Partially Adaptive Beamformer Design with Performance Constraints
Abstract
Partially adaptive beamformers use only a subset of adaptive degrees of freedom to alleviate the computational burden and improve the convergence properties of adaptive algorithms for arrays with large numbers of sensors. However, reducing the number of adaptive degrees of freedom generally diminishes the beamformer's steady state interference cancellation capability. The goal of partially adaptive beamformer design is to choose a low dimensional adaptation space that provides acceptable steady state interference cancellation. Several design procedures have been proposed. Eigenstructure and beam based designs can result in excellent steady state interference cancellation, but often require an excessive number of adaptive weights. Power minimization designs attempt to minimize the average interference output power over a set of likely interference scenarios Q for a given adaptive dimension. Unfortunately this optimization problem is intractable so a suboptimal solution is proposed wherein each component of the adaptation space is optimized separately over a distinct subset of Q. Although good performance is obtained with relatively small numbers of adaptive weights, the procedure is not very systematic; the subsets of Q used to design individual components are selected through a hand-crafting trial and error process in order to obtain the best performance. Here we propose an alternate perspective to the design problem. Our objective is to minimize the number of adaptive degrees of freedom subject to a constraint on the worst case interference cancellation performance loss over a set of interference scenarios Q. Each component of the adaptation space is chosen to give fully adaptive performance at a specific interference scenario.... Adaptive beamforming, Interference cancellation, Partially adaptive beamformer designs.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1992
- Accession Number
- ADA260397
Entities
People
- Barry D. Van Veen
- Feng Qian
Organizations
- University of Wisconsin–Madison