In this paper generation of binary sequences derived from chaotic sequences defined over Z4 is proposed.
The six chaotic map equations considered in this paper are Logistic map, Tent Map, Cubic Map, Quadratic
Map and Bernoulli Map. Using these chaotic map equations, sequences over Z4 are generated which are
converted to binary sequences using polynomial mapping. Segments of sequences of different lengths are
tested for cross correlation and linear complexity properties. It is found that some segments of different
length of these sequences have good cross correlation and linear complexity properties. The Bit Error Rate
performance in DS-CDMA communication systems using these binary sequences is found to be better than
Gold sequences and Kasami sequences.
1. The document presents a new approach for steganography detection using a combination of Fisher's linear discriminant function (FLD) and radial basis function neural network (RBF).
2. In the training phase, FLD is used to project high-dimensional image data onto a lower dimensional space, then an RBF network is trained to classify images as containing hidden data or not.
3. Experiments show the combined FLD-RBF method provides promising results for steganography detection compared to existing supervised methods, though extracting the hidden information remains challenging.
PERFORMANCE ASSESSMENT OF CHAOTIC SEQUENCE DERIVED FROM BIFURCATION DEPENDENT...IJCNCJournal
In CDMA system, m-sequence and Gold codes are often utilized for spreading-despreading and
scrambling-descrambling operations. In a previous work, a design framework was created for generating
large family of codes from logistic map, which have comparable autocorrelation and cross correlation to
m-sequence and Gold codes. The purpose of this work is to evaluate the performance of these chaotic
codes in a CDMA environment. In the bit error rate (BER) simulation, matched filter, decorrelator and
MMSE receiver have been utilized. The received signal was modelled for synchronous CDMA uplink for
simulation simplicity purpose. Additive White Gaussian Noise channel model was assumed for the
simulation.
AN EFFICIENT PARALLEL ALGORITHM FOR COMPUTING DETERMINANT OF NON-SQUARE MATRI...ijdpsjournal
One of the most significant challenges in Computing Determinant of Rectangular Matrices is high time
complexity of its algorithm. Among all definitions of determinant of rectangular matrices, Radic’s
definition has special features which make it more notable. But in this definition, C(N
M
) sub matrices of the
order m×m needed to be generated that put this problem in np-hard class. On the other hand, any row or
column reduction operation may hardly lead to diminish the volume of calculation. Therefore, in this paper
we try to present the parallel algorithm which can decrease the time complexity of computing the
determinant of non-square matrices to O(N).
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
A design of parity check matrix for short irregular ldpc codes via magicIAEME Publication
This document summarizes a research paper that proposes a new algorithm called the Magic Square Based Algorithm (MSBA) to construct parity check matrices for short irregular low-density parity-check (LDPC) codes. The MSBA applies concepts from magic squares to implicitly generate the cyclic shifts in the parity check matrix in a structured way, rather than using random generation. Simulation results show that codes constructed with the MSBA can achieve a bit error rate of 10-4 at a signal-to-noise ratio of 5 dB with a moderate number of decoding iterations.
A landing gear assembly consists of various components viz. Lower side stay, Upperside stay, Locking actuators, Extension actuators, Tyres, and Locking pins to name a few. Each unit having a specific operation to deal with, in this project the main unit being studied is the lower brace. The primary objective is to analyse stresses in the element of the lower brace unit using strength of materials or RDM method and Finite Element Method (FEM) and compare both. Using the obtained data a suitable material is proposed for the component. The approach used here is to study the overall behaviour of the element by taking up each aspect, finally summing up the total effect of all the aspects in the functioning of the element.
This document summarizes a directed research report on using singular value decomposition (SVD) to reconstruct images with missing pixel values. It describes how images can be represented as matrices and SVD is commonly used for matrix completion problems. The report explores using an alternating least squares (ALS) algorithm based on SVD to fill in missing pixel values by finding feature matrices that approximate the rank k reconstruction of an image matrix. The ALS algorithm works by alternating between optimizing one feature matrix while holding the other fixed, minimizing the reconstruction error between the known pixel values and predicted values from multiplying the feature matrices.
This document discusses principal component analysis (PCA) and its applications in image processing and facial recognition. PCA is a technique used to reduce the dimensionality of data while retaining as much information as possible. It works by transforming a set of correlated variables into a set of linearly uncorrelated variables called principal components. The first principal component accounts for as much of the variability in the data as possible, and each succeeding component accounts for as much of the remaining variability as possible. The document provides an example of applying PCA to a set of facial images to reduce them to their principal components for analysis and recognition.
1. The document presents a new approach for steganography detection using a combination of Fisher's linear discriminant function (FLD) and radial basis function neural network (RBF).
2. In the training phase, FLD is used to project high-dimensional image data onto a lower dimensional space, then an RBF network is trained to classify images as containing hidden data or not.
3. Experiments show the combined FLD-RBF method provides promising results for steganography detection compared to existing supervised methods, though extracting the hidden information remains challenging.
PERFORMANCE ASSESSMENT OF CHAOTIC SEQUENCE DERIVED FROM BIFURCATION DEPENDENT...IJCNCJournal
In CDMA system, m-sequence and Gold codes are often utilized for spreading-despreading and
scrambling-descrambling operations. In a previous work, a design framework was created for generating
large family of codes from logistic map, which have comparable autocorrelation and cross correlation to
m-sequence and Gold codes. The purpose of this work is to evaluate the performance of these chaotic
codes in a CDMA environment. In the bit error rate (BER) simulation, matched filter, decorrelator and
MMSE receiver have been utilized. The received signal was modelled for synchronous CDMA uplink for
simulation simplicity purpose. Additive White Gaussian Noise channel model was assumed for the
simulation.
AN EFFICIENT PARALLEL ALGORITHM FOR COMPUTING DETERMINANT OF NON-SQUARE MATRI...ijdpsjournal
One of the most significant challenges in Computing Determinant of Rectangular Matrices is high time
complexity of its algorithm. Among all definitions of determinant of rectangular matrices, Radic’s
definition has special features which make it more notable. But in this definition, C(N
M
) sub matrices of the
order m×m needed to be generated that put this problem in np-hard class. On the other hand, any row or
column reduction operation may hardly lead to diminish the volume of calculation. Therefore, in this paper
we try to present the parallel algorithm which can decrease the time complexity of computing the
determinant of non-square matrices to O(N).
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
A design of parity check matrix for short irregular ldpc codes via magicIAEME Publication
This document summarizes a research paper that proposes a new algorithm called the Magic Square Based Algorithm (MSBA) to construct parity check matrices for short irregular low-density parity-check (LDPC) codes. The MSBA applies concepts from magic squares to implicitly generate the cyclic shifts in the parity check matrix in a structured way, rather than using random generation. Simulation results show that codes constructed with the MSBA can achieve a bit error rate of 10-4 at a signal-to-noise ratio of 5 dB with a moderate number of decoding iterations.
A landing gear assembly consists of various components viz. Lower side stay, Upperside stay, Locking actuators, Extension actuators, Tyres, and Locking pins to name a few. Each unit having a specific operation to deal with, in this project the main unit being studied is the lower brace. The primary objective is to analyse stresses in the element of the lower brace unit using strength of materials or RDM method and Finite Element Method (FEM) and compare both. Using the obtained data a suitable material is proposed for the component. The approach used here is to study the overall behaviour of the element by taking up each aspect, finally summing up the total effect of all the aspects in the functioning of the element.
This document summarizes a directed research report on using singular value decomposition (SVD) to reconstruct images with missing pixel values. It describes how images can be represented as matrices and SVD is commonly used for matrix completion problems. The report explores using an alternating least squares (ALS) algorithm based on SVD to fill in missing pixel values by finding feature matrices that approximate the rank k reconstruction of an image matrix. The ALS algorithm works by alternating between optimizing one feature matrix while holding the other fixed, minimizing the reconstruction error between the known pixel values and predicted values from multiplying the feature matrices.
This document discusses principal component analysis (PCA) and its applications in image processing and facial recognition. PCA is a technique used to reduce the dimensionality of data while retaining as much information as possible. It works by transforming a set of correlated variables into a set of linearly uncorrelated variables called principal components. The first principal component accounts for as much of the variability in the data as possible, and each succeeding component accounts for as much of the remaining variability as possible. The document provides an example of applying PCA to a set of facial images to reduce them to their principal components for analysis and recognition.
IRJET- An Efficient Reverse Converter for the Three Non-Coprime Moduli Set {4...IRJET Journal
This paper proposes a new and efficient reverse converter for converting residue numbers to decimal numbers for the three moduli set {6, 10, 15} which shares the common factor of 5. The proposed converter replaces larger multipliers used in previous converters with smaller multipliers and adders, reducing the hardware requirements. The hardware implementation of the proposed converter is presented and compared to other state-of-the-art converters, showing it performs better with fewer adders and multipliers. The proposed converter efficiently implements reverse conversion for the non-coprime three moduli set while requiring less hardware than previous approaches.
Implementation performance analysis of cordiciaemedu
This document discusses the implementation of a CORDIC (COordinate Rotation Digital Computer) algorithm in an OFDM-based wireless local area network receiver. It first provides background on the CORDIC algorithm and its basic principles. It then describes the design of an OFDM-based WLAN transmitter in MATLAB that provides phase angle values to a CORDIC module. This CORDIC module is implemented using VHDL and analyzes the phase angles to compute sine and cosine functions. Simulation results show that the VHDL-implemented CORDIC produces the same output waveforms as MATLAB, validating the accuracy of the hardware implementation.
