The motive of any wireless communication system is to reduce BER for the corresponding SNR. Through this OFDM based receiver diversity system we analyze BER for different diversity combining techniques such as EGC, MRC, SC in a rayliegh faded environment. This model serves two benefits: first noise limited system performance is improved by combating ISI through OFDM and second use of diversity combining which helps combat multipath fading. We also try to achieve an optimum trade-off between BER improvement and increase in number of receiver antennas. This is just to make less-complex receiver as it requires only one DFT processor.
High Speed Low Power Veterbi Decoder Design for TCM Decodersijsrd.com
It is well known that the Viterbi decoder (VD) is the dominant module determining the overall power consumption of TCM decoders. High-speed, low-power design of Viterbi decoders for trellis coded modulation (TCM) systems is presented in this paper. We propose a pre-computation architecture incorporated with -algorithm for VD, which can effectively reduce the power consumption without degrading the decoding speed much. A general solution to derive the optimal pre-computation steps is also given in the paper. Implementation result of a VD for a rate-3/4 convolutional code used in a TCM system shows that compared with the full trellis VD, the precomputation architecture reduces the power consumption by as much as 70% without performance loss, while the degradation in clock speed is negligible.
High Speed Low Power Veterbi Decoder Design for TCM Decodersijsrd.com
It is well known that the Viterbi decoder (VD) is the dominant module determining the overall power consumption of TCM decoders. High-speed, low-power design of Viterbi decoders for trellis coded modulation (TCM) systems is presented in this paper. We propose a pre-computation architecture incorporated with -algorithm for VD, which can effectively reduce the power consumption without degrading the decoding speed much. A general solution to derive the optimal pre-computation steps is also given in the paper. Implementation result of a VD for a rate-3/4 convolutional code used in a TCM system shows that compared with the full trellis VD, the precomputation architecture reduces the power consumption by as much as 70% without performance loss, while the degradation in clock speed is negligible.
BER Analysis ofImpulse Noise inOFDM System Using LMS,NLMS&RLSiosrjce
IOSR Journal of Computer Engineering (IOSR-JCE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of computer engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in computer technology. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Simulation Study and Performance Comparison of OFDM System with QPSK and BPSKpaperpublications3
Abstract: FDMA, TDMA and CDMA are the well-known multiplexing techniques used in wireless communication systems. While working with the wireless systems using these techniques various problems are encountered especially when a typical transmitted signal arrives at the receiver using various paths of different lengths. Since multiple versions of the signal interfere with each other, it becomes difficult to extract the original information. The use of orthogonal frequency division multiplexing (OFDM) technique provides better solution for the above mentioned problem. OFDM technique distributes the data over a large number of carriers that are spaced apart at precise frequencies. This spacing provides the "orthogonality", which prevents the demodulator from seeing frequencies other than their own. The benefits of OFDM are high spectral efficiency, resiliency of RF interference, and lower multi-path distortion. OFDM is a powerful modulation technique that is capable of high data rate and is able to eliminate ISI. Using MATLAB, simulation of OFDM was done with different modulation techniques using different transform techniques. The digital modulation schemes such as BPSK and QPSK were selected to assess the performance of the designed OFDM system.
Energy Efficient Bit Extension Type Accelerator Chip for Detection AlgorithmsIJERA Editor
This paper presents an energy efficient bit extension type accelerator chip that targets decoding tasks of MIMO(Multiple input multiple output) - orthogonal frequency-division multiplexing (OFDM) systems. The work is motivated by the adoption of MIMO and OFDM by almost all existing and emerging high-speed wireless data communication systems. MIMO is an antenna technology for wireless communications in which multiple antennas are used at both the source (transmitter) and the destination (receiver). MIMO decoder or sometimes called MIMO equalizer detects or decodes or recovers the transmitted signals from multiple antennas. MIMO decoding process for a certain application is hard and time consuming. This motivates the need for a programmable accelerator block to implement the MIMO decoder task as fast and easy application. In this paper proposing a new pipeline architecture in arithmetic units inside the processing core of accelerator chip. The proposed architecture can perform with higher frequency with the help of pipeline structure and also improving the speed of operation of rotation unit with a new arithmetic rotation unit instead of native CORDIC algorithm. This proposed architecture helps to reduce dynamic power consumption. The accelerator is an ideal solution for today’s smart phones that implement multiple MIMO-OFDM waveforms on the same platform.
Performance evaluation on the basis of bit error rate for different order of ...ijmnct
Today, we have required to accommodate a large number of users under a single base station. This can be
possible only if we have some flexibility over the spectrum. Previously we have lots of multiplexing methods
to accommodate large number of signals in time and frequency domain. But now we have required to
accommodate a large number of users in the same bandwidth, without any fading over the received signal.
