Robust MVDR Beamforming via Polynomial Rooting Calibration for CDMA Signals

Ann-Chen CHANG  Chun HSU  Ing-Jiunn SU  

Publication
IEICE TRANSACTIONS on Communications   Vol.E90-B   No.11   pp.3298-3302
Publication Date: 2007/11/01
Online ISSN: 1745-1345
DOI: 10.1093/ietcom/e90-b.11.3298
Print ISSN: 0916-8516
Type of Manuscript: LETTER
Category: Wireless Communication Technologies
Keyword: 
polynomial rooting,  pointing error,  minimum variance distortionless response,  code-division multiple access,  multiple access interference,  

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Summary: 
This letter deals with adaptive array beamforming based on a minimum variance distortionless response (MVDR) technique with robust capabilities for code-division multiple access signals. It has been shown that the MVDR beamformer suffers from the drawback of being very sensitive to pointing error over the eigenspace-based beamformers. For the purpose of efficient estimation and calibration, a highly efficient approach has been proposed that is implemented on polynomial rooting rather than spectral searching. However, this rooting method is suboptimal in the presence of the noise and multiple access interference (MAI). In this letter, we propose an improved polynomial rooting calibration method that is robust in both of the low signal-to-noise ratio and large MAI scenarios. Several computer simulations are provided for illustrating the effectiveness of the proposed method.