A combined structure of a Decision Feedback Equaliser (DFE) and a Viterbi processor which allows soft decisions to be made and incorrect decisions to be changed in the feedback filter of the DFE is described.Digital phase modulation (DPM) of data was performed and transmitted via Time Division Multiple Access (TDMA) at 250 kbits/s over fixed and fading multipath channels.We found that for a fixed two-path channel,an improvement of 7.5dB in channel signal-to-noise ratio (SNR) was obtained by using the new equaliser compared to the conventional DFE,and it was only about 1dB worse than the more complex maximum likelihood sequence estimation (MLSE) detector.For wideband mobile radio channels having two independent Rayleigh fading paths the corresponding gains in channel SNR compared to the conventional DFE was 8 to 10 dB.
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