Soft decision feedback equaliser for CPM signals

Author

Cheung, Joseph C S ; Steele, Raymond

Author_Institution

Dept. of Electron. & Comput. Sci., Southampton Univ., UK

fYear

1991

Firstpage

1469

Abstract

A combined structure of a decision feedback equalizer (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 kb/s over fixed and fading multipath channels. It is found that for a fixed two-path channel, an improvement of 7.5 dB in channel signal-to-noise ratio (SNR) was obtained by using the new equalizer compared to the conventional DFE, and it was only about 1 dB worse than the more complex maximum-likelihood 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 were 8 to 10 dB

Keywords

digital radio systems; equalisers; fading; feedback; mobile radio systems; phase modulation; signal processing; telecommunication channels; time division multiple access; 250 kbit/s; CPM signals; DPM; Rayleigh fading paths; SNR; TDMA; Viterbi processor; channel signal-to-noise ratio; digital phase modulation; feedback filter; soft decision feedback equaliser; time-division multiple-access; two-path channel; wideband mobile radio channels; Decision feedback equalizers; Detectors; Fading; Filters; Maximum likelihood estimation; Multipath channels; Phase modulation; Signal to noise ratio; Time division multiple access; Viterbi algorithm;

fLanguage

English

Publisher

ieee

Conference_Titel

Communications, 1991. ICC '91, Conference Record. IEEE International Conference on

Conference_Location

Denver, CO

Print_ISBN

0-7803-0006-8

Type

conf

DOI

10.1109/ICC.1991.162250

Filename

162250