Title :
A fuzzy logic method for modulation classification in nonideal environments
Author :
Wei, Wen ; Mendel, Jerry M.
Author_Institution :
Signal & Image Process. Inst., Univ. of Southern California, Los Angeles, CA, USA
fDate :
6/1/1999 12:00:00 AM
Abstract :
In this paper, we present a fuzzy logic modulation classifier that works in nonideal environments in which it is difficult or impossible to use precise probabilistic methods. We first transform a general pattern classification problem into one of function approximation, so that fuzzy logic systems (FLS) can be used to construct a classifier; then, we introduce the concepts of fuzzy modulation type and fuzzy decision and develop a nonsingleton fuzzy logic classifier (NSFLC) by using an additive FLS as a core building block. Our NSFLC uses 2D fuzzy sets, whose membership functions are isotropic so that they are well suited for a modulation classifier (MC). We establish that our NSFLC, although completely based on heuristics, reduces to the maximum-likelihood modulation classifier (ML MC) in ideal conditions, In our application of NSFLC to MC in a mixture of α-stable and Gaussian noises, we demonstrate that our NSFLC performs consistently better than the ML MC and it gives the same performance as the ML MC when no impulsive noise is present
Keywords :
function approximation; fuzzy logic; fuzzy set theory; heuristic programming; maximum likelihood estimation; modulation; noise; pattern classification; α-stable noise; 2D fuzzy sets; FLS; Gaussian noise; ML MC; NSFLC; additive FLS; function approximation; fuzzy decision; fuzzy logic systems; fuzzy modulation type; heuristics; isotropic membership functions; maximum-likelihood modulation classifier; modulation classification; nonideal environments; nonsingleton fuzzy logic classifier; Additive noise; Function approximation; Fuzzy logic; Fuzzy sets; Fuzzy systems; Gaussian noise; Noise level; Pattern classification; Two dimensional displays; Working environment noise;
Journal_Title :
Fuzzy Systems, IEEE Transactions on