Finding Neighbors in Images Represented By Quadtreeiosrjce
In this paper, we propose an algorithm for neighbors finding in images represented by quadtree data
structure. We first present a scheme for addressing image pixels that takes into account the order defined on a
quadtree blocks. We study various properties of this method, and then we develop a formula that establishes
links between quadtree blocks. Based on these results, we present an efficient algorithm that generates the list of
location codes of all possible neighbors, in all directions, for a given block of the quadtree.
The document provides a course calendar for a class on Bayesian estimation methods. It lists the dates and topics to be covered over 15 class periods from September to January. The topics progress from basic concepts like Bayes estimation and the Kalman filter, to more modern methods like particle filters, hidden Markov models, Bayesian decision theory, and applications of principal component analysis and independent component analysis. One class is noted as having no class.
A new algorithm is presented which determines the dimensionality and signature of a measured space. The
algorithm generalizes the Map Maker’s algorithm
from 2D to n dimensions and works the same for 2D
measured spaces as the Map Maker’s algorithm but with better efficiency. The difficulty of generalizing the
geometric approach of the Map Maker’s algorithm from 2D to 3D and then to higher dimensions is
avo
ided by using this new approach. The new algorithm preserves all distances of the distance matrix and
also leads to a method for building the curved space as a subset of the N
-
1 dimensional embedding space.
This algorithm has direct application to Scientif
ic Visualization for data viewing and searching based on
Computational Geometry.
Illustration Clamor Echelon Evaluation via Prime Piece PsychotherapyIJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
Tensor representations in signal processing and machine learning (tutorial ta...Tatsuya Yokota
Tutorial talk in APSIPA-ASC 2020.
Title: Tensor representations in signal processing and machine learning.
Introduction to tensor decomposition (テンソル分解入門)
Basics of tensor decomposition (テンソル分解の基礎)
The document provides information about computer graphics output primitives like points and lines. It discusses how points and lines are displayed on different output devices like raster and vector systems. It also describes algorithms for drawing lines, including the Digital Differential Analyzer (DDA) algorithm and Bresenham's line drawing algorithm, which uses only incremental integer calculations to determine pixel positions along a line path.
This document provides a course calendar for a machine learning course with the following contents:
- The course covers topics like Bayesian estimation, Kalman filters, particle filters, hidden Markov models, Bayesian decision theory, principal component analysis, independent component analysis, and clustering algorithms over 13 classes between September and January.
- One lecture plan discusses nonparametric density estimation approaches like histogram density estimation, kernel density estimation, and k-nearest neighbor density estimation. It also covers cross-validation techniques.
- Another document section provides an example of applying kernel density estimation and k-nearest neighbor classification to automatically sort fish based on lightness, including discussing training and test phase classification. It compares different bandwidths and values of k.
EXTENDED K-MAP FOR MINIMIZING MULTIPLE OUTPUT LOGIC CIRCUITSVLSICS Design
This paper proposes an extended Karnaugh map (K-map) technique for minimizing multiple output logic circuits using a single K-map. The algorithm accumulates the minterms of multiple functions into a single K-map. Clusters are generated from the extended K-map and popped from a stack to obtain the minimized Boolean expressions for each output function. Experimental results on circuits with up to 5 variables and outputs show the extended K-map approach is more space efficient than using multiple standard K-maps. A complexity analysis indicates the extended K-map uses O(2n) space compared to O(k*2n) for k functions using standard K-maps.
The document contains data and results from a finite element analysis case study involving two cases. MATLAB software was used to solve the cases. The summary includes:
1) Tables of node coordinate and element connectivity data are provided for Cases 1 and 2, along with the results of the finite element analysis showing displacements and stresses.
2) Questions are posed about how renumbering the nodes would affect the structural stiffness matrix and computational efficiency.
3) The algorithm used by the skyline function to calculate half bandwidths is described.
This document discusses different approaches to identifying clusters or "assemblages" in graph data. It defines assemblages as dense subgraphs with more internal than external connections. Several algorithms are described for finding assemblages, including k-medoids, Newman-Girvan, Louvain, and MCL. Evaluation metrics like modularity and weighted community clustering are also covered. The document aims to explain how to analyze real-world network data to discover meaningful assemblages.
This document discusses using principal component analysis (PCA) and the discrete cosine transform (DCT) to recognize images from a database. It explains how bitmaps store image data, DCT compacts image energy, and PCA reduces dimensionality by finding the principal components via eigenvectors of the covariance matrix. An algorithm is proposed that uses DCT, PCA on a 3x3 block, characteristic equations to find the maximum eigenvector, and least mean square comparison to recognize queries against the database images.
The method of identifying similar groups of data in a data set is called clustering. Entities in each group are comparatively more similar to entities of that group than those of the other groups.
This document provides a summary of a lecture on simulation-based Bayesian estimation methods, specifically particle filters. It begins by explaining why simulation-based methods are needed for nonlinear and non-Gaussian problems where analytical solutions are not possible. It then discusses Monte Carlo sampling methods including historical examples, Monte Carlo integration to approximate integrals, and importance sampling to generate samples from a target distribution. The key steps of importance sampling are outlined.
Optimising Data Using K-Means Clustering AlgorithmIJERA Editor
K-means is one of the simplest unsupervised learning algorithms that solve the well known clustering problem. The procedure follows a simple and easy way to classify a given data set through a certain number of clusters (assume k clusters) fixed a priori. The main idea is to define k centroids, one for each cluster. These centroids should be placed in a cunning way because of different location causes different result. So, the better choice is to place them as much as possible far away from each other.
This document provides an overview of dimensionality reduction techniques including PCA and manifold learning. It discusses the objectives of dimensionality reduction such as eliminating noise and unnecessary features to enhance learning. PCA and manifold learning are described as the two main approaches, with PCA using projections to maximize variance and manifold learning assuming data lies on a lower dimensional manifold. Specific techniques covered include LLE, Isomap, MDS, and implementations in scikit-learn.
2012 mdsp pr12 k means mixture of gaussiannozomuhamada
The document provides the course calendar and lecture plan for a machine learning course. The course calendar lists the class dates and topics to be covered from September to January, including Bayes estimation, Kalman filters, particle filters, hidden Markov models, Bayesian decision theory, principal component analysis, and clustering algorithms. The lecture plan focuses on clustering methods, including k-means clustering, mixtures of Gaussians models, and using the expectation-maximization (EM) algorithm to estimate the parameters of Gaussian mixture models.
This document discusses face recognition using Fisher face analysis (LDA). It provides an overview of LDA and how it is used for face recognition. LDA works by finding a linear transformation that maximizes between-class variance and minimizes within-class variance to achieve better class separation. The document outlines the LDA algorithm which involves computing within-class and between-class scatter matrices to find discriminant vectors that project faces into a space where classes are well separated. It also mentions the ORL face database is used and provides references for further information.
A SURVEY ON UNDULATORY MOTION BASED ROBOTIC FISH DESIGNcaijjournal
Robotic fish design (Biomimetic) is an upcoming research area in which undulation motion has its own set
of parameters to decide its efficiency. To analyse its swimming efficiency several existing robotic models
using undulation motion have been thoroughly studied and few critical parameters such as fin size, shape,
flexibility of material, fin flapping rate etc., have been identified. After simulating the above critical
parameters using a MATLAB based CFD tool, mainly to design prototypes for research purpose which
concentrates on optimizing its swimming efficiency. Several combinations of critical parameters are
discussed for robotic fish prototype design by identifying critical parameters and maximizing the swimming
efficiency of robotic fish based on the above properties. The fin models have been tested using Matlab
based CFD tool through simulation and the swimming speed, direction have also been tested for various
models. An improved benchmark for designing robotic fish model is proposed in order to simplify selection
of components, architecture, and cost involve.
In today’s network-based cloud computing era, software applications are playing big role. The security of these software applications is paramount to the successful use of these applications. These applications utilize cryptographic algorithms to secure the data over the network through encryption and decryption
processes. The use of parallel processors is now common in both mobile and cloud computing scenarios.
Cryptographic algorithms are compute intensive and can significantly benefit from parallelism. This paper
introduces a parallel approach to symmetric stream cipher security algorithm known as RC4A, which is
one of the strong variants of RC4. We present an efficient parallel implementation to the compute intensive
PRGA that is pseudo-random generation algorithm portion of the RC4A algorithm and the resulted
algorithm will be named as PARC4-I. We have added some functionality in terms of lookup tables.
Modified algorithm is having four lookup tables instead of two and is capable of returning four distinct
output bytes at each iteration. Further, with the help of Parallel Additive Stream Cipher Structure and loop
unrolling method, encryption/decryption is being done on multi core machine. Finally, the results shows
that PARC4-I is a time efficient algorithm.
IRJET- An Efficient Reverse Converter for the Three Non-Coprime Moduli Set {4...IRJET Journal
This paper proposes a new and efficient reverse converter for converting residue numbers to decimal numbers for the three moduli set {6, 10, 15} which shares the common factor of 5. The proposed converter replaces larger multipliers used in previous converters with smaller multipliers and adders, reducing the hardware requirements. The hardware implementation of the proposed converter is presented and compared to other state-of-the-art converters, showing it performs better with fewer adders and multipliers. The proposed converter efficiently implements reverse conversion for the non-coprime three moduli set while requiring less hardware than previous approaches.
Implementation performance analysis of cordiciaemedu
This document discusses the implementation of a CORDIC (COordinate Rotation Digital Computer) algorithm in an OFDM-based wireless local area network receiver. It first provides background on the CORDIC algorithm and its basic principles. It then describes the design of an OFDM-based WLAN transmitter in MATLAB that provides phase angle values to a CORDIC module. This CORDIC module is implemented using VHDL and analyzes the phase angles to compute sine and cosine functions. Simulation results show that the VHDL-implemented CORDIC produces the same output waveforms as MATLAB, validating the accuracy of the hardware implementation.
