Title :
Soft decision feedback equaliser for CPM signals
Author :
Cheung, Joseph C S ; Steele, Raymond
Author_Institution :
Dept. of Electron. & Comput. Sci., Southampton Univ., UK
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;
Conference_Titel :
Communications, 1991. ICC '91, Conference Record. IEEE International Conference on
Conference_Location :
Denver, CO
Print_ISBN :
0-7803-0006-8
DOI :
10.1109/ICC.1991.162250
