In this paper, a combined approach where low density
parity check (LDPC) codes are used to reduce the complexity
and power consumption of pulsed orthogonal frequencydivision
multiplexing (pulsed-OFDM) ultra-wideband (UWB)
systems is described. The proposed system uses LDPC codes
to achieve higher code rates without using convolution
encoding and puncturing thereby reducing the complexity and
power consumption of pulsed-OFDM system. The LDPCpulsed-
OFDM system achieves channel capacity with different
code rates and has good performance in different channel
fading scenarios. The pulsed OFDM system is used where
pulsed signals could spread the frequency spectrum of the
OFDM signal. The performance of LDPC-pulsed-OFDM
system for wireless personal area networks (WPAN) is
analyzed for different UWB indoor propagation channels (CM3
and CM4) provided by the IEEE 802.15.3a Standard activity
committee. To establish this, a design of LDPC-pulsed-OFDM
system using the digital video broadcasting-satellite-second
generation (DVB-S2) standard and provide the simulation
results for the different code rates supported by LDPC codes
is presented.
This document discusses improving the bit error rate of OFDM transmission using turbo codes. It provides an overview of OFDM and its benefits, including its ability to combat multipath interference. However, OFDM results in burst errors that can degrade coding efficiency. The document proposes using turbo codes with OFDM since turbo codes can achieve performance close to the Shannon limit. It reviews the basic principles of turbo code design and encoding/decoding. The rest of the document outlines simulations done to test the performance of a turbo code combined with OFDM over AWGN and impulsive noise channels.
This document describes the design and implementation of a wideband digital down converter (DDC) on an FPGA. It discusses the theoretical blocks of a DDC including a numerically controlled oscillator (NCO), mixer, cascaded integrate-comb (CIC) filter, compensation FIR filter, and programmable FIR filter. It also describes implementing each block using advanced methods and testing the design on an FPGA using Xilinx software and a Chip Scope Pro Analyzer tool. Simulation results showing the output at each DDC block are presented.
The document analyzes the performance of LDPC coded WLAN physical layer under BPSK and 16-QAM modulation. It finds that an LDPC encoded WLAN system with a code rate of (48,46) performs best under BPSK modulation in an AWGN channel, achieving the lowest bit error rate. Simulation results show LDPC coding improves performance by reducing bit error rates compared to without coding. The best performing configuration provides power efficiency through lower transmitted power requirements for a given bit error rate.
This document summarizes issues related to medium access control (MAC) protocols for wireless ad hoc networks. It discusses common MAC protocols like ALOHA, Slotted ALOHA, CSMA, and their variants. It also covers protocols specific to wireless networks like MACA, MACAW, and CSMA/CA. Additional topics covered include Bluetooth, wireless mesh networks, mobile ad hoc networks, and wireless sensor networks. Simulation tools for modeling wireless ad hoc networks are also mentioned.
Comparative performance analysis of different modulation techniques for papr ...IJCNCJournal
One of the most important multi-carrier tran
smission techniques used in the latest wireless com
munication
arena is known as Orthogonal Frequency Division Mul
tiplexing (OFDM). It has several characteristics
such as providing greater immunity to multipath fad
ing & impulse noise, eliminating Inter Symbol
Interference (ISI) & Inter Carrier Interference (IC
I) using a guard interval known as Cyclic Prefix (C
P). A
regular difficulty of OFDM signal is high peak to a
verage power ratio (PAPR) which is defined as the r
atio
of the peak power to the average power of OFDM Sign
al. An improved design of amplitude clipping &
filtering technique of us previously reduced signif
icant amount of PAPR with slightly increase bit err
or rate
(BER) compare to an existing method in case of Quad
rature Phase Shift Keying (QPSK) & Quadrature
Amplitude Modulation (QAM). This paper investigates
a comparative performance analysis of the differen
t
higher order modulation techniques on that design.
Orthogonal Frequency Division Multiplexing (OFDM)Gagan Randhawa
The document discusses Orthogonal Frequency Division Multiplexing (OFDM), including its principles, advantages, disadvantages and applications. OFDM divides the available spectrum into multiple orthogonal subcarriers, each modulated with a low data rate stream. This makes OFDM robust to multipath fading and intersymbol interference. While OFDM provides high data rates and spectral efficiency, it suffers from issues like high peak-to-average power ratio and sensitivity to frequency errors. OFDM is used in technologies like WiFi, WiMAX and digital audio/video broadcasting.
CDMA Transmitter and Receiver Implementation Using FPGAIOSR Journals
Abstract: Code Division Multiple Access (CDMA) is a spread spectrum technique that uses neither frequency channels nor time slots. With CDMA, the narrow band message (typically digitized voice data) is multiplied by a large bandwidth signal that is a pseudo random noise code (PN code). All users in a CDMA system use the same frequency band and transmit simultaneously. The transmitted signal is recovered by correlating the received signal with the PN code used by the transmitter. The DS - CDMA is expected to be the major medium access technology in the future mobile systems owing to its potential capacity enhancement and the robustness against noise. The CDMA is uniquely featured by its spectrum-spreading randomization process employing a pseudo-noise (PN) sequence, thus is often called the spread spectrum multiple access (SSMA). As different CDMA users take different PN sequences, each CDMA receiver can discriminate and detect its own signal, by regarding the signals transmitted by other users as noise- like interferences. In this project direct sequence principle based CDMA transmitter and receiver is implemented in VHDL for FPGA. Modelsim 6.2(MXE) tool will be used for functional and logic verification at each block. The Xilinx synthesis technology (XST) of Xilinx ISE 9.2i tool will be used for synthesis of transmitter and receiver on FPGA Spartan 3E. Keywords: CDMA, DSSS, BPSK, GOLD code.
Orthogonal frequency-division multiplexing (OFDM) is a promising technique for achieving high data rate transmission in mobile environments. It is a form of multicarrier modulation where a single data stream is transmitted over multiple orthogonal subcarriers. OFDM divides the total available bandwidth into multiple sub-bands and transmits low rate data streams over each sub-band in parallel to construct a high-rate communication system. It offers robustness against fading, narrowband interference, and inter-symbol interference.
This document discusses improving the bit error rate of OFDM transmission using turbo codes. It provides an overview of OFDM and its benefits, including its ability to combat multipath interference. However, OFDM results in burst errors that can degrade coding efficiency. The document proposes using turbo codes with OFDM since turbo codes can achieve performance close to the Shannon limit. It reviews the basic principles of turbo code design and encoding/decoding. The rest of the document outlines simulations done to test the performance of a turbo code combined with OFDM over AWGN and impulsive noise channels.
This document describes the design and implementation of a wideband digital down converter (DDC) on an FPGA. It discusses the theoretical blocks of a DDC including a numerically controlled oscillator (NCO), mixer, cascaded integrate-comb (CIC) filter, compensation FIR filter, and programmable FIR filter. It also describes implementing each block using advanced methods and testing the design on an FPGA using Xilinx software and a Chip Scope Pro Analyzer tool. Simulation results showing the output at each DDC block are presented.
The document analyzes the performance of LDPC coded WLAN physical layer under BPSK and 16-QAM modulation. It finds that an LDPC encoded WLAN system with a code rate of (48,46) performs best under BPSK modulation in an AWGN channel, achieving the lowest bit error rate. Simulation results show LDPC coding improves performance by reducing bit error rates compared to without coding. The best performing configuration provides power efficiency through lower transmitted power requirements for a given bit error rate.
This document summarizes issues related to medium access control (MAC) protocols for wireless ad hoc networks. It discusses common MAC protocols like ALOHA, Slotted ALOHA, CSMA, and their variants. It also covers protocols specific to wireless networks like MACA, MACAW, and CSMA/CA. Additional topics covered include Bluetooth, wireless mesh networks, mobile ad hoc networks, and wireless sensor networks. Simulation tools for modeling wireless ad hoc networks are also mentioned.
Comparative performance analysis of different modulation techniques for papr ...IJCNCJournal
One of the most important multi-carrier tran
smission techniques used in the latest wireless com
munication
arena is known as Orthogonal Frequency Division Mul
tiplexing (OFDM). It has several characteristics
such as providing greater immunity to multipath fad
ing & impulse noise, eliminating Inter Symbol
Interference (ISI) & Inter Carrier Interference (IC
I) using a guard interval known as Cyclic Prefix (C
P). A
regular difficulty of OFDM signal is high peak to a
verage power ratio (PAPR) which is defined as the r
atio
of the peak power to the average power of OFDM Sign
al. An improved design of amplitude clipping &
filtering technique of us previously reduced signif
icant amount of PAPR with slightly increase bit err
or rate
(BER) compare to an existing method in case of Quad
rature Phase Shift Keying (QPSK) & Quadrature
Amplitude Modulation (QAM). This paper investigates
a comparative performance analysis of the differen
t
higher order modulation techniques on that design.
