Title :
Performance of beam-combining scheme for DS-CDMA using weighting factor based on interference level
Author :
Sano, Hiroyasu ; Murai, Hideshi ; Miyake, Makoto
Author_Institution :
Inf. Technol. R&D Center, Mitsubishi Electr. Corp., Kanagawa, Japan
Abstract :
In order to increase the link capacity of DS-CDMA, various multi-beam combining systems have been proposed. We focus our attention on the multi-beam combining scheme for a DS-CDMA system, which has RAKE combiners in multiple overlapped beams. It is a very attractive technique in the sense that the maximal ratio combining is carried out in the space and time domains. However, in a practical situation, since terminals in their own sector are not uniformly located, the interference levels in different beams are different. Therefore, the receivers at the base station do not achieve ideal combining. This paper proposes a multi-beam combining scheme for DS-CDMA using a weighting factor based on the interference level of each beam. The performance of the proposed scheme in the reverse link is evaluated by computer simulation. The results show that the proposed scheme has a good performance even if the terminals in their own sector are not uniformly located
Keywords :
array signal processing; cellular radio; channel capacity; code division multiple access; multiuser channels; radio links; radiofrequency interference; spread spectrum communication; DS-CDMA system; RAKE combiners; base station; beamforming; cellular radio; computer simulation; link capacity; maximal ratio combining; multi-beam combining systems; multiple access interference level; multiple overlapped beams; performance; reverse link; space domain; terminals; time domain; weighting factor; Base stations; Computer simulation; Diversity reception; Fading; Information technology; Linear antenna arrays; Multiaccess communication; Multiple access interference; RAKE receivers; Research and development;
Conference_Titel :
Vehicular Technology Conference, 1999. VTC 1999 - Fall. IEEE VTS 50th
Conference_Location :
Amsterdam
Print_ISBN :
0-7803-5435-4
DOI :
10.1109/VETECF.1999.798584