So, orthogonality can be maintained over the frequency response. This technology is now more popular in
the mobile communication domain, called Orthogonal Frequency Division Multiplexing (OFDM). Actually
user data can be converted into the parallel form and then they are modulated using digital modulation
techniques. Finally, they have followed by OFDM Modulator and cyclic prefix can be inserted into the
OFDM symbols. Here, I have worked on the measurement of Bit error rate for different modulation
techniques in OFDM technology. It has been considered that subchannel size is not constant. According to
that I have concluded the overall idea regarding the performance under OFDM technology.
Implementation Cost Analysis of the Interpolator for the Wimax Technologyiosrjce
The design of the multirate filter (programmable) has been proposed which can be used in digital
transceivers that meets 802.16d/e (wimax) standard in the wireless communication system. Wimax is a
technology emerging in the wireless communication system in order to increase the broadband wireless internet
access. As there is wide spread need of the digital representation of the signal for the transmission and storage
which create the challenges in DSP [1]. In this paper, analysis of the implementation cost of interpolator for the
wimax technology, and cost of interpolator is analyzed on the basis of number of adders and multiplier. The
Filters are designed using the FDA (filters design and analysis) tool in MATLAB.
Bessel Companding Transform for reducing PAPR, OBI and BER in OFDM SystemsIOSR Journals
Abstract : Orthogonal Frequency division multiplexing (OFDM) is a very popular technique in wireless communications which provides excellent robustness to channel fading and immune to interference. OFDM is one of a popular modulation technique for transmitting large amounts of digital data over radio carriers. One of the major problems that had been observed in this is the Peak-To Average power Ratio (PAPR). PAPR is a distortion that had occurred due to large number of sub carriers that are used in OFDM for modulating the digital data. Many techniques were available to reduce the PAPR in OFDM systems, among them the companding technique can be used to enhance the OFDM transmission performance by decreasing the PAPR effectively and hence BER. Here we proposed “Bessel Companding Algorithm” to reduce this significant drawback in OFDM Systems. Keywords : Orthogonal Frequency Division Multiplexing (OFDM), peak to average power ratio (PAPR), bit error rate (BER), Out Band Interference (OBI), Additive White Gaussian Noise (AWGN), Bessel Companding Algorithm, Quadrature Amplitude Modulation (QAM) and Multi Carrier Modulation (MCM).
Capacity Enhancement of MIMO-OFDM System in Rayleigh Fading ChannelIOSR Journals
MIMO-OFDM system in Rayleigh Fading Channel is very popular technique for mobile
communication now a day’s for research. Here we want increase the capacity of MIMO-OFDM of system by
using adaptive modulation, Algebraic Space-Time Codes (ASTC) encoder for MIMO Systems are based on
quaternion algebras .we found that ergodic capacity has some limitation which reduce the system’s
performance to overcome this we use ASTC code . ASTC code are full rank, full rate and non vanishing constant
minimum determinant for increasing spectral efficiency and reducing Peak to Average Power Ratio (PAPR) .
Performance Analysis of Fractional Sample Rate Converter Using Audio Applicat...iosrjce
Fractional rate converters which are generally used for many applications with different frequencies
and are an essential part of communication systems. In this paper fractional rate converter with use of both
FIR and Nyquist FIR have been compared and analyzed. Its implementation can be easily found in the
developing communication systems, but here results are taken for audio applications. The proposed design and
analysis have been developed with the help of MATLAB with order 50 for FIR and 71 for Nyquist, sampling
frequency 48000Hz. The filters are then interpolated by an interpolation factor 2 and decimated by a decimation
factor of 3. The cost implementation of both has been taken into consideration and a result is drawn which
concludes that fractional rate converter for Nyquist FIR filter much more cost effective as compared to the
fractional rate converter for FIR filter
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.
Applications of Time Division multiplexing : statistical TDMDr Rajiv Srivastava
These slides cover a topic on Applications of Time Division multiplexing and statistical TDM in Data Communication. All the slides are explained in a very simple manner. It is useful for engineering students & also for the candidates who want to master data communication & computer networking.
Pin Profile and Shoulder Geometry Effects in Friction Stir Spot Welded Polyme...theijes
The effects pin profile and shoulder geometry in friction stir spot welded polymer sheets were studied. Six different tool pin geometries were testedin friction stir spot welding(FSSW). The effects of tool shoulder diameter and shoulder cavity angle were also investigated. In the tests 4 mm thick high density polyethylene (HDPE) and polypropylene (PP) were used. All the welding operations were done at the room temperature. Lap-shear tensile tests were carried out to find the weld static strength. Weld cross section appearance observations were also examined. From the experiments the effect of pin profile and shoulder geometry on friction stir spot weld formation and weld strength were determined. The tapered cylindrical pin was found the optimum pin profile. 30 mm shoulder diameter and 6o shoulder cavity angle gave the best results.