Orthogonal Frequency Division Multiplexing (OFDM)Gagan Randhawa
The document discusses Orthogonal Frequency Division Multiplexing (OFDM), including its principles, advantages, disadvantages and applications. OFDM divides the available spectrum into multiple orthogonal subcarriers, each modulated with a low data rate stream. This makes OFDM robust to multipath fading and intersymbol interference. While OFDM provides high data rates and spectral efficiency, it suffers from issues like high peak-to-average power ratio and sensitivity to frequency errors. OFDM is used in technologies like WiFi, WiMAX and digital audio/video broadcasting.
CDMA Transmitter and Receiver Implementation Using FPGAIOSR Journals
Abstract: Code Division Multiple Access (CDMA) is a spread spectrum technique that uses neither frequency channels nor time slots. With CDMA, the narrow band message (typically digitized voice data) is multiplied by a large bandwidth signal that is a pseudo random noise code (PN code). All users in a CDMA system use the same frequency band and transmit simultaneously. The transmitted signal is recovered by correlating the received signal with the PN code used by the transmitter. The DS - CDMA is expected to be the major medium access technology in the future mobile systems owing to its potential capacity enhancement and the robustness against noise. The CDMA is uniquely featured by its spectrum-spreading randomization process employing a pseudo-noise (PN) sequence, thus is often called the spread spectrum multiple access (SSMA). As different CDMA users take different PN sequences, each CDMA receiver can discriminate and detect its own signal, by regarding the signals transmitted by other users as noise- like interferences. In this project direct sequence principle based CDMA transmitter and receiver is implemented in VHDL for FPGA. Modelsim 6.2(MXE) tool will be used for functional and logic verification at each block. The Xilinx synthesis technology (XST) of Xilinx ISE 9.2i tool will be used for synthesis of transmitter and receiver on FPGA Spartan 3E. Keywords: CDMA, DSSS, BPSK, GOLD code.
Orthogonal frequency-division multiplexing (OFDM) is a promising technique for achieving high data rate transmission in mobile environments. It is a form of multicarrier modulation where a single data stream is transmitted over multiple orthogonal subcarriers. OFDM divides the total available bandwidth into multiple sub-bands and transmits low rate data streams over each sub-band in parallel to construct a high-rate communication system. It offers robustness against fading, narrowband interference, and inter-symbol interference.
This document summarizes a research paper that investigates reducing peak-to-average power ratio (PAPR) in an MC-CDMA system using partial transmit sequence (PTS) technique with a suboptimal combination algorithm. The paper simulates a downlink MC-CDMA system with BPSK and QPSK modulation under varying system parameters like number of users and phase sequences. Results show the complementary cumulative distribution function (CCDF) of PAPR for the original and PTS-processed signals. Using PTS with 4, 8, or 16 phase sequences provides 1dB, 2dB, and 4.2dB of PAPR reduction respectively compared to the original signal for a 8-user BPSK modulated MC-CD
This document discusses the use of cyclic prefixes in OFDM transmission to mitigate inter-block interference caused by multipath propagation. It contains the following key points:
1) OFDM divides the frequency band into multiple narrow sub-carriers to combat frequency selectivity of channels. Cyclic prefixes are added to prevent interference between blocks.
2) The last samples of each OFDM symbol are copied and prefixed to form the cyclic prefix, which absorbs multipath interference from previous symbols.
3) At the receiver, the cyclic prefix is removed and the remaining samples are processed. The cyclic prefix prevents symbol spreading during convolution with the channel, allowing independent processing of each block.
OFDM allows tightly packed carriers to convey information orthogonally and with high bandwidth efficiency
Objectives Description:
Concepts
Basic idea
Introduction to OFDM
Implementation
Advantages and Drawbacks.
FDMA
The document discusses Orthogonal Frequency Division Multiplexing (OFDM) and its applications in various wireless communication standards. It begins with the motivation for moving from single carrier to multi-carrier modulation schemes to support higher data rates. It then provides an overview of Frequency Division Multiplexing (FDM) and OFDM, explaining the basic principles of OFDM including orthogonality, modulation, and an illustrative example. The document discusses the OFDM transceiver and bit error rate performance in AWGN and Rayleigh fading channels. It also covers some applications and standards that use OFDM such as Digital Audio Broadcasting (DAB), Digital Video Broadcasting (DVB-T), and various IEEE 802.11 wireless networking standards.
Orthogonal Frequency Division Multiplexing, OFDM uses a large number of narrow sub-carriers for multi-carrier transmission to overcome the effect of multi path fading problem. LTE uses OFDM for the downlink, from base station to terminal to transmit the data over many narrow band careers of 180 KHz each instead of spreading one signal over the complete 5MHz career bandwidth. OFDM meets the LTE requirement for spectrum flexibility and enables cost-efficient solutions for very wide carriers with high peak rates.
The primary advantage of OFDM over single-carrier schemes is its ability to cope with severe channel conditions. Channel equalization is simplified. The low symbol rate makes the use of a guard interval between symbols affordable, making it possible to eliminate inter symbol interference (ISI).
This document discusses spread spectrum multiple access (SSMA) techniques. It describes spread spectrum systems and their applications including security, robustness against interference, and providing multiple access. It then discusses two SSMA techniques - frequency hopped multiple access (FHMA) and direct sequence multiple access (DSMA), also called code division multiple access (CDMA). It provides details on how FHMA and CDMA work, including advantages of CDMA such as low power spectral density, interference limited operation, and privacy.
Performance analysis of DWT based OFDM over FFT based OFDM and implementing o...VLSICS Design
Growth in technology has led to unprecedented demand for high speed architectures for complex signal processing applications. In 4G wireless communication systems, bandwidth is a precious commodity, and service providers are continuously met with the challenge of accommodating more users with in a limited allocated bandwidth. To increase data rate of wireless medium with higher performance, OFDM (orthogonal frequency division multiplexing) is used. Recently DWT (Discrete wavelet transforms) is adopted in place of FFT (Fast Fourier transform) for frequency translation. Modulation schemes such as 16-QAM, 32-QAM, 64-QAM and 128-QAM (Quadrature amplitude modulation) have been used in the developed OFDM system for both DWT and FFT based model. In this paper we propose a DWT-IDWT based OFDM transmitter and receiver that achieve better performance in terms SNR and BER for AWGN channel. It proves all the wavelet families better over the IFFT-FFT implementation. The OFDM model is developed using Simulink, various test cases have been considered to verify its performance. The DWTOFDM using Lifting Scheme architecture is implemented on FPGA optimizing hardware, speed & cost. The wavelet filter used for this is Daubechies (9, 7) with N=2. The RTL code is written in Verilog-HDL and simulated in Modelsim. The design is then synthesized in Xilinx and implemented on Virtex5 FPGA board and the results were validated using ChipScope.
This document compares frequency division duplexing (FDD) and time division duplexing (TDD) for the IEEE 802.3 EPoC Study Group. It finds that FDD can support the target throughput of 1 Gbps upstream and 10 Gbps downstream over existing coaxial cable infrastructure using frequencies up to 1200 MHz. TDD may be beneficial in limited node+0 scenarios above 1 GHz but with significantly increased complexity and costs. The document concludes that FDD should be adopted for EPoC as it can start deployment immediately with available technology and supports the requirements over all installation scenarios, while TDD provides minimal benefits and added complexity.
This document summarizes a research paper that analyzes the performance of different pilot-based channel estimation schemes for OFDM systems using QPSK and 16-QAM modulation over Rayleigh fading channels with Doppler frequency shifts. It compares block-type pilot arrangement, which inserts pilots into all subcarriers periodically, to comb-type arrangement, which inserts pilots into each symbol and requires interpolation. It evaluates channel estimation algorithms like LS, LMMSE, SVD for block pilots and linear, quadratic, and cubic spline interpolation for comb pilots. The goal is to analyze how bit error rate is affected by Doppler shifts. Simulations are conducted in MATLAB to compare the schemes.
Qo s provisioning for scalable video streaming over ad hoc networks using cro...Mshari Alabdulkarim
This document discusses providing quality of service (QoS) for scalable video streaming over ad-hoc networks using cross-layer design. It begins by introducing multi-hop wireless networks and ad-hoc networks, noting their advantages and challenges. It then discusses QoS and cross-layer design approaches. The document proposes using cross-layer design to provision QoS for scalable video streaming over ad-hoc networks in order to overcome challenges like variable topology, limited resources and interference.
