Title :
Minimum mean-square error design of decorrelator detectors for QS-CDMA
Author :
Iltis, Ronald A.
Author_Institution :
Dept. of Electr. & Comput. Eng., California Univ., Santa Barbara, CA, USA
Abstract :
We consider a quasi-synchronous CDMA cellular system (QS-CDMA), in which all users attempt to transmit in synchrony using local GPS-derived clocks. A linear decorrelator detector for QS-CDMA is presented, which is designed according to a minimum mean-square error (MMSE) criterion. By using a time-averaged version of the interfering signal covariance matrix, it is shown that multiuser interference can be rejected without the need to estimate signal time-of-arrival. Furthermore, unlike previous MMSE receiver designs, estimation of the received signal covariance matrix is not required. Bit-error rate results are presented which demonstrate the superiority of the MMSE receiver compared with the conventional matched-filter detector under strong near-far conditions
Keywords :
approximation theory; cellular radio; code division multiple access; coding errors; correlation methods; covariance matrices; error statistics; interference suppression; land mobile radio; radiofrequency interference; signal detection; CDMA cellular system; GPS derived clocks; MMSE criterion; MMSE receiver design; QS-CDMA; bit error rate results; decorrelator detectors; interfering signal covariance matrix; linear decorrelator detector; matched filter detector; minimum mean-square error; minimum mean-square error design; multiuser interference rejection; near-far conditions; quasisynchronous CDMA; time-averaged version; Bit error rate; Code division multiplexing; Covariance matrix; Decorrelation; Delay; Detectors; Interference; Multiaccess communication; Signal design; Uncertainty;
Conference_Titel :
Military Communications Conference, 1995. MILCOM '95, Conference Record, IEEE
Conference_Location :
San Diego, CA
Print_ISBN :
0-7803-2489-7
DOI :
10.1109/MILCOM.1995.483543
