DocumentCode :
1895753
Title :
Synchronization algorithms for iterative demodulated M-ary DS-CDMA systems
Author :
Xiao, Pei ; StröM, Erik
Author_Institution :
Commun. Syst. Group, Chalmers Univ. of Technol., Goteborg, Sweden
Volume :
2
fYear :
2001
fDate :
2001
Firstpage :
1371
Abstract :
In this paper, we developed several algorithms to combat the impact of synchronization errors on demodulating M-ary orthogonal signaling formats in asynchronous DS-CDMA systems. The system under study resembles the uplink of an IS-95 system. The channel is assumed to be a time-varying flat Rayleigh-fading channel. Investigation shows that synchronization errors severely deteriorate the performance of multi-user detectors. We proposed an adaptive algorithm to estimate the errors in synchronization. Based on this information, remedial actions are taken to alleviate the performance degradation caused by sampling the received signals at the incorrect timing. Simulation results show considerable capacity gains when the proposed algorithms are performed to erroneously sampled signals
Keywords :
Rayleigh channels; cellular radio; channel capacity; code division multiple access; demodulation; interference suppression; iterative methods; spread spectrum communication; synchronisation; time-varying channels; IS-95 system; M-ary DS-CDMA systems; Rayleigh channel; adaptive algorithm; asynchronous systems; capacity gains; flat fading channel; incorrect timing; iterative demodulated systems; multiuser detectors; orthogonal signaling formats; synchronization algorithms; synchronization errors; time-varying channel; uplink; Channel estimation; Degradation; Delay estimation; Fading; Interference cancellation; Interference suppression; Iterative algorithms; Multiaccess communication; Multiple access interference; Robustness;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Global Telecommunications Conference, 2001. GLOBECOM '01. IEEE
Conference_Location :
San Antonio, TX
Print_ISBN :
0-7803-7206-9
Type :
conf
DOI :
10.1109/GLOCOM.2001.965713
Filename :
965713
Link To Document :
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