Almost one-third of older people experience fallscaused bymedical factors and/or frailty.Falls may lead to devastating results. The rapid increase in life expectancy has made fall-detection and analysis an important issue. In order to identify trends and the state of the art in fall risk and balance assessment in older people,this paper carries out a review of the literature in this field. The focus has been on works that studied various assessment tools developed for fall risk assessment in people above 65 years old. The reviewed papers are categorized into two large groups of Clinical Fall Risk Assessment Methods and Quantitative Fall Risk Analysis Methods. For the studies in the first group, in addition to the contribution and limitations of each cited work, thevalidity and reliability factors are highlighted. The majority of the works reported in the second group are still in the development stage and have not been applied in real clinical applications. Hence, issues such as sensitivity and specificity are not considered. The review reveals that despite the high number of studies, there is no consistent worldwide standard for fall risk and balance disorder analysis and assessment. Many of the methods proposed havenot been validated forlarge groups of subjects and the results are generalized without reliable evidence. High cost, complexity, and length of the procedure are the major drawbacks of many of the proposed methods. The frailty of older people can make routine gait analysis challenging. The results of the analysis of the current literature reveal a lack of any comprehensive, objective and accurate method.
Impact of Soil Moisture Conservation Practices and Nutrient Management Under ...theijes
A field experiment was conducted at Cotton Research Unit, Dr. Panjabrao Deshmukh Krishi Vidyapeeth , Akola during the year 2014-15 with a view to study the moisture conservation techniques and nutrient requirement for cotton variety AKH-081 which is suitable genotype recommended for High Density Planting System for Vidharbha condition of Maharashtra. The experiment was laid out in split plot design replicated thrice with twelve treatments. The plot size was 6.0 x 4.5 meters spacing at 60 x 10 cm with 1.66 lakh plants per hectare. Three moisture conservation techniques consisting flat sowing, opening of furrow at 40-60 days after sowing and sowing on Broad Bed Furrow (BBF) 3 rows marked at 60 cm along with nutrient management levels RDF (60:30:30 NPK kg ha-1) ,RDF + 2.5 kg Zn ha-1, 125 % RDF (75:37.5:37.5 NPK kg ha-1) and 125 % RDF +2.5 kg Zn ha-1. The growth parameters viz. Plant height and sympodia was significantly influenced due to different moisture conservation techniques. BBF exihibited highest Plant height, Sympodia and Dry matter over the other parameter. The plant height, sympodia and dry matter per plant was increased significantly with increased in nutrient levels with micronutrients for high density planting system of cotton. Nutrients with different levels significantly influenced the yield attributes i.e Boll weight and Seed cotton yield under high density planting system. Significantly highest Seed cotton yield of (1786 kg ha-1) and was recorded with 125 % RDF + 2.5 kg Zn ha-1 which was at par with 125 % RDF. The highest gross monetary return, net monetary returns and benefit cost ratio was recorded with 125 % RDF (75:37.5:37.5 NPK kg ha-1) + 2.5 Kg Zn ha-1 which was at par with125 % RDF (75:37.5:37.5 NPK kg ha-1) which is the need of higher plant density. The highest WUE (3.02 kghamm-1) was noticed in 125 % RDF + Zn.
BER Analysis ofImpulse Noise inOFDM System Using LMS,NLMS&RLSiosrjce
IOSR Journal of Computer Engineering (IOSR-JCE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of computer engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in computer technology. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Simulation Study and Performance Comparison of OFDM System with QPSK and BPSKpaperpublications3
Abstract: FDMA, TDMA and CDMA are the well-known multiplexing techniques used in wireless communication systems. While working with the wireless systems using these techniques various problems are encountered especially when a typical transmitted signal arrives at the receiver using various paths of different lengths. Since multiple versions of the signal interfere with each other, it becomes difficult to extract the original information. The use of orthogonal frequency division multiplexing (OFDM) technique provides better solution for the above mentioned problem. OFDM technique distributes the data over a large number of carriers that are spaced apart at precise frequencies. This spacing provides the "orthogonality", which prevents the demodulator from seeing frequencies other than their own. The benefits of OFDM are high spectral efficiency, resiliency of RF interference, and lower multi-path distortion. OFDM is a powerful modulation technique that is capable of high data rate and is able to eliminate ISI. Using MATLAB, simulation of OFDM was done with different modulation techniques using different transform techniques. The digital modulation schemes such as BPSK and QPSK were selected to assess the performance of the designed OFDM system.
