Abstract Blind multiuser detection algorithms are used to eliminate the Multiple Access Interference (MAI) and the Near-Far effect in mobile communication systems. Four kinds of blind multiuser detection algorithms applied to code-division multiple-access (CDMA) communication system are studied in this paper. Those algorithms are the Least Mean Squares (LMS), Recursive Least Squares (RLS), Kalman filter and subspace-based Kalman filter algorithms. The resultant signal to interference ratio (SIR) at the output of the receivers controlled by the four kinds of multi-user detection algorithm has been discussed in this paper. Simulation results show that the subspace based Kalman filter algorithm outperforms all other three algorithms. Subspace-based Kalman filter algorithm has faster convergence speed, more practical and the capability of CDMA system can be increased. Keywords: Blind multiuser detection, Code-division multiple access, Mean output energy, Adaptive filtering.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Ad hoc networks are mobile wireless networks where each node is acting as a router. The existing routing protocols such as Destination sequences distance vector, Optimized list state routing protocols, Ad hoc on demand routing protocol, Ad hoc on demand multipath routing protocol, Dynamic source routing are optimized versions of distance vector or link state routing protocols. In this paper, existing protocols such as DSDV, AODV, AOMDV, OLSR and DSR are analyzed on 50 nodes Mobile Ad Hoc network with random mobility. Packet delivery ratio, delay, control overhead and throughput parameters are used for performance analysis.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Use of location aided algorithm using wi fi in indoor ad-hoc systemseSAT Journals
Abstract Mobile Ad-Hoc networks are designed to establish a network anytime and anywhere. Unlike other networks, ad-hoc does not require a fixed infrastructure. There are various routing techniques which are related to ad-hoc networking like Destination Sequenced Distance Vector Protocol (DSDV), Dynamic Source Routing Protocol (DSR) and Ad-Hoc On Demand Distance Vector Protocol (AODV). One such routing protocol named Location Aided Routing uses GPS (Global Positioning System) to get the co-ordinates of the nodes which would assist in routing. There is a definite set of drawbacks where GPS is used to get the location for the nodes in the ad-hoc network which is implemented indoor. In this paper, we propose an alternative of using Wi-Fi Positioning System to get the location of the co-ordinates which may prove to be a better solution than GPS indoor. Index Terms: Ad-Hoc Networks, DSDV, DSR, AODV, LAR, GPS, Wi-Fi Positioning System
Performance Analysis and Comparative Study of Cognitive Radio Spectrum Sensin...IOSR Journals
In cognitive radio, spectrum sensing is an emergent technology to find available and unused
spectrum for increasing spectrum utilization and to overcome spectrum scarcity problem without harmful
interference to licensed users. Cooperative spectrum sensing is used to give reliable performance in terms of
detection probability and false alarm probability as well as in order to reduce fading, noise and shadowing
effects on cognitive radio users. In this paper according to detection performance and complexity various
cooperative spectrum sensing schemes have been discussed. We have analyzed spectrum sensing with different fusion rules and their comparative behavior has also been studied. Furthermore, we introduced AND-OR fusion rules in 2-bit and 3-bit hard combination schemes
An efficient ant optimized multipath routing in wireless sensor networkEditor Jacotech
Today, the Wireless Sensor Network is increasingly gaining popularity and importance. It is the more interesting and stimulating area of research. Now, the WSN is applied in object tracking and environmental monitoring applications. This paper presents the self-optimized model of multipath routing algorithm for WSN which considers definite parameters like delay, throughput level and loss and generates the outcomes that maximizes data throughput rate and minimizes delay and loss. This algorithm is based on ANT optimization technique that will bring out an optimal and organized route for WSN and is also to avoid congestion in WSN, the algorithm incorporate multipath capability..
Investigations on real time RSSI based outdoor target tracking using kalman f...IJECEIAES
Target tracking is essential for localization and many other applications in Wireless Sensor Networks (WSNs). Kalman filter is used to reduce measurement noise in target tracking. In this research TelosB motes are used to measure Received Signal Strength Indication (RSSI). RSSI measurement doesn‟t require any external hardware compare to other distance estimation methods such as Time of Arrival (TOA), Time Difference of Arrival (TDoA) and Angle of Arrival (AoA). Distances between beacon and non-anchor nodes are estimated using the measured RSSI values. Position of the nonanchor node is estimated after finding the distance between beacon and nonanchor nodes. A new algorithm is proposed with Kalman filter for location estimation and target tracking in order to improve localization accuracy called as MoteTrack InOut system. This system is implemented in real time for indoor and outdoor tracking. Localization error reduction obtained in an outdoor environment is 75%.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Ad hoc networks are mobile wireless networks where each node is acting as a router. The existing routing protocols such as Destination sequences distance vector, Optimized list state routing protocols, Ad hoc on demand routing protocol, Ad hoc on demand multipath routing protocol, Dynamic source routing are optimized versions of distance vector or link state routing protocols. In this paper, existing protocols such as DSDV, AODV, AOMDV, OLSR and DSR are analyzed on 50 nodes Mobile Ad Hoc network with random mobility. Packet delivery ratio, delay, control overhead and throughput parameters are used for performance analysis.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Use of location aided algorithm using wi fi in indoor ad-hoc systemseSAT Journals
Abstract Mobile Ad-Hoc networks are designed to establish a network anytime and anywhere. Unlike other networks, ad-hoc does not require a fixed infrastructure. There are various routing techniques which are related to ad-hoc networking like Destination Sequenced Distance Vector Protocol (DSDV), Dynamic Source Routing Protocol (DSR) and Ad-Hoc On Demand Distance Vector Protocol (AODV). One such routing protocol named Location Aided Routing uses GPS (Global Positioning System) to get the co-ordinates of the nodes which would assist in routing. There is a definite set of drawbacks where GPS is used to get the location for the nodes in the ad-hoc network which is implemented indoor. In this paper, we propose an alternative of using Wi-Fi Positioning System to get the location of the co-ordinates which may prove to be a better solution than GPS indoor. Index Terms: Ad-Hoc Networks, DSDV, DSR, AODV, LAR, GPS, Wi-Fi Positioning System
Performance Analysis and Comparative Study of Cognitive Radio Spectrum Sensin...IOSR Journals
In cognitive radio, spectrum sensing is an emergent technology to find available and unused
spectrum for increasing spectrum utilization and to overcome spectrum scarcity problem without harmful
interference to licensed users. Cooperative spectrum sensing is used to give reliable performance in terms of
detection probability and false alarm probability as well as in order to reduce fading, noise and shadowing
effects on cognitive radio users. In this paper according to detection performance and complexity various
cooperative spectrum sensing schemes have been discussed. We have analyzed spectrum sensing with different fusion rules and their comparative behavior has also been studied. Furthermore, we introduced AND-OR fusion rules in 2-bit and 3-bit hard combination schemes
An efficient ant optimized multipath routing in wireless sensor networkEditor Jacotech
Today, the Wireless Sensor Network is increasingly gaining popularity and importance. It is the more interesting and stimulating area of research. Now, the WSN is applied in object tracking and environmental monitoring applications. This paper presents the self-optimized model of multipath routing algorithm for WSN which considers definite parameters like delay, throughput level and loss and generates the outcomes that maximizes data throughput rate and minimizes delay and loss. This algorithm is based on ANT optimization technique that will bring out an optimal and organized route for WSN and is also to avoid congestion in WSN, the algorithm incorporate multipath capability..
Investigations on real time RSSI based outdoor target tracking using kalman f...IJECEIAES
Target tracking is essential for localization and many other applications in Wireless Sensor Networks (WSNs). Kalman filter is used to reduce measurement noise in target tracking. In this research TelosB motes are used to measure Received Signal Strength Indication (RSSI). RSSI measurement doesn‟t require any external hardware compare to other distance estimation methods such as Time of Arrival (TOA), Time Difference of Arrival (TDoA) and Angle of Arrival (AoA). Distances between beacon and non-anchor nodes are estimated using the measured RSSI values. Position of the nonanchor node is estimated after finding the distance between beacon and nonanchor nodes. A new algorithm is proposed with Kalman filter for location estimation and target tracking in order to improve localization accuracy called as MoteTrack InOut system. This system is implemented in real time for indoor and outdoor tracking. Localization error reduction obtained in an outdoor environment is 75%.
Optimization of workload prediction based on map reduce frame work in a cloud...eSAT Journals
Abstract Nowadays cloud computing is emerging Technology. It is used to access anytime and anywhere through the internet. Hadoop is an open-source Cloud computing environment that implements the Googletm MapReduce framework. Hadoop is a framework for distributed processing of large datasets across large clusters of computers. This paper proposes the workload of jobs in clusters mode using Hadoop. MapReduce is a programming model in hadoop used for maintaining the workload of the jobs. Depend on the job analysis statistics the future workload of the cluster is predicted for potential performance optimization by using genetic algorithm. Key Words: Cloud computing, Hadoop Framework, MapReduce Analysis, Workload
An ann based call handoff management scheme for mobile cellular networkijwmn
Handoff decisions are usually signal strength based because of simplicity and effectiveness. Apart from the
conventional techniques, such as threshold and hysteresis based schemes, recently many artificial
intelligent techniques such as Fuzzy Logic, Artificial Neural Network (ANN) etc. are also used for taking
handoff decision. In this paper, an Artificial Neural Network based handoff algorithm is proposed and it’s
performance is studied. We have used ANNhere for taking fast and accurate handoff decision. In our
proposed handoff algorithm, Backpropagation Neural Network model is used.The advantages of
Backpropagation method are its simplicity and reasonable speed. The algorithm is designed, tested and
found to give optimum results.
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.
Signal classification of second order cyclostationarity signals using bt scld...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
A New Approach for Error Reduction in Localization for Wireless Sensor Networksidescitation
Localization is one of the most challenging and
important issues in wireless sensor networks (WSNs),
especially if cost effective approaches are demanded. Distance
measurement based on RSSI (Received Signal Strength
Indication) is a low cost and low complexity of the distance
measurement technique, and it is widely applied in the range-
based localization of the WSN. The RSS (Received Signal
Strength) used to estimate the distance between an unknown
node and a number of reference nodes with known co-ordinates.
Location of the target node is then determined by trilateration.
Log-normal shadowing model, can better describe the
relationship between the RSSI value and distance. Non-line
of sight and multipath transmission effects as the indoor
environment, the distance error or ranging error is large. In
this paper, experimental results that are carried out to analyze
the sensitivity of RSSI measurements in an indoor
environment for various power levels are presented. Location
error influenced by distance measure error and network
connectivity is analyzed.