Finding Neighbors in Images Represented By Quadtreeiosrjce
In this paper, we propose an algorithm for neighbors finding in images represented by quadtree data
structure. We first present a scheme for addressing image pixels that takes into account the order defined on a
quadtree blocks. We study various properties of this method, and then we develop a formula that establishes
links between quadtree blocks. Based on these results, we present an efficient algorithm that generates the list of
location codes of all possible neighbors, in all directions, for a given block of the quadtree.
The document provides a course calendar for a class on Bayesian estimation methods. It lists the dates and topics to be covered over 15 class periods from September to January. The topics progress from basic concepts like Bayes estimation and the Kalman filter, to more modern methods like particle filters, hidden Markov models, Bayesian decision theory, and applications of principal component analysis and independent component analysis. One class is noted as having no class.
A new algorithm is presented which determines the dimensionality and signature of a measured space. The
algorithm generalizes the Map Maker’s algorithm
from 2D to n dimensions and works the same for 2D
measured spaces as the Map Maker’s algorithm but with better efficiency. The difficulty of generalizing the
geometric approach of the Map Maker’s algorithm from 2D to 3D and then to higher dimensions is
avo
ided by using this new approach. The new algorithm preserves all distances of the distance matrix and
also leads to a method for building the curved space as a subset of the N
-
1 dimensional embedding space.
This algorithm has direct application to Scientif
ic Visualization for data viewing and searching based on
Computational Geometry.
Illustration Clamor Echelon Evaluation via Prime Piece PsychotherapyIJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
Tensor representations in signal processing and machine learning (tutorial ta...Tatsuya Yokota
Tutorial talk in APSIPA-ASC 2020.
Title: Tensor representations in signal processing and machine learning.
Introduction to tensor decomposition (テンソル分解入門)
Basics of tensor decomposition (テンソル分解の基礎)
The document provides information about computer graphics output primitives like points and lines. It discusses how points and lines are displayed on different output devices like raster and vector systems. It also describes algorithms for drawing lines, including the Digital Differential Analyzer (DDA) algorithm and Bresenham's line drawing algorithm, which uses only incremental integer calculations to determine pixel positions along a line path.
This document provides a course calendar for a machine learning course with the following contents:
- The course covers topics like Bayesian estimation, Kalman filters, particle filters, hidden Markov models, Bayesian decision theory, principal component analysis, independent component analysis, and clustering algorithms over 13 classes between September and January.
- One lecture plan discusses nonparametric density estimation approaches like histogram density estimation, kernel density estimation, and k-nearest neighbor density estimation. It also covers cross-validation techniques.
- Another document section provides an example of applying kernel density estimation and k-nearest neighbor classification to automatically sort fish based on lightness, including discussing training and test phase classification. It compares different bandwidths and values of k.
EXTENDED K-MAP FOR MINIMIZING MULTIPLE OUTPUT LOGIC CIRCUITSVLSICS Design
This paper proposes an extended Karnaugh map (K-map) technique for minimizing multiple output logic circuits using a single K-map. The algorithm accumulates the minterms of multiple functions into a single K-map. Clusters are generated from the extended K-map and popped from a stack to obtain the minimized Boolean expressions for each output function. Experimental results on circuits with up to 5 variables and outputs show the extended K-map approach is more space efficient than using multiple standard K-maps. A complexity analysis indicates the extended K-map uses O(2n) space compared to O(k*2n) for k functions using standard K-maps.
The document contains data and results from a finite element analysis case study involving two cases. MATLAB software was used to solve the cases. The summary includes:
1) Tables of node coordinate and element connectivity data are provided for Cases 1 and 2, along with the results of the finite element analysis showing displacements and stresses.
2) Questions are posed about how renumbering the nodes would affect the structural stiffness matrix and computational efficiency.
3) The algorithm used by the skyline function to calculate half bandwidths is described.
This document discusses different approaches to identifying clusters or "assemblages" in graph data. It defines assemblages as dense subgraphs with more internal than external connections. Several algorithms are described for finding assemblages, including k-medoids, Newman-Girvan, Louvain, and MCL. Evaluation metrics like modularity and weighted community clustering are also covered. The document aims to explain how to analyze real-world network data to discover meaningful assemblages.
This document discusses using principal component analysis (PCA) and the discrete cosine transform (DCT) to recognize images from a database. It explains how bitmaps store image data, DCT compacts image energy, and PCA reduces dimensionality by finding the principal components via eigenvectors of the covariance matrix. An algorithm is proposed that uses DCT, PCA on a 3x3 block, characteristic equations to find the maximum eigenvector, and least mean square comparison to recognize queries against the database images.
The method of identifying similar groups of data in a data set is called clustering. Entities in each group are comparatively more similar to entities of that group than those of the other groups.
This document provides a summary of a lecture on simulation-based Bayesian estimation methods, specifically particle filters. It begins by explaining why simulation-based methods are needed for nonlinear and non-Gaussian problems where analytical solutions are not possible. It then discusses Monte Carlo sampling methods including historical examples, Monte Carlo integration to approximate integrals, and importance sampling to generate samples from a target distribution. The key steps of importance sampling are outlined.
Optimising Data Using K-Means Clustering AlgorithmIJERA Editor
K-means is one of the simplest unsupervised learning algorithms that solve the well known clustering problem. The procedure follows a simple and easy way to classify a given data set through a certain number of clusters (assume k clusters) fixed a priori. The main idea is to define k centroids, one for each cluster. These centroids should be placed in a cunning way because of different location causes different result. So, the better choice is to place them as much as possible far away from each other.
This document provides an overview of dimensionality reduction techniques including PCA and manifold learning. It discusses the objectives of dimensionality reduction such as eliminating noise and unnecessary features to enhance learning. PCA and manifold learning are described as the two main approaches, with PCA using projections to maximize variance and manifold learning assuming data lies on a lower dimensional manifold. Specific techniques covered include LLE, Isomap, MDS, and implementations in scikit-learn.
2012 mdsp pr12 k means mixture of gaussiannozomuhamada
The document provides the course calendar and lecture plan for a machine learning course. The course calendar lists the class dates and topics to be covered from September to January, including Bayes estimation, Kalman filters, particle filters, hidden Markov models, Bayesian decision theory, principal component analysis, and clustering algorithms. The lecture plan focuses on clustering methods, including k-means clustering, mixtures of Gaussians models, and using the expectation-maximization (EM) algorithm to estimate the parameters of Gaussian mixture models.
This document discusses face recognition using Fisher face analysis (LDA). It provides an overview of LDA and how it is used for face recognition. LDA works by finding a linear transformation that maximizes between-class variance and minimizes within-class variance to achieve better class separation. The document outlines the LDA algorithm which involves computing within-class and between-class scatter matrices to find discriminant vectors that project faces into a space where classes are well separated. It also mentions the ORL face database is used and provides references for further information.
A SURVEY ON UNDULATORY MOTION BASED ROBOTIC FISH DESIGNcaijjournal
Robotic fish design (Biomimetic) is an upcoming research area in which undulation motion has its own set
of parameters to decide its efficiency. To analyse its swimming efficiency several existing robotic models
using undulation motion have been thoroughly studied and few critical parameters such as fin size, shape,
flexibility of material, fin flapping rate etc., have been identified. After simulating the above critical
parameters using a MATLAB based CFD tool, mainly to design prototypes for research purpose which
concentrates on optimizing its swimming efficiency. Several combinations of critical parameters are
discussed for robotic fish prototype design by identifying critical parameters and maximizing the swimming
efficiency of robotic fish based on the above properties. The fin models have been tested using Matlab
based CFD tool through simulation and the swimming speed, direction have also been tested for various
models. An improved benchmark for designing robotic fish model is proposed in order to simplify selection
of components, architecture, and cost involve.
In today’s network-based cloud computing era, software applications are playing big role. The security of these software applications is paramount to the successful use of these applications. These applications utilize cryptographic algorithms to secure the data over the network through encryption and decryption
processes. The use of parallel processors is now common in both mobile and cloud computing scenarios.
Cryptographic algorithms are compute intensive and can significantly benefit from parallelism. This paper
introduces a parallel approach to symmetric stream cipher security algorithm known as RC4A, which is
one of the strong variants of RC4. We present an efficient parallel implementation to the compute intensive
PRGA that is pseudo-random generation algorithm portion of the RC4A algorithm and the resulted
algorithm will be named as PARC4-I. We have added some functionality in terms of lookup tables.
Modified algorithm is having four lookup tables instead of two and is capable of returning four distinct
output bytes at each iteration. Further, with the help of Parallel Additive Stream Cipher Structure and loop
unrolling method, encryption/decryption is being done on multi core machine. Finally, the results shows
that PARC4-I is a time efficient algorithm.
This paper deals with different loss mechanisms within the single mode fiber (SMF) in optical fiber communication. A number of mechanisms are responsible for the signal attenuation within optical fibers. As the optical signal propagates over long stretch of fiber, it becomes attenuated because of absorption,
scattering, fiber bends by material impurities, and other effects. The transmission using high bandwidth
can handle vast amounts of information, which can be further improved by reduction in fiber losses,
increase in data rates and distances, and using appropriate operating wavelength in optical fiber communication. The recent development in the area of fiber optic communication as well as the advances in different fiber types and their properties such as attenuation or loss and bandwidth are also discussed in this paper. The performance improvement of the proposed different loss, such as Rayleigh scattering, Stimulated Brillouin Scattering (SBS), Stimulated Raman Scattering (SRS), and bending loss within the various loss mechanisms in fiber optic communication is shown through simulations.
