Title :
A 2-stage soft-output equalizer for EDGE
Author :
Zeng, Hanks H. ; Li, Ye Geoffrey ; Winters, Jack H. ; Sadjadpour, Hamid R.
Author_Institution :
Dept. of Wireless Syst. Res., AT&T Labs.-Res., Red Bank, NJ, USA
Abstract :
We propose a new 2-stage soft-output equalizer (TSSOE) structure for spatial-temporal processing in EDGE. The TSSOE is the cascade of a delayed decision-feedback sequence estimator (DDFSE) and maximum a posteriori probability (MAP) estimator. The TSSOE uses the final-decision symbols from the DDFSE to estimate the noise variance and truncates the channel memory for the following MAP estimator. Compared with the soft-output DDFSE, the TSSOE reduces both the feedback symbol errors and the noise variance estimation error. At a 10% block error rate and 20 dB signal-to-noise ratio, the TSSOE requires about 10 dB lower signal-to-interference ratio than the soft-output DDFSE for the GSM typical urban channel profile
Keywords :
cellular radio; cochannel interference; decision feedback equalisers; fading channels; interference suppression; multipath channels; noise; probability; sequential estimation; 2-stage soft-output equalizer; EDGE; GSM; MAP estimator; SNR; block error rate; channel memory truncation; co-channel interference; delayed decision-feedback sequence estimator; feedback symbol error reduction; final-decision symbols; maximum a posteriori probability estimator; multipath fading; noise variance estimation error; signal-to-interference ratio; signal-to-noise ratio; soft-output DDFSE; spatial-temporal processing; urban channel profile; Additive white noise; Delay estimation; Equalizers; Error analysis; Feedback; GSM; Gaussian noise; Maximum likelihood estimation; Noise reduction; Radiofrequency interference;
Conference_Titel :
Wireless Communications and Networking Confernce, 2000. WCNC. 2000 IEEE
Conference_Location :
Chicago, IL
Print_ISBN :
0-7803-6596-8
DOI :
10.1109/WCNC.2000.904664
