Title :
Asymptotically optimal CDMA receiver: perfect MAI cancellation
Author_Institution :
Dept. of Electr. Eng., California Univ., Riverside, CA, USA
Abstract :
Multiple access interference (MAI) as well as multipath distortions are two major obstacles in multiuser communication. The MAI in the received data vectors can be eliminated by projecting the received data onto the subspace orthogonal to the code space of interfering users. After this operation, an equivalent single user model with AWGN is obtained. Therefore various detection techniques, e.g., maximum SNR, subspace, constrained optimization, iterative least squares with projection (ILSP), etc. can be successfully applied to estimate transmitted symbols and the multipath channel of the desired user, but with reduced complexity and asymptotically optimal performance. The proposed receiver is simulated by ILSP and constrained optimization method and its performance compared with the RAKE receiver and the decorrelating receiver. Much lower bit error probability is achieved for a wide range of SNRs
Keywords :
AWGN; code division multiple access; error statistics; interference suppression; least squares approximations; multipath channels; multiuser channels; optimisation; radio receivers; radiofrequency interference; signal detection; spread spectrum communication; AWGN; DS-CDMA; RAKE receiver; asymptotically optimal CDMA receiver; asymptotically optimal performance; bit error probability; code space; complexity reduction; constrained optimization; decorrelating receiver; detection techniques; iterative least squares with projection; maximum SNR; multipath channel; multipath distortion; multiple access interference; multiuser communication; multiuser detection; perfect MAI cancellation; received data vectors; single user model; subspace; transmitted symbols estimation; AWGN; Constraint optimization; Fading; Least squares approximation; Multiaccess communication; Multipath channels; Multiple access interference; Optimization methods; RAKE receivers; Subspace constraints;
Conference_Titel :
Wireless Communications and Networking Confernce, 2000. WCNC. 2000 IEEE
Conference_Location :
Chicago, IL
Print_ISBN :
0-7803-6596-8
DOI :
10.1109/WCNC.2000.904856