In this paper, we examine WiMAX – based network and evaluate the performance for quality of service (QoS) using an idea of IEEE 802.16 technology. In our models, the study used a multiprocessor architecture organized by the interconnection network. OPNET Modeler is used to simulate the architecture and to calculate the performance criteria (i.e. throughput, delay and data dropped) that
slightly concerned in network estimation. It is concluded that our models shorten the time quite a bit for
obtaining the performance measures of an end-to-end delay as well as throughput can be used as an
effective tool for this purpose.
Telemedicine; use of telecommunication and information technological services, which permits the
communication between the users with convenience and fidelity, as well transmitting medical, images and
health informatics data. Numerous image processing applications like Satellite Imaging, Medical Imaging
and Video has images with too large size or stream size, with a large amount of space or high bandwidth
for communication in its original form. Integrity of the transmitted medical images and the informatics
data, without any compromise in the data is an essential product of telecommunication and information
technology. A colossal need for an adequate compression methodology, in adoption for the compression of
medical images /data, to domicile for various metrics like high bandwidth, resolution factors, storage of the
images/data, the obligation to perpetuate the validity and precision of data for subsequent perceived
diagnosis transactions. This leverages exacting coercions on the restoration error. In this paper we survey
the literature related to the Image Processing Methodologies based on ROI technique/s for Digital Imaging
and Communication for Medicine (DICOM). A scrutiny as such persuades with the several congestions
related to prospective techniques of lossless compression, recommending for a better and a unique image
compression technique.
People who have problems with talking, in general, are facing difficulty in communication with others,
these disabilities may cause embarrassment to them. Therefore, we have developed a new tool that could
help speechless people to share their ideas and conversations with others. This tool will overcome these
problems by turning sign language into spoken words, allowing easier communication with others. This
project based on hardware device that convert Sign Language to voice. So, the person who cannot speck
could be able to use it to transfer his sign to voice. The tool can be used by wearing the special hardware
which consists of the smart gloves, a speaker and the interpreter box. Indeed, the sign language only used
by speechless people so it’s not clear to anyone , so this tool convert the sign language to voice throw
smart gloves that will understand the sign, and generate voice throw speaker .
Zinc supplementation may reduce the risk of hepatocellular carcinoma using bi...caijjournal
Hepatocellular carcinoma (HCC) is a primary liver cancer with poor survival rates. Gene expression data
of HCC are investigated to screen target genes and core genes, which are employed to propose a new
strategy for the treatment of HCC. New concepts such as gene data streams, gene characteristic strength
(CS), gene impact factor (GIF) and gene force (GF) are proposed. Together with gene community network
(GCN), a novel algorithm, that is, called gene force algorithm (GFA), is presented to screen feature genes,
target genes and core genes. The fifteen target genes are obtained, which can be divided into three
clustering sets including HAMP Cluster = {HAMP, Trans, AQP4, VIPR1}, MT Cluster ={MT1H, MT1B,
MT1G, MT1E, MTIL, RNAHP, DNASE1L3} and GPC3 Cluster ={GPC3}. The core genes of each clusters
are HAMP, Metallothionein genes (MTs) and GPC3 respectively, where MTs is a general name for a group
of metallothionein genes. According to the relationship between the three core genes and the metals
including copper, iron and zinc, a treatment strategy for HCC is proposed, namely, "Supplement Zinc after
surgery" for HCC patients. The proposed treatment method can be used to regulate the expression levels of
HCC core genes.
Low level features for image retrieval basedcaijjournal
In this paper, we present a novel approach for image retrieval based on extraction of low level features
using techniques such as Directional Binary Code (DBC), Haar Wavelet transform and Histogram of
Oriented Gradients (HOG). The DBC texture descriptor captures the spatial relationship between any pair
of neighbourhood pixels in a local region along a given direction, while Local Binary Patterns (LBP)
descriptor considers the relationship between a given pixel and its surrounding neighbours. Therefore,
DBC captures more spatial information than LBP and its variants, also it can extract more edge
information than LBP. Hence, we employ DBC technique in order to extract grey level texture features
(texture map) from each RGB channels individually and computed texture maps are further combined
which represents colour texture features (colour texture map) of an image. Then, we decomposed the
extracted colour texture map and original image using Haar wavelet transform. Finally, we encode the
shape and local features of wavelet transformed images using Histogram of Oriented Gradients (HOG) for
content based image retrieval. The performance of proposed method is compared with existing methods on
two databases such as Wang’s corel image and Caltech 256. The evaluation results show that our
approach outperforms the existing methods for image retrieval.
TOPOLOGY DISCOVERY IN MULTI-HOP CLUSTERING VEHICULAR NETWORKScaijjournal
In this paper, we propose a novel multi-hop cluster architecture for location service protocol in vehicular ad
hoc networks. The proposed scheme uses two parameters which are the connectivity between vehicles and the
vehicle mobility to select cluster head. The performance of the proposed scheme is the tradeoff between the
vehicle locations and the communication overheads. The proposed scheme is not only scalable but also
reliable and is able to achieve high load balancing with fast convergence. The cluster constructed by the
proposed scheme is more stable than exiting vehicular ad hoc network clustering schemes. Specifically, the
proposed scheme can increase the cluster-head lifetime up to 50%. The reason behind this achievement is
that the proposed scheme considers vehicle mobility in terms of average link expiration time while selecting
cluster-head.
Model driven process for real time embeddedcaijjournal
Embedded systems shape our world nowadays. It’s almost impossible to imagine our day to day life without
it. Examples can include cell phones, home appliances, energy generators, satellites, automotive
components …etc. it is even far more complex if there are real-time and interface constraints.
Developing real-time embedded systems is significantly challenging to developers. Results need not be only
correct, but also in a timely manner. New software development approaches are needed due to the
complexity of functional and non-functional requirements of embedded systems.
Due to the complex context of embedded systems, defects can cause life threatening situations. Delays can
create huge costs, and insufficient productivity can impact the entire industry. The rapid evolution of
software engineering technologies will be a key factor in the successful future development of even more
complex embedded systems.
Software development is shifting from manual programming, to model-driven engineering (MDE). One of
the most important challenges is to manage the increasing complexity of embedded software development,
while maintaining the product’s quality, reducing time to market, and reducing development cost.
MDE is a promising approach that emerged lately. Instead of directly coding the software using
programming languages, developers model software systems using expressive, graphical notations, which
provide a higher abstraction level than programming languages. This is called Model Based Development
(MBD).
Model Based Development if accompanied by Model Based Validation (MBV), will help identify problems
early thus reduce rework cost. Applying tests based on the designed models not only enable early detection
of defects, but also continuous quality assurance. Testing can start in the first iteration of the development
process.
As a result of the model based approach, and in addition to the major advantage of early defects detection,
several time consuming tasks within the classical software development life cycle will be excluded. For
embedded systems development, it’s really important to follow a more time efficient approach.
Collaborative learning with think pair -caijjournal
Today is a knowledge age so that world needs to become a more richer palace for everyone. Students can
learn their lectures and students can do their exercises on the web as individually or collaboratively with
their peers like directed by the teacher by using the think-pair-share technique. The system provides the
ability to clear to decide on their choices about the questions. The K-means clustering method is used to
modify the pair state and support for determining students’ grade of classes. The main objective of this
study is to design a model for java programming learning system that facilitates the collaborative learning
activities in a virtual classroom.
Digital Restaurant Menu is an application that replaces paper menus with tablets to enhance the dining experience for customers. It aims to reduce wait times, decrease staff workloads, and increase profits for businesses. The app allows restaurants to easily update menus, call servers, generate business reports, translate menus, share promotions, place and pay bills digitally. It concludes that the digital app can improve customer satisfaction and boost the restaurant and hotel industries.
IOSR Journal of Electronics and Communication Engineering(IOSR-JECE) is an open access international journal that provides rapid publication (within a month) of articles in all areas of electronics and communication engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electronics and communication engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Performance Assessment of Polyphase Sequences Using Cyclic Algorithmrahulmonikasharma
Polyphase Sequences (known as P1, P2, Px, Frank) exist for a square integer length with good auto correlation properties are helpful in the several applications. Unlike the Barker and Binary Sequences which exist for certain length and exhibits a maximum of two digit merit factor. The Integrated Sidelobe level (ISL) is often used to define excellence of the autocorrelation properties of given Polyphase sequence. In this paper, we present the application of Cyclic Algorithm named CA which minimizes the ISL (Integrated Sidelobe Level) related metric which in turn improve the Merit factor to a greater extent is main thing in applications like RADAR, SONAR and communications. To illustrate the performance of the P1, P2, Px, Frank sequences when cyclic Algorithm is applied. we presented a number of examples for integer lengths. CA(Px) sequence exhibits the good Merit Factor among all the Polyphase sequences that are considered.
Super-resolution reconstruction is a method for reconstructing higher resolution images from a set of low resolution observations. The sub-pixel differences among different observations of the same scene allow to create higher resolution images with better quality. In the last thirty years, many methods for creating high resolution images have been proposed. However, hardware implementations of such methods are limited. Wiener filter design is one of the techniques we will use initially for this process. Wiener filter design involves matrix inversion. A novel method for the matrix inversion has been proposed in the report. QR decomposition will be the computational algorithm used using Givens Rotation.
