Title
Fully complex-valued radial basis function networks: Orthogonal least squares regression and classification
Abstract
We consider a fully complex-valued radial basis function (RBF) network for regression and classification applications. For regression problems, the locally regularised orthogonal least squares (LROLS) algorithm aided with the D-optimality experimental design, originally derived for constructing parsimonious real-valued RBF models, is extended to the fully complex-valued RBF (CVRBF) network. Like its real-valued counterpart, the proposed algorithm aims to achieve maximised model robustness and sparsity by combining two effective and complementary approaches. The LROLS algorithm alone is capable of producing a very parsimonious model with excellent generalisation performance while the D-optimality design criterion further enhances the model efficiency and robustness. By specifying an appropriate weighting for the D-optimality cost in the combined model selecting criterion, the entire model construction procedure becomes automatic. An example of identifying a complex-valued nonlinear channel is used to illustrate the regression application of the proposed fully CVRBF network. The proposed fully CVRBF network is also applied to four-class classification problems that are typically encountered in communication systems. A complex-valued orthogonal forward selection algorithm based on the multi-class Fisher ratio of class separability measure is derived for constructing sparse CVRBF classifiers that generalise well. The effectiveness of the proposed algorithm is demonstrated using the example of nonlinear beamforming for multiple-antenna aided communication systems that employ complex-valued quadrature phase shift keying modulation scheme.
Year
DOI
Venue
2008
10.1016/j.neucom.2007.12.003
Neurocomputing
Keywords
Field
DocType
classification,d optimal design,radial basis function,model selection,communication system,regression,radial basis function network
Beamforming,Mathematical optimization,Weighting,Nonlinear system,Radial basis function,Regression,Generalization,Communications system,Robustness (computer science),Artificial intelligence,Mathematics,Machine learning
Journal
Volume
Issue
ISSN
71
16-18
0925-2312
Citations 
PageRank 
References 
6
0.50
23
Authors
4
Name
Order
Citations
PageRank
Sheng Chen11035111.98
X. Hong215711.12
Chris J. Harris370066.65
Lajos Hanzo410889849.85