The document summarizes a proposed scheme for rapid signal acquisition in direct sequence spread spectrum (DSSS) communication systems operating in high Doppler environments. The scheme uses time domain correlation of differential signals to estimate pseudo-noise (PN) code phase, followed by fast Fourier transform (FFT) to precisely estimate Doppler frequency. An area-efficient field programmable gate array (FPGA) architecture is presented that combines time and frequency domain approaches. The architecture achieves 52% area occupancy when synthesized for a Virtex-6 FPGA and operates at 134 MHz, allowing for fast signal acquisition needed in applications like missile guidance systems.
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
This document discusses the design and analysis of multirate filters for WiMAX applications. It proposes a programmable multirate filter architecture that can be implemented using software-defined radio technology and multirate signal processing principles. The filters are designed using MATLAB's filter design and analysis tool to meet WiMAX specifications. A digital upconverter is presented that uses three cascaded FIR filters with interpolation factors of 1, 2, and 4 to achieve an overall interpolation factor of 8 as required by WiMAX. The filters are analyzed and simulated in MATLAB to verify they satisfy WiMAX's spectral mask requirements.
This document provides an overview of Orthogonal Frequency Division Multiplexing (OFDM), Orthogonal Frequency Division Multiple Access (OFDMA) and Scalable OFDMA (SOFDMA). It describes how OFDM divides available bandwidth into multiple orthogonal subcarriers to combat multipath interference in wireless channels. OFDMA further divides subcarriers to enable multiple access by multiple users. SOFDMA, defined in IEEE 802.16e, allows dynamic allocation of subcarriers for scalable bandwidth allocation to users.
Cooperative Diversity - An Introduction to Cooperative CommAshish Meshram
The document provides an introduction to cooperative diversity and cooperative communication techniques. It discusses the motivation for cooperative diversity as a way to achieve spatial diversity without multiple antennas at mobile units. The key aspects covered include:
- Cooperative diversity protocols like amplify-and-forward (AF) and decode-and-forward (DF) where the relay assists transmission from the source to the destination.
- The application of cooperative diversity techniques to improve cellular capacity and coverage, wireless local area networks, vehicle-to-vehicle communication, and wireless sensor networks.
- The mathematical modeling of the relay channel and simplified single-relay system models for AF and DF protocols.
- Analysis of outage probability for the AF protocol and
CDMA allows multiple users to share the same channel by assigning each user a unique code. It spreads the user's data signal over a wider bandwidth through multiplication with a pseudo-random code. This allows different signals to be separated at the receiver through correlation with the corresponding code. Major technologies using CDMA include WiFi, Bluetooth, and GPS, which employ techniques like DSSS, FHSS, and long/short codes. Performance of 802.11 networks can be analyzed based on collision probability and throughput calculations under saturated traffic conditions. Later developments expanded CDMA capabilities with techniques like W-CDMA, TD-CDMA, and TD-SCDMA.
This slide includes
Advanced multiplexing
Code Division Multiplexing
Dense Wavelength Division Multiplexing
OFDM
Connectionless
LAN
L3 SWTICH
SLIP
PPP
CORE AND DISTRIBUTION NETWORKS.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
This document summarizes a research paper that proposes a space-time block coded (STBC) orthogonal frequency-division multiplexing (OFDM) system for text message transmission over fading channels using multiple transmit antennas. The system utilizes low-density parity-check channel coding concatenated with convolutional coding. Simulation results show that the proposed system achieves good error rate performance, especially when using BPSK modulation with 2x4 transmit antennas in AWGN, Rayleigh, and Rician fading channels. The system is effective in properly identifying and retrieving transmitted text messages in noisy and fading environments.
This document describes a space-time block coding (STBC) orthogonal frequency-division multiplexing (OFDM) system for text message transmission over fading channels using multiple transmit antennas. It evaluates the bit error rate (BER) performance of the system using different digital modulation schemes (BPSK, QPSK, QAM-8) over additive white Gaussian noise (AWGN) channels and fading channels. Low-density parity-check (LDPC) coding is concatenated with convolutional coding in the system to improve error performance. Simulation results show that the system is effective in retrieving the transmitted text message under noise and fading conditions, and that BER performance degrades with increasing noise power as expected.
This document discusses the use of cyclic prefixes in OFDM transmission to mitigate inter-block interference caused by multipath propagation. It contains the following key points:
1) OFDM divides the frequency band into multiple narrow sub-carriers to combat frequency selectivity of channels. Cyclic prefixes are added to prevent interference between blocks.
2) The last samples of each OFDM symbol are copied and added to the front as a cyclic prefix, which absorbs multipath interference from previous symbols.
3) At the receiver, the cyclic prefix is removed and the remaining samples are processed. The cyclic prefix prevents symbol spreading during convolution with the channel, allowing independent processing of each block.
OPTICAL SWITCHING CONTROLLER USING FPGA AS A CONTROLLER FOR OCDMA ENCODER SYSTEMEditor IJCATR
This paper proposed a design of optical switching controller using FPGA for OCDMA encoder system. The encoder is one
of the new technologies that use to transmit the coded data in the optical communication system by using FPGA and optical switches.
It is providing a high security for data transmission due to all data will be transmitting in binary code form. The output signals from
FPGA are coded with a binary code that given to an optical switch before it signal modulate with the carrier and transmit to the
receiver. In this paper, AA and 55 data were used for source 1 and source 2. It is generated sample data and sent packet data to the
FPGA and stored it into RAM. The simulation results have done by using software Verilog Spartan 2 programming to simulate. After
that the output will produces at waveform to display the output. The main function of FPGA controlling unit is producing single pulse
and configuring optical switching system.
This document summarizes a research paper that investigates reducing peak-to-average power ratio (PAPR) in an MC-CDMA system using partial transmit sequence (PTS) technique with a suboptimal combination algorithm. The paper simulates a downlink MC-CDMA system with BPSK and QPSK modulation under varying system parameters like number of users and phase sequences. Results show the complementary cumulative distribution function (CCDF) of PAPR for the original and PTS-processed signals. Using PTS with 4, 8, or 16 phase sequences provides 1dB, 2dB, and 4.2dB of PAPR reduction respectively compared to the original signal for a 8-user BPSK modulated MC-CD
This document discusses the use of cyclic prefixes in OFDM transmission to mitigate inter-block interference caused by multipath propagation. It contains the following key points:
1) OFDM divides the frequency band into multiple narrow sub-carriers to combat frequency selectivity of channels. Cyclic prefixes are added to prevent interference between blocks.
2) The last samples of each OFDM symbol are copied and prefixed to form the cyclic prefix, which absorbs multipath interference from previous symbols.
3) At the receiver, the cyclic prefix is removed and the remaining samples are processed. The cyclic prefix prevents symbol spreading during convolution with the channel, allowing independent processing of each block.
OFDM allows tightly packed carriers to convey information orthogonally and with high bandwidth efficiency
Objectives Description:
Concepts
Basic idea
Introduction to OFDM
Implementation
Advantages and Drawbacks.
FDMA
The document discusses Orthogonal Frequency Division Multiplexing (OFDM) and its applications in various wireless communication standards. It begins with the motivation for moving from single carrier to multi-carrier modulation schemes to support higher data rates. It then provides an overview of Frequency Division Multiplexing (FDM) and OFDM, explaining the basic principles of OFDM including orthogonality, modulation, and an illustrative example. The document discusses the OFDM transceiver and bit error rate performance in AWGN and Rayleigh fading channels. It also covers some applications and standards that use OFDM such as Digital Audio Broadcasting (DAB), Digital Video Broadcasting (DVB-T), and various IEEE 802.11 wireless networking standards.
Orthogonal Frequency Division Multiplexing, OFDM uses a large number of narrow sub-carriers for multi-carrier transmission to overcome the effect of multi path fading problem. LTE uses OFDM for the downlink, from base station to terminal to transmit the data over many narrow band careers of 180 KHz each instead of spreading one signal over the complete 5MHz career bandwidth. OFDM meets the LTE requirement for spectrum flexibility and enables cost-efficient solutions for very wide carriers with high peak rates.
The primary advantage of OFDM over single-carrier schemes is its ability to cope with severe channel conditions. Channel equalization is simplified. The low symbol rate makes the use of a guard interval between symbols affordable, making it possible to eliminate inter symbol interference (ISI).