Energy Efficient Bit Extension Type Accelerator Chip for Detection AlgorithmsIJERA Editor
This paper presents an energy efficient bit extension type accelerator chip that targets decoding tasks of MIMO(Multiple input multiple output) - orthogonal frequency-division multiplexing (OFDM) systems. The work is motivated by the adoption of MIMO and OFDM by almost all existing and emerging high-speed wireless data communication systems. MIMO is an antenna technology for wireless communications in which multiple antennas are used at both the source (transmitter) and the destination (receiver). MIMO decoder or sometimes called MIMO equalizer detects or decodes or recovers the transmitted signals from multiple antennas. MIMO decoding process for a certain application is hard and time consuming. This motivates the need for a programmable accelerator block to implement the MIMO decoder task as fast and easy application. In this paper proposing a new pipeline architecture in arithmetic units inside the processing core of accelerator chip. The proposed architecture can perform with higher frequency with the help of pipeline structure and also improving the speed of operation of rotation unit with a new arithmetic rotation unit instead of native CORDIC algorithm. This proposed architecture helps to reduce dynamic power consumption. The accelerator is an ideal solution for today’s smart phones that implement multiple MIMO-OFDM waveforms on the same platform.
Performance evaluation on the basis of bit error rate for different order of ...ijmnct
Today, we have required to accommodate a large number of users under a single base station. This can be
possible only if we have some flexibility over the spectrum. Previously we have lots of multiplexing methods
to accommodate large number of signals in time and frequency domain. But now we have required to
accommodate a large number of users in the same bandwidth, without any fading over the received signal.
So, orthogonality can be maintained over the frequency response. This technology is now more popular in
the mobile communication domain, called Orthogonal Frequency Division Multiplexing (OFDM). Actually
user data can be converted into the parallel form and then they are modulated using digital modulation
techniques. Finally, they have followed by OFDM Modulator and cyclic prefix can be inserted into the
OFDM symbols. Here, I have worked on the measurement of Bit error rate for different modulation
techniques in OFDM technology. It has been considered that subchannel size is not constant. According to
that I have concluded the overall idea regarding the performance under OFDM technology.
Implementation Cost Analysis of the Interpolator for the Wimax Technologyiosrjce
The design of the multirate filter (programmable) has been proposed which can be used in digital
transceivers that meets 802.16d/e (wimax) standard in the wireless communication system. Wimax is a
technology emerging in the wireless communication system in order to increase the broadband wireless internet
access. As there is wide spread need of the digital representation of the signal for the transmission and storage
which create the challenges in DSP [1]. In this paper, analysis of the implementation cost of interpolator for the
wimax technology, and cost of interpolator is analyzed on the basis of number of adders and multiplier. The
Filters are designed using the FDA (filters design and analysis) tool in MATLAB.
Bessel Companding Transform for reducing PAPR, OBI and BER in OFDM SystemsIOSR Journals
Abstract : Orthogonal Frequency division multiplexing (OFDM) is a very popular technique in wireless communications which provides excellent robustness to channel fading and immune to interference. OFDM is one of a popular modulation technique for transmitting large amounts of digital data over radio carriers. One of the major problems that had been observed in this is the Peak-To Average power Ratio (PAPR). PAPR is a distortion that had occurred due to large number of sub carriers that are used in OFDM for modulating the digital data. Many techniques were available to reduce the PAPR in OFDM systems, among them the companding technique can be used to enhance the OFDM transmission performance by decreasing the PAPR effectively and hence BER. Here we proposed “Bessel Companding Algorithm” to reduce this significant drawback in OFDM Systems. Keywords : Orthogonal Frequency Division Multiplexing (OFDM), peak to average power ratio (PAPR), bit error rate (BER), Out Band Interference (OBI), Additive White Gaussian Noise (AWGN), Bessel Companding Algorithm, Quadrature Amplitude Modulation (QAM) and Multi Carrier Modulation (MCM).
Capacity Enhancement of MIMO-OFDM System in Rayleigh Fading ChannelIOSR Journals
MIMO-OFDM system in Rayleigh Fading Channel is very popular technique for mobile
communication now a day’s for research. Here we want increase the capacity of MIMO-OFDM of system by
using adaptive modulation, Algebraic Space-Time Codes (ASTC) encoder for MIMO Systems are based on
quaternion algebras .we found that ergodic capacity has some limitation which reduce the system’s
performance to overcome this we use ASTC code . ASTC code are full rank, full rate and non vanishing constant
minimum determinant for increasing spectral efficiency and reducing Peak to Average Power Ratio (PAPR) .
Performance Analysis of Fractional Sample Rate Converter Using Audio Applicat...iosrjce
Fractional rate converters which are generally used for many applications with different frequencies
and are an essential part of communication systems. In this paper fractional rate converter with use of both
FIR and Nyquist FIR have been compared and analyzed. Its implementation can be easily found in the
developing communication systems, but here results are taken for audio applications. The proposed design and
analysis have been developed with the help of MATLAB with order 50 for FIR and 71 for Nyquist, sampling
frequency 48000Hz. The filters are then interpolated by an interpolation factor 2 and decimated by a decimation
factor of 3. The cost implementation of both has been taken into consideration and a result is drawn which
concludes that fractional rate converter for Nyquist FIR filter much more cost effective as compared to the
fractional rate converter for FIR filter
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.