This document summarizes a research paper that proposes a novel architecture for implementing a 1D lifting integer wavelet transform (IWT) using residue number system (RNS). The key aspects covered are:
1) RNS offers advantages over binary representations for digital signal processing by avoiding carry propagation. A ROM-based approach is proposed for RNS division.
2) The lifting scheme for discrete wavelet transforms is summarized, including split, predict, and update stages.
3) A novel RNS-based architecture is proposed using three main blocks - split, predict, and update - that repeat at each decomposition level. Pipelined implementations of the predict and update blocks are detailed.
This document proposes a new method for designing dynamical key-dependent S-boxes based on two chaotic maps: the 2D logistic map and 2D cross map. The method uses these chaotic maps to generate integer values that are inserted into an S-box table. Each byte of an encrypted message is then substituted using this dynamically generated S-box. The generated S-boxes are analyzed based on criteria like avalanche effect, strict avalanche effect, key sensitivity, and resistance to differential and linear cryptanalysis. Results show the proposed method can create secure dynamical S-boxes suitable for use in block ciphers.
The key is the important part at any security system because it determines whether the system is strength or weakness. This paper aimed to proposed new way to generate keystream based on a combination between 3D Henoun map and 3D Cat map. The principle of the method consists in generating random numbers by using 3D Henon map and these numbers will transform to binary sequence. These sequence positions is permuted and Xoredusing 3D Cat map. The new key stream generator has successfully passed theNIST statistical test suite. The security analysisshows that it has large key space and its very sensitive initial conditions.
Time of arrival based localization in wireless sensor networks a non linear ...sipij
In this paper, we aim to obtain the location information of a sensor node deployed in a Wireless Sensor Network (WSN). Here, Time of Arrival based localization technique is considered. We calculate the position information of an unknown sensor node using the non- linear techniques. The performances of the techniques are compared with the Cramer Rao Lower bound (CRLB). Non-linear Least Squares and the Maximum Likelihood are the non-linear techniques that have been used to estimate the position of the unknown sensor node. Each of these non-linear techniques are iterative approaches, namely, Newton
Raphson estimate, Gauss Newton Estimate and the Steepest Descent estimate for comparison. Based on the
results of the simulation, the approaches have been compared. From the simulation study, Localization
based on Maximum Likelihood approach is having higher localization accuracy.
This document discusses shape functions in the finite element method. Shape functions are used to interpolate values within discrete elements. Linear shape functions are defined for a bar element that linearly interpolate deformation values between nodes. Quadratic shape functions are also presented, which use a third mid-side node and quadratic interpolation. Strain-displacement and stress-strain relationships are derived for the bar element using these shape functions. The document explains that shape functions form the basis for approximating continuous models with discrete elements in finite element analysis.
CONCURRENT TERNARY GALOIS-BASED COMPUTATION USING NANO-APEX MULTIPLEXING NIBS...VLSICS Design
This document summarizes a research article that proposes a novel method for implementing ternary Galois logic functions using three-dimensional lattice networks with carbon-based field emission devices. Specifically:
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- The document reviews fundamentals of ternary Shannon and Davio expansions that are used to formally synthesize the three-dimensional lattice networks. Joining rules are defined to realize non-symmetric functions using variable repetition.
- Carbon field emission devices are proposed to implement the basic controlled switch building block using nano
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Novel realizations of concurrent computations utilizing three-dimensional lattice networks and their
corresponding carbon-based field emission controlled switching is introduced in this article. The
formalistic ternary nano-based implementation utilizes recent findings in field emission and nano
applications which include carbon-based nanotubes and nanotips for three-valued lattice computing via
field-emission methods. The presented work implements multi-valued Galois functions by utilizing
concurrent nano-based lattice systems, which use two-to-one controlled switching via carbon-based field
emission devices by using nano-apex carbon fibers and carbon nanotubes that were presented in the first
part of the article. The introduced computational extension utilizing many-to-one carbon field-emission
devices will be further utilized in implementing congestion-free architectures within the third part of the
article. The emerging nano-based technologies form important directions in low-power compact-size
regular lattice realizations, in which carbon-based devices switch less-costly and more-reliably using
much less power than silicon-based devices. Applications include low-power design of VLSI circuits for
signal processing and control of autonomous robots.
IMAGE ENCRYPTION BASED ON DIFFUSION AND MULTIPLE CHAOTIC MAPSIJNSA Journal
This document proposes an image encryption algorithm that uses diffusion and multiple chaotic maps. It begins by generating subkeys using chaotic logistic maps. The image is then encrypted using one subkey via logistic map transformation, diffusing the image. Additional subkeys are generated from four chaotic maps by hopping through various map orbits. The image is treated as a 1D array via raster and zigzag scanning, divided into blocks, and those blocks undergo position permutation and value transformation controlled by the chaotic subkeys, fully encrypting the image. Decryption reverses the process using the same subkeys.
The Geometric Characteristics of the Linear Features in Close Range Photogram...IJERD Editor
The accuracy of photogrammetry can be increased with better instruments, careful geometric
characteristics of the system, more observations and rigorous adjustment. The main objective of this research is
to develop a new mathematical model of two types of linear features (straight line, spline curve) in addition to
relating linear features in object space to the image space using the Direct Linear Transformation (DLT). The
second main objective of the present paper is to study of some geometric characteristics of the system, when the
linear features are used in close range photogrammetric reduction processes. In this research, the accuracy
improvement has been evaluated by adopting certain assessment criteria, this will be performed by computing
the positional discrepancies between the photogrammetrically calculated object space coordinates of some check
object points, with the original check points of the test field, in terms of their respective RMS errors values. In
addition, the resulting least squares estimated covariance matrices of the check object point's space coordinates.
To perform the above purposes, some experiments are performed with synthetic images. The obtained results
showed significant improvements in the positional accuracy of close range photogrammetry, when starting node,
end nodes, and interior node on straight line and spline curve are increased with certain specifications regarding
the location and magnitude of each type of them.
CONCURRENT TERNARY GALOIS-BASED COMPUTATION USING NANO-APEX MULTIPLEXING NIBS...VLSICS Design
Novel layout realizations for congestion-free three-dimensional lattice networks using the corresponding
carbon-based field emission controlled switching is introduced in this article. The developed nano-based
implementations are performed in three dimensions to perform the required concurrent computations for
which two-dimensional implementations are a special case. The introduced realizations for congestion-free
concurrent computations utilize the field-emission controlled switching devices that were presented in the
first and second parts of the article for the solution of synthesis congestion and by utilizing field-emission
from carbon nanotubes and nanotips. Since the concept of symmetry indices has been related to regular
logic design, a more general method called Iterative Symmetry Indices Decomposition that produces
regular three-dimensional lattice networks via carbon field-emission multiplexing is presented, where one
obtains multi-stage decompositions whenever volume-specific layout constraints have to be satisfied. The
introduced congestion-free nano-based lattice computations form new and important paths in regular
lattice realizations, where applications include low-power IC design for the control of autonomous robots
and for signal processing implementations.
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International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
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Macromodel of High Speed Interconnect using Vector Fitting Algorithmijsrd.com
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Performance evaluation of ds cdma
1. Computer Applications: An International Journal (CAIJ), Vol.2, No.1, February 2015
DOI : 10.5121/caij.2015.2104 37
PERFORMANCE EVALUATION OF DS-CDMA
SYSTEM USING CHAOTIC BINARY SEQUENCES
Mahalinga V. Mandi 1
, K. N. Hari Bhat 2
and R. Murali 3
1
Associate Professor, Department of Electronics & Communication Engineering, Dr.
Ambedkar Institute of Technology, INDIA.
2
Dean Academic, Professor & Head, Department of Electronics & Communication
Engineering, Nagarjuna College of Engineering & Technology, INDIA.
3
Professor, Department of Mathematics, Dr. Ambedkar Institute of Technology,
INDIA.
ABSTRACT
In this paper generation of binary sequences derived from chaotic sequences defined over Z4 is proposed.
The six chaotic map equations considered in this paper are Logistic map, Tent Map, Cubic Map, Quadratic
Map and Bernoulli Map. Using these chaotic map equations, sequences over Z4 are generated which are
converted to binary sequences using polynomial mapping. Segments of sequences of different lengths are
tested for cross correlation and linear complexity properties. It is found that some segments of different
length of these sequences have good cross correlation and linear complexity properties. The Bit Error Rate
performance in DS-CDMA communication systems using these binary sequences is found to be better than
Gold sequences and Kasami sequences.
KEYWORDS
DS-CDMA, Chaos, Chaotic map, Polynomial mapping
1. INTRODUCTION
A chaotic map xn+1 = F(xn) is typically a non-linear discrete dynamical iteration equation, which
exhibits some sort of chaotic behavior. Chaos is characterized by deterministic, nonlinear, non-
periodic, non-converging and bounded behavior. The main characteristic of chaos is the sensitive
dependence on initial conditions. Certain maps exhibit this property and it is possible to achieve
chaotic behaviour by recursively evaluating these maps in discrete time. The sequences generated
by iterating a given chaotic map will diverge to different trajectories in a few cycles even though
their initial conditions differ by less than 1% [1].
One of the well known one-dimensional iterative maps which exhibit chaotic properties is the
Logistic Map [2]. The other chaotic maps which are of interest are Tent map [3], Cubic map [4],
Quadratic map [5] and Bernoulli map [4]. Chaotic sequences are easy to generate and store. Only
few parameters and functions are needed for generating very long sequences. In addition, an
enormous number of different sequences can be generated simply by changing its initial
condition. The inherent properties of chaotic sequences make them suitable for communication
systems. It also enhances the security of transmission.