Index Terms—
Abstract In optical circuit switching the high values of blocking probability is resolved by dynamic wavelength routing algorithms with wavelength conversion. The aim of this paper is to study these algorithms. Then the algorithm is selected which gives good results with and without wavelength conversion. The selected algorithm is then checked for other parameters of networking namely throughput, packet delivery ratio, and delay. A comparative study is then carried out for increasing traffic. We try to prove that these algorithms satisfy the criteria of QoS parameters by this comparative study. The results of simulation show that the parameters follow the trend of blocking probability of the selected algorithm. Keywords: optical burst switching, throughput, packet delivery ratio, delay.
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.
Performance Evaluation of DV-HOP and Amorphous Algorithms based on Localizati...TELKOMNIKA JOURNAL
In the field of high-risk observation, the nodes in Wireless Sensor Network (WSN) are distributed
randomly. The result from sensing becomes meaningless if it is not known from where the originating node
is. Therefore, a sensor node positioning scheme, known as the localization scheme, is required. The
localization scheme consists of distance estimation and position computing. Thus, this research used
connectivity as distance estimation within range free algorithm DV-Hop and Amorphous, and then trilateral
algorithm for computing the position. Besides that, distance estimation using the connectivity between
nodes is not needed for the additional hardware ranging as required by a range-based localization
scheme. In this research compared the localization algorithm based on range free localization, which are
DV-Hop algorithm and Amorphous algorithm. The simulation result shows that the amorphous alg orithm
have achieved 13.60% and 24.538% lower than dv-hop algorithm for each parameter error localization and
energy consumption. On node density variations, dv-hop algorithm gained a localization error that is
26.95% lower than amorphous algorithm, but for energy consumption parameter, amorphous gained
14.227% lower than dv-hop algorithm. In the communication range variation scenario, dv-hop algorithm
gained a localization error that is50.282% lower than amorphous. However, for energy consumption
parameter, amorphous algorithm gained 12.35%. lower than dv-hop algorithm.
A SURVEY ON DYNAMIC SPECTRUM ACCESS TECHNIQUES FOR COGNITIVE RADIOijngnjournal
Cognitive radio (CR) is a new paradigm that utilizes the available spectrum band. The key characteristic of CR system is to sense the electromagnetic environment to adapt their operation and dynamically vary its radio operating parameters. The technique of dynamically accessing the unused spectrum band is known as Dynamic Spectrum Access (DSA). The dynamic spectrum access technology helps to minimize unused spectrum bands. In this paper, main functions of Cognitive Radio (CR) i.e. spectrum sensing, spectrum management, spectrum mobility and spectrum sharing are discussed. Then DSA models are discussed along with different methods of DSA such as Command and Control, Exclusive-Use, Shared Use of Primary Licensed User and Commons method. Game-theoretic approach using Bertrand game model, Markovian Queuing Model for spectrum allocation in centralized architecture and Fuzzy logic based method are also discussed and result are shown.
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.
Performance Analysis of Group-Blind Multiuser Detectors for Synchronous CDMAidescitation
Blind multiuser detectors are attractive for the
suppression of interference in a CDMA environment. This
paper deals with the performance of group blind multiuser
detector for synchronous CDMA is analyzed. The blind multi
user detectors are Direct Matrix Inversion(DMI),Subspace
and group blind multiuser detector. The performance
analysis is performed by means of the Signal to Interference
Noise Ratio(SINR) and Bit Error Rate(BER). The numerical
results are plotted as variation of SINR Vs SNR, K and M,
SINR with respect to correlation coefficient( ) and BER
Vs Number of samples(M) for three detectors using
MATLAB software. The gain rises in group blind multiuser
detector over the DMI and subspace detectors. The
comparison is carried out for equicorrelated signals for
mathematical simplicity.
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.
Implementation of Vacate on Demand Algorithm in Various Spectrum Sensing Netw...IJERA Editor
In present days the wireless communications are widely increases because of this reason spectrum utilization can be rapidly increased.For efficient usage of spectrum we can implement the Vacate on demand algorithm in different networks. CR users also need to sense the spectrum and vacate the channel upon the detection of the PU‟s presence to protectPUs from harmful interference. To achieve these fundamental CR functions, CR users usually coordinate with each other by using a common medium for control message exchange ensuring a priority of PUs over CR users. This paper presents the Vacate on Demand (VD) algorithm which enables dynamic spectrum access and ensures to vacate the assigned channel in case of PU activity and move the CR user to some other vacant channel to make spectrum available to PUs as well as to CR users. The basic idea is to use a ranking table of the available channels based on the PU activity detected on each channel. To improve the spectrum efficiency we can implement the Vacate on demand algorithm in MANET Network.
Optimization of workload prediction based on map reduce frame work in a cloud...eSAT Journals
Abstract Nowadays cloud computing is emerging Technology. It is used to access anytime and anywhere through the internet. Hadoop is an open-source Cloud computing environment that implements the Googletm MapReduce framework. Hadoop is a framework for distributed processing of large datasets across large clusters of computers. This paper proposes the workload of jobs in clusters mode using Hadoop. MapReduce is a programming model in hadoop used for maintaining the workload of the jobs. Depend on the job analysis statistics the future workload of the cluster is predicted for potential performance optimization by using genetic algorithm. Key Words: Cloud computing, Hadoop Framework, MapReduce Analysis, Workload
An ann based call handoff management scheme for mobile cellular networkijwmn
Handoff decisions are usually signal strength based because of simplicity and effectiveness. Apart from the
conventional techniques, such as threshold and hysteresis based schemes, recently many artificial
intelligent techniques such as Fuzzy Logic, Artificial Neural Network (ANN) etc. are also used for taking
handoff decision. In this paper, an Artificial Neural Network based handoff algorithm is proposed and it’s
performance is studied. We have used ANNhere for taking fast and accurate handoff decision. In our
proposed handoff algorithm, Backpropagation Neural Network model is used.The advantages of
Backpropagation method are its simplicity and reasonable speed. The algorithm is designed, tested and
found to give optimum results.
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.
Signal classification of second order cyclostationarity signals using bt scld...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
A New Approach for Error Reduction in Localization for Wireless Sensor Networksidescitation
Localization is one of the most challenging and
important issues in wireless sensor networks (WSNs),
especially if cost effective approaches are demanded. Distance
measurement based on RSSI (Received Signal Strength
Indication) is a low cost and low complexity of the distance
measurement technique, and it is widely applied in the range-
based localization of the WSN. The RSS (Received Signal
Strength) used to estimate the distance between an unknown
node and a number of reference nodes with known co-ordinates.
Location of the target node is then determined by trilateration.
Log-normal shadowing model, can better describe the
relationship between the RSSI value and distance. Non-line
of sight and multipath transmission effects as the indoor
environment, the distance error or ranging error is large. In
this paper, experimental results that are carried out to analyze
the sensitivity of RSSI measurements in an indoor
environment for various power levels are presented. Location
error influenced by distance measure error and network
connectivity is analyzed.
Index Terms—
Abstract In optical circuit switching the high values of blocking probability is resolved by dynamic wavelength routing algorithms with wavelength conversion. The aim of this paper is to study these algorithms. Then the algorithm is selected which gives good results with and without wavelength conversion. The selected algorithm is then checked for other parameters of networking namely throughput, packet delivery ratio, and delay. A comparative study is then carried out for increasing traffic. We try to prove that these algorithms satisfy the criteria of QoS parameters by this comparative study. The results of simulation show that the parameters follow the trend of blocking probability of the selected algorithm. Keywords: optical burst switching, throughput, packet delivery ratio, delay.
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.
Performance Evaluation of DV-HOP and Amorphous Algorithms based on Localizati...TELKOMNIKA JOURNAL
In the field of high-risk observation, the nodes in Wireless Sensor Network (WSN) are distributed
randomly. The result from sensing becomes meaningless if it is not known from where the originating node
is. Therefore, a sensor node positioning scheme, known as the localization scheme, is required. The
localization scheme consists of distance estimation and position computing. Thus, this research used
connectivity as distance estimation within range free algorithm DV-Hop and Amorphous, and then trilateral
algorithm for computing the position. Besides that, distance estimation using the connectivity between
nodes is not needed for the additional hardware ranging as required by a range-based localization
scheme. In this research compared the localization algorithm based on range free localization, which are
DV-Hop algorithm and Amorphous algorithm. The simulation result shows that the amorphous alg orithm
have achieved 13.60% and 24.538% lower than dv-hop algorithm for each parameter error localization and
energy consumption. On node density variations, dv-hop algorithm gained a localization error that is
26.95% lower than amorphous algorithm, but for energy consumption parameter, amorphous gained
14.227% lower than dv-hop algorithm. In the communication range variation scenario, dv-hop algorithm
gained a localization error that is50.282% lower than amorphous. However, for energy consumption
parameter, amorphous algorithm gained 12.35%. lower than dv-hop algorithm.
A SURVEY ON DYNAMIC SPECTRUM ACCESS TECHNIQUES FOR COGNITIVE RADIOijngnjournal
Cognitive radio (CR) is a new paradigm that utilizes the available spectrum band. The key characteristic of CR system is to sense the electromagnetic environment to adapt their operation and dynamically vary its radio operating parameters. The technique of dynamically accessing the unused spectrum band is known as Dynamic Spectrum Access (DSA). The dynamic spectrum access technology helps to minimize unused spectrum bands. In this paper, main functions of Cognitive Radio (CR) i.e. spectrum sensing, spectrum management, spectrum mobility and spectrum sharing are discussed. Then DSA models are discussed along with different methods of DSA such as Command and Control, Exclusive-Use, Shared Use of Primary Licensed User and Commons method. Game-theoretic approach using Bertrand game model, Markovian Queuing Model for spectrum allocation in centralized architecture and Fuzzy logic based method are also discussed and result are shown.
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.
Performance Analysis of Group-Blind Multiuser Detectors for Synchronous CDMAidescitation
Blind multiuser detectors are attractive for the
suppression of interference in a CDMA environment. This
paper deals with the performance of group blind multiuser
detector for synchronous CDMA is analyzed. The blind multi
user detectors are Direct Matrix Inversion(DMI),Subspace
and group blind multiuser detector. The performance
analysis is performed by means of the Signal to Interference
Noise Ratio(SINR) and Bit Error Rate(BER). The numerical
results are plotted as variation of SINR Vs SNR, K and M,
SINR with respect to correlation coefficient( ) and BER
Vs Number of samples(M) for three detectors using
MATLAB software. The gain rises in group blind multiuser
detector over the DMI and subspace detectors. The
comparison is carried out for equicorrelated signals for
mathematical simplicity.
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.