Applications of Time Division multiplexing : statistical TDMDr Rajiv Srivastava
These slides cover a topic on Applications of Time Division multiplexing and statistical TDM in Data Communication. All the slides are explained in a very simple manner. It is useful for engineering students & also for the candidates who want to master data communication & computer networking.
Pin Profile and Shoulder Geometry Effects in Friction Stir Spot Welded Polyme...theijes
The effects pin profile and shoulder geometry in friction stir spot welded polymer sheets were studied. Six different tool pin geometries were testedin friction stir spot welding(FSSW). The effects of tool shoulder diameter and shoulder cavity angle were also investigated. In the tests 4 mm thick high density polyethylene (HDPE) and polypropylene (PP) were used. All the welding operations were done at the room temperature. Lap-shear tensile tests were carried out to find the weld static strength. Weld cross section appearance observations were also examined. From the experiments the effect of pin profile and shoulder geometry on friction stir spot weld formation and weld strength were determined. The tapered cylindrical pin was found the optimum pin profile. 30 mm shoulder diameter and 6o shoulder cavity angle gave the best results.
Almost one-third of older people experience fallscaused bymedical factors and/or frailty.Falls may lead to devastating results. The rapid increase in life expectancy has made fall-detection and analysis an important issue. In order to identify trends and the state of the art in fall risk and balance assessment in older people,this paper carries out a review of the literature in this field. The focus has been on works that studied various assessment tools developed for fall risk assessment in people above 65 years old. The reviewed papers are categorized into two large groups of Clinical Fall Risk Assessment Methods and Quantitative Fall Risk Analysis Methods. For the studies in the first group, in addition to the contribution and limitations of each cited work, thevalidity and reliability factors are highlighted. The majority of the works reported in the second group are still in the development stage and have not been applied in real clinical applications. Hence, issues such as sensitivity and specificity are not considered. The review reveals that despite the high number of studies, there is no consistent worldwide standard for fall risk and balance disorder analysis and assessment. Many of the methods proposed havenot been validated forlarge groups of subjects and the results are generalized without reliable evidence. High cost, complexity, and length of the procedure are the major drawbacks of many of the proposed methods. The frailty of older people can make routine gait analysis challenging. The results of the analysis of the current literature reveal a lack of any comprehensive, objective and accurate method.
Impact of Soil Moisture Conservation Practices and Nutrient Management Under ...theijes
A field experiment was conducted at Cotton Research Unit, Dr. Panjabrao Deshmukh Krishi Vidyapeeth , Akola during the year 2014-15 with a view to study the moisture conservation techniques and nutrient requirement for cotton variety AKH-081 which is suitable genotype recommended for High Density Planting System for Vidharbha condition of Maharashtra. The experiment was laid out in split plot design replicated thrice with twelve treatments. The plot size was 6.0 x 4.5 meters spacing at 60 x 10 cm with 1.66 lakh plants per hectare. Three moisture conservation techniques consisting flat sowing, opening of furrow at 40-60 days after sowing and sowing on Broad Bed Furrow (BBF) 3 rows marked at 60 cm along with nutrient management levels RDF (60:30:30 NPK kg ha-1) ,RDF + 2.5 kg Zn ha-1, 125 % RDF (75:37.5:37.5 NPK kg ha-1) and 125 % RDF +2.5 kg Zn ha-1. The growth parameters viz. Plant height and sympodia was significantly influenced due to different moisture conservation techniques. BBF exihibited highest Plant height, Sympodia and Dry matter over the other parameter. The plant height, sympodia and dry matter per plant was increased significantly with increased in nutrient levels with micronutrients for high density planting system of cotton. Nutrients with different levels significantly influenced the yield attributes i.e Boll weight and Seed cotton yield under high density planting system. Significantly highest Seed cotton yield of (1786 kg ha-1) and was recorded with 125 % RDF + 2.5 kg Zn ha-1 which was at par with 125 % RDF. The highest gross monetary return, net monetary returns and benefit cost ratio was recorded with 125 % RDF (75:37.5:37.5 NPK kg ha-1) + 2.5 Kg Zn ha-1 which was at par with125 % RDF (75:37.5:37.5 NPK kg ha-1) which is the need of higher plant density. The highest WUE (3.02 kghamm-1) was noticed in 125 % RDF + Zn.
