Open Access

Selective Frequency Invariant Uniform Circular Broadband Beamformer

EURASIP Journal on Advances in Signal Processing20102010:678306

Received: 16 April 2009

Accepted: 3 December 2009

Published: 19 January 2010


Frequency-Invariant (FI) beamforming is a well known array signal processing technique used in many applications. In this paper, an algorithm that attempts to optimize the frequency invariant beampattern solely for the mainlobe, and relax the FI requirement on the sidelobe is proposed. This sacrifice on performance in the undesired region is traded off for better performance in the desired region as well as reduced number of microphones employed. The objective function is designed to minimize the overall spatial response of the beamformer with a constraint on the gain being smaller than a pre-defined threshold value across a specific frequency range and at a specific angle. This problem is formulated as a convex optimization problem and the solution is obtained by using the Second Order Cone Programming (SOCP) technique. An analysis of the computational complexity of the proposed algorithm is presented as well as its performance. The performance is evaluated via computer simulation for different number of sensors and different threshold values. Simulation results show that, the proposed algorithm is able to achieve a smaller mean square error of the spatial response gain for the specific FI region compared to existing algorithms.


Convex OptimizationConvex Optimization ProblemSignal Processing TechniqueSelective FrequencyPublisher Note

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Authors’ Affiliations

Center for Signal Processing, Nanyang Technological University, Singapore, Singapore
EADS Innovation Works, EADS Singapore Pte Ltd., Singapore, Singapore


© Xin Zhang et al. 2010

This article is published under license to BioMed Central Ltd. 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.