Adaptive Beamforming to Overcome Coherent Interferences and Steering Errors

Jin-Hee JO  Sung-Hoon MOON  Dong-Seog HAN  Myeong-Je CHO  

Publication
IEICE TRANSACTIONS on Communications   Vol.E87-B   No.4   pp.873-879
Publication Date: 2004/04/01
Online ISSN: 
DOI: 
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Wireless Communication Technology
Keyword: 
adaptive array,  coherent interference,  steering error,  split polarity transform,  

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Summary: 
A sequentially and linearly constrained minimum variance beamformer (SLCMV), based on a split polarity transformation (SPT) and, called an SPT-SLCMV beamformer, is proposed to minimize the degree of freedom loss, steering error, and a desired signal elimination phenomenon under coherent interferences. The SPT-SLCMV beamformer reduces the degree of freedom loss, which is inevitable in the conventional SPT-LCMV beamformer, by successively applying sub-constraint matrices. Sub-constraint matrices are derived from a complete constraint matrix to remove the correlation between the desired signal and interferences. In addition, the SPT-SLCMV beamformer is combined with the iterative steering error correction method to reduce the steering error between the look direction of the beamformer and the incident angle of the desired signal. As a result, the proposed beamformer reduces the number of array elements while maintaining the performance of an exactly steered SPT-LCMV beamformer having sufficient array elements under coherent interferences.