A Novel Feature Selection with Annealing For Computer Vision And Big Data Lea...theijes
Numerous PC vision and medical imaging issues a confronted with gaining from expansive scale datasets, with a huge number of perceptions furthermore, highlights.A novel productive learning plan that fixes a sparsity imperative by continuously expelling variables taking into account a measure and a timetable. The alluring actuality that the issue size continues dropping all through the cycles makes it especially reasonable for enormous information learning. Methodology applies nonexclusively to the advancement of any differentiable misfortune capacity, and discovers applications in relapse, order and positioning. The resultant calculations assemble variable screening into estimation and are amazingly easy to execute. It gives hypothetical assurances of joining and determination consistency. Investigates genuine and engineered information demonstrate that the proposed strategy contrasts exceptionally well and other cutting edge strategies in relapse, order and positioning while being computationally exceptionally effective and adaptable.
Prevalence of Cardiovascular Risk Factors among Healthy Subjects with or With...theijes
Metabolic syndrome (MetS) is defined by a constellation of interconnected physiological, biochemical, clinical, and metabolic factors that directly increases the risk of cardiovascular disease, type 2 diabetes mellitus, and all cause mortality. It is estimated that around a quarter of the world’s adult population have MetS and they are twice as likely to die from and three times as likely to have a heart attack or stroke compared with people without the syndrome. Data from a total of 401 healthy individuals was analysed and there it was found the prevalence of MetS and there were evaluated the risk factors of CVD in people with MetS. The prevalence of MetS resulted 22%. It was found that in the group of people with MetS there was insulin resistance and a lower insulin sensitivity comparing to the group without MetS. There were studied the modifiable and the nonmodifiable cardiovascular risk factors including : age, gender, BMI, HDL cholesterol, triglycerides, glycaemia, blood pressure. As a conclusion to this study was found that in the group of people with MetS, were present a significant number of CVD risk factors including modifiable and non-modifiable risk factors
Experimental Study on Corrosion of Wire Rope Strands under Sulfuric Acid Attacktheijes
A corrosive medium is typically found in the working environment of a wire rope. The wire rope structure has certain characteristics such as complex details, high working stress, and extremely difficult control. Thus, corrosion is the key problem related to the use of wire ropes. The corrosion behaviors of strands extracted from wire rope of type 19x7 in acid medium was investigated in this paper. The results obtained from tensile tests on virgin and corroded specimens show a decrease in strength as function of immersion hours. This progressive decrease of strength allowed us to quantify the damage. Thereafter, and with the establishment of the Damage-Reliability relationship, three stages of damage are distinguished and the value of the critical life fraction is identified (βC = 0.62).
Kinetics, Isotherm And Thermodynamics Studies of Swiss Blue Dye Desorption fr...theijes
Chloroform desorption of Swiss blue dye from saturated activated carbon prepared from hamburger seed shell via microwave technique has been studied and the kinetics, isotherm and thermodynamic data determined. Initial solid loading concentrations of the activated carbon after saturation were 123.72mg/g, 248.58mg/g, 373.28mg/g, and 498.11mg/g using 100mg/l, 200mg/l, 300mg/l, and 400mg/l initial concentration of Swiss blue dye respectively. The kinetic data were fitted to first order, second order, pseudo first order, pseudo second intraparticle diffusion, and Elovich models. The data fitted pseudo second order perfectly due to the high correlation coefficient. The isotherm data was fitted to Langmuir, Freundlich, Dublin-Radushkevich (D-R), Temkin, Flory-Huggins, Redlich-Peterson and Toth models. The data fitted well to Freundlich model. Activation energy for desorption process was calculated at different initial solid phase concentration. Arrhenius relationship was developed to represent the rate constant dependency on temperature at different initial solid phase concentrations. Thermodynamic parameters calculated confirmed the process as endothermic, feasible and spontaneous. The process had increased disorder as temperature was increased.
Phishing Websites Detection Using Back Propagation Algorithm: A Reviewtheijes
Phishing is an illicit modus operandi employing both societal engineering and technological subterfuge to theft client’s private identity data and monetary account credentials. Influence of phishing is pretty radical as it engrosses the menace of identity larceny and financial losses. This paper elucidates the back propagation paradigm to instruct the neural network for phishing forecast. We execute the root-cause analysis of phishing and incentive for phishing. This analysis is intended at serving developers the effectiveness of neural networks in data mining and provides the grounds proving neural networks in phishing detection.
RADAR (RAdio Detection and Ranging) use modulated waveforms and directive antennas to transmit electromagnetic energy into a specific volume in space to search for targets. The targets within the volume reflect echoes back to the radar which are further processed to extract target information. A better SNR (Signal to Noise Ratio) to for radar surveillance is achieved. The results are provided by Matlab simulation.
