95 / 2016-01-17 16:32:35

Efficient Weight Matrix Measurement for Beam-Forming Network based on DS-CDMA

9166,9167,9168,9169

The high performance of spatial signal processing techniques relies on accurate beamforming. In a practical antenna system, there exists an inconsistency between the designed Beam-forming Network (BFN) Weighted Matrix (WM) and the actual value of it due to some inevitable random errors. However, as the number of the input and output channels of BFN increases, the measurement of the BFN WM requires troublesome repeat measurements. To solve the problem, this paper proposes a novel efficient WM measurement method for BFN based on Direct Sequence-Code Division Multiple Access (DS-CDMA), which significantly reduces the efforts and time of the test by multi-port testing and parallel signal processing. Moreover, benefiting from the correlation characteristics of Direct Sequence Spread Spectrum (DSSS) signals, the measurement precision of the proposed method achieves 0.1dB in amplitude and 1° in phase. The paper also discusses the imperfection of the proposed method, i.e., the acquisition difficulty of orthogonal codes. Fortunately, by borrowing the concept of Multi-User Detection (MUD) we provide a decorrelation algorithm to tackle this problem. Hardware implementation and practical tests have strongly demonstrated the feasibility and accuracy of the method.