The applications of chaotic sequences generated by nonlinear dynamical systems to direct
sequence spread-spectrum (DS/SS) systems is discussed in [6] - [12]. As there are an infinite
number of sequences that can be generated by any chaotic system, exploiting such systems for
2. Computer Applications: An International Journal (CAIJ), Vol.2, No.1, February 2015
38
generating spreading sequences for use in DS/SS systems have received a lot of attention in
recent times. In recent years several methods to generate chaotic binary sequences using
Threshold function [13] and Coupled Chaotic Systems [14] are proposed in the literature.
Generation of discrete sequences over Z4 from chaotic sequences is discussed in [15]. Using
binary conversion, binary sequences are obtained from chaotic sequences over Z4. Their
correlation and linear complexity properties are discussed in [16] and [17]. Deriving binary
sequences from sequence over Z4 using polynomial mapping is discussed in [18]. The three
polynomial mappings considered in [18] for x Є Z4 is given by,
P1(x) = (x2
– x) mod4 (1)
P3(x) = (x2
+ x) mod4 (2)
P2(x) = 2x mod4 and (3)
In this paper chaotic binary sequences are obtained from sequence over Z4 using polynomial
mappings given by equation (1). The generated binary sequences are investigated for pairwise
cross correlation and linear complexity properties. The six chaotic map equations such as Logistic
map, Tent Map, Cubic Map, Quadratic Map and Bernoulli Map are considered for generating
sequences over Z4.
The work is organized as follows: In Section 2, a brief introduction to chaotic functions is
presented. In Section 3, we present generation of chaotic binary sequences, applying polynomial
mapping [18] to sequence over Z4. In Section 4, Cross Correlation and linear complexity
properties of generated binary sequences and their application in DS-CDMA are investigated.
Finally, Section 5 contains concluding remarks.
2. INTRODUCTION TO CHAOTIC FUNCTIONS
The different chaotic map equations considered in this work are as follows,
1) Logistic Map equations [2]
Logistic Map (1): , defined over real, 0 < x < 1 (4)
where r is called bifurcation parameter or control parameter and 3.57 < r < 4.
Logistic Map (2): -1 < x < 1 (5)
where 1.72 < r < 2.
2) Tent Map equation [3]
0 < x < 1 (6)
3) Cubic Map equation [4]
-1 < x < 1 (7)
4) Quadratic Map equation [5]
- 0.5 < x < 0.5 (8)
Control parameter r is chosen to be 0.36 < r < 0.5
5) Bernoulli Map equation [4]
3. Computer Applications: An International Journal (CAIJ), Vol.2, No.1, February 2015
39
- 0.5 < x < 0.5 (9)
Control parameter r is chosen to be 1.2 < r < 2
For the choice of control parameter r, within the range given along with the equation (4), (5), (8)
and (9), the sequence produced is non-periodic and non-converging. Even with two initial values
differing by a very small value, the resulting sequences are highly uncorrelated.
3. GENERATION OF BINARY SEQUENCES DERIVED FROM CHAOTIC
SEQUENCE OVER Z4 USING POLYNOMIAL MAPPING
A scheme of generating chaotic sequence over Z4 is shown in figure 1. In this case each element
Yk of sequence {xi} is multiplied by a large integer n and the fraction part is discarded. The
integer part is Qk. The large value of integer part Qk is then reduced to small integer Yk modulo 4.
It is necessary that n > 4. Thus the sequence {Yk} is over Z4. A method of deriving binary
sequence from sequence over Z4 using polynomial mapping P1(x) = (x2
– x) mod4 is considered
in this paper. Any integer Yk in the range 0 to 3 in the sequence {Yk} is mapped to {0, 2}. The
sequence over {0, 2} is further mapped to binary sequence by mapping (0, 2) Є Z4 to (1, -1) in
binary. Mapping from Z4 to binary is shown in Table 1.
Table 1. Binary mapping using P1(x) = (x2
– x) mod4
x 0 1 2 3
P1(x) = (x2
– x) mod4 0 0 2 2
Binary mapping 1 1 -1 -1
Thus model shown in Figure 1 can be used to derive discrete sequence {Yk} over Z4; where Yk Є
{0, 1, 2, 3} or binary {bk}, from the chaotic sequence {Xk}.
The scheme is governed by equation (10) and is given by
Yk = [ { Xk } n ] mod 4 , (10)
where {Xk } n = Qk, integer part of product Xk n.
Using polynomial mapping, the length of the resulting binary sequence turns out to be same as
sequence over Z4.
Figure 1. Scheme of generating chaotic binary sequence
4. Computer Applications: An International Journal (CAIJ), Vol.2, No.1, February 2015
40
4. CROSS CORRELATION (CCR) AND LINEAR COMPLEXITY (LC)
PROPERTIES
4.1. Cross Correlation Property
Definition: The normalized cyclic Hamming cross correlation function of two sequences x and y
of length N symbols is defined [19] as
Where 0 ≤ τ ≤ N-1. (11)
Where nτ and dτ are the number of locations at which symbols agree and disagree respectively
between the two sequences x and y. τ is the number of locations by which one sequence say y is
shifted with respect to the other sequence x. It is easy to see that when symbols of the sequence
are 1 and -1, the normalized cyclic cross correlation values and normalized cyclic Hamming cross
correlation values are same.
4.2. Linear Complexity
Definition: Linear complexity [20] of a binary sequence of finite length is the length of the
shortest LFSR that generates the same sequence. Berlekamp – Massey algorithm is an efficient
algorithm for determining the linear complexity of binary sequence of finite length. The binary
sequence with values 1, -1 is changed to 1, 0 to apply Berlekamp – Massey algorithm.
4.3. Properties of Segments of Chaotic Binary Sequences
For each of the six chaotic functions discussed in Section 2, real valued sequence {xk} is
generated by choosing arbitrarily the initial values x0 and appropriate bifurcation parameter r as
given in equations (4) to (9). This real valued sequence {xk} is converted to sequence over Z4
using the model shown in Fig 1 by arbitrarily choosing value of multiplication factor ‘n’ reducing
the integer part to modulo 4. The sequence over Z4 is converted to binary using polynomial
mapping given by equation (1). The resulting binary sequence is an infinite sequence. To study
the properties of the sequence, as an example, first 12600 bits of the generated binary sequence as
shown in Fig 2 are considered which is divided into 63 bit non-overlapping segments. The
number of segments of 63 bit that we get is 200. Each of these segments is numbered as Segment
1, Segment 2, … and is shown in equation (12).
4434421443442143421
200
1259912536
2
1256463
1
6210 ,...,...,...,,,...,
SegmentSegmentSegment
bbbbbbbbenceBinarySequ =
(12)
Similarly non-overlapping segments of 127 bits and 255 bits are considered. The linear
complexity of non-overlapping segments of sequences of different lengths (63, 127 and 255 bits)
is computed using Berlekamp – Massey algorithm and pairwise cross correlation values are
computed using equation (11). The number of sequences having pairwise cross correlation values
denoted by α is determined for different α values based on the segment lengths. The arbitrarily
chosen values of multiplication factor n are from {5, 6, 7 …10}. We consider Polynomial
mapping given by equation (1) for all the six chaotic map equations considered.
If we consider Gold sequence of length 63 their pairwise CCR value α is less than or equal to
0.2698 [21] and there are 65 Gold sequences with linear complexity 12. For Gold sequences of
length 127 the pairwise CCR value α is less than or equal to 0.1339 and there are 129 Gold
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41
sequences with linear complexity 14. If the Gold sequence is of length 255 bits then their
pairwise CCR value α is less than or equal to 0.1294 and there are 257 Gold sequences with linear
complexity 16. In the proposed scheme it is possible to obtain also sequences of same length
whose pairwise CCR value α is less than that of Gold sequences and linear complexity greater
than that of Gold sequences.
4.4. Deriving binary sequence using Polynomial mapping given by equation (1)
4.4.1. Logistic map equation
First we consider Logistic map equation given by equation (4) where initial value x0 is taken as
0.4 and bifurcation parameter r = 3.99, the number of sequences having pairwise CCR value less
than α are tabulated in Table 2. First column of Table 2 gives trial number with different n.
Second column give the value of n chosen. The number of sequences of different lengths having
pairwise CCR value less than or equal to α is given in the remaining columns.
Details of trial number 1 are given in first row of Table 2. For n value chosen as 5, there are 25
segments of sequences whose pairwise α ≤ 0.2063, 46 sequences whose pairwise α ≤ 0.2381 and
73 sequences whose pairwise α ≤ 0.2698 of length 63 bits. Likewise the details are tabulated for
Trial numbers 2 to 6 for different arbitrarily chosen values of n.
Table 2. Number of sequences having pairwise CCR value less than or equal to α with initial
value x0 = 0.4 and r = 3.99
The linear complexity is determined using Berlekamp – Massey algorithm and is shown in Table
3.
Table 3. Linear complexity of Gold sequences and proposed sequences using Logistic map
equation (1)
Length of
sequence
Linear complexity in
case of Gold sequences
Linear complexity of
proposed scheme
63 12 29 to 35
127 14 58 to 65
255 16 125 to 131
Next we consider logistic map given by equation (5) with the same initial value x0 = 0.4 and
bifurcation parameter r = 1.99. The number of sequences having pairwise CCR value less than or
equal to α is tabulated in Table 3.
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Details of trial number 1 are given in first row of Table 4. For n = 5 there are 23 sequences whose
pairwise α ≤ 0.2063, 40 sequences whose pairwise α ≤ 0.2381 and 72 sequences of length 63 bits
whose pairwise α ≤ 0.2698. Likewise the details are tabulated for Trial numbers 2 to 6 for
different arbitrarily chosen values of n.
