Robust Wideband Beamforming by the Hybrid Steepest Descent Method

This paper uses the hybrid steepest descent method (HSDM) to design robust smart antennas. Several design criteria as well as robustness are mathematically described by a finite collection of closed convex sets in a real Euclidean space. Desirable beamformers are defined as points of the generalized convex feasible set which is well defined even in the case of inconsistent design criteria. A quadratic cost function is formed by the correlations of the incoming data, and the HSDM constructs a point sequence that (strongly) converges to the (unique) minimizer of the cost function over the generalized convex feasible set. Numerical examples validate the proposed design.

[1]  P. L. Combettes The foundations of set theoretic estimation , 1993 .

[2]  H. Stark,et al.  Wide-band smart antenna design using vector space projection methods , 2004, IEEE Transactions on Antennas and Propagation.

[3]  Masakazu Kojima,et al.  Numerical Evaluation of SDPA (Semidefinite Programming Algorithm) , 2000 .

[4]  Stephen P. Boyd,et al.  Antenna array pattern synthesis via convex optimization , 1997, IEEE Trans. Signal Process..

[5]  Michael T. Chryssomallis,et al.  Smart antennas , 2000 .

[6]  Heinz H. Bauschke,et al.  Projection algorithms and monotone operators , 1996 .

[7]  Boaz Porat,et al.  Digital Processing of Random Signals: Theory and Methods , 2008 .

[8]  Harry L. Van Trees,et al.  Optimum Array Processing: Part IV of Detection, Estimation, and Modulation Theory , 2002 .

[9]  Josef A. Nossek,et al.  Smart antennas , 2001, Eur. Trans. Telecommun..

[10]  E. Kreyszig Introductory Functional Analysis With Applications , 1978 .

[11]  Hein Hundal An alternating projection that does not converge in norm , 2004 .

[12]  Isao Yamada,et al.  Robust Capon Beamforming by the Adaptive Projected Subgradient Method , 2006, 2006 IEEE International Conference on Acoustics Speech and Signal Processing Proceedings.

[13]  I. Yamada The Hybrid Steepest Descent Method for the Variational Inequality Problem over the Intersection of Fixed Point Sets of Nonexpansive Mappings , 2001 .

[14]  Stephen P. Boyd,et al.  Convex Optimization , 2004, Algorithms and Theory of Computation Handbook.

[15]  Ovidio Mario Bucci,et al.  Power synthesis of conformal arrays by a generalised projection method , 1995 .

[16]  Patrick L. Combettes,et al.  Hard-constrained inconsistent signal feasibility problems , 1999, IEEE Trans. Signal Process..

[17]  Yongyi Yang,et al.  Vector Space Projections: A Numerical Approach to Signal and Image Processing, Neural Nets, and Optics , 1998 .

[18]  Dimitris G. Manolakis,et al.  Statistical and Adaptive Signal Processing: Spectral Estimation, Signal Modeling, Adaptive Filtering and Array Processing , 1999 .

[19]  Jian Li,et al.  On robust Capon beamforming and diagonal loading , 2003, 2003 IEEE International Conference on Acoustics, Speech, and Signal Processing, 2003. Proceedings. (ICASSP '03)..

[20]  Jos F. Sturm,et al.  A Matlab toolbox for optimization over symmetric cones , 1999 .

[21]  Heinz H. Bauschke,et al.  On Projection Algorithms for Solving Convex Feasibility Problems , 1996, SIAM Rev..

[22]  N. K. Bose,et al.  Digital filters: Theory and applications , 1985 .

[23]  Stephen P. Boyd,et al.  Robust minimum variance beamforming , 2003, The Thrity-Seventh Asilomar Conference on Signals, Systems & Computers, 2003.

[24]  Masakazu Kojima,et al.  SDPA (SemiDefinite Programming Algorithm) User's Manual Version 6.2.0 , 1995 .

[25]  Constantine A. Balanis,et al.  Antenna Theory: Analysis and Design , 1982 .

[26]  Wei Yu,et al.  An introduction to convex optimization for communications and signal processing , 2006, IEEE Journal on Selected Areas in Communications.

[27]  D. M. Pozar,et al.  Microstrip antennas , 1995, Proc. IEEE.

[28]  Hong-Kun Xu,et al.  Convergence of Hybrid Steepest-Descent Methods for Variational Inequalities , 2003 .

[29]  Billy E. Rhoades Quadratic optimization of fixed points for a family of nonexpansive mappings in Hilbert space , 2004 .

[30]  Boris Polyak,et al.  The method of projections for finding the common point of convex sets , 1967 .

[31]  Stephen P. Boyd,et al.  Applications of second-order cone programming , 1998 .

[32]  I. Yamada,et al.  The Adaptive Projected Subgradient Method over the Fixed Point Set of Strongly Attracting Nonexpansive Mappings , 2006 .

[33]  Mohammad Ghavami Wideband smart antenna theory using rectangular array structures , 2002, IEEE Trans. Signal Process..

[34]  Zhi-Quan Luo,et al.  Robust adaptive beamforming for general-rank signal models , 2003, IEEE Trans. Signal Process..

[35]  I. Yamada,et al.  Hybrid Steepest Descent Method for Variational Inequality Problem over the Fixed Point Set of Certain Quasi-nonexpansive Mappings , 2005 .

[36]  Yukawa Masahiro,et al.  Efficient robust adaptive beamforming by the Adaptive Projected Subgradient Method -- A set-theoretic time-varying approach over multiple a priori constraints , 2005 .

[37]  Zhi-Quan Luo,et al.  Robust adaptive beamforming using worst-case performance optimization: a solution to the signal mismatch problem , 2003, IEEE Trans. Signal Process..

[38]  Kevin Barraclough,et al.  I and i , 2001, BMJ : British Medical Journal.

[39]  Mokhtar S. Bazaraa,et al.  Nonlinear Programming: Theory and Algorithms , 1993 .