Title :
Multiuser detection in multirate DS/CDMA communications
Author :
Chen, Ming ; Li, Yueheng
Author_Institution :
Nat. Mobile Commun. Res. Lab., Southeast Univ., Nanjing, China
Abstract :
In this paper, multiuser detection in multirate long-code DS/CDMA systems is considered. Regarding the slower transmission rate of a symbol in the system as repeated transmission of the symbol at the fastest rate in the system, we reduce the multirate transmission model to a single-rate one with repeated transmission of symbols which can be viewed as a binary repetition code or a form of time-diversity signaling. Thus, traditional multiuser detection for single-rate encoded data can be applied. Several typical multiuser detection methods, such as decorrelating, MMSE and parallel interference cancellation (PIC), are investigated for multirate systems. An integrated preconditioned soft decision PIC (PSD-PIC) structure is proposed to improve the performance of partitioned decorrelating (or MMSE) multirate detector. Numerical simulations show that the performance of integrated PSD-PIC is better than that of integrated hard decision PIC (HD-PIC) for multirate systems
Keywords :
binary codes; cellular radio; code division multiple access; decorrelation; diversity reception; interference suppression; least mean squares methods; maximum likelihood detection; multiuser channels; radiofrequency interference; signal detection; spread spectrum communication; MMSE detector; binary repetition code; integrated PSD-PIC; integrated hard decision PIC; integrated preconditioned soft decision PIC; maximum likelihood detection; multirate DS/CDMA communications; multirate long-code; multirate transmission model; multiuser access interference; multiuser detection; numerical simulations; parallel interference cancellation; partitioned decorrelating multirate detector; performance; repeated symbol transmission; single-rate encoded data; third generation cellular mobile systems; time-diversity signaling; transmission rate; Decorrelation; Detectors; Interference cancellation; Maximum likelihood decoding; Maximum likelihood detection; Mobile communication; Multiaccess communication; Multiple access interference; Multiuser detection; Numerical simulation;
Conference_Titel :
MILCOM 2000. 21st Century Military Communications Conference Proceedings
Conference_Location :
Los Angeles, CA
Print_ISBN :
0-7803-6521-6
DOI :
10.1109/MILCOM.2000.905030
