A novel two-dimensional space-time processing scheme for DS/CDMA code acquisition

In the literature [1], a novel adaptive filtering scheme is proposed which can perform beamforming and code acquisition simultaneously. Compared with the conventional correlator-based approach, the mean acquisition time of the proposed approach is much shorter. However, we find that the spatial filter and temporal filter weights are not unique in the proposed scheme; theoretical analysis and computer simulation show there are undesired trivial solutions which are related with the PN code sequence's time domain and frequency domain structure. Inspired by this literature, we propose a novel two-dimensional space-time processing scheme in this paper. The proposed scheme performs beamforming and code acquisition simultaneously like the approach in [1], but can avoid the undesired trivial solutions. For the additive white Gaussian noise (AWGN) channel scenario, we obtain the closed-form expression for optimum filter weights and propose an adaptive implementation algorithm for the proposed structure.