volume | PIER Journals

Abstract

Generalized sidelobe canceller (GSC) based adaptive beamformer possesses a main advantage of superior interference rejection due to its capability in tracking the interference characteristics. However, its performance is very sensitive to even a small mismatch in array scenarios. For example, the mismatch due to mutual coupling between array sensors is a common phenomenon in practical environments. Two common problems considered are as follows. (1) The existing adaptive array beamformers are very sensitive to MCE. (2) The existing robust methods inevitably suffer from the problems, including additional computational complexity and estimate accuracy. In this paper, we present an efficient method to deal with the performance degradation induced by the MCE to achieve robust beamforming. The proposed method simply utilizes a well-known scheme, namely the zero-forcing (ZF) equalizer. The ZF equalizer simply preprocesses the data vector received by the antenna array and then inputs the processed data vector into a GSC based adaptive array processor. The combination of a ZF equalizer and a GSC based adaptive array processor results in an adaptive array beamformer providing satisfactory beamforming performance in the presence of the MCE. The performance analysis regarding the proposed method is analyzed. Simulation results are also presented for confirmation and comparison. The simulation results show that the ZF equalizer alleviates the MCE and the GSC based adaptive beamformer can subdue the background noise enhanced by ZF equalizer.

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Mr. Cheng-Jie Wang

Prof. Ju-Hong Lee