Table 4. Number of sequences having pairwise CCR value less than or equal to α with initial
value x0 = 0.4 and r = 1.99
4.4.2. Tent map equation
Tent map equation given by equation (6) is considered with initial value x0 = 0.4. As in the earlier
cases the results for pairwise CCR value less than or equal to α are summarized in Table 5.
Table 5. Number of sequences having pairwise CCR value less than or equal to α with initial
value x0 = 0.4
4.4.3. Cubic map equation
Cubic map equation given by equation (7) is considered next with initial value x0 = 0.4. As in the
earlier cases the results for pairwise CCR value less than or equal to α are summarized in Table 6
for n = 5, 6, 7 ….10.
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43
Table 6. Number of sequences having pairwise CCR value less than or equal to α with initial
value x0 = 0.4
In this case also there are sequences whose pairwise CCR value is less than that of Gold
sequences and the number of sequences is more than Gold sequences.
4.4.4. Quadratic map equation
Quadratic map equation given by equation (8) is considered next with initial value x0 = 0.4,
bifurcation parameter r = 0.4. The results for pairwise CCR value less than or equal to α are
summarized in Table 7.
Table 7. Number of sequences having pairwise CCR value less than or equal to α with initial
value x0 = 0.4 and r = 0.4
4.4.5. Bernoulli map equation
Bernoulli map equation given by equation (9) is considered with initial value x0 = 0.4, bifurcation
parameter r = 1.99 and the results for pair wise CCR value less than or equal to α are summarized
in Table 8.
The properties of segments of binary sequences of different lengths derived from sequence over
Z4 using different chaotic map equations are almost same. It is also seen that the properties of
binary sequences derived from sequences over Z4 using polynomial mapping given by equations
(2) and (3) are almost identical.
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Table 8. Number of sequences having pair wise CCR value less than or equal to α with initial
value x0 = 0.4 and r = 1.99
The linear complexities of proposed sequences are more or less the same for sequences generated
using different chaotic functions.
4.5. Bit Error Rate (BER) Performance
In a DS-CDMA system the average BER performance depends mainly on the correlation
properties of the spreading sequences assigned to the users. In order to have low interference
between users it is necessary to select sets of sequences that form a quasi-orthogonal set. This
assumes desirable cross-correlation properties. Most DS-CDMA systems presented have used
binary PN sequences including Gold sequences and Kasami sequences that possess some quasi-
orthogonality correlation properties.
A new family of spreading sequences is represented by chaotic sequences, generated from the
orbits of some dynamical discrete systems. These sequences represent noise-like features that
make them good for DS-CDMA systems. The pseudo-chaotic systems generate long periodic
sequences and their time evolution (their orbit) depends totally on the initial state of the system.
So, a single system, described by its discrete chaotic map, can generate a very large number of
distinct pseudo-chaotic sequences, each sequence being uniquely specified by its initial value.
This dependency on the initial state and the nonlinear character of the discrete map make the DS-
CDMA system using these sequences more secure.
A simplified diagram of a K-user CDMA system is presented in Fig 2 [19]. In the receiving part
(the base station for the uplink direction or a mobile station for the downlink direction) the
received signal Sj(t), originating from user j, is given by the expression
(13)
where Pj is the received power of user j, aj(t) is the spreading sequence, with the chip period
Tc=T/N, and mj(t) is the data sequence for user j, both of them being binary sequences with
values ±1. The signal r(t) at the input of a receiver is
(14)
Where n(t) is Additive White Gaussian Noise (AWGN) with two-sided power spectral density
(PSD) N0/2. It is considered that different user signals are in synchronism. The correlator output
Zi
(j)
for user j at the end ith
bit period T is given by,
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45
(15)
where Ii
(j)
is the useful component (desired contribution from user j), is the multiple access
interference from the other (K-1) users and is the noise contribution. Considering the Euclidian
normalization, Ii
(j)
is given by,
(16)
where mj,i is data of the jth
user at the end of the ith
bit period T. T is the period of the symbols, Pj
is the received power of user j.
Figure 2. A simplified diagram of a CDMA system
In [22] it is shown that for a synchronous system that assumes synchronized spreading sequences
and constant power levels for all K users Pi = Pj at the receiving part, dependency of the average
BER on the white noise PSD and Multiple Access Interference (MAI) power is given by,
(17)
Where Eb = PjT is the signal energy per bit period, E b/N 0 is the signal-to-noise ratio expressed in
dB, K is number of users, C2
is the mean square cross-correlation value and N is the length of the
spreading sequence.
(18)
Equation (18) represents the cross-correlation function of the two sequences {aj(l)} and {ak(l)} on
the ith
bit period.
Transmitting part for K users Receiving part for user j
m1(t)
a1(t) cos(ω0t+Φ1)
aK(t) cos(ω0t+ΦK)
mK(t)
SK(t)
∑
S1(t)
∫ (.)dt Threshold
r (t)
cos(ω0t+Φj) aj(t)
Zi
(j)
mj
*
(t)
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46
The CCR values between two sequences of same length depend on the two sequences considered
and the shift. Smaller the CCR values better the immunity against MAI. To study the
performance, the peak pairwise CCR value α is considered and with reference to this
corresponding BER is computed.
Here C = max [C (i)
j, k for all j, k ] (19)
i
For Gold sequences of 63 bits the pairwise CCR value α is less than or equal to 0.2698 and there
are 65 Gold sequences. But using the proposed scheme there are sequences of 63 bits having
pairwise CCR value α ≤ 0.2381 and α ≤ 0.2063. Similarly for sequences of length 127 and 255
bits, there are sequences having pairwise CCR value α which is less than that of Gold sequences.
Hence to study the performance of the proposed scheme, α is considered to be worst case CCR
value.
It can be seen that the average BER of a synchronous DS-CDMA system versus the number of
users depends on the MAI term. The MAI contribution to BER grows with the number of
simultaneous users ‘K’ in the system. K depends on the number of sequences having pairwise
CCR value less than α, type of chaotic function and type of binary conversion. This MAI term
depends proportionally on the mean square cross-correlation value C2
= E [(C (i)
j, k) 2
] of the
spreading sequences’ set. Hence, in order to have lower BER values one has to choose sets of
spreading sequences with low mean square cross-correlation values. Since α is considered to be
the worst case CCR value, α2
is computed and equated to the mean square cross-correlation value
and the BER performance is investigated. Therefore equation (17) interms of α is given by,
(20)
The non-zero pairwise CCR value α considered becomes interference for other users. As a result,
as the number of users increases, the BER degrades. This is shown in Figures 4 to 6. In each case
the available number of code sequences is also indicated. Taking into consideration α2
value, the
BER performances given by equation (20) for the chaotic sequences generated (for six equations
(4) to (9)) using polynomial mapping given by equation (1) and are compared with Gold
sequences and Kasami sequences. The BER versus number of user’s plots for sequence generated
using polynomial mapping given by equation (1) of length 63 bits, 127 bits and 255 bits is shown
in Figure 3, 4 and 5 respectively. Figures 6, 7 and 8 depict the BER versus SNR plots for the
sequences of length 63 bits, 127 bits and 255 bits respectively.
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0 10 20 30 40 50 60 70 80
10
-4.36
10
-4.35
10
-4.34
10
-4.33
Number of Users
BER
BER performance for SNR = 8
Gold Sequences
Long Kasami Sequences
Proposed Sequences
Proposed Sequences with peak CCR value <=0.2381
(Available number of sequences about 45)
Proposed Sequences with peak CCR value <= 0.2063
(Available number of sequences about 25)
Gold Sequences with peak CCR value <=0.2698
(Available number of sequences 65)
Figure 3. BER versus Number of users plot for sequence of length 63 bits
0 50 100 150
10
-4.36
10
-4.359
10
-4.358
10
-4.357
Number of Users
BER
BER performance for SNR = 8
Gold Sequences
Long Kasami Sequences
Proposed Sequences
Gold Sequences with peak CCR value <= 0.1339
(Available number of sequences 129)
Proposed Sequences with peak CCR value <= 0.1181
(Available number of sequences about 75)
Proposed Sequences with peak CCR value <=0.1023
(Available number of sequences about 45)
Figure 4. BER versus Number of users plot for sequence of length 127 bits
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0 50 100 150 200 250 300
10
-4.36
10
-4.359
Number of Users
BER
BER performance for SNR = 8
Gold Sequences
LongKasami Sequences
Proposed Sequences
ProposedSequences withpeakCCR value <= 0.1215
(Available number of sequences about 120)
GoldandKasami Sequences withpeakCCR value <= 0.1294
(Available number of sequences 257)
ProposedSequences withpeakCCR value <= 0.1137
(Available number of sequences about 65)
Figure 5. BER versus Number of users plot for sequence of length 255 bits
0 1 2 3 4 5 6 7 8 9 10
10
-6
10
-5
10
-4
10
-3
10
-2
10
-1
10
0
SNR in dB
BER
BER performance for Number OfSimultaneous Users =20
GoldSequences
Long Kasami Sequences
Proposed Sequences
Figure 6. BER versus SNR plot for sequence of length 63 bits
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0 1 2 3 4 5 6 7 8 9 10
10
-6
10
-5
10
-4
10
-3
10
-2
10
-1
10
0
SNR in dB
BER
BER performance for Number OfSimultaneous Users =40
Gold Sequences
Long Kasami Sequences
ProposedSequences
Figure 7. BER versus SNR plot for sequence of length 127 bits
0 1 2 3 4 5 6 7 8 9 10
10
-6
10
-5
10
-4
10
-3
10
-2
10
-1
10
0
SNR in dB
BER
BER performance for Number OfSimultaneous Users =60
Gold Sequences
Long Kasami Sequences
ProposedSequences
Figure 8. BER versus SNR plot for sequence of length 255 bits
In general as number of users increases BER also increases for a fixed value of SNR. However in
the proposed scheme set of sequences whose pairwise CCR value α less than that of Gold
sequences exhibit better BER performance. This is shown in figures 3, 4 and 5. If the number of
users is fixed and pairwise CCR value α is considered to be same as that of Gold sequences, BER
decreases uniformly as SNR increases in all the cases. This can be seen in Figures 6, 7 and 8.
