Title :
Linear multiuser transmission for CDMA with reduced computational complexity
Author :
Irmer, Ralf ; Gaur, Jayesh ; Fettweis, Gerhard
Author_Institution :
Dresden Univ. of Technol., Germany
Abstract :
CDMA system capacity is interference limited. Whereas for the uplink multiuser detection can be applied, for the downlink multiuser transmission (MUT) is required. Using channel knowledge, the transmit signal is jointly preprocessed in such a way that the performance in the receivers is optimized. Linear MUT methods like joint transmission (JT) or the transmit Wiener filter are computational intensive due to the inversion of the system matrix. Efficient algorithms are proposed and compared, such as the block tridiagonal algorithm or the band Cholesky algorithm. Approximations of the former and frequency-domain processing are also considered. The MUT complexity and performance is compared for TD-SCDMA.
Keywords :
3G mobile communication; Wiener filters; channel capacity; code division multiple access; computational complexity; matrix inversion; multiuser channels; optimisation; time division multiple access; CDMA; TD-SCDMA; band Cholesky algorithm; block tridiagonal algorithm; channel knowledge; code division multiple access; frequency-domain processing; joint transmission; linear multiuser transmission; performance optimization; receivers; reduced computational complexity; system capacity; system matrix inversion; third generation standards; transmit Wiener filter; transmit signal preprocessing; Computational complexity; Downlink; Frequency; Multiaccess communication; Multiple access interference; Multiuser detection; Receiving antennas; Time division synchronous code division multiple access; Transmitters; Wiener filter;
Conference_Titel :
Vehicular Technology Conference, 2004. VTC 2004-Spring. 2004 IEEE 59th
Print_ISBN :
0-7803-8255-2
DOI :
10.1109/VETECS.2004.1390503
