Title
On the Circularity of a Complex Random Variable
Abstract
Abstract—An important characteristic of a complex random variable is the so-called circularity property or lack of it. We study the properties of the degree of circularity based on second-order moments, called circularity quotient, that is shown to possess an intuitive geometrical interpretation: the modulus and phase of its principal square-root are equal to the eccentricity and angle of orientation of the ellipse defined by the covariance matrix of the real and imaginary part of . Hence, when the eccentricity approaches the minimum zero (ellipse is a circle), the circularity quotient vanishes; when the eccentricity approaches the maximum one, the circularity quotient lies on the unit complex circle. Con- nection with the correlation coefficient is established and bounds on,given the circularity quotient (and vice versa) are derived. A generalized likelihood ratio test (GLRT) of circularity assuming complex normal sample is shown to be a function of the modulus of the circularity quotient with asymptotic distribution. Index Terms—Circularity coefficient, complex random variable, correlation coefficient, eccentricity, EVD, noncircular random variable.
Year
DOI
Venue
2008
10.1109/LSP.2008.2005050
IEEE Signal Process. Lett.
Keywords
Field
DocType
correlation methods,covariance matrices,geometry,random processes,asymptotic chi2 2 distribution,circularity property,circularity quotient,complex random variable,correlation coefficient,covariance matrix,eccentricity approach,generalized likelihood ratio test,intuitive geometrical interpretation,principal square-root,second-order moment,Circularity coefficient,EVD,complex random variable,correlation coefficient,eccentricity,noncircular random variable
Correlation coefficient,Random variable,Likelihood-ratio test,Eccentricity (behavior),Mathematical analysis,Quotient,Stochastic process,Covariance matrix,Ellipse,Mathematics
Journal
Volume
ISSN
Citations 
15
1070-9908
28
PageRank 
References 
Authors
1.38
9
1
Name
Order
Citations
PageRank
Esa Ollila135133.51