Implementation of Vacate on Demand Algorithm in Various Spectrum Sensing Netw...IJERA Editor
In present days the wireless communications are widely increases because of this reason spectrum utilization can be rapidly increased.For efficient usage of spectrum we can implement the Vacate on demand algorithm in different networks. CR users also need to sense the spectrum and vacate the channel upon the detection of the PU‟s presence to protectPUs from harmful interference. To achieve these fundamental CR functions, CR users usually coordinate with each other by using a common medium for control message exchange ensuring a priority of PUs over CR users. This paper presents the Vacate on Demand (VD) algorithm which enables dynamic spectrum access and ensures to vacate the assigned channel in case of PU activity and move the CR user to some other vacant channel to make spectrum available to PUs as well as to CR users. The basic idea is to use a ranking table of the available channels based on the PU activity detected on each channel. To improve the spectrum efficiency we can implement the Vacate on demand algorithm in MANET Network.
Performance Analysis and Comparative Study of Cognitive Radio Spectrum Sensin...IOSR Journals
Abstract : In cognitive radio, spectrum sensing is an emergent technology to find available and unused spectrum for increasing spectrum utilization and to overcome spectrum scarcity problem without harmful interference to licensed users. Cooperative spectrum sensing is used to give reliable performance in terms of detection probability and false alarm probability as well as in order to reduce fading, noise and shadowing effects on cognitive radio users. In this paper according to detection performance and complexity various cooperative spectrum sensing schemes have been discussed. We have analyzed spectrum sensing with different fusion rules and their comparative behavior has also been studied. Furthermore, we introduced AND-OR fusion rules in 2-bit and 3-bit hard combination schemes. Keywords - Cognitive radio, cooperative spectrum sensing, energy detector, spectrum sensing, hard combination
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Beam steering in smart antennas by using low complex adaptive algorithmseSAT Journals
Abstract Array antenna systems are often used to enhance the received signal to interference and noise ratio when the signal operates in heavily jammed environment. Proper modeling of the received data at different antenna elements is important when evaluating the performance of this system, especially when both the signal and interference have wide frequency bands.. The antenna output is the linear combination of data from all the antenna elements. In conventional narrowband beam forming, time sequences at different antenna elements are related by some fixed phase shift. The phase shift is determined by the wave forms direction of arrival (DOA). In this paper, an efficient method for the pattern synthesis of the linear antenna arrays with the prescribed nulling and steering lobe is presented. The proposed method is based on Least Mean Square (LMS) algorithm provide a comprehensive and detailed treatment of the signal model used for beam forming, as well as, describing adaptive algorithms to adjust the weights of an array. In order to improve the convergence rate of LMS algorithm in smart antenna system, in this paper we proposes a new normalized LMS (NLMS) algorithm, This new algorithm can be treated as a block based simplification of NLMS algorithm which gives satisfactory performance in certain applications in comparison with conventional NLMS recursion, i.e., BBNLMS algorithm. By taking advantage of spatial filtering, the proposed scheme promises to reduce the bandwidth required for transmitting data by improving convergence rate. The performance of the BBNLMS algorithm in the presence of Multi-path effects and multiple users is analyzed using MATLAB simulations. The simulations when compared to that of the LMS algorithm, the results suggest that BBNLMS algorithm can improve the convergence rate and lead to better system efficiency. Keywords: BBNLMS, Convergence Rate, DOA, LMS, NLMS, Smart antenna.
Classical Discrete-Time Fourier TransformBased Channel Estimation for MIMO-OF...IJCSEA Journal
In this document, we look at various time domain channel estimation methods with this constraint of null carriers at spectrumborders.We showin detail howto gauge the importance of the “border effect” depending on the number of null carriers, which may vary from one system to another. Thereby we assess the limit of the technique discussed when the number of null carriers is large. Finally the DFT with the truncated singular value decomposition (SVD) technique is proposed to completely eliminate the impact of the null subcarriers whatever their number. A technique for the determination of the truncation threshold for any MIMO-OFDM system is also proposed.
Spectrum Sensing Detection with Sequential Forward Search in Comparison to Kn...IJMTST Journal
FCC is currently working on the concept of white space users “borrowing” spectrum from free license
holders temporarily to improve the spectrum utilization.
This project provides a relation between a Pf and the SNR value of any spectrum detector to have a
certain performance. Previous spectrum sensing detection techniques are only suitable for Low SNR and
are based on signal information values. But these methods are purely narrow band spectrum applications
In order to overcome the above said drawbacks we propose a novel method of spectrum sensing method
and is suitable for low and high SNR values, the sensed spectrum applicable for wide band applications.
Our proposed method does not require signal information at the receiver and channel information, because
this flexibility sensing rate is very high compared to previous techniques.
OPTIMIZATION OF THE RECURSIVE ONE-SIDED HYPOTHESIS TESTING TECHNIQUE FOR AUTO...ijwmn
In this paper, an optimized Recursive One-Sided Hypothesis Testing (ROHT) threshold estimation algorithm for energy detection based on Cognitive Radio (CR) application is presented. The ROHT algorithm is well known to compute and correct threshold values based on the choice of the parameter
values; namely the coefficient of standard deviation (z-value) and the stopping criteria (). A fixed computational process has been employed in most cases to estimate these parameter values, thus rendering them non-adaptive under different sensing conditions. Also, this fixed (manual tuning) process requires prior knowledge of some noise level to enable pre-configuration of a predefined target false alarm rate. This renders the parameter estimation process cumbrous and unworkable for real-time purposes, particularly for autonomous CR applications. Furthermore, using wrong parameter values may lead to either too high or too low false alarms or detection rates of the algorithm. Sequel to aforementioned mentioned constraints, we propose a new mechanism for instantaneous parameter optimization of the ROHT algorithm using Particle Swarm Optimization (PSO) algorithm. Our PSO-ROHT model design was extensively tested under different conditions and results were compared to the non-optimized ROHT. The
results obtained show that the proposed design effectively adapts the parameter values of the Recursive One-Sided Hypothesis Testing algorithm in accordance with the input dataset under consideration. Also, that the proposed optimized model outperforms its non-optimized counterpart following the estimated detection probability and false alarm probability of both schemes, particularly in detecting Orthogonal Frequency-Division Multiplexing signals. In detecting the Orthogonal Frequency-Division Multiplexingsignals at signal-to-noise ratio of 3dB and above, the proposed model achieved a higher detection rate of 96.23% while maintaining a low false alarm rate below 10%, which complies with the IEEE 802.22
standard for Cognitive Radio application. Our PSO-ROHT algorithm is shown to be highly effective for autonomous and full blind signal detection in CR, with strong potentials for application in other areas requiring automatic threshold estimation.
OPTIMIZATION OF THE RECURSIVE ONE-SIDED HYPOTHESIS TESTING TECHNIQUE FOR AUTO...ijwmn
In this paper, an optimized Recursive One-Sided Hypothesis Testing (ROHT) threshold estimation algorithm for energy detection based on Cognitive Radio (CR) application is presented. The ROHT algorithm is well known to compute and correct threshold values based on the choice of the parameter
values; namely the coefficient of standard deviation (z-value) and the stopping criteria (). A fixed computational process has been employed in most cases to estimate these parameter values, thus rendering them non-adaptive under different sensing conditions. Also, this fixed (manual tuning) process requires prior knowledge of some noise level to enable pre-configuration of a predefined target false alarm rate.
This renders the parameter estimation process cumbrous and unworkable for real-time purposes, particularly for autonomous CR applications. Furthermore, using wrong parameter values may lead to either too high or too low false alarms or detection rates of the algorithm. Sequel to aforementioned mentioned constraints, we propose a new mechanism for instantaneous parameter optimization of the ROHT algorithm using Particle Swarm Optimization (PSO) algorithm. Our PSO-ROHT model design was extensively tested under different conditions and results were compared to the non-optimized ROHT. The
results obtained show that the proposed design effectively adapts the parameter values of the Recursive One-Sided Hypothesis Testing algorithm in accordance with the input dataset under consideration. Also, that the proposed optimized model outperforms its non-optimized counterpart following the estimated detection probability and false alarm probability of both schemes, particularly in detecting Orthogonal Frequency-Division Multiplexing signals. In detecting the Orthogonal Frequency-Division Multiplexing signals at signal-to-noise ratio of 3dB and above, the proposed model achieved a higher detection rate of 96.23% while maintaining a low false alarm rate below 10%, which complies with the IEEE 802.22standard for Cognitive Radio application. Our PSO-ROHT algorithm is shown to be highly effective for autonomous and full blind signal detection in CR, with strong potentials for application in other areas requiring automatic threshold estimation.
An Approach to Spectrum Sensing in Cognitive Radio IOSR Journals
Recent research shows that more than 70% of the available spectrum is not utilized
efficiently. The bandwidth becomes expensive due to a shortage of frequencies. Therefore for efficient
utilization of spectrum, we need to sniff the spectrum to determine whether it is being used by primary user or
not. The term cognitive radio refers to the adoption of radio parameters using the sensed information
of the spectrum. There are various spectrum sensing techniques proposed in the literature but still there is
room for researchers in this field to explore more sophisticated approaches. There are three major
categories of spectrum sensing techniques; transmitter detection, receiver detection and interference
temperature detection. This thesis presents a survey of techniques suggested in the literature for
spectrum sensing with a performance analysis of transmitter-based detection techniques.
An Approach to Spectrum Sensing in Cognitive RadioIOSR Journals
Abstract: Recent research shows that more than 70% of the available spectrum is not utilized efficiently. The bandwidth becomes expensive due to a shortage of frequencies. Therefore for efficient utilization of spectrum, we need to sniff the spectrum to determine whether it is being used by primary user or not. The term cognitive radio refers to the adoption of radio parameters using the sensed information of the spectrum. There are various spectrum sensing techniques proposed in the literature but still there is room for researchers in this field to explore more sophisticated approaches. There are three major categories of spectrum sensing techniques; transmitter detection, receiver detection and interference temperature detection. This thesis presents a survey of techniques suggested in the literature for spectrum sensing with a performance analysis of transmitter-based detection techniques. Keywords— Include at least 5 keywords or phrases
Effect of Channel Variations on the Spectral Efficiency of Multiuser Diversit...IDES Editor
The high spectral efficiency or high user data rates
from multiuser diversity scheme using MIMO systems with
antenna selection and MRC reception is very important
development for modern cellular communications. Usually in
a service area of such system, the channel type is assumed to
remain constant, and in a Rayleigh fading environment such
systems are found to provide the highest data rate to a scheduled
user. In a service area using multiuser diversity MIMO
technology, the users at different locations may not experience
the same channel type and hence practically observed data
rates differ from the assumed values. We present in this report
how the scheduled user data rate suffers if the channel type
deviates from Rayleigh to Nakagami-m fading in the cellular
service area, both for absolute or dedicated SNR scheduling
scheme and proportional or normalized SNR scheduling
scheme. We explore the loss of user data rates in different
received SNR regime 0 dB, 10 dB, and 20 dB, and for different
m values with different MIMO configurations. We find that at
0 dB per antenna received SNR the loss of user data rates are
the highest.