Applying IPA on Services Quality for Farm Irrigation Engineering - A Case S...theijes
The purpose of development Irrigation Association in Taiwan is to service farmers, improve irrigation and drainage facilities and get the most out of the economy for all members. Therefore, this study takes a case of Kaohsiung Irrigation Association as object, and explores the effect on the service quality to maintain the sustainable development of agriculture. The research takes the service quality scale of Kaohsiung Irrigation Association as the questionnaire and applies importance-performance analysis (IPA) to view the demand on service quality. Through 22 factors and 5 phases to analysis the questionnaire by statistical method including difference analysis, independent T test, one-way analysis of variance and correlation analysis. The result shows that the background parameters and five phases have significant effects such as level of education and position. The analysis of IPA is found that 17 factors in the first quadrant mean that members and users will have confidence and extreme recognition and identity on service quality of water conservancy. The results will explore the important issues of concern on service quality in Kaohsiung Irrigation Association, and could give as a reference to improve the future of construction and provide the ability to play a good role in supervision to strengthen the quality and service efficient in farmers' organizations.
High Gain Interleaved Cuk Converter with Phase Shifted PWMtheijes
DC-DC converters with ripple on input source current inject harmonics to the power system which in turn cause harmful to other connected devices. These converters with high efficiency and low input current ripple are essential in most common applications. Cuk converter provide reduction in the ripple of input and output current compared to other traditional converters which can be used for either step up or step down applications. Generally, a conventional cuk converter in continuous conduction mode brings in large current ripple on input side which in turn injects harmonics to the source. This undesirable input current ripple is mitigated by employing the interleaved cuk converter (ICC). Simulation results of ICC shows that the input ripple current has been reduced significantly from 7.5A to 1A compared to conventional cuk converter. The energy-transfer-capacitor in basic cuk converters is splitted into two capacitors. The rectifier diode is replaced by two diodes that form with the two capacitors a switched-capacitor circuit, which appears connected between the input and output inductances of the original converter. A hybrid circuit, presenting a higher DC voltage ratio than the classical Cuk circuit can be obtained. A high gain interleaved cuk converter is designed and simulated in MATLAB/SIMULINK for 40V with an input of 20V.
Teaching Mathematics Based On “Mathematization” Of Theory of Realistic Mathem...theijes
Theory of Realistic Mathematics Education (RME) was originated in The Netherlands in 1970. It was developed from Freudenthal’ point of view which considered mathematics as human activity. This theory suggested that teaching mathematics should begin with realistic context; the teacher guides his students to reinvent knowledge by process of mathematization. In this paper, we present our research results obtained from application of RME into try-out of teaching linear function in Vietnamese schools
Identification and Selection of the Best Industrial Wastewater Treatment Tech...theijes
A bench scale model and treatability study was developed for chemical product “detergents, shampoos, toilet soaps and sanitary paper” industry to study the analysis of waste discharge. The main process lines used in the industry are fabric and home care production unit, soap production unit, and sanitary paper production unit. The main environmental problem of the industry is that the industrial wastewater resulting from the facility is not meeting the limits of the environmental regulations for the discharge of wastewater to the sewer network. Accordingly, the industry has to treat the wastewater prior to its discharge to the wastewater sanitary network. The main objectives of this study are management and control of liquid and solid wastes in the industry as well as selecting the different possible treatment trains for the waste water prior to its discharge to the sewer system in order to protect the environment and to gain benefits as much as possible from the wasted materials and identify opportunities for introducing pollution prevention measures and best method for waste minimization as cleaner production system. The study is taking into account all types of waste production including wastewater and solid waste during the production processes activities. Treatment Procedure is conducted through treatability study using two proposed streams of techniques; biological treatment technique (Anaerobic Treatment) and chemical treatment followed by biological treatment technique (Coagulation followed by Sedimentation). According to the different treatment alternatives conducted through the study, it is proved the biological method is not suitable for this type of waste, as the antifoaming chemicals and enzymes present in the wastewater leads to death of the microorganisms and accordingly the failure of the treatment system. As for the chemical treatment, it provided good results in both industrial wastewater mixed with domestic wastewater, and industrial wastewater alone. It also provided good results when using both ferric chloride and aluminum sulphate. It is concluded that the coagulation and Flocculation process followed by plain sedimentation is the most reliable alternative treatment method for this kind of industry using ferric chloride for the wastewater without domestic wastewater. The removal efficiency reached 72 to 79%, 86 to 96%, 83 to 88% and 86% for COD, TSS, Phosphorous, and Oil and Grease respectively.
The Recycling of Steel and Brass Chips to Produce Composite Materials via Col...theijes
In this study a novel method of direct conversion of brass (CuZn30) and steel (S355JR) chips into finished product without melting is introduced as an alternative to melting process. CuZn30 Brass and S355JR steel chips were used as constituents of composite materials. The chips were cold pressed at room temperature and were subjected to liquid phase sinterization. Hardness, compression and three point bending tests were used to investigate the mechanical properties of the obtained composite materials and compared with cast CuZn30 brass. The produced composite materials are shown to have comparable mechanical properties with bulk brass. It is also shown that the proposed method can be considered as an alternative to conventional production methods such as melting, extrusion ect. with relatively low costs.
