Performance of beam-combining scheme for DS-CDMA using weighting factor based on interference level

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.