Title :
Channel-shortening multiuser detector for DS-CDMA systems
Author :
Medvedev, Irina ; Tarokh, Vahid
Author_Institution :
Lab. for Inf. & Decision Syst., MIT, Cambridge, MA, USA
Abstract :
The multiple-access interference (MAI) encountered by direct-sequence code-division multiple access (DS-CDMA) users in a multipath environment is a key issue in the detection of mobile communication users. MAI is one of the major reasons for the degradation in performance of multiuser communication systems over single user systems. Although the optimum detection technique, maximum-likelihood sequence estimation (MLSE), is well known, its complexity is exponential with the number of users, which makes it computationally unattractive. This paper presents a multiuser detector that performs close to the optimum MLSE while drastically reducing the decoding complexity. The detection technique is based on a channel shortening algorithm and allows for group detection of a subset of the users via MLSE
Keywords :
cellular radio; code division multiple access; computational complexity; maximum likelihood detection; maximum likelihood sequence estimation; multipath channels; multiuser channels; radiofrequency interference; spread spectrum communication; DS-CDMA systems; channel shortening algorithm; decoding complexity; direct-sequence code-division multiple access; maximum-likelihood sequence estimation; mobile communication; multipath environment; multiple-access interference; multiuser detector; wireless cellular phone environment; AWGN; Additive white noise; Degradation; Detectors; Direct-sequence code-division multiple access; Gaussian noise; Maximum likelihood detection; Maximum likelihood estimation; Multiaccess communication; Multiple access interference;
Conference_Titel :
Vehicular Technology Conference, 2001. VTC 2001 Spring. IEEE VTS 53rd
Conference_Location :
Rhodes
Print_ISBN :
0-7803-6728-6
DOI :
10.1109/VETECS.2001.945011
