A Multi-Beam Combining Scheme for DS-CDMA Systems Using Weighting Factor Based on Interference Level

Hiroyasu SANO  Nobuhisa KATAOKA  Hiroshi KUBO  Makoto MIYAKE  

Publication
IEICE TRANSACTIONS on Communications   Vol.E84-B   No.5   pp.1328-1336
Publication Date: 2001/05/01
Online ISSN: 
DOI: 
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Wireless Communication Technology
Keyword: 
multi-beam combining,  multipath fading,  interference level,  weighting factor,  

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Summary: 
This paper focuses on a multi-beam combining scheme for DS-CDMA systems, which has RAKE combiners in multiple overlapped beams, in order to increase the reverse link capacity of DS-CDMA. This scheme is a very attractive technique because the maximal ratio combining (MRC) is carried out in space and time domains. However, in a practical situation, since the terminals in own sector are not uniformly located, the interference levels in respective beams are different. Therefore, receivers at the base station do not achieve ideal combining. This paper proposes a multi-beam combining scheme for DS-CDMA systems using weighting factor based on interference level of each beam. A fast closed loop transmission power control (TPC) scheme for the multi-beam combining system is also proposed. It is confirmed by computer simulation that the proposed scheme has excellent performance in the reverse link even if terminals in own sector are not uniformly located.