This document discusses spread spectrum multiple access (SSMA) techniques. It describes spread spectrum systems and their applications including security, robustness against interference, and providing multiple access. It then discusses two SSMA techniques - frequency hopped multiple access (FHMA) and direct sequence multiple access (DSMA), also called code division multiple access (CDMA). It provides details on how FHMA and CDMA work, including advantages of CDMA such as low power spectral density, interference limited operation, and privacy.
Performance analysis of DWT based OFDM over FFT based OFDM and implementing o...VLSICS Design
Growth in technology has led to unprecedented demand for high speed architectures for complex signal processing applications. In 4G wireless communication systems, bandwidth is a precious commodity, and service providers are continuously met with the challenge of accommodating more users with in a limited allocated bandwidth. To increase data rate of wireless medium with higher performance, OFDM (orthogonal frequency division multiplexing) is used. Recently DWT (Discrete wavelet transforms) is adopted in place of FFT (Fast Fourier transform) for frequency translation. Modulation schemes such as 16-QAM, 32-QAM, 64-QAM and 128-QAM (Quadrature amplitude modulation) have been used in the developed OFDM system for both DWT and FFT based model. In this paper we propose a DWT-IDWT based OFDM transmitter and receiver that achieve better performance in terms SNR and BER for AWGN channel. It proves all the wavelet families better over the IFFT-FFT implementation. The OFDM model is developed using Simulink, various test cases have been considered to verify its performance. The DWTOFDM using Lifting Scheme architecture is implemented on FPGA optimizing hardware, speed & cost. The wavelet filter used for this is Daubechies (9, 7) with N=2. The RTL code is written in Verilog-HDL and simulated in Modelsim. The design is then synthesized in Xilinx and implemented on Virtex5 FPGA board and the results were validated using ChipScope.
This document compares frequency division duplexing (FDD) and time division duplexing (TDD) for the IEEE 802.3 EPoC Study Group. It finds that FDD can support the target throughput of 1 Gbps upstream and 10 Gbps downstream over existing coaxial cable infrastructure using frequencies up to 1200 MHz. TDD may be beneficial in limited node+0 scenarios above 1 GHz but with significantly increased complexity and costs. The document concludes that FDD should be adopted for EPoC as it can start deployment immediately with available technology and supports the requirements over all installation scenarios, while TDD provides minimal benefits and added complexity.
This document summarizes a research paper that analyzes the performance of different pilot-based channel estimation schemes for OFDM systems using QPSK and 16-QAM modulation over Rayleigh fading channels with Doppler frequency shifts. It compares block-type pilot arrangement, which inserts pilots into all subcarriers periodically, to comb-type arrangement, which inserts pilots into each symbol and requires interpolation. It evaluates channel estimation algorithms like LS, LMMSE, SVD for block pilots and linear, quadratic, and cubic spline interpolation for comb pilots. The goal is to analyze how bit error rate is affected by Doppler shifts. Simulations are conducted in MATLAB to compare the schemes.
Qo s provisioning for scalable video streaming over ad hoc networks using cro...Mshari Alabdulkarim
This document discusses providing quality of service (QoS) for scalable video streaming over ad-hoc networks using cross-layer design. It begins by introducing multi-hop wireless networks and ad-hoc networks, noting their advantages and challenges. It then discusses QoS and cross-layer design approaches. The document proposes using cross-layer design to provision QoS for scalable video streaming over ad-hoc networks in order to overcome challenges like variable topology, limited resources and interference.
The document summarizes a proposed scheme for rapid signal acquisition in direct sequence spread spectrum (DSSS) communication systems operating in high Doppler environments. The scheme uses time domain correlation of differential signals to estimate pseudo-noise (PN) code phase, followed by fast Fourier transform (FFT) to precisely estimate Doppler frequency. An area-efficient field programmable gate array (FPGA) architecture is presented that combines time and frequency domain approaches. The architecture achieves 52% area occupancy when synthesized for a Virtex-6 FPGA and operates at 134 MHz, allowing for fast signal acquisition needed in applications like missile guidance systems.
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
This document discusses the design and analysis of multirate filters for WiMAX applications. It proposes a programmable multirate filter architecture that can be implemented using software-defined radio technology and multirate signal processing principles. The filters are designed using MATLAB's filter design and analysis tool to meet WiMAX specifications. A digital upconverter is presented that uses three cascaded FIR filters with interpolation factors of 1, 2, and 4 to achieve an overall interpolation factor of 8 as required by WiMAX. The filters are analyzed and simulated in MATLAB to verify they satisfy WiMAX's spectral mask requirements.
This document provides an overview of Orthogonal Frequency Division Multiplexing (OFDM), Orthogonal Frequency Division Multiple Access (OFDMA) and Scalable OFDMA (SOFDMA). It describes how OFDM divides available bandwidth into multiple orthogonal subcarriers to combat multipath interference in wireless channels. OFDMA further divides subcarriers to enable multiple access by multiple users. SOFDMA, defined in IEEE 802.16e, allows dynamic allocation of subcarriers for scalable bandwidth allocation to users.
Cooperative Diversity - An Introduction to Cooperative CommAshish Meshram
The document provides an introduction to cooperative diversity and cooperative communication techniques. It discusses the motivation for cooperative diversity as a way to achieve spatial diversity without multiple antennas at mobile units. The key aspects covered include:
- Cooperative diversity protocols like amplify-and-forward (AF) and decode-and-forward (DF) where the relay assists transmission from the source to the destination.
- The application of cooperative diversity techniques to improve cellular capacity and coverage, wireless local area networks, vehicle-to-vehicle communication, and wireless sensor networks.
- The mathematical modeling of the relay channel and simplified single-relay system models for AF and DF protocols.
- Analysis of outage probability for the AF protocol and
CDMA allows multiple users to share the same channel by assigning each user a unique code. It spreads the user's data signal over a wider bandwidth through multiplication with a pseudo-random code. This allows different signals to be separated at the receiver through correlation with the corresponding code. Major technologies using CDMA include WiFi, Bluetooth, and GPS, which employ techniques like DSSS, FHSS, and long/short codes. Performance of 802.11 networks can be analyzed based on collision probability and throughput calculations under saturated traffic conditions. Later developments expanded CDMA capabilities with techniques like W-CDMA, TD-CDMA, and TD-SCDMA.
This slide includes
Advanced multiplexing
Code Division Multiplexing
Dense Wavelength Division Multiplexing
OFDM
Connectionless
LAN
L3 SWTICH
SLIP
PPP
CORE AND DISTRIBUTION NETWORKS.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
This document summarizes a research paper that proposes a space-time block coded (STBC) orthogonal frequency-division multiplexing (OFDM) system for text message transmission over fading channels using multiple transmit antennas. The system utilizes low-density parity-check channel coding concatenated with convolutional coding. Simulation results show that the proposed system achieves good error rate performance, especially when using BPSK modulation with 2x4 transmit antennas in AWGN, Rayleigh, and Rician fading channels. The system is effective in properly identifying and retrieving transmitted text messages in noisy and fading environments.
This document describes a space-time block coding (STBC) orthogonal frequency-division multiplexing (OFDM) system for text message transmission over fading channels using multiple transmit antennas. It evaluates the bit error rate (BER) performance of the system using different digital modulation schemes (BPSK, QPSK, QAM-8) over additive white Gaussian noise (AWGN) channels and fading channels. Low-density parity-check (LDPC) coding is concatenated with convolutional coding in the system to improve error performance. Simulation results show that the system is effective in retrieving the transmitted text message under noise and fading conditions, and that BER performance degrades with increasing noise power as expected.
This document discusses the use of cyclic prefixes in OFDM transmission to mitigate inter-block interference caused by multipath propagation. It contains the following key points:
1) OFDM divides the frequency band into multiple narrow sub-carriers to combat frequency selectivity of channels. Cyclic prefixes are added to prevent interference between blocks.
2) The last samples of each OFDM symbol are copied and added to the front as a cyclic prefix, which absorbs multipath interference from previous symbols.
3) At the receiver, the cyclic prefix is removed and the remaining samples are processed. The cyclic prefix prevents symbol spreading during convolution with the channel, allowing independent processing of each block.
OPTICAL SWITCHING CONTROLLER USING FPGA AS A CONTROLLER FOR OCDMA ENCODER SYSTEMEditor IJCATR
This paper proposed a design of optical switching controller using FPGA for OCDMA encoder system. The encoder is one
of the new technologies that use to transmit the coded data in the optical communication system by using FPGA and optical switches.