Scenarios of Lifetime Extension Algorithms for Wireless Ad Hoc NetworksIJCNCJournal
An Algorithm to extend sensor lifetime and energy is implemented for different scenarios of ad hoc and wireless sensor networks. The goal is to prolong the lifetimes of sensors, covering a number of targeted zones by creating subsets of sensors, in which each subset covers entirely the targeted zones. Probabilistic analysis is assumed in which each sensor covers one or more targets, according to their coverage failure probabilities. Case studies of different sensor subsets arrangements are considered such as load switching, variable target load demands as well as a perturbation in sensor planner locations.
Mechanical properties of hybrid fiber reinforced concrete for pavementseSAT Journals
Abstract
The effect of addition of mono fibers and hybrid fibers on the mechanical properties of concrete mixture is studied in the present
investigation. Steel fibers of 1% and polypropylene fibers 0.036% were added individually to the concrete mixture as mono fibers and
then they were added together to form a hybrid fiber reinforced concrete. Mechanical properties such as compressive, split tensile and
flexural strength were determined. The results show that hybrid fibers improve the compressive strength marginally as compared to
mono fibers. Whereas, hybridization improves split tensile strength and flexural strength noticeably.
Keywords:-Hybridization, mono fibers, steel fiber, polypropylene fiber, Improvement in mechanical properties.
Material management in construction – a case studyeSAT Journals
Abstract
The objective of the present study is to understand about all the problems occurring in the company because of improper application
of material management. In construction project operation, often there is a project cost variance in terms of the material, equipments,
manpower, subcontractor, overhead cost, and general condition. Material is the main component in construction projects. Therefore,
if the material management is not properly managed it will create a project cost variance. Project cost can be controlled by taking
corrective actions towards the cost variance. Therefore a methodology is used to diagnose and evaluate the procurement process
involved in material management and launch a continuous improvement was developed and applied. A thorough study was carried
out along with study of cases, surveys and interviews to professionals involved in this area. As a result, a methodology for diagnosis
and improvement was proposed and tested in selected projects. The results obtained show that the main problem of procurement is
related to schedule delays and lack of specified quality for the project. To prevent this situation it is often necessary to dedicate
important resources like money, personnel, time, etc. To monitor and control the process. A great potential for improvement was
detected if state of the art technologies such as, electronic mail, electronic data interchange (EDI), and analysis were applied to the
procurement process. These helped to eliminate the root causes for many types of problems that were detected.
Managing drought short term strategies in semi arid regions a case studyeSAT Journals
Abstract
Drought management needs multidisciplinary action. Interdisciplinary efforts among the experts in various fields of the droughts
prone areas are helpful to achieve tangible and permanent solution for this recurring problem. The Gulbarga district having the total
area around 16, 240 sq.km, and accounts 8.45 per cent of the Karnataka state area. The district has been situated with latitude 17º 19'
60" North and longitude of 76 º 49' 60" east. The district is situated entirely on the Deccan plateau positioned at a height of 300 to
750 m above MSL. Sub-tropical, semi-arid type is one among the drought prone districts of Karnataka State. The drought
management is very important for a district like Gulbarga. In this paper various short term strategies are discussed to mitigate the
drought condition in the district.
Keywords: Drought, South-West monsoon, Semi-Arid, Rainfall, Strategies etc.
Life cycle cost analysis of overlay for an urban road in bangaloreeSAT Journals
Abstract
Pavements are subjected to severe condition of stresses and weathering effects from the day they are constructed and opened to traffic
mainly due to its fatigue behavior and environmental effects. Therefore, pavement rehabilitation is one of the most important
components of entire road systems. This paper highlights the design of concrete pavement with added mono fibers like polypropylene,
steel and hybrid fibres for a widened portion of existing concrete pavement and various overlay alternatives for an existing
bituminous pavement in an urban road in Bangalore. Along with this, Life cycle cost analyses at these sections are done by Net
Present Value (NPV) method to identify the most feasible option. The results show that though the initial cost of construction of
concrete overlay is high, over a period of time it prove to be better than the bituminous overlay considering the whole life cycle cost.
The economic analysis also indicates that, out of the three fibre options, hybrid reinforced concrete would be economical without
compromising the performance of the pavement.
Keywords: - Fatigue, Life cycle cost analysis, Net Present Value method, Overlay, Rehabilitation
Laboratory studies of dense bituminous mixes ii with reclaimed asphalt materialseSAT Journals
Abstract
The issue of growing demand on our nation’s roadways over that past couple of decades, decreasing budgetary funds, and the need to
provide a safe, efficient, and cost effective roadway system has led to a dramatic increase in the need to rehabilitate our existing
pavements and the issue of building sustainable road infrastructure in India. With these emergency of the mentioned needs and this
are today’s burning issue and has become the purpose of the study.
In the present study, the samples of existing bituminous layer materials were collected from NH-48(Devahalli to Hassan) site.The
mixtures were designed by Marshall Method as per Asphalt institute (MS-II) at 20% and 30% Reclaimed Asphalt Pavement (RAP).
RAP material was blended with virgin aggregate such that all specimens tested for the, Dense Bituminous Macadam-II (DBM-II)
gradation as per Ministry of Roads, Transport, and Highways (MoRT&H) and cost analysis were carried out to know the economics.
Laboratory results and analysis showed the use of recycled materials showed significant variability in Marshall Stability, and the
variability increased with the increase in RAP content. The saving can be realized from utilization of recycled materials as per the
methodology, the reduction in the total cost is 19%, 30%, comparing with the virgin mixes.
Keywords: Reclaimed Asphalt Pavement, Marshall Stability, MS-II, Dense Bituminous Macadam-II
Laboratory investigation of expansive soil stabilized with natural inorganic ...eSAT Journals
Abstract
Soil stabilization has proven to be one of the oldest techniques to improve the soil properties. Literature review conducted revealed
that uses of natural inorganic stabilizers are found to be one of the best options for soil stabilization. In this regard an attempt has
been made to evaluate the influence of RBI-81 stabilizer on properties of black cotton soil through laboratory investigations. Black
cotton soil with varying percentages of RBI-81 viz., 0, 0.5, 1, 1.5, 2, and 2.5 percent were studied for moisture density relationships
and strength behaviour of soils. Also the effect of curing period was evaluated as literature review clearly emphasized the strength
gain of soils stabilized with RBI-81 over a period of time. The results obtained shows that the unconfined compressive strength of
specimens treated with RBI-81 increased approximately by 250% for a curing period of 28 days as compared to virgin soil. Further
the CBR value improved approximately by 400%. The studies indicated an increasing trend for soil strength behaviour with
increasing percentage of RBI-81 suggesting its potential applications in soil stabilization.
Influence of reinforcement on the behavior of hollow concrete block masonry p...eSAT Journals
Abstract
Reinforced masonry was developed to exploit the strength potential of masonry and to solve its lack of tensile strength. Experimental
and analytical studies have been carried out to investigate the effect of reinforcement on the behavior of hollow concrete block
masonry prisms under compression and to predict ultimate failure compressive strength. In the numerical program, three dimensional
non-linear finite elements (FE) model based on the micro-modeling approach is developed for both unreinforced and reinforced
masonry prisms using ANSYS (14.5). The proposed FE model uses multi-linear stress-strain relationships to model the non-linear
behavior of hollow concrete block, mortar, and grout. Willam-Warnke’s five parameter failure theory has been adopted to model the
failure of masonry materials. The comparison of the numerical and experimental results indicates that the FE models can successfully
capture the highly nonlinear behavior of the physical specimens and accurately predict their strength and failure mechanisms.
Keywords: Structural masonry, Hollow concrete block prism, grout, Compression failure, Finite element method,
Numerical modeling.
Influence of compaction energy on soil stabilized with chemical stabilizereSAT Journals
Abstract
Increase in traffic along with heavier magnitude of wheel loads cause rapid deterioration in pavements. There is a need to improve
density, strength of soil subgrade and other pavement layers. In this study an attempt is made to improve the properties of locally
available loamy soil using twin approaches viz., i) increasing the compaction of soil and ii) treating the soil with chemical stabilizer.
Laboratory studies are carried out on both untreated and treated soil samples compacted by different compaction efforts. Studies
show that increase in compaction effort results in increase in density of soil. However in soil treated with chemical stabilizer, rate of
increase in density is not significant. The soil treated with chemical stabilizer exhibits improvement in both strength and performance
properties.
Keywords: compaction, density, subgradestabilization, resilient modulus
Geographical information system (gis) for water resources managementeSAT Journals
Abstract
Water resources projects are inherited with overlapping and at times conflicting objectives. These projects are often of varied sizes
ranging from major projects with command areas of millions of hectares to very small projects implemented at the local level. Thus,
in all these projects there is seldom proper coordination which is essential for ensuring collective sustainability.
Integrated watershed development and management is the accepted answer but in turn requires a comprehensive framework that can
enable planning process involving all the stakeholders at different levels and scales is compulsory. Such a unified hydrological
framework is essential to evaluate the cause and effect of all the proposed actions within the drainage basins.
The present paper describes a hydrological framework developed in the form of a Hydrologic Information System (HIS) which is
intended to meet the specific information needs of the various line departments of a typical State connected with water related aspects.
The HIS consist of a hydrologic information database coupled with tools for collating primary and secondary data and tools for
analyzing and visualizing the data and information. The HIS also incorporates hydrological model base for indirect assessment of
various entities of water balance in space and time. The framework would be maintained and updated to reflect fully the most
accurate ground truth data and the infrastructure requirements for planning and management.
