Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2010, Article ID 873916, 7 pages doi: Research Article Robust Adaptive Beamforming for Multiple Signals of Interest with Cycle Frequency Error Ju-Hong Lee1 and Chia-Cheng Huang2 1 Department of Electrical Engineering, Graduate Institute of Communication Engineering, and Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei 10617, Taiwan 2 Graduate Institute of Communication Engineering, National Taiwan University, Taipei 10617, Taiwan Correspondence should be addressed to Ju-Hong Lee, juhong@ Received 3 September 2010; Revised 6 December 2010; Accepted 10 December 2010 Academic Editor: Enrico Capobianco Copyright © 2010 . Lee and | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2010 Article ID 873916 7 pages doi 2010 873916 Research Article Robust Adaptive Beamforming for Multiple Signals of Interest with Cycle Frequency Error Ju-Hong Lee1 and Chia-Cheng Huang2 department of Electrical Engineering Graduate Institute of Communication Engineering and Graduate Institute of Biomedical Electronics and Bioinformatics National Taiwan University Taipei 10617 Taiwan 2 Graduate Institute of Communication Engineering National Taiwan University Taipei 10617 Taiwan Correspondence should be addressed to Ju-Hong Lee juhong@ Received 3 September 2010 Revised 6 December 2010 Accepted 10 December 2010 Academic Editor Enrico Capobianco Copyright 2010 . Lee and . Huang. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. This paper deals with the problem of robust adaptive array beamforming by exploiting the signal cyclostationarity. Recently a novel cyclostationarity-exploiting beamforming method has been proposed by . Lee and . Huang 2009 for dealing with the situation of multiple signals of interest SOI based on the LS-SCORE algorithm. This method is referred to as the multiple LS-SCORE MLS-SCORE algorithm. However the MLS-SCORE algorithm suffers from severe performance degradation even if there is a small mismatch in the cycle frequencies of the SOIs. In this paper we evaluate the performance of the MLS-SCORE algorithm in the presence of cycle frequency error CFE . The output SINR of an adaptive beamforming using the MLS-SCORE algorithm deteriorates like a sinc function as the number of data snapshots increases. To tackle this difficulty we present an efficient method to find an appropriate estimate for each of the cycle frequencies of the SOIs iteratively to achieve robust