It is providing a high security for data transmission due to all data will be transmitting in binary code form. The output signals from
FPGA are coded with a binary code that given to an optical switch before it signal modulate with the carrier and transmit to the
receiver. In this paper, AA and 55 data were used for source 1 and source 2. It is generated sample data and sent packet data to the
FPGA and stored it into RAM. The simulation results have done by using software Verilog Spartan 2 programming to simulate. After
that the output will produces at waveform to display the output. The main function of FPGA controlling unit is producing single pulse
and configuring optical switching system.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
This document summarizes a seminar presentation on Optical Code Division Multiple Access (OCDMA). OCDMA allows multiple users to transmit simultaneously over the same bandwidth using unique optical codes. It provides advantages over TDMA and FDMA such as supporting more users and asynchronous transmission without packet collisions. The presentation describes OCDMA network implementation using optical orthogonal codes assigned to transmitters and receivers for communication. It also discusses enhanced security provided by OCDMA through increasing the signal-to-noise ratio required for eavesdropping.
Project Report on Optical Fiber Cables and Systems (MTNL Mumbai)Pradeep Singh
This document provides a summary of a project report on optical fiber cables and systems used by MTNL Mumbai. It discusses the basic optical fiber transmission system including digital distribution frames, multiplexers, optical line terminating units, and repeaters. It also covers topics like Pulse Code Modulation (PCM), digital transmission hierarchies including Synchronous Digital Hierarchy (SDH), data circuits, Dense Wavelength Division Multiplexing (DWDM), and the construction, maintenance and fault detection of optical fiber cables. Network elements of SDH like terminal multiplexers, add/drop multiplexers, and digital cross-connects are also described.
This presentation provides an overview of Dense Wavelength Division Multiplexing (DWDM) technology. It discusses the basic components and operation of a DWDM system, including terminal multiplexers and demultiplexers, optical amplifiers, transponders, reconfigurable optical add-drop multiplexers, and optical cross connects. It also covers topics like wavelength converting transponders, channel spacing, categories of wavelength switches, integrating DWDM with SONET, using DWDM for IP networks, and the value of DWDM in metropolitan areas. The presentation was given by Nitesh Srivastava from the ECE department.
Performance Improvement of IEEE 802.22 WRAN Physical LayerIOSR Journals
The spectrum available for the wireless services is limited, the increased demand of wireless
application has put a lot of limitations on the utilization of available radio spectrum. For the efficient spectrum
utilization for wireless application IEEE 802.22 standard i.e. WRAN (Wireless Regional Area Network) is
developed which is based on cognitive radio technique that senses the free available spectrum. It allows sharing
of geographically unused channels allocated to the TV Broadcast Service, without interference.
In this paper we are evaluating the performance of WRAN over physical layer with QPSK, 16-QAM
and 64-QAM modulation with Convolution coding with code rate of 1/2, 2/3, 3/4, 5/6 and obtaining the BER
curves for rician channel. Simulation is performed in MATLAB
Performance Improvement of IEEE 802.22 WRAN Physical LayerIOSR Journals
Abstract: The spectrum available for the wireless services is limited, the increased demand of wireless
application has put a lot of limitations on the utilization of available radio spectrum. For the efficient spectrum
utilization for wireless application IEEE 802.22 standard i.e. WRAN (Wireless Regional Area Network) is
developed which is based on cognitive radio technique that senses the free available spectrum. It allows sharing
of geographically unused channels allocated to the TV Broadcast Service, without interference.
In this paper we are evaluating the performance of WRAN over physical layer with QPSK, 16-QAM
and 64-QAM modulation with Convolution coding with code rate of 1/2, 2/3, 3/4, 5/6 and obtaining the BER
curves for rician channel. Simulation is performed in MATLAB.
Keywords - CC, CP, CR, OFDMA, PHY Layer, WRAN
Performance Improvement of IEEE 802.22 WRAN Physical LayerIOSR Journals
Abstract: The spectrum available for the wireless services is limited, the increased demand of wireless application has put a lot of limitations on the utilization of available radio spectrum. For the efficient spectrum utilization for wireless application IEEE 802.22 standard i.e. WRAN (Wireless Regional Area Network) is developed which is based on cognitive radio technique that senses the free available spectrum. It allows sharing of geographically unused channels allocated to the TV Broadcast Service, without interference. In this paper we are evaluating the performance of WRAN over physical layer with QPSK, 16-QAM and 64-QAM modulation with Convolution coding with code rate of 1/2, 2/3, 3/4, 5/6 and obtaining the BER curves for rician channel. Simulation is performed in MATLAB. Keywords - CC, CP, CR, OFDMA, PHY Layer, WRAN
CDMA is a technique that allows multiple users to access the network using the same frequency band at the same time. It works by spreading each user's signal across the entire bandwidth using unique codes. This allows signals to overlap without interfering with each other. Key advantages of CDMA include larger network capacity, less transmit power per user, seamless handoffs between cells, no need for frequency planning, high tolerance of interference, and multiple diversity techniques. A typical CDMA network can support 400 subscribers per sector using 1.25MHz of spectrum, allowing a cell with 6 sectors to support up to 2,400 subscribers on a single frequency channel.
1) The document analyzes the effect of intercarrier interference (ICI) on single carrier orthogonal frequency division multiplexing (SC-OFDM) systems.
2) It proposes a novel magnitude-keyed modulation scheme that provides SC-OFDM immunity to ICI. This outperforms other modulation schemes like OFDM, SC-OFDM, and MC-CDMA that use phase shift keying or quadrature amplitude modulation in environments with severe ICI.
3) The analysis shows that the effect of ICI on SC-OFDM signals is simply a phase offset on each data symbol, whereas ICI introduces interference between subcarriers for OFDM. Therefore, SC-OFDM has significantly better performance
Performance evaluation of VLC system using new modulation approachjournalBEEI
This document evaluates the performance of a new modulation scheme called catenated-OFDM for visible light communications (VLC) systems. Catenated-OFDM involves transmitting multiple OFDM signals simultaneously over different optical bands. The proposed system is simulated using Optisys software. Results show the system can achieve transmission distances of up to 12 meters for 2 dBm input power with 3 optical bands and a data rate of 10 Gbps. Higher data rates, up to 15 Gbps, are also possible. Increasing the number of optical bands or decreasing the data rate improves the receiver sensitivity. The catenated-OFDM approach shows potential for high-speed optical wireless communications.
Design Ofdm System And Remove Nonlinear Distortion In OFDM Signal At Transmit...Rupesh Sharma
although OFDM seems to be a solution to keep up with
the demand of increasing data rates, it has some drawbacks.
Sensitivity to high PAPR is the most significant of these
drawbacks. The main objective of this paper was to investigate
and document the effects of PAPR on the performance of OFDM
based digital communications under different channel conditions.
A step-by-step approach was adopted in order to achieve the
objective of this paper. The first step is to provide a basic
background on the principles of OFDM. The reasons for the
PAPR and a theoretical analysis of these effects on OFDM
systems are documented. The OFDM system has a high peak-toaverage
power ratio (PAPR) that can cause unwanted saturation
in the power amplifiers, leading to in-band distortion and out-ofband
radiation. To be able to observe the system behavior, the
simulation results for different channel models are presented in
graphical form. Next, the simulation results obtained in this work
are compared to the simulation results reported in related studies
Implementation of High Speed OFDM Transceiver using FPGAMangaiK4
Abstract - Proficient, multi mode and re-configurable architecture of interleaver/de-interleaver for multiple standards, like DVB, OFDM and WLAN is presented. Interleaver plays vital role in 4G technologies to recover symbols from burst errors. The aim of our work is to design a reconfigurable modulation technique called Adaptive modulation scheme uses QAM, QPSK and BPSK modulation that adapt themselves based on channel Signal to Noise ratio. Subcarrier allocation algorithm specifically used to focus on utilizing channels with high gains. Our proposed model can achieves a data rate of min 2.5 Gbps as per 3GPP standard by adaptive modulation technique using QAM, BPSK and QPSK.
Analysis of Women Harassment inVillages Using CETD Matrix ModalMangaiK4
Abstract-It is commonly understood that misbehavior intends to upset .Law says ,the repeated intentional misbehavior towards women is an offensive. The main concept of this paper can find something interesting that will make us reflect on what is done by women’s rights and gender equality. To solve such problem, in this paper we are interested to adopt CETD matrix.