Keywords: Hydrological Information System (HIS); WebGIS; Data Model; Web Mapping Services
Forest type mapping of bidar forest division, karnataka using geoinformatics ...eSAT Journals
Abstract
The study demonstrate the potentiality of satellite remote sensing technique for the generation of baseline information on forest types
including tree plantation details in Bidar forest division, Karnataka covering an area of 5814.60Sq.Kms. The Total Area of Bidar
forest division is 5814Sq.Kms analysis of the satellite data in the study area reveals that about 84% of the total area is Covered by
crop land, 1.778% of the area is covered by dry deciduous forest, 1.38 % of mixed plantation, which is very threatening to the
environmental stability of the forest, future plantation site has been mapped. With the use of latest Geo-informatics technology proper
and exact condition of the trees can be observed and necessary precautions can be taken for future plantation works in an appropriate
manner
Keywords:-RS, GIS, GPS, Forest Type, Tree Plantation
Factors influencing compressive strength of geopolymer concreteeSAT Journals
Abstract
To study effects of several factors on the properties of fly ash based geopolymer concrete on the compressive strength and also the
cost comparison with the normal concrete. The test variables were molarities of sodium hydroxide(NaOH) 8M,14M and 16M, ratio of
NaOH to sodium silicate (Na2SiO3) 1, 1.5, 2 and 2.5, alkaline liquid to fly ash ratio 0.35 and 0.40 and replacement of water in
Na2SiO3 solution by 10%, 20% and 30% were used in the present study. The test results indicated that the highest compressive
strength 54 MPa was observed for 16M of NaOH, ratio of NaOH to Na2SiO3 2.5 and alkaline liquid to fly ash ratio of 0.35. Lowest
compressive strength of 27 MPa was observed for 8M of NaOH, ratio of NaOH to Na2SiO3 is 1 and alkaline liquid to fly ash ratio of
0.40. Alkaline liquid to fly ash ratio of 0.35, water replacement of 10% and 30% for 8 and 16 molarity of NaOH and has resulted in
compressive strength of 36 MPa and 20 MPa respectively. Superplasticiser dosage of 2 % by weight of fly ash has given higher
strength in all cases.
Keywords: compressive strength, alkaline liquid, fly ash
Experimental investigation on circular hollow steel columns in filled with li...eSAT Journals
Abstract
Composite Circular hollow Steel tubes with and without GFRP infill for three different grades of Light weight concrete are tested for
ultimate load capacity and axial shortening , under Cyclic loading. Steel tubes are compared for different lengths, cross sections and
thickness. Specimens were tested separately after adopting Taguchi’s L9 (Latin Squares) Orthogonal array in order to save the initial
experimental cost on number of specimens and experimental duration. Analysis was carried out using ANN (Artificial Neural
Network) technique with the assistance of Mini Tab- a statistical soft tool. Comparison for predicted, experimental & ANN output is
obtained from linear regression plots. From this research study, it can be concluded that *Cross sectional area of steel tube has most
significant effect on ultimate load carrying capacity, *as length of steel tube increased- load carrying capacity decreased & *ANN
modeling predicted acceptable results. Thus ANN tool can be utilized for predicting ultimate load carrying capacity for composite
columns.
Keywords: Light weight concrete, GFRP, Artificial Neural Network, Linear Regression, Back propagation, orthogonal
Array, Latin Squares
Experimental behavior of circular hsscfrc filled steel tubular columns under ...eSAT Journals
Abstract
This paper presents an outlook on experimental behavior and a comparison with predicted formula on the behaviour of circular
concentrically loaded self-consolidating fibre reinforced concrete filled steel tube columns (HSSCFRC). Forty-five specimens were
tested. The main parameters varied in the tests are: (1) percentage of fiber (2) tube diameter or width to wall thickness ratio (D/t
from 15 to 25) (3) L/d ratio from 2.97 to 7.04 the results from these predictions were compared with the experimental data. The
experimental results) were also validated in this study.
Keywords: Self-compacting concrete; Concrete-filled steel tube; axial load behavior; Ultimate capacity.
Evaluation of punching shear in flat slabseSAT Journals
Abstract
Flat-slab construction has been widely used in construction today because of many advantages that it offers. The basic philosophy in
the design of flat slab is to consider only gravity forces; this method ignores the effect of punching shear due to unbalanced moments
at the slab column junction which is critical. An attempt has been made to generate generalized design sheets which accounts both
punching shear due to gravity loads and unbalanced moments for cases (a) interior column; (b) edge column (bending perpendicular
to shorter edge); (c) edge column (bending parallel to shorter edge); (d) corner column. These design sheets are prepared as per
codal provisions of IS 456-2000. These design sheets will be helpful in calculating the shear reinforcement to be provided at the
critical section which is ignored in many design offices. Apart from its usefulness in evaluating punching shear and the necessary
shear reinforcement, the design sheets developed will enable the designer to fix the depth of flat slab during the initial phase of the
design.
Keywords: Flat slabs, punching shear, unbalanced moment.
Evaluation of performance of intake tower dam for recent earthquake in indiaeSAT Journals
Abstract
Intake towers are typically tall, hollow, reinforced concrete structures and form entrance to reservoir outlet works. A parametric
study on dynamic behavior of circular cylindrical towers can be carried out to study the effect of depth of submergence, wall thickness
and slenderness ratio, and also effect on tower considering dynamic analysis for time history function of different soil condition and
by Goyal and Chopra accounting interaction effects of added hydrodynamic mass of surrounding and inside water in intake tower of
dam
Key words: Hydrodynamic mass, Depth of submergence, Reservoir, Time history analysis,
Evaluation of operational efficiency of urban road network using travel time ...eSAT Journals
Abstract
Efficiency of the road network system is analyzed by travel time reliability measures. The study overlooks on an important measure of
travel time reliability and prioritizing Tiruchirappalli road network. Traffic volume and travel time were collected using license plate
matching method. Travel time measures were estimated from average travel time and 95th travel time. Effect of non-motorized vehicle
on efficiency of road system was evaluated. Relation between buffer time index and traffic volume was created. Travel time model has
been developed and travel time measure was validated. Then service quality of road sections in network were graded based on
travel time reliability measures.
Keywords: Buffer Time Index (BTI); Average Travel Time (ATT); Travel Time Reliability (TTR); Buffer Time (BT).
Estimation of surface runoff in nallur amanikere watershed using scs cn methodeSAT Journals
Abstract
The development of watershed aims at productive utilization of all the available natural resources in the entire area extending from
ridge line to stream outlet. The per capita availability of land for cultivation has been decreasing over the years. Therefore, water and
the related land resources must be developed, utilized and managed in an integrated and comprehensive manner. Remote sensing and
GIS techniques are being increasingly used for planning, management and development of natural resources. The study area, Nallur
Amanikere watershed geographically lies between 110 38’ and 110 52’ N latitude and 760 30’ and 760 50’ E longitude with an area of
415.68 Sq. km. The thematic layers such as land use/land cover and soil maps were derived from remotely sensed data and overlayed
through ArcGIS software to assign the curve number on polygon wise. The daily rainfall data of six rain gauge stations in and around
the watershed (2001-2011) was used to estimate the daily runoff from the watershed using Soil Conservation Service - Curve Number
(SCS-CN) method. The runoff estimated from the SCS-CN model was then used to know the variation of runoff potential with different
land use/land cover and with different soil conditions.
Keywords: Watershed, Nallur watershed, Surface runoff, Rainfall-Runoff, SCS-CN, Remote Sensing, GIS.
Estimation of morphometric parameters and runoff using rs & gis techniqueseSAT Journals
Abstract
Land and water are the two vital natural resources, the optimal management of these resources with minimum adverse environmental
impact are essential not only for sustainable development but also for human survival. Satellite remote sensing with geographic
information system has a pragmatic approach to map and generate spatial input layers of predicting response behavior and yield of
watershed. Hence, in the present study an attempt has been made to understand the hydrological process of the catchment at the
watershed level by drawing the inferences from moprhometric analysis and runoff. The study area chosen for the present study is
Yagachi catchment situated in Chickamaglur and Hassan district lies geographically at a longitude 75⁰52’08.77”E and
13⁰10’50.77”N latitude. It covers an area of 559.493 Sq.km. Morphometric analysis is carried out to estimate morphometric
parameters at Micro-watershed to understand the hydrological response of the catchment at the Micro-watershed level. Daily runoff
is estimated using USDA SCS curve number model for a period of 10 years from 2001 to 2010. The rainfall runoff relationship of the
study shows there is a positive correlation.
Keywords: morphometric analysis, runoff, remote sensing and GIS, SCS - method
-
Effect of variation of plastic hinge length on the results of non linear anal...eSAT Journals
Abstract The nonlinear Static procedure also well known as pushover analysis is method where in monotonically increasing loads are applied to the structure till the structure is unable to resist any further load. It is a popular tool for seismic performance evaluation of existing and new structures. In literature lot of research has been carried out on conventional pushover analysis and after knowing deficiency efforts have been made to improve it. But actual test results to verify the analytically obtained pushover results are rarely available. It has been found that some amount of variation is always expected to exist in seismic demand prediction of pushover analysis. Initial study is carried out by considering user defined hinge properties and default hinge length. Attempt is being made to assess the variation of pushover analysis results by considering user defined hinge properties and various hinge length formulations available in literature and results compared with experimentally obtained results based on test carried out on a G+2 storied RCC framed structure. For the present study two geometric models viz bare frame and rigid frame model is considered and it is found that the results of pushover analysis are very sensitive to geometric model and hinge length adopted. Keywords: Pushover analysis, Base shear, Displacement, hinge length, moment curvature analysis
Effect of use of recycled materials on indirect tensile strength of asphalt c...eSAT Journals
Abstract
Depletion of natural resources and aggregate quarries for the road construction is a serious problem to procure materials. Hence
recycling or reuse of material is beneficial. On emphasizing development in sustainable construction in the present era, recycling of
asphalt pavements is one of the effective and proven rehabilitation processes. For the laboratory investigations reclaimed asphalt
pavement (RAP) from NH-4 and crumb rubber modified binder (CRMB-55) was used. Foundry waste was used as a replacement to
conventional filler. Laboratory tests were conducted on asphalt concrete mixes with 30, 40, 50, and 60 percent replacement with RAP.
These test results were compared with conventional mixes and asphalt concrete mixes with complete binder extracted RAP
aggregates. Mix design was carried out by Marshall Method. The Marshall Tests indicated highest stability values for asphalt
concrete (AC) mixes with 60% RAP. The optimum binder content (OBC) decreased with increased in RAP in AC mixes. The Indirect
Tensile Strength (ITS) for AC mixes with RAP also was found to be higher when compared to conventional AC mixes at 300C.
Keywords: Reclaimed asphalt pavement, Foundry waste, Recycling, Marshall Stability, Indirect tensile strength.
Democratizing Fuzzing at Scale by Abhishek Aryaabh.arya
Presented at NUS: Fuzzing and Software Security Summer School 2024
This keynote talks about the democratization of fuzzing at scale, highlighting the collaboration between open source communities, academia, and industry to advance the field of fuzzing. It delves into the history of fuzzing, the development of scalable fuzzing platforms, and the empowerment of community-driven research. The talk will further discuss recent advancements leveraging AI/ML and offer insights into the future evolution of the fuzzing landscape.
