Title :
A novel scheme for linear multiuser detection in asynchronous DS-CDMA systems with frequency selective fading
Author :
Uzmi, Zartash Afzal ; Mujtaba, Syed Aon
Author_Institution :
Dept. of Electr. Eng., Stanford Univ., CA, USA
fDate :
6/21/1905 12:00:00 AM
Abstract :
A novel scheme for linear multiuser detection (MUD) based on sub-symbol diversity is presented that is applicable to asynchronous CDMA systems with frequency selective fading. Traditional solutions for asynchronous linear MUD result in a prohibitively large decorrelation matrix. The new scheme transforms the asynchronous problem into a synchronous one by creating sub-symbols that are, by design, time-aligned with all other users and their respective multipath signals. The resulting decorrelation matrix is dramatically reduced in size, thus offering a viable solution for implementation. We also present an optimal scheme for combining the sub-symbols that is based on the condition number of the decorrelation matrices
Keywords :
AWGN; code division multiple access; decorrelation; diversity reception; fading channels; interference suppression; land mobile radio; matrix algebra; multipath channels; multiuser channels; radio receivers; radiofrequency interference; signal detection; spread spectrum communication; AWGN; RAKE receiver; asynchronous DS-CDMA systems; asynchronous linear MUD; condition number; decorrelation matrix; frequency selective fading; interference suppression; linear multiuser detection; mobile communications; multipath signals; multiple access interference; optimal scheme; sub-symbol diversity; sub-symbol diversity combining algorithms; synchronous problem; time-aligned sub-symbols; AWGN; Bit error rate; Decorrelation; Detectors; Fading; Frequency diversity; Multiaccess communication; Multiple access interference; Multiuser detection; Signal design;
Conference_Titel :
Global Telecommunications Conference, 1999. GLOBECOM '99
Conference_Location :
Rio de Janeireo
Print_ISBN :
0-7803-5796-5
DOI :
10.1109/GLOCOM.1999.830232
