Direction of arrival estimation by array interpolation in randomly distributed sensor arrays

Akyıldız, Işın
In this thesis, DOA estimation using array interpolation in randomly distributed sensor arrays is considered. Array interpolation is a technique in which a virtual array is obtained from the real array and the outputs of the virtual array, computed from the real array using a linear transformation, is used for direction of arrival estimation. The idea of array interpolation techniques is to make simplified and computationally less demanding high resolution direction finding methods applicable to the general class of non-structured arrays.In this study,we apply an interpolation technique for arbitrary array geometries in an attempt to extend root-MUSIC algorithm to arbitrary array geometries.Another issue of array interpolation related to direction finding is spatial smoothing in the presence of multipath sources.It is shown that due to the Vandermonde structure of virtual array manifold vector obtained from the proposed interpolation method, it is possible to use spatial smoothing algorithms for the case of multipath sources.


Application of ODSA to population calculation
Ulukaya, Mustafa; Demirbaş, Kerim; Department of Electrical and Electronics Engineering (2006)
In this thesis, Optimum Decoding-based Smoothing Algorithm (ODSA) is applied to well-known Discrete Lotka-Volterra Model. The performance of the algorithm is investigated for various parameters by simulations. Moreover, ODSA is compared with the SIR Particle Filter Algorithm. The advantages and disadvantages of the both algorithms are presented.
Frame synchronization in OFDM systems
Gürsan, Hakan Yesari; Tuncer, Temel Engin; Department of Electrical and Electronics Engineering (2005)
In this thesis, we considered the problem of frame synchronization and channel estimation in Orthogonal Frequency Division Multiplexing (OFDM) systems. Since framing error may cause severe ISI and may disturb the orthogonality of the subcarriers, frame synchronization must be accomplished at the OFDM receiver. Furthermore, the effects of channel must be compensated to obtain the symbols accurately. We investigated several frame synchronization algorithms including a maximum likelihood (ML) synchronizer whic...
Implementation of a DF algorithm on an FPGA platform
İpek, Abdullah Volkan; Severcan, Mete; Department of Electrical and Electronics Engineering (2006)
In this thesis work, the implementations of the monopulse amplitude comparison and phase comparison DF algorithms are performed on an FPGA platform. After the mathematical formulation of the algorithms using maximum-likelihood approach is done, software simulations are carried out to validate and find the DF accuracies of the algorithms under various conditions. Then the algorithms are implemented on an FPGA platform by utilizing platform specific software tools. Block diagrams of the hardware implementatio...
Path extraction of low SNR dim targets from grayscale 2-D image sequences
Ergüven, Sait; Demirbaş, Kerim; Department of Electrical and Electronics Engineering (2006)
In this thesis, an algorithm for visual detecting and tracking of very low SNR targets, i.e. dim targets, is developed. Image processing of single frame in time cannot be used for this aim due to the closeness of intensity spectrums of the background and target. Therefore; change detection of super pixels, a group of pixels that has sufficient statistics for likelihood ratio testing, is proposed. Super pixels that are determined as transition points are signed on a binary difference matrix and grouped by 4-...
Analysis of circular waveguides coupled by axially uniform slots
Öztürk, Mensur; Çağlayan, Fatih; Department of Electrical and Electronics Engineering (2006)
The characteristics of slotted circular waveguides with different dimensions, including cutoff frequencies of TE and TM modes, impedance and modal field distributions will be analyzed using the generalized spectral domain approach. The Method of Moment will be applied, basis functions that include the edge conditions will be used and a computer program will be developed. Obtained results will be presented for different number, depth and thickness of coupling slots, and compared with available data to demons...
Citation Formats
I. Akyıldız, “Direction of arrival estimation by array interpolation in randomly distributed sensor arrays,” M.S. - Master of Science, Middle East Technical University, 2006.