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
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Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
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Performance comparison of blind adaptive multiuser detection algorithms
1. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
__________________________________________________________________________________________
Volume: 02 Issue: 11 | Nov-2013, Available @ http://www.ijret.org 454
PERFORMANCE COMPARISON OF BLIND ADAPTIVE MULTIUSER
DETECTION ALGORITHMS
Khalifa Hunki1
, EhabM. Shaheen2
, Mohamed Soliman3
, K. A. El-Barbary4
1, 2, 3
Military Technical College, Cairo, Egypt
4
Suez Canal University, Suez, Egypt
hunki07@gmai.com, efareed2007@yahoo.com, mnna3000@yahoo.com, khbar2000@yahoo.com
Abstract
Blind multiuser detection algorithms are used to eliminate the Multiple Access Interference (MAI) and the Near-Far effect in mobile
communication systems. Four kinds of blind multiuser detection algorithms applied to code-division multiple-access (CDMA)
communication system are studied in this paper. Those algorithms are the Least Mean Squares (LMS), Recursive Least Squares
(RLS), Kalman filter and subspace-based Kalman filter algorithms. The resultant signal to interference ratio (SIR) at the output of the
receivers controlled by the four kinds of multi-user detection algorithm has been discussed in this paper. Simulation results show that
the subspace based Kalman filter algorithm outperforms all other three algorithms. Subspace-based Kalman filter algorithm has
faster convergence speed, more practical and the capability of CDMA system can be increased.
Keywords: Blind multiuser detection, Code-division multiple access, Mean output energy, Adaptive filtering.
---------------------------------------------------------------------***----------------------------------------------------------------------
1. INTRODUCTION
Direct-sequence code-division multiple-access (DS-CDMA)
has been widely studied in the literatures. Recently, adaptive
interference suppression techniques based on multiuser
detection have been considered as powerful methods for
increasing the quality, capacity, and coverage of CDMA
systems [1].
The mitigation of MAI in CDMA systems is a problem of
continuing interest since MAI is the dominant impairment for
CDMA systems. It is widely recognized that MAI exists even
in perfect power-controlled CDMA systems [2]. Multiuser
detectors perform better than the conventional detector under
all power distributions, except in pathological cases, such as
the decorrelating detector in extremely low signal to noise
ratio (SNR) [2]. Therefore, multiuser detection is not only a
solution to the near-far problem but is also useful even with
power control.
In order to successfully eliminate the MAI and detect the
desired user‟s information bits, one or more of the following is
usually required at the receiver end:
1) Spreading waveform of the desired user;
2) Spreading waveforms of the interfering users;
3) Propagation delay (timing) of the desired user;
4) Propagation delays of the interfering users;
5) Received amplitudes of the interfering users (relative to that
of the desired user);
6) Training data sequences for every active user
The “blind” adaptive multiuser detectors require only the
knowledge of (1) and (3), which is, the same knowledge as the
conventional receiver.
Previous work on blind adaptive multiuser detection dates
back to a 1995 paper by Honig et al. [3], who established a
canonical representation for blind multiuser detectors and used
stochastic gradient algorithms such as LMS to implement the
blind adaptive mean output energy (MOE) detector. As
elegantly shown by Roy [4], the blind adaptive MOE detector
has a smaller eigenvalue spread than the training-based
adaptive LMS detector; hence, the blind LMS algorithm
always provides (nominally) faster convergence than the
training driven LMS-MMSE receiver but at the cost of
increased tap-weight fluctuation or misadjustment.
It is well-known that the RLS algorithm and the Kalman
filtering algorithm are better than the LMS algorithm in
convergence rate and tracking capability [2]. Using the
exponentially weighted sum of error squares cost function,
Chen and Roy [5] proposed an RLS algorithm that requires the
knowledge of (1)–(4) and, thus, is not a blind multiuser
detector. Later, Poor and Wang [6] proposed an exponentially
windowed RLS algorithm for blind multiuser detection
requiring only the knowledge of (1) and (3).
On the other hand, the RLS is a special case of the Kalman
filter [7], [8], whereas the Kalman filter is known to be a
linear minimum variance state estimator [7], [9] and [10].
Motivated probably by these two facts, some attention has
been focused on Kalman filter-based adaptive multiuser
2. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
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Volume: 02 Issue: 11 | Nov-2013, Available @ http://www.ijret.org 455
detection [11]–[15]. In particular, it is shown in [13] that when
applied in an asynchronous CDMA system, the RLS algorithm
performs more poorly than the more general Kalman filter
algorithm.
Zhang and Wei [2] proposed a simple and effective state space
model for the multiuser detection problem in a stationary or
slowly fading channel and employed Kalman filter as the
adaptive algorithm. Compared with the LMS approach in [3]
and the RLS approach in [6], this detector demonstrates lower
steady-state excess output energy in adaptation. Interestingly,
though the state space model for the Kalman filter was devised
under a time-invariant assumption, the resulting algorithm
could work well in a slowly time-varying environment.
Motivated by the signal subspace concept in [16], Zhou et al.
[17] proposed a modified version of this blind adaptive
multiuser detector by modeling the detector as a vector in the
signal subspace and employing a Kalman filter philosophy
similar to that in [2] to derive the coefficients adaptively.
Compared with the full-rank approach in [2], despite some
similarity in the state-space model, this new subspace-based
multiuser detector has some significantly important merits.
First it has lower computational complexity and faster
convergence rate in terms of SIR. Secondly, it is less
conditioned on some system parameters such as the desired
users‟ signal amplitude than the full-rank method, thus it is a
blind detection method in a more strict sense. Additionally, the
detection effectiveness is maintained both in additive Gaussian
noise channels and in slowly time-varying Rayleigh fading
channels. In a dynamical system where users can enter and
leave at random, the structure of the signal subspace is also
time-varying. In this case a subspace tracking algorithm is
seamlessly integrated into the proposed detector to track the
changes and provide an online estimation of the signal
subspace.
To this end; this paperpresents and comparesthe four
mentioned algorithms.Their performances in the case of static
and dynamic channels are presented and comments are
provided to fulfill the comparative study.
2. SIGNAL MODEL
Consider an antipodal K-user synchronous DS-CDMA system
signaling through an additive white Gaussian noise channel.
By passing through a chip-matched filter, followed by a chip-
rate sampler, the discrete-time output of the receiver during
one symbol interval can be modeled as
𝑟 𝑛 = 𝐴 𝑘 𝑏 𝑘 𝑛 𝑠 𝑘 𝑛 + 𝜎𝑣 𝑛 , (1)
𝐾
𝑘=1
𝑛 = 0,1, … … . 𝑇𝑠 − 1
Where
𝑣 𝑛 ambient channel noise;
𝐾number of users;
𝐴 𝑘received amplitude of the kth
user;
𝑏 𝑘 𝑛 information symbol sequence from the kth
user,
chosen independentlyand equally from {-1,+1} ;
𝑠 𝑘 𝑛 signature waveform of the kth
user;
It is assumed that𝑠 𝑘 𝑛 is supported only on the
interval[0, 𝑇𝑠 − 1],
Where
𝑇𝑠 = 𝑁𝑇𝑐 symbol interval;
𝑇𝑐chip interval;
Nprocessing gain.
Defining
𝒓 𝑛 = 𝑟 0 , 𝑟 1 , … , 𝑟 𝑁 − 1 𝑇
𝒗 𝑛 = [𝑣 0 , 𝑣 1 , … , 𝑣 𝑁 − 1 ] 𝑇
(2)
We can express (1) in vector form
𝒓 𝑛 = 𝐴1 𝑏1 𝑛 𝒔1 + 𝐴 𝑘 𝑏 𝑘(𝑛)𝒔 𝑘
𝐾
𝑘=2
+ 𝜎𝒗 𝑛 (3)
Where
𝒔 𝑘 = (1/ 𝑁)[𝑠 𝑘 0 , 𝑠 𝑘 1 , … , 𝑠 𝑘 𝑁 − 1 ] 𝑇
is the code
sequence assigned to the kth
user.
For convenience, we will assume that the desired user is k=1.
It is well known that any linear multiuser detector for user 1
can be characterized by the tap-weight vector 𝒄1(𝑛) such that
the decision on 𝑏1 𝑛 during the nth
symbol interval is given by
𝑏1 𝑛 = 𝑠𝑔𝑛 𝒄1, 𝒓 = 𝑠𝑔𝑛 𝒄1
𝑇
, 𝒓 𝑛 (4)
Where 𝒂, 𝒃 denotes the dot product of the vectors 𝒂, 𝒃
3. BLIND ADAPTIVE MULTIUSER DETECTORS
3.1 Blind LMS Multiuser Detector
The canonical representation of a linear blind adaptive
multiuser detector for user 1 was firstly established [3] as
follows:
𝒄1 𝑛 = 𝒔1 + 𝒙1 𝑛 (5)
Subject to
𝒔1, 𝒙1 = 0 (6)
3. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
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Volume: 02 Issue: 11 | Nov-2013, Available @ http://www.ijret.org 456
Where𝒔1 is the spreading vector of the first user and 𝒄1(𝑛) is
the adaptive part of the detector. By minimizing a MOE cost
function of the form.
𝑀𝑂𝐸 𝒄1 = 𝐸 𝒓, 𝒄1
2
(7)
Honig et al. [3] have proposed a blind LMS based algorithm to
update the adaptive
𝒙1 𝑛 = 𝒙1 𝑛 − 1 − 𝜇𝑧 𝑛 𝒓 𝑛 − 𝑧 𝑀𝐹 𝑛 𝒔1 (8)
Where𝑧 𝑛 = 𝒓 𝑛 , 𝒔1 + 𝒙1(𝑛 − 1) is the output of the
detector 𝑧 𝑀𝐹 𝑛 = 𝒓 𝑛 , 𝒔1 is the output of the conventional
matched-filter, and 𝜇is the step-size that controls the
adaptation speed. The step size is given by (70) in [3], when
implementing the LMS algorithm, the step-size must satisfy
the stability condition of convergence of output MSE:
𝜇 <
2
𝐴 𝑘
2
+ 𝑁𝜎2𝐾
𝑘=1
(9)
3.2 Blind RLS Multiuser Detector
Using the minimum output energy criterion, Poor and Wang
[6] proposed a RLS algorithm for blind multiuser detection.
