fourth-order Butterworth data using a Butterworth interpolation filter and no presampling filter. It is shown that using 100-percent duty cycle samples (rather than impulsive samples) can greatly improve the rms error.