PERFORMANCE ANALYSIS OF QOS PARAMETERS LIKE PSNR, MAE & RMSE USED IN IMAGE TR...Journal For Research
Wireless designers constantly seek to improve the spectrum efficiency/capacity, coverage of wireless networks and link reliability. In this direction, Space-time wireless technology that uses multiple antennas along with appropriate signaling and receiver techniques that offers a powerful tool for improving the wireless performance is used in this thesis work. A special version of STBC called ‘Alamouti code’ is used. PSK modulation scheme is used for modulation of data. In this thesis work, the Space-Time Block Codes (STBC) is used in WLAN wireless network that uses multiple numbers of antennas at both transmitter and receiver. The STBC which includes the Alamouti Scheme for 2 transmit antenna and a different number of receiving antenna has been studied, simulated and analyzed. The simulation has been done in MATLAB. Throughput and several parameter performance has been analyzed using the MATLAB.A sample image is transmitted to compare the performance of various parameters like RMSE, PSNR, MAE etc. All the parameters are plotted against SNR (in dB) values ranging from -18 to 30. Various observations being made for the improvement in various parameters with increasing SNR and/or with changing diversity scheme. AWGN channel is used here for communication of sampled image data.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Iaetsd ber performance of cdma, wcdma, ieee802.11g in awgnIaetsd Iaetsd
This document discusses and compares the bit error rate (BER) performance of CDMA, WCDMA, and IEEE 802.11g wireless standards in additive white Gaussian noise (AWGN) and fading channels. It proposes an integrated low power code synchronizer for these three standards using techniques like power management, absolute weighted magnitude calculation, and spurious power suppression in the adders. Simulation results show that the proposed techniques reduce power consumption in the correlator element array, especially for WCDMA in AWGN channels where power is reduced by half. Fading channels generally consume less power than AWGN channels.
Similar to Performance analysis of Multiband - OFDM systems using LDPC coder in pulsed - OFDM modulation for UWB communications (20)
Power System State Estimation - A ReviewIDES Editor
This document provides a review of power system state estimation techniques. It discusses both static and dynamic state estimation algorithms. For static state estimation, it covers weighted least squares, decoupled, and robust estimation methods. Weighted least squares is commonly used but can have numerical instability issues. Decoupled state estimation approximates the gain matrix for faster computation. Robust estimation uses M-estimators and other techniques to handle outliers and bad data. Dynamic state estimation applies Kalman filtering, leapfrog algorithms, and other methods to continuously monitor system states over time.
Artificial Intelligence Technique based Reactive Power Planning Incorporating...IDES Editor
This document summarizes a research paper that proposes using artificial intelligence techniques and FACTS controllers for reactive power planning in real-time power transmission systems. The paper formulates the reactive power planning problem and incorporates flexible AC transmission system (FACTS) devices like static VAR compensators (SVC), thyristor controlled series capacitors (TCSC), and unified power flow controllers (UPFC). Evolutionary algorithms like evolutionary programming (EP) and differential evolution (DE) are applied to find the optimal locations and settings of the FACTS controllers to minimize losses and costs. Simulation results on IEEE 30-bus and 72-bus Indian test systems show that UPFC performs best in reducing losses compared to SVC and TCSC.
Design and Performance Analysis of Genetic based PID-PSS with SVC in a Multi-...IDES Editor
Damping of power system oscillations with the help
of proposed optimal Proportional Integral Derivative Power
System Stabilizer (PID-PSS) and Static Var Compensator
(SVC)-based controllers are thoroughly investigated in this
paper. This study presents robust tuning of PID-PSS and
SVC-based controllers using Genetic Algorithms (GA) in
multi machine power systems by considering detailed model
of the generators (model 1.1). The effectiveness of FACTSbased
controllers in general and SVC-based controller in
particular depends upon their proper location. Modal
controllability and observability are used to locate SVC–based
controller. The performance of the proposed controllers is
compared with conventional lead-lag power system stabilizer
(CPSS) and demonstrated on 10 machines, 39 bus New England
test system. Simulation studies show that the proposed genetic
based PID-PSS with SVC based controller provides better
performance.
Optimal Placement of DG for Loss Reduction and Voltage Sag Mitigation in Radi...IDES Editor
This paper presents the need to operate the power
system economically and with optimum levels of voltages has
further led to an increase in interest in Distributed
Generation. In order to reduce the power losses and to improve
the voltage in the distribution system, distributed generators
(DGs) are connected to load bus. To reduce the total power
losses in the system, the most important process is to identify
the proper location for fixing and sizing of DGs. It presents a
new methodology using a new population based meta heuristic
approach namely Artificial Bee Colony algorithm(ABC) for
the placement of Distributed Generators(DG) in the radial
distribution systems to reduce the real power losses and to
improve the voltage profile, voltage sag mitigation. The power
loss reduction is important factor for utility companies because
it is directly proportional to the company benefits in a
competitive electricity market, while reaching the better power
quality standards is too important as it has vital effect on
customer orientation. In this paper an ABC algorithm is
developed to gain these goals all together. In order to evaluate
sag mitigation capability of the proposed algorithm, voltage
in voltage sensitive buses is investigated. An existing 20KV
network has been chosen as test network and results are
compared with the proposed method in the radial distribution
system.
Line Losses in the 14-Bus Power System Network using UPFCIDES Editor
Controlling power flow in modern power systems
can be made more flexible by the use of recent developments
in power electronic and computing control technology. The
Unified Power Flow Controller (UPFC) is a Flexible AC
transmission system (FACTS) device that can control all the
three system variables namely line reactance, magnitude and
phase angle difference of voltage across the line. The UPFC
provides a promising means to control power flow in modern
power systems. Essentially the performance depends on proper
control setting achievable through a power flow analysis
program. This paper presents a reliable method to meet the
requirements by developing a Newton-Raphson based load
flow calculation through which control settings of UPFC can
be determined for the pre-specified power flow between the
lines. The proposed method keeps Newton-Raphson Load Flow
(NRLF) algorithm intact and needs (little modification in the
Jacobian matrix). A MATLAB program has been developed to
calculate the control settings of UPFC and the power flow
between the lines after the load flow is converged. Case studies
have been performed on IEEE 5-bus system and 14-bus system
to show that the proposed method is effective. These studies
indicate that the method maintains the basic NRLF properties
such as fast computational speed, high degree of accuracy and
good convergence rate.
Study of Structural Behaviour of Gravity Dam with Various Features of Gallery...IDES Editor
The size and shape of opening in dam causes the
stress concentration, it also causes the stress variation in the
rest of the dam cross section. The gravity method of the analysis
does not consider the size of opening and the elastic property
of dam material. Thus the objective of study is comprises of
the Finite Element Method which considers the size of
opening, elastic property of material, and stress distribution
because of geometric discontinuity in cross section of dam.
Stress concentration inside the dam increases with the opening
in dam which results in the failure of dam. Hence it is
necessary to analyses large opening inside the dam. By making
the percentage area of opening constant and varying size and
shape of opening the analysis is carried out. For this purpose
a section of Koyna Dam is considered. Dam is defined as a
plane strain element in FEM, based on geometry and loading
condition. Thus this available information specified our path
of approach to carry out 2D plane strain analysis. The results
obtained are then compared mutually to get most efficient
way of providing large opening in the gravity dam.
Assessing Uncertainty of Pushover Analysis to Geometric ModelingIDES Editor
Pushover Analysis a popular tool for seismic
performance evaluation of existing and new structures and is
nonlinear Static procedure where in monotonically increasing
loads are applied to the structure till the structure is unable
to resist the further load .During the analysis, whatever the
strength of concrete and steel is adopted for analysis of
structure may not be the same when real structure is
constructed and the pushover analysis results are very sensitive
to material model adopted, geometric model adopted, location
of plastic hinges and in general to procedure followed by the
analyzer. In this paper attempt has been made to assess
uncertainty in pushover analysis results by considering user
defined hinges and frame modeled as bare frame and frame
with slab modeled as rigid diaphragm and results compared
with experimental observations. Uncertain parameters
considered includes the strength of concrete, strength of steel
and cover to the reinforcement which are randomly generated
and incorporated into the analysis. The results are then
compared with experimental observations.
Secure Multi-Party Negotiation: An Analysis for Electronic Payments in Mobile...IDES Editor
This document summarizes and analyzes secure multi-party negotiation protocols for electronic payments in mobile computing. It presents a framework for secure multi-party decision protocols using lightweight implementations. The main focus is on synchronizing security features to avoid agreement manipulation and reduce user traffic. The paper describes negotiation between an auctioneer and bidders, showing multiparty security is better than existing systems. It analyzes the performance of encryption algorithms like ECC, XTR, and RSA for use in the multiparty negotiation protocols.