The exponentially windowed RLS algorithm selects the
weight vector to minimize the sum of exponentially weighted
output energy, namely
minimize 𝜆 𝑛−1
𝒄1
𝑇
𝑛 𝒓(𝑛) 2
𝑛
𝑖=1
(10)
Subject to
𝒔1
𝑇
𝒄1 𝑛 = 1 (11)
Where0 < 𝜆 > 1 is the forgetting factor. The solution to this
constrained optimization problem yields the linear MMSE
detector, which is given by [4], [11]
𝒄1 𝑛 =
𝑹−1
(𝑛)𝒔1
𝒔1
𝑇
𝑹−1(𝑛)𝒔1
(12)
Where
𝑹 𝑛 = 𝜆 𝑛−𝑖
𝒓(𝑖)𝒓 𝑇
(𝑖)
𝑛
𝑖=1
(13)
A recursive procedure for 𝒄 𝑛 updating can be obtained as
follows:
𝒌 𝑛 ≜
𝑹−1
𝑛 − 1 𝒓 𝑛
𝜆 + 𝒓 𝑇 𝑛 𝑹−1 𝑛 𝒓 𝑛
(14)
𝒉 𝑛 ≜ 𝑹−1
𝑛 𝒔1 =
1
𝜆
𝒉 𝑛 − 1 − 𝒌 𝑛 𝒓 𝑇
𝑛 𝒉(𝑛 − 1) (15)
𝒄 𝑛 =
1
𝒔 𝑇 𝒉 𝑛
𝒉 𝑛 (16)
𝑹−1
𝑛 =
1
𝜆
𝑹−1
𝑛 − 1 − 𝒌(𝑛)𝒓 𝑇
(𝑛)𝑹−1
(𝑛 − 1) (17)
3.3 Blind Multiuser Detection Based on Kalman
Filtering
In [2], Zhang et al. have proposed to use an alternative
standard representation for the blind adaptive multiuser
detector:
𝒄1 𝑛 = 𝒔1 − 𝑪1,𝑛𝑢𝑙𝑙 𝒘1 𝑛 (18)
Where the columns of the N × N− 1 matrix 𝑪1,𝑛𝑢𝑙𝑙 span the null
space of𝒔1, i.e
𝒔1
𝑇
𝑪1,𝑛𝑢𝑙𝑙 = 0 (19)
It should be noted that 𝑪1,𝑛𝑢𝑙𝑙 can be pre-computed off-line via
one of many orthogonalization procedures such as the Gram-
Schmidt orthogonalization. Unlike (5), the adaptive part
𝒘1 𝑛 in (18) is now of size (N − 1) × 1 and has the advantage
of being unconstraint. Let us define the output of the detector
as follows:
𝑧 𝑛 = 𝒄1
𝑇
𝑛 𝒓 𝑛 (20)
Then 𝑧 𝑛 has zero-mean and its variance is given by
Paragraph comes content here.
𝐸 𝑧2
(𝑛) = 𝑀𝑂𝐸 𝒄1(𝑛) = 𝑀𝑆𝐸 𝒄1 𝑛 + 𝐴1
2
(21)
Thus, when the detector is optimal (i.e., 𝑀𝑆𝐸 𝒄1(𝑛) attains
its MMSE value), the variance of 𝑧 𝑛 corresponds to the
minimum MOE and is dominated by the power of the desired
user 𝐴1
2
.
Substituting (18) in (20) yields
𝑧 𝑛 = 𝒔1
𝑇
𝒓 𝑛 − 𝒓 𝑇
𝑛 𝑪1,𝑛𝑢𝑙𝑙 𝒘1 𝑛 (22)
Put 𝑧 𝑀𝐹 (𝑛) = 𝒔1
𝑇
𝒓(𝑛)and 𝒅 𝑇
𝑛 = 𝒓 𝑇
(𝑛)𝑪1,𝑛𝑢𝑙𝑙 . If
𝒘1achieves 𝒘 𝑜𝑝𝑡 1, then (22) can be rewritten as the following
measurement equation:
𝑧 𝑀𝐹 𝑛 = 𝒅 𝑇
𝑛 𝒘 𝑜𝑝𝑡 1 𝑛 + 𝑧 𝑛 (23)
4. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
__________________________________________________________________________________________
Volume: 02 Issue: 11 | Nov-2013, Available @ http://www.ijret.org 457
If the detector is assumed to be time-invariant, one can write:
𝒘 𝑜𝑝𝑡 1 𝑛 = 𝒘 𝑜𝑝𝑡 1 𝑛 − 1 (24)
As (23) and (24) define a state-space representation of the
adaptive part of the detector, Kalman filtering makes it
possible to recursively update 𝒘 𝑛 [2].
𝒈 𝑛 = 𝑲 𝑛, 𝑛 − 1 𝒅 𝑛
× 𝒅 𝑇
𝑛 𝑲 𝑛, 𝑛 − 1 𝒅 𝑛 + 𝜉 𝑚𝑖𝑛
−1
(25)
𝑲 𝑛 + 1, 𝑛 = 𝑲 𝑛, 𝑛 − 1
−𝒈 𝑛 𝒅 𝑇
𝑛 𝑲 𝑛, 𝑛 − 1 (26)
𝒘 𝑜𝑝𝑡 1 𝑛 = 𝒘 𝑜𝑝𝑡 1 𝑛 − 1
+𝒈 𝑛 𝑧 𝑀𝐹 𝑛 − 𝒅 𝑇
𝑛 𝒘 𝑜𝑝𝑡 1 𝑛 − 1 (27)
𝒄1 𝑛 = 𝒔1 − 𝑪1,𝑛𝑢𝑙𝑙 𝒘 𝑜𝑝𝑡 1 𝑛 (28)
Where 𝒈(𝑛) is (N-1)×1 Kalman gain vector, 𝐾(𝑛 + 1, 𝑛) is
(N-1)×(N-1) correlation matrix of predicted state error and
𝜉 𝑚𝑖𝑛 = 𝑀𝑂𝐸(𝒄1(𝑛)) is the minimum MOE of the dynamical
system of user 1. The initial value𝒘 𝑜𝑝𝑡1 0 = 0and 𝑲 1,0 =
𝑰.
3.4 Subspace-based Blind Multiuser Detector using
Kalman Filter
Based on the signal model (3) and the associated independent
assumptions, the autocorrelation matrix of the received signal
𝒓(𝑛)can be expressed as
𝑹 = 𝐸 𝒓 𝑛 𝒓 𝑛 𝑇
= 𝐴 𝑘
2
𝒔 𝑘 𝒔 𝑘
𝑇
+ 𝜎2
𝑰 𝑁
𝐾
𝑘=1
= 𝑺𝑨𝑺 𝑇
+ 𝜎2
𝑰 𝑁 (29)
Where 𝑺 = 𝒔1 𝒔2 … 𝒔 𝐾 denotes the signature matrix, and
𝑨 = 𝑑𝑖𝑎𝑔 𝐴1
2
𝐴2
2
… 𝐴 𝐾
2
denotes the diagonal matrix of the
signal amplitude. On the other hand, applying an eigende
composition to the matrix 𝑹 yields
𝑹 = 𝑼𝜦𝑼 𝑇
= 𝑼 𝑠 𝜦 𝑠 𝑼 𝑠
𝑇
+ 𝑼 𝑛 𝜦 𝑛 𝑼 𝑛
𝑇
(30)
where 𝑼 = 𝑼 𝑠 𝑼 𝑛 , 𝜦 = 𝑑𝑖𝑎𝑔 𝜦 𝑠 𝜦 𝑛 . 𝚲s =
diag λ1λ2 … λK contains the K largest eigenvalues of 𝑹in
descending order, and 𝑼 𝑠contains the corresponding
orthonormal eigenvectors. 𝜦 𝑛 = 𝜎2
𝑰 𝑁−𝐾contains another N–K
eigenvalues of 𝑹and 𝑼 𝑛 contains the corresponding N–K
orthonormal eigenvectors. The column vectors of 𝑼 𝑠 and 𝑼 𝑛
span two orthogonal subspaces, namely, the signal subspace
and the noise subspace with𝑼 𝑠
𝑇
𝑼 𝑛 = 0.
In [17], Zhou et al. have proposed a new blind adaptive
multiuser detection scheme based on a hybrid of Kalman filter
and subspace estimation. The detector can be expressed as an
anchored signal in the signal subspace as follows
𝒄1 = 𝒔1 + 𝒔1𝑛𝑢𝑙𝑙 𝒘1 (31)
Subject to
𝒄1
𝑇
𝒔1 = 1 (32)
Where the column vectors of the matrix 𝒔1 𝒔1𝑛𝑢𝑙𝑙 compose
the signal subspace basis set and 𝒘1is a weight vector.
Now,𝒔1𝑛𝑢𝑙𝑙 its columns span the null space of𝒔1, i.e.
𝒔1
𝑇
𝒔1𝑛𝑢𝑙𝑙 = 0 , and they are orthonormal, i.e. 𝒔1𝑛𝑢𝑙𝑙
𝑇
𝒔1𝑛𝑢𝑙𝑙 =
𝑰 𝐾−1 . Since 𝒔1is assumed to be known and 𝒔1𝑛𝑢𝑙𝑙 can be
obtained, for example, by applying eigenvalue decomposition
(EVD) to the autocorrelation matrix𝑹.
In order to find the optimal weight vector 𝒘1that minimizes
the MAI. It is demonstrated this vector can be estimated by
using the Kalman filter method [2]. The Subspace Kalman
blind adaptive algorithm is summarized in Table-1.
Table -1: Subspace-Based Kalman Filtering Estimation for
Blind Multiuser Detection
Step 1:
Signal Subspace Estimation:
*Compute autocorrelation matrix 𝑹 for a batch of J
symbols
𝑹 =
1
𝐽
𝒓𝑗 𝒓𝑗
𝑇
𝐽
𝑗=1
* Perform eigenvalue decomposition of 𝑹
𝑹 = 𝑼𝜦𝑼 𝑇
= 𝑼 𝑠 𝜦 𝑠 𝑼 𝑠
𝑇
+ 𝑼 𝑛 𝜦 𝑛 𝑼 𝑛
𝑇
* From matrix
𝒁 = 𝒔1 𝒖1 … 𝒖 𝐾−1
where
𝒖𝑖 is the ith
column vector of 𝑼 𝑠, ∀𝑖 = 1, … , 𝐾 − 1
* Apply Gram-Schmidt method on 𝒁 to obtain an
orthonormal matrix
𝒀 = 𝒔1 𝒚1 … 𝒚 𝐾−1
* Let
𝒔1𝑛𝑢𝑙𝑙 = 𝒚1 … 𝒚 𝐾−1
be the null signal subspace of 𝒔1
Step 2:
Kalman Filtering Estimation in Symbol-rate Adaptation:
* For n=1, 2, …
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Volume: 02 Issue: 11 | Nov-2013, Available @ http://www.ijret.org 458
* Implement Kalman filter algorithm according to
(25)-(27)
* Signal detection
𝒄1(𝑛) = 𝒔1 + 𝒔1𝑛𝑢𝑙𝑙 𝒘 𝑜𝑝𝑡 1(𝑛)
𝑏1(𝑛) = 𝑠𝑔𝑛 𝒄1
𝑇
(𝑛), 𝒓(𝑛)
* End
4. COMPUTATION COMPLEXITY
We now compare the computational complexity of LMS [3],
RLS [6], Kalman [2], and Subspace Kalman blind adaptive
algorithms [17]. The computational complexities of four
algorithms are compared in term of the number of
multiplications and additions per adaptation iteration as shown
in Table-2.
