Title :
Linear multiuser detectors for quasi-synchronous CDMA systems
Author :
Iltis, Ronald A. ; Mailaender, Laurence
Author_Institution :
Dept. of Electr. & Comput. Eng., California Univ., Santa Barbara, CA, USA
fDate :
31 Oct-2 Nov 1994
Abstract :
A linear decorrelator detector is proposed for a quasi-synchronous code-division multiple-access (QS-CDMA) cellular system. It is assumed that each of N users has a GPS generated local clock and attempts to transmit in synchrony with the other users in its cell. The base station thus receives N signature waveforms which are approximately synchronized, but with a small timing error due to local oscillator drift and Doppler shifts. The residual timing offset is discretized, and a decorrelator is constructed which attempts to reject the multiuser interference vectors corresponding to the set of possible offsets. Bounds and analytical results for the bit error rate (BER) are obtained for various interferer conditions
Keywords :
Doppler effect; Doppler shift; cellular radio; code division multiple access; error statistics; interference suppression; land mobile radio; radiofrequency interference; signal detection; synchronisation; Doppler shifts; GPS generated local clock; analytical results; base station; bit error rate; bounds; cellular system; code-division multiple-access; linear decorrelator detector; linear multiuser detectors; local oscillator drift; multiuser interference vectors rejection; quasi-synchronous CDMA systems; residual timing offset; signature waveforms; small timing error; Base stations; Bit error rate; Clocks; Decorrelation; Detectors; Global Positioning System; Local oscillators; Multiaccess communication; Synchronization; Timing;
Conference_Titel :
Signals, Systems and Computers, 1994. 1994 Conference Record of the Twenty-Eighth Asilomar Conference on
Conference_Location :
Pacific Grove, CA
Print_ISBN :
0-8186-6405-3
DOI :
10.1109/ACSSC.1994.471426