Selfish Node Isolation & Incentivation using Progressive ThresholdsIDES Editor
The problems associated with selfish nodes in
MANET are addressed by a collaborative watchdog approach
which reduces the detection time for selfish nodes thereby
improves the performance and accuracy of watchdogs[1]. In
the related works they make use of credit based systems, reputation
based mechanisms, pathrater and watchdog mechanism
to detect such selfish nodes. In this paper we follow an approach
of collaborative watchdog which reduces the detection
time for selfish nodes and also involves the removal of such
selfish nodes based on some progressively assessed thresholds.
The threshold gives the nodes a chance to stop misbehaving
before it is permanently deleted from the network.
The node passes through several isolation processes before it
is permanently removed. Another version of AODV protocol
is used here which allows the simulation of selfish nodes in
NS2 by adding or modifying log files in the protocol.
Various OSI Layer Attacks and Countermeasure to Enhance the Performance of WS...IDES Editor
Wireless sensor networks are networks having non
wired infrastructure and dynamic topology. In OSI model each
layer is prone to various attacks, which halts the performance
of a network .In this paper several attacks on four layers of
OSI model are discussed and security mechanism is described
to prevent attack in network layer i.e wormhole attack. In
Wormhole attack two or more malicious nodes makes a covert
channel which attracts the traffic towards itself by depicting a
low latency link and then start dropping and replaying packets
in the multi-path route. This paper proposes promiscuous mode
method to detect and isolate the malicious node during
wormhole attack by using Ad-hoc on demand distance vector
routing protocol (AODV) with omnidirectional antenna. The
methodology implemented notifies that the nodes which are
not participating in multi-path routing generates an alarm
message during delay and then detects and isolate the
malicious node from network. We also notice that not only
the same kind of attacks but also the same kind of
countermeasures can appear in multiple layer. For example,
misbehavior detection techniques can be applied to almost all
the layers we discussed.
Responsive Parameter based an AntiWorm Approach to Prevent Wormhole Attack in...IDES Editor
The recent advancements in the wireless technology
and their wide-spread deployment have made remarkable
enhancements in efficiency in the corporate and industrial
and Military sectors The increasing popularity and usage of
wireless technology is creating a need for more secure wireless
Ad hoc networks. This paper aims researched and developed
a new protocol that prevents wormhole attacks on a ad hoc
network. A few existing protocols detect wormhole attacks but
they require highly specialized equipment not found on most
wireless devices. This paper aims to develop a defense against
wormhole attacks as an Anti-worm protocol which is based on
responsive parameters, that does not require as a significant
amount of specialized equipment, trick clock synchronization,
no GPS dependencies.
Cloud Security and Data Integrity with Client Accountability FrameworkIDES Editor
This document summarizes a proposed cloud security and data integrity framework that provides client accountability. The framework aims to address issues like lack of user control over cloud data, need for data transparency and tracking, and ensuring data integrity. It proposes using JAR (Java Archive) files for data sharing due to benefits like portability. The framework incorporates client-side verification using MD5 hashing, digital signature-based authentication of JAR files, and use of HMAC to ensure data integrity. It also uses password-based encryption of log files to keep them tamper-proof. The framework is intended to provide both accountability and security for data sharing in cloud environments.
Genetic Algorithm based Layered Detection and Defense of HTTP BotnetIDES Editor
A System state in HTTP botnet uses HTTP protocol
for the creation of chain of Botnets thereby compromising
other systems. By using HTTP protocol and port number 80,
attacks can not only be hidden but also pass through the
firewall without being detected. The DPR based detection
leads to better analysis of botnet attacks [3]. However, it
provides only probabilistic detection of the attacker and also
time consuming and error prone. This paper proposes a Genetic
algorithm based layered approach for detecting as well as
preventing botnet attacks. The paper reviews p2p firewall
implementation which forms the basis of filtering.
Performance evaluation is done based on precision, F-value
and probability. Layered approach reduces the computation
and overall time requirement [7]. Genetic algorithm promises
a low false positive rate.
Enhancing Data Storage Security in Cloud Computing Through SteganographyIDES Editor
This document summarizes a research paper that proposes a method for enhancing data security in cloud computing through steganography. The method hides user data in digital images stored on cloud servers. When data needs to be accessed, it is extracted from the images. The document outlines the cloud architecture and security issues addressed. It then describes the proposed system architecture, security model, and data storage and retrieval process. Data is partitioned and hidden in multiple images to improve security. The goal is to prevent unauthorized access to user data stored on cloud servers.
The main tasks of a Wireless Sensor Network
(WSN) are data collection from its nodes and communication
of this data to the base station (BS). The protocols used for
communication among the WSN nodes and between the WSN
and the BS, must consider the resource constraints of nodes,
battery energy, computational capabilities and memory. The
WSN applications involve unattended operation of the network
over an extended period of time. In order to extend the lifetime
of a WSN, efficient routing protocols need to be adopted. The
proposed low power routing protocol based on tree-based
network structure reliably forwards the measured data towards
the BS using TDMA. An energy consumption analysis of the
WSN making use of this protocol is also carried out. It is
found that the network is energy efficient with an average
duty cycle of 0:7% for the WSN nodes. The OmNET++
simulation platform along with MiXiM framework is made
use of.
Permutation of Pixels within the Shares of Visual Cryptography using KBRP for...IDES Editor
The security of authentication of internet based
co-banking services should not be susceptible to high risks.
The passwords are highly vulnerable to virus attacks due to
the lack of high end embedding of security methods. In order
for the passwords to be more secure, people are generally
compelled to select jumbled up character based passwords
which are not only less memorable but are also equally prone
to insecurity. Multiple use of distributed shares has been
studied to solve the problem of authentication by algorithms
based on thresholding of pixels in image processing and visual
cryptography concepts where the subset of shares is considered
for the recovery of the original image for authentication using
correlation function[1][2].The main disadvantage in the above
study is the plain storage of shares and also one of the shares
is being supplied to the customer, which will lead to the
possibility of misuse by a third party. This paper proposes a
technique for scrambling of pixels by key based random
permutation (KBRP) within the shares before the
authentication has been attempted. Total number of shares to
be created is dependent on the multiplicity of ownership of
the account. By this method the problem of uncertainty among
the customers with regard to security, storage, retrieval of
holding of half of the shares is minimized.
This paper presents a trifocal Rotman Lens Design
approach. The effects of focal ratio and element spacing on
the performance of Rotman Lens are described. A three beam
prototype feeding 4 element antenna array working in L-band
has been simulated using RLD v1.7 software. Simulated
results show that the simulated lens has a return loss of –
12.4dB at 1.8GHz. Beam to array port phase error variation
with change in the focal ratio and element spacing has also
been investigated.
Band Clustering for the Lossless Compression of AVIRIS Hyperspectral ImagesIDES Editor
Hyperspectral images can be efficiently compressed
through a linear predictive model, as for example the one
used in the SLSQ algorithm. In this paper we exploit this
predictive model on the AVIRIS images by individuating,
through an off-line approach, a common subset of bands, which
are not spectrally related with any other bands. These bands
are not useful as prediction reference for the SLSQ 3-D
predictive model and we need to encode them via other
prediction strategies which consider only spatial correlation.
We have obtained this subset by clustering the AVIRIS bands
via the clustering by compression approach. The main result
of this paper is the list of the bands, not related with the
others, for AVIRIS images. The clustering trees obtained for
AVIRIS and the relationship among bands they depict is also
an interesting starting point for future research.
Microelectronic Circuit Analogous to Hydrogen Bonding Network in Active Site ...IDES Editor
A microelectronic circuit of block-elements
functionally analogous to two hydrogen bonding networks is
investigated. The hydrogen bonding networks are extracted
from â-lactamase protein and are formed in its active site.
Each hydrogen bond of the network is described in equivalent
electrical circuit by three or four-terminal block-element.
Each block-element is coded in Matlab. Static and dynamic
analyses are performed. The resultant microelectronic circuit
analogous to the hydrogen bonding network operates as
current mirror, sine pulse source, triangular pulse source as
well as signal modulator.
Texture Unit based Monocular Real-world Scene Classification using SOM and KN...IDES Editor
In this paper a method is proposed to discriminate
real world scenes in to natural and manmade scenes of similar
depth. Global-roughness of a scene image varies as a function
of image-depth. Increase in image depth leads to increase in
roughness in manmade scenes; on the contrary natural scenes
exhibit smooth behavior at higher image depth. This particular
arrangement of pixels in scene structure can be well explained
by local texture information in a pixel and its neighborhood.
