关键词: DS-CDMA系统, 自适应阵列, PN码捕获, 特征值分布

Abstract:

In this paper，we propose a novel antenna array system based on covariance matrix pair analysis，including PN synchronization followed by a beamforming process.Generally，conventional blind beamformers in DS-CDMA systems generally have either unreliable convergence rate or signal cancellation problems in practical signal environment.In our method，we use an orthogonal projection scheme to realize both the synchronization and beamforming，which requires neither the direction of the desired signal nor the array geometry information.Actually we are capable of acquiring antenna vector in the synchronization part，and constructing the corresponding beamformer as a by-product.The promising advantage of our scheme is that，by utilizing a small number of signal-free interference samples，the beamformer has a high convergence rate and is independent of signal strength.Simulation results prove that it has better performance than the pre and post correlation（PAPC）scheme and filter pair （FP）scheme，especially under strong multiple access interference（MAI）and jammings.

Key words: DS-CDMA system, adaptive antenna, PN code acquisition, eigenvalue distribution