Table -1: Comparison of Computational Complexity
Algorithm Computational
Complexity
LMS algorithm [3] O(N)
RLS algorithm [6] O(N2
)
Kalman filtering algorithm [2] O(N2
)
Subspace Kalman filtering
algorithm [17] O(NK)
Generally, N>>K; thus, Subspace Kalman has much less
computational complexity than the RLS and Kalman filtering
algorithms.
5. SIMULATION RESULTS
In this section, several simulation results that compare among
the four algorithms for blind multiuser detection are presented.
As a figure of merit for assessing the MAI suppression
capability of the blind LMS, RLS, Kalman filtering, and
subspace-based Kalman filtering algorithms, the time-
averaged SIR (in decibels) at the nth
iteration is given by [3]
𝑆𝐼𝑅 𝑛 = 10𝑙𝑜𝑔
𝒄1𝑙
𝑇
𝑛 𝒔1
2𝑀
𝑙=1
𝒄1𝑙
𝑇
𝑛 𝒓𝑙 𝑛 − 𝑏1,𝑙 𝑛 𝒔1
2𝑀
𝑙=1
(33)
Where 𝑀 is the number of independent runs, and the subscript
𝑙 indicates that the associated variable depends on the
particular run. All signal energies are given in decibels relative
to the background noise variance 𝜎2
, i.e., the SNR of user 𝑘 is
defined by 𝑆𝑁𝑅 = 10𝑙𝑜𝑔 𝐸𝑘 𝜎2
, where 𝐸𝑘 = 𝐴 𝑘
2
is the bit
energy of user 𝑘. In all simulations, user 1 is assumed to be
the desired user that has the unit energy 𝐴1
2
= 1 and an SNR of
20 dB (i.e., 𝜎2
= 0.01), and the processing gain 𝑁 = 31. In
the following, the data in each plot are the average over 500
independent runs.
5.1 Convergence Rate Comparison
In Example 1, DS-CDMA systems in a Gaussian channel are
simulated, and there are nine multiple-access interfering users
among which five users have an SNR of 30 dB each, three
users have SNR of 40 dB each, and another user has an SNR
of 50 dB, i.e., 𝐴2
2
= … = 𝐴6
2
= 10, 𝐴7
2
= 𝐴8
2
= 𝐴9
2
= 100, and
𝐴10
2
= 1000. Then, from (9), it follows that the step size
should satisfy 𝜇 < 1.47 × 10−3
, and thus, μ = 3 × 10−4
was
used in the LMS algorithm. When applying the RLS
algorithm, the initial value 𝑹−1
0 = 𝛿−1
𝑰takes 𝛿 = 0.01, and
the forgetting factor 𝜆 = 0.997 is taken. In Kalman filtering,
we used, the estimate 𝜁 𝑚𝑖𝑛 = 1in (25),
The time-averaged SIR versus iteration numbers for the four
algorithms is plotted in Fig. 1. It is seen that the performance
of the subspace-based Kalman filtering algorithms outperform
the rest. When n is sufficiently large subspace-based Kalman
filtering algorithm approach SNR=19dB. This means that the
MAI in the SIR has been eliminated almost completely.
However, note that the subspace-based algorithm achieves this
near-optimum performance at a significantly reduced
computational complexity compared with the full-rank
algorithm. Fig. 2 shows the mean square error (MSE) versus
iteration number (time) for the four algorithms applied in a
synchronous CDMA system. The most slow algorithm is the
LMS while the other three algorithms reach the minimum
MSE faster than LMS.
Fig -1: Time-averaged SIR versus time for 500 runs when
using the four algorithms to a synchronous CDMA system
with processing gain N = 31.
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Volume: 02 Issue: 11 | Nov-2013, Available @ http://www.ijret.org 459
Fig -2: MSE versus time for 500 runs when using the four
algorithms to a synchronous CDMA system with processing
gain N = 31.
5.2 Tracking Dynamical Environment
In Example 2, we compare the tracking capabilities of the
LMS, RLS, Kalman filtering, and subspace-based Kalman
filtering algorithms in a dynamical environment with a time-
varying number of users for DS-CDMA systems in a Gaussian
channel. When 𝑛 < 600, the configuration is the same as
Example 1. At 𝑛 = 600, three interfering users with SNR of
40 dB are added to the CDMA system at the same time. At
𝑛 = 1200, four interfering users with SNR of 40 dB and one
interfering user with SNR of 50 dB are removed from the
system. The subspace-based Kalman filter use projection
approximation subspace tracking with deflation (PASTd)
algorithm to track the rank and signal subspace with the
forgetting factor 𝛽 = 0.997. Fig. 3 show the tracking
behaviors of the four blind adaptive algorithms in a
synchronous system.
In Fig. 3, It is also seen that the Kalman filter tracks faster
than the subspace approaches due to the reason that in the
subspace tracking strategy, the subspace-based algorithm
includes two adaptation phases, that is, adaptive subspace
tracking and then adaptive signal detection, whereas the full-
rank detector includes only one adaptation phase.
Fig -3: Time-averaged SIR versus time for 500 runs when
using the four algorithms to a synchronous CDMA system
with processing gain N = 31 and the time-varying number of
users.
5.3 Slowly Time-Varying Environment
Example 3 is a synchronous DS-CDMA system in a Rayleigh
fading channel. We assume a single-path Rayleigh-fading
channel with a Doppler frequency of 22 Hz, which is obtained
based on Jakesmodel [18]. The signal model is expressed by
𝑟 𝑛 = 𝐴 𝑘 𝑏 𝑘 𝑛 ℎ 𝑘 𝑠 𝑘 𝑛 + 𝜎𝑣 𝑛 , (34)
𝐾
𝑘=1
𝑛 = 0,1, … , 𝑇𝑠 − 1
Where ℎ 𝑘 is the channel coefficient for the kth
user and is a
random variable following Rayleigh distribution The
convergence curves for the subspace-based Kalman filter, the
Kalman filter and the RLS are plotted in Fig. 4. The results
show that all algorithms can track the slow channel
fluctuation, and the subspace-based Kalman filtering detector
still yields better performance than the other two detectors.
The MSE curves of the three algorithms are shown in Fig. 5.
The curves show that all of them have the same residual error
while the subspace-based Kalman filter is the faster algorithm.
5.4 BER Performance Comparison
In Example 4, we evaluate the BER performance of the four
algorithms versus SNR in Rayleigh fading channel, the
configuration is the same as Example 1. The receivers process
10000 symbols and averaged over 100 independent runs for all
BER simulations. The results in Fig. 6 indicate that the
subspace-based Kalman filter and the full-rank Kalman
filtering algorithms outperform the RLS and LMS algorithms.
The performance of the subspace-based Kalman filter
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Volume: 02 Issue: 11 | Nov-2013, Available @ http://www.ijret.org 460
algorithm is close to the Kalman filtering algorithm but with
much lower complexity.
Fig -4: Time-averaged SIR versus time for 500 runs when
using the three algorithms with 𝜆 = 0.997 to a synchronous
CDMA system in Rayleigh fading channel; the processing
gain is N = 31.
Fig -5: MSE versus time for 500 runs when using the three
algorithms with 𝜆 = 0.997 to a synchronous CDMA system in
Rayleigh fading channel; the processing gain is N = 31.
Fig -6: BER versus SNR for 100 runs when using the four
algorithms to a synchronous CDMA system in Rayleigh
fading channel.
CONCLUSIONS
In this paper, we have analyzed the SIR and MSE performance
of four blind-adaptive algorithms. Subspace-based Kalman
filter has near-far resistant, lower computational complexity,
and better convergence performance compared with another
algorithms. It is effective in both AWGN channel and slowly
time-varying Rayleigh-fading channel. It is also a blind
detection method in a stricter sense because it is less
conditioned on the knowledge of the signal amplitude of the
desired user. Adaptation in the dynamic environment with
variable number of users is enabled by seamlessly integrating
a subspace tracking methodology at the cost of slight
increment in computational complexity.
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BIOGRAPHIES
KhalifaHunkireceived the B.S. degree in
electronic engineering from Engineering
Academy Tajoura, Tajoura, Libya, in 2001
and the M.Sc. degree in electronic engineering
from the Military Technical College, Cairo,
Egypt, in 2008.Currently, he is working
toward the Ph.D. degree with the Department of Electronic
Warfare, Military Technical College, Egypt. His research
interests include multiuser detection, and adaptive signal
processing.
Ehab M. Shaheenwas born in Cairo, Egypt,
on March 16, 1973 Obtained the B.Sc. and
M.Sc. in electrical engineering in 1995 and
2000 respectively, both from Military
Technical College in Cairo, Egypt, and the
Ph.D. in Computer and Electrical Engineering
from Carleton University, Ottawa, Ontario, Canada in
2010.He joined the Military Technical College in 2011 and he
is currently astaff in the Electronic Warfare Department where
his current research interests include ultra-wideband (UWB)
radio communications, spread-spectrum and secure
communication signalsand digital communications over multi-
path fading channels.
Mohamed Soliman received the BEng.
degree in Comunication and the Master of
Science degree from the Military Technical
College, Egypt 1993 and 2001, respectively.
Between 1993 and 2006, he was an
engineering officer in Egyptian armed forces. Since 2006, he
has been a PhD student in the School of Electrical and
Electronic Engineering, University of Manchester. He
received his PhD from the Manchester University in January
2009.
K.A. El-Barbary received the B. S. degree
(with Average Grade Very Good) in Electric
Engineering from Military Technical
College, Egypt , the M.S. degree in Electric
Engineering from Military Technical
College, Egypt, the Ph.D. degree in
Communications from George Washington University,
Washington DC, USA, in 1981, 1986 and 1993, respectively.
He was faculty member at Military Technical College, Egypt
in the Electric Engineering Department (Chair of
communications and Electronic warfare) (1994-2010). There
he became a professor of Electric Engineering (2009), Head of
Electronic Warfare Engineering Department (2000), and Head
of Electrical Engineering Department (2009). He has been a
professor of signal and systems and Communications at Suez
Canal University, Egypt in Electric Engineering Department.
Currently he is the Head of Electric Engineering Department,
Suez Canal University, Egypt. His research interests include
Statistical signal and array processing and related applications
in communications, radar, Electronic Intelligence, Multi user
Detectors and wideband systems.