Our proposed method analyses local texture information of a
scene image using texture unit matrix. For final classification
we have used both supervised and unsupervised learning using
K-Nearest Neighbor classifier (KNN) and Self Organizing
Map (SOM) respectively. This technique is useful for online
classification due to very less computational complexity.
"Frontline Battles with DDoS: Best practices and Lessons Learned", Igor IvaniukFwdays
At this talk we will discuss DDoS protection tools and best practices, discuss network architectures and what AWS has to offer. Also, we will look into one of the largest DDoS attacks on Ukrainian infrastructure that happened in February 2022. We'll see, what techniques helped to keep the web resources available for Ukrainians and how AWS improved DDoS protection for all customers based on Ukraine experience
Connector Corner: Seamlessly power UiPath Apps, GenAI with prebuilt connectorsDianaGray10
Join us to learn how UiPath Apps can directly and easily interact with prebuilt connectors via Integration Service--including Salesforce, ServiceNow, Open GenAI, and more.
The best part is you can achieve this without building a custom workflow! Say goodbye to the hassle of using separate automations to call APIs. By seamlessly integrating within App Studio, you can now easily streamline your workflow, while gaining direct access to our Connector Catalog of popular applications.
We’ll discuss and demo the benefits of UiPath Apps and connectors including:
Creating a compelling user experience for any software, without the limitations of APIs.
Accelerating the app creation process, saving time and effort
Enjoying high-performance CRUD (create, read, update, delete) operations, for
seamless data management.
Speakers:
Russell Alfeche, Technology Leader, RPA at qBotic and UiPath MVP
Charlie Greenberg, host
Driving Business Innovation: Latest Generative AI Advancements & Success StorySafe Software
Are you ready to revolutionize how you handle data? Join us for a webinar where we’ll bring you up to speed with the latest advancements in Generative AI technology and discover how leveraging FME with tools from giants like Google Gemini, Amazon, and Microsoft OpenAI can supercharge your workflow efficiency.
During the hour, we’ll take you through:
Guest Speaker Segment with Hannah Barrington: Dive into the world of dynamic real estate marketing with Hannah, the Marketing Manager at Workspace Group. Hear firsthand how their team generates engaging descriptions for thousands of office units by integrating diverse data sources—from PDF floorplans to web pages—using FME transformers, like OpenAIVisionConnector and AnthropicVisionConnector. This use case will show you how GenAI can streamline content creation for marketing across the board.
Ollama Use Case: Learn how Scenario Specialist Dmitri Bagh has utilized Ollama within FME to input data, create custom models, and enhance security protocols. This segment will include demos to illustrate the full capabilities of FME in AI-driven processes.
Custom AI Models: Discover how to leverage FME to build personalized AI models using your data. Whether it’s populating a model with local data for added security or integrating public AI tools, find out how FME facilitates a versatile and secure approach to AI.
We’ll wrap up with a live Q&A session where you can engage with our experts on your specific use cases, and learn more about optimizing your data workflows with AI.
This webinar is ideal for professionals seeking to harness the power of AI within their data management systems while ensuring high levels of customization and security. Whether you're a novice or an expert, gain actionable insights and strategies to elevate your data processes. Join us to see how FME and AI can revolutionize how you work with data!
HCL Notes and Domino License Cost Reduction in the World of DLAUpanagenda
Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-and-domino-license-cost-reduction-in-the-world-of-dlau/
The introduction of DLAU and the CCB & CCX licensing model caused quite a stir in the HCL community. As a Notes and Domino customer, you may have faced challenges with unexpected user counts and license costs. You probably have questions on how this new licensing approach works and how to benefit from it. Most importantly, you likely have budget constraints and want to save money where possible. Don’t worry, we can help with all of this!
We’ll show you how to fix common misconfigurations that cause higher-than-expected user counts, and how to identify accounts which you can deactivate to save money. There are also frequent patterns that can cause unnecessary cost, like using a person document instead of a mail-in for shared mailboxes. We’ll provide examples and solutions for those as well. And naturally we’ll explain the new licensing model.
Join HCL Ambassador Marc Thomas in this webinar with a special guest appearance from Franz Walder. It will give you the tools and know-how to stay on top of what is going on with Domino licensing. You will be able lower your cost through an optimized configuration and keep it low going forward.
These topics will be covered
- Reducing license cost by finding and fixing misconfigurations and superfluous accounts
- How do CCB and CCX licenses really work?
- Understanding the DLAU tool and how to best utilize it
- Tips for common problem areas, like team mailboxes, functional/test users, etc
- Practical examples and best practices to implement right away
Conversational agents, or chatbots, are increasingly used to access all sorts of services using natural language. While open-domain chatbots - like ChatGPT - can converse on any topic, task-oriented chatbots - the focus of this paper - are designed for specific tasks, like booking a flight, obtaining customer support, or setting an appointment. Like any other software, task-oriented chatbots need to be properly tested, usually by defining and executing test scenarios (i.e., sequences of user-chatbot interactions). However, there is currently a lack of methods to quantify the completeness and strength of such test scenarios, which can lead to low-quality tests, and hence to buggy chatbots.
To fill this gap, we propose adapting mutation testing (MuT) for task-oriented chatbots. To this end, we introduce a set of mutation operators that emulate faults in chatbot designs, an architecture that enables MuT on chatbots built using heterogeneous technologies, and a practical realisation as an Eclipse plugin. Moreover, we evaluate the applicability, effectiveness and efficiency of our approach on open-source chatbots, with promising results.
Programming Foundation Models with DSPy - Meetup SlidesZilliz
Prompting language models is hard, while programming language models is easy. In this talk, I will discuss the state-of-the-art framework DSPy for programming foundation models with its powerful optimizers and runtime constraint system.
What is an RPA CoE? Session 1 – CoE VisionDianaGray10
In the first session, we will review the organization's vision and how this has an impact on the COE Structure.
Topics covered:
• The role of a steering committee
• How do the organization’s priorities determine CoE Structure?
Speaker:
Chris Bolin, Senior Intelligent Automation Architect Anika Systems
Essentials of Automations: Exploring Attributes & Automation ParametersSafe Software
Building automations in FME Flow can save time, money, and help businesses scale by eliminating data silos and providing data to stakeholders in real-time. One essential component to orchestrating complex automations is the use of attributes & automation parameters (both formerly known as “keys”). In fact, it’s unlikely you’ll ever build an Automation without using these components, but what exactly are they?
Attributes & automation parameters enable the automation author to pass data values from one automation component to the next. During this webinar, our FME Flow Specialists will cover leveraging the three types of these output attributes & parameters in FME Flow: Event, Custom, and Automation. As a bonus, they’ll also be making use of the Split-Merge Block functionality.
You’ll leave this webinar with a better understanding of how to maximize the potential of automations by making use of attributes & automation parameters, with the ultimate goal of setting your enterprise integration workflows up on autopilot.
Taking AI to the Next Level in Manufacturing.pdfssuserfac0301
Read Taking AI to the Next Level in Manufacturing to gain insights on AI adoption in the manufacturing industry, such as:
1. How quickly AI is being implemented in manufacturing.
2. Which barriers stand in the way of AI adoption.
3. How data quality and governance form the backbone of AI.
4. Organizational processes and structures that may inhibit effective AI adoption.
6. Ideas and approaches to help build your organization's AI strategy.
How to Interpret Trends in the Kalyan Rajdhani Mix Chart.pdfChart Kalyan
A Mix Chart displays historical data of numbers in a graphical or tabular form. The Kalyan Rajdhani Mix Chart specifically shows the results of a sequence of numbers over different periods.
How information systems are built or acquired puts information, which is what they should be about, in a secondary place. Our language adapted accordingly, and we no longer talk about information systems but applications. Applications evolved in a way to break data into diverse fragments, tightly coupled with applications and expensive to integrate. The result is technical debt, which is re-paid by taking even bigger "loans", resulting in an ever-increasing technical debt. Software engineering and procurement practices work in sync with market forces to maintain this trend. This talk demonstrates how natural this situation is. The question is: can something be done to reverse the trend?
The Microsoft 365 Migration Tutorial For Beginner.pptxoperationspcvita
This presentation will help you understand the power of Microsoft 365. However, we have mentioned every productivity app included in Office 365. Additionally, we have suggested the migration situation related to Office 365 and how we can help you.
You can also read: https://www.systoolsgroup.com/updates/office-365-tenant-to-tenant-migration-step-by-step-complete-guide/