Sequence families with good correlation distribution

Tekin, Eda
In this thesis we focus on two main properties of sequences which have wide range of applications in code division multiple access: autocorrelation and cross-correlation. First, necessary properties of sequences, some known perfect autocorrelation sequences and some known sequence families with their cross-correlation properties are given. Then, a perfect autocorrelation sequence [18] is generalized with respect to a number theoretic constraint of n for a given prime power q. This generalization enables the designers to have more flexibility in terms of the deployment of these sequences. Later, a sequence family with low maximum correlation magnitude is constructed for an arbitrary even positive integer n and its correlation distribution is given. Gold-like sequence family [6] is generalized depending on a plateaued function f(x), for all possible p and n values and its correlation values are obtained. Finally, using Gold function as f(x), the generalized family’s correlation distribution is given depending on p and n. 


Correlation of sequences and quadratic forms
Genişel, Cansu; Özbudak, Ferruh; Tekin, Eda; Department of Cryptography (2017)
Sequences are widely used in code division multiple access communication systems. In a shared communication channel distinct sequences are assigned to distinct users. Low correlation sequences should be used in order to separate each user. In this thesis, quadratic forms and their properties are introduced. Sequence families constructed by quadratic forms and their correlations are studied. We give a construction of a binary sequence family when n = 3k and k is an odd integer. This sequence family has six- ...
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Yılmaztürk, Mehmet; Ulusoy Parnas, İlkay; Çiçekli, Fehime Nihan (Springer, Dordrecht; 2010-05-08)
Different from previous automatic but offline annotation systems, this paper studies automatic and online face annotation for personal videos/episodes of TV series considering Nearest Neighbourhood, LDA and SVM classification with Local Binary Patterns, Discrete Cosine Transform and Histogram of Oriented Gradients feature extraction methods in terms of their recognition accuracies and execution times. The best performing feature extraction method and the classifier pair is found out to be SVM classification...
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Tiku, Moti L.; İslam, Muhammed Qamarul; SAZAK, HAKAN SAVAŞ (Elsevier BV, 2008-01-01)
Data sets in numerous areas of application can be modelled by symmetric bivariate nonnormal distributions. Estimation of parameters in such situations is considered when the mean and variance of one variable is a linear and a positive function of the other variable. This is typically true of bivariate t distribution. The resulting estimators are found to be remarkably efficient. Hypothesis testing procedures are developed and shown to be robust and powerful. Real life examples are given.
Numerical implementation of magneto-acousto-electrical tomography (MAET) using a linear phased array transducer
GÖZÜ, Mehmet Soner; ZENGİN, Reyhan; Gençer, Nevzat Güneri (2018-02-01)
In this study, the performance and implementation of magneto-acousto-electrical tomography (MAET) is investigated using a linear phased array (LPA) transducer. The goal of MAET is to image the conductivity distribution in biological bodies. It uses the interaction between ultrasound and a static magnetic field to generate velocity current density distribution inside the body. The resultant voltage due to velocity current density is sensed by surface electrodes attached on the body. In this study, the theory...
Non-Binary LDPC Codes for Magnetic Recording Channels: Error Floor Analysis and Optimized Code Design
Hareedy, Ahmed; Amiri, Behzad; Galbraith, Rick; Dolecek, Lara (2016-08-01)
© 2016 IEEE.In this paper, we provide a comprehensive analysis of the error floor along with code optimization guidelines for structured and regular non-binary low-density parity-check (NB-LDPC) codes in magnetic recording (MR) applications. While the topic of the error floor performance of binary LDPC codes over additive white Gaussian noise (AWGN) channels has recently received considerable attention, very little is known about the error floor performance of NB-LDPC codes over other types of channels, des...
Citation Formats
E. Tekin, “Sequence families with good correlation distribution,” Ph.D. - Doctoral Program, Middle East Technical University, 2016.