Title :
An EM Technique for Multiple Transmitter Localization
Author :
Nelson, Jill K. ; Gupta, Maya R.
Author_Institution :
George Mason Univ., Fairfax
Abstract :
We propose an expectation-maximization (EM) technique for locating multiple transmitters based on power levels observed by a set of arbitrarily-placed receivers. Multiple transmitter localization is of interest for uncoordinated cognitive radio systems, which must identify and transmit over unused radio spectrum without cooperation from conventional transmitters. We employ the EM algorithm to reduce the dimensionality of the maximum-likelihood estimation problem. Because the EM algorithm finds only a locally optimal solution, we explore the use of clustering to generate "smart" initial estimates of the transmitter locations. Simulation results show that, as the number of sensors increases, the proposed EM technique achieves gains of up to an order of magnitude over constricted particle swarm optimization, a popular global optimization technique.
Keywords :
cognitive radio; expectation-maximisation algorithm; radio receivers; radio transmitters; EM technique; arbitrarily-placed receivers; expectation-maximization technique; maximum-likelihood estimation problem; multiple transmitter localization; smart initial estimates; uncoordinated cognitive radio systems; unused radio spectrum; Bandwidth; Clustering algorithms; Cognitive radio; Frequency; Interference; Power measurement; Radio transmitters; Radiofrequency identification; Receivers; Wireless sensor networks;
Conference_Titel :
Information Sciences and Systems, 2007. CISS '07. 41st Annual Conference on
Conference_Location :
Baltimore, MD
Print_ISBN :
1-4244-1063-3
Electronic_ISBN :
1-4244-1037-1
DOI :
10.1109/CISS.2007.4298380