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50
3. CONCLUSIONS
In this paper, polynomial mapping suggested in [18], P1(x) = (x2
– x) mod4 is chosen for the
conversion of sequence over Z4 to binary for the 6 chaotic map equations. Some segments of
length 63, 127 and 255 bits of the generated chaotic binary sequences are tested for cross
correlation and linear complexity properties. The investigation is done for segments of 63, 127
and 255 bit binary sequences for each case of n = 5, 6, 7….10 and compared with Gold sequences
and Kasami sequences. From the results it is observed that there are segments of 63 bit, 127 bit
and 255 bit with pairwise CCR value less than that of Gold sequences. Hence using the proposed
model it is possible to generate sequences with pairwise CCR value less than that of Gold
sequences. The BER performance of these sequences as code sequences in CDMA is better than
that of Gold and Kasami sequences.
It is seen that the sequences chosen using the proposed method have linear complexity greater
than that of Gold sequences of same length.
It is shown that, there are set of sequences with peak pairwise CCR value same as that of Gold
sequences. However, number of such sequences is more than that of Gold sequences.
Also there are set of sequences whose peak pairwise CCR value is less than that of Gold
sequences. But the number of such sequences is less than that of Gold sequences.
However in the proposed scheme, set of sequences whose pairwise CCR value α less than that of
Gold sequences exhibit better BER performance and as the number of users increases BER also
increases for a fixed value of SNR. Also if the number of users is fixed and pairwise CCR value α
is considered to be same as that of Gold sequences, BER decreases uniformly as SNR increases in
all the cases.
ACKNOWLEDGEMENTS
The authors would like to thank the Management and Principal, Dr. Ambedkar Institute of
technology, Bengaluru for providing the facilities to carry out this work. Authors also thank Dr.
Ramesh S, Prof. Shivaputra and Prof. Chetan S for their valuable suggestions.
REFERENCES
[1] K T Alligood, J A Yorke and T D Sauer, Chaos: An Introduction to Dynamical Systems, Springer-
Verlag Inc., 1997.
[2] Robert M. May, Simple Mathematical Models with Very Complicated Dynamics, Nature 261 (1976)
459–467.
[3] Martin Hasler, and Yuri L. Maistrenko, An Introduction to the Synchronization of Chaotic Systems:
Coupled Skew Tent Maps, IEEE Trans. Circuits and Systems-I: Fundamental Theory and
Applications, Vol. 44, No.10 (1997) 856 – 866.
[4] Robert M. May, Mathematical Modelling: The Cubic Map in Theory and Practice, Nature 311 (1984)
13 - 14 ; doi:10.1038/311013a0.
[5] P. Morton, Arithmetic Properties of Periodic Points of Quadratic Maps, Acta Arithmetica (1998) 89 –
102.
[6] Heidari-Bateni G., McGillem C.D. and Tenorio M.F, A Novel Multiple-address Digital
Communication System Using Chaotic Signals, Proc. International Communication Conference,
Chicago, USA (1992) 1232–1236.
[7] Zhiyu Zhang, Jiulong Zhang, Wei Xiao, Yanjun Lu, Performance Enhancement of DS/SS System
Using Hybrid Chaotic Spreading Sequence, Proc. of IEEE ICCT, Guilin, China, Vol. 1(2006) 522-
526.
15. Computer Applications: An International Journal (CAIJ), Vol.2, No.1, February 2015
51
[8] B. Jovic, C.P. Unsworth, G.S. Sandhu and S.M. Berber, A Robust Sequence Synchronization Unit for
Multi-User DS-CDMA Chaos-Based Communication Systems, Signal Processing, Vol. 87, Issue 7
(2007) 1692-1708.
[9] Georges Kaddoum, Daniel Roviras, Pascal Charge and Daniele Fournier-Prunaret, Accurate Bit Error
Rate Calculation for Asynchronous Chaos-Based DS-CDMA over Multipath Channel, Hindawi
Publishing Corporation, EURASIP Journal on Advances in Signal Processing, Vol. 2009, Article ID
571307 (2009) 1-12.
[10] Georges Kaddoum, Martial Coulon, Daniel Roviras and Pascal Chargé, Theoretical Performance for
Asynchronous Multi-User Chaos-Based Communication Systems on Fading Channels, Signal
Processing, Vol. 90, Issue 11 (2010) 2923-2933.
[11] R. Vali, S.M. Berber and S.K. Nguang, Effect of Rayleigh Fading on Non-Coherent Sequence
Synchronization for Multi-User Chaos Based DS-CDMA, Signal Processing, Vol. 90, Issue 6 (2010)
1924-1939.
[12] Venkatesh S, Poonam Singh, Multi User Chaos Based DS-CDMA System Using Orthogonal Chaotic
Vector, Proc. International Conference on Electronic Systems (2011) 339 – 342.
[13] G. Venkat Reddy, Bibhudendra Acharya and Sarat Kumar Patra, Performance Evaluation of Different
DS-CDMA Receivers Using Chaotic Sequences, International Conference on RF and Signal
Processing Systems (2008) 426 – 431.
[14] V.Nagarajan and P. Dananjayan, Performance Analysis of MIMO MC-DS/CDMA System using
Chaotic Spreading Sequence, Int. Jnl. of Computer and Electrical Engineering, Vol. 2, No. 2 (2010)
329 – 333.
[15] Mahalinga V. Mandi , K.N. Haribhat , R. Murali, Generation of Discrete Spreading Sequences using
Chaotic Functions and their use in Spread Spectrum Communication, Proc. Sonata International Conf.
Computer, Communication and Controls (2006) 128 - 133.
[16] Mahalinga V. Mandi , K.N. Haribhat , R. Murali, Chaotic Functions for Generating Binary Sequences
and their Suitability in Multiple Access, Proc. IEEE International Conference on Communication
Technology 2006 (IEEE-ICCT 2006), Vol. 1 (2006) 217 – 220.
[17] Mahalinga V. Mandi, K. N. Haribhat, R. Murali, Generation of Large Set of Binary Sequences
Derived from Chaotic Functions with Large Linear Complexity and Good Cross Correlation
Properties, International Journal of Advanced Engineering and Applications (IJAEA), Vol. III (2010)
313 – 322, ISSN: 0975 – 7783 (Print), 0975 – 7791 (Online).
[18] P. Udaya and M.U Siddiqi, Optimal Biphase Sequences with Large Linear Complexity Derived from
Sequences Over Z4, IEEE Trans. Information Theory, Vol. 42, No. 1 (1996) 206 – 216.
[19] Abraham Lempel and Haim Greenberger, Families of Sequences with Optimal Hamming Correlation
Properties, IEEE Trans. on Information Theory, Vol. IT-20, No.1 (1974) 90-94.
[20] J.L. Massey, Shift Register Synthesis and BCH Decoding, IEEE Trans. Information Theory, Vol. IT-
15 (1969) 122-127.
[21] Robert Gold, Maximal Recursive Sequences with 3-Valued Recursive Cross-Correlation Functions,
IEEE Trans. on Information Theory, (1968) 154 – 1556.
[22] C. Vladeanu and I. Banica, Performance of Iterative Multistage Detectors for DS-CDMA Systems,
Proc. of IEEE-ICT 2001 (2001) 35-39.
Authors
Mahalinga V. Mandi received the B.E. Degree in Electronics and
Communication Engineering from Mysore University, Karnataka, India in
1990, M.Tech Degree in Industrial Electronics from Mysore Univeristy,
Karnataka, India in 1998 and Ph.D Degree from Dr MGR University, Chennai,
India in 2013. He is working as Associate Professor in the Department of
Electronics & Communication Engineering, Dr Ambedkar Institute of
Technology, Bangalore, India. His research areas include Digital
Communication, Cryptography and Network Security and Digital Signal
Processing.
16. Computer Applications: An International Journal (CAIJ), Vol.2, No.1, February 2015
52
Dr K N Haribhat received the B.E Degree with honors from Mysore University
in 1966, M.Tech and Ph.D in Electronics & Communication Engineering from
Indian Institute of Technology, Kanpur, in 1973 and 1986, respectively. He is
Dean Academic and Head (Retired), Department of Electronics & Communication
Engineering at Nagarjuna College of Engineering & Technology, Bangalore,
India. He was with Karnataka Regional Engineering College, Suratkal, India
(Currently known as NIT-K) for more than 30 years. His research areas include Analog
Communication, Digital Communication and Cryptography. He has authored more
than 25 papers in National/international Conferences and Journals. He has coauthored
three books on communication.
Dr Murali R received the M.Sc Degree in Mathematics from Bangalore
University, Karnataka, India in 1990 and Ph.D Degree in Mathematics from
Bangalore University, India in 1999 and currently working as Professor in the
Department of Mathematics, at Dr Ambedkar Institute of Technology, Bangalore,
India. His research areas include Graph Theory-Hamiltonian graphs. He has
authored more than 20 papers in National/International Journals.