Influence of Temperature on Corrosion Characteristics of Metals in Used Cooki...theijes
Biodiesel has become a rapid growing liquid biofuel across the world as a substitute for fossil fuel. Corrosion of metals in biodiesel poses a great threat as this can affect durability of engine parts with which it comes in contact. This study aims at investigating influence of temperature on the corrosion characteristics of metals in used cooking oil methyl ester. The corrosion characteristics of copper-magnesium alloy, mild steel, aluminium, and stainless steel in used cooking oil methyl ester, commercial diesel and diesel- methyl ester blends were studied and the results of corrosion rates obtained in methyl ester and diesel methyl ester blends were compared with that obtained in commercial diesel. Static immersion tests of each metal were carried out in B0, B20, B40, B60, B80, and B100 fuels at room temperature (25-30 °C) for 965 hours, 40 °C, 60 °C, 80 °C, and 100 °C for 8 hours. At the end of the test, the corrosion rates of each metal were investigated by converting loss in weight into corrosion rate. Results showed that the corrosion rate of each metal sample increased as temperature increased. Also, Copper-magnesium alloy presented highest corrosion rates in all test fuels.
Impact of Abattoir Wastes on the Physicochemical Properties of Soils within P...theijes
The impact of abattoir wastes on the physicochemical properties of soils within Port Harcourt metropolis has been investigated. Soil samples from twelve different abattoir locations within Port Harcourt metropolis labeled ABP1 to ABP12 were analyzed for possible contamination of physicochemical and heavy metal parameters. Theywere equally compared with a control site of no abattoir activities (ABPc) as well as WHO and FEPA standard set limits. The soil temperature which was carried out in-situ gave an average value of 30.00C. The mean values of the physicochemical parameters revealed that pH and electrical conductivity had average values of 7.00 and 78.33µScm-1 respectively. Chloride, salinity and nitrates had average values of 335.00mgKg-1 , 601.74mgKg-1 and 39.30mgKg-1 respectively. These values were slightly higher than both the control site as well as the standard set limit byWHO. Thus, indicating the possibility of contamination/pollution from the abattoir activities. However, average the values for the phosphates, sulphates and heavy metals (Pb, Cu, Cd, Ni, Cr) though slightly higher than those of the control site (ABPc) were all within the standard set limits by WHO and FEPA. Statistical correlation equally showed positive correlations between chloride and salinity (1.0000), phosphate and cadmium (0.9939), conductivity and iron (0.9485). Also, negative correlations were equally observed between sulphate/chloride and sulphate/salinity with same values of -0.9192. Therefore abattoir activities within Port Harcourt metropolis imparts negatively on the arable soil and measures should be put in place for proper control.
FTIR Spectrum of BiFeO3 Ceramic Produced By Sol-Gel Method Based On Variation...theijes
High purity BiFeO3 (BFO) powder was synthesized by sol-gel method using bismuth nitrate, iron nitrate as sources and citric acid as fuel. The calcination treatment of the citric acid gel was at 160oC and 200oC for 4 hours respectively. Sintering treatment was varied at 600oC for 4, 6 and 8 hours respectively. The powder has been characterized by Thermogravimetric Analysis/Differential Thermal Analysis (TGA/DTA) to know reference temperatures of calcination and sintering, X Ray Diffraction (XRD) test to confirm BFO phase and Fourier Trasform Infra Red (FTIR) to identify chemical bonds in a molecule by producing an infrared absorption spectrum. TGA/DTA results show that loss of mass and heat flow is at 160oC approximately, it is used as reference of calcination temperature. XRD results show that the BFO powder sintered at 600oC for 8 hours exhibits no secondary phase, Bi2O3. Meanwhile, FTIR Spectrum shows that powder had single phase BFO is having wave number 1385 cm-1 (C-H), 1560 cm-1 (C-C) and 2930 cm-1 (C-H).
Applying K-Means Clustering Algorithm to Discover Knowledge from Insurance Da...theijes
Data mining works to extract information known in advance from the enormous quantities of data which can lead to knowledge. It provides information that helps to make good decisions. The effectiveness of data mining in access to knowledge to achieve the goal of which is the discovery of the hidden facts contained in databases and through the use of multiple technologies. Clustering is organizing data into clusters or groups such that they have high intra-cluster similarity and low inter cluster similarity. This paper deals with K-means clustering algorithm which collect a number of data based on the characteristics and attributes of this data, and process the Clustering by reducing the distances between the data center. This algorithm is applied using open source tool called WEKA, with the Insurance dataset as its input
Environmental Monitoring Model of Health, Parasitological, And Colorimetric C...theijes
The sanitary quality of water was evaluated in two micro basins, Bacaxá and Capivari belonging to the Lakes Basin St. John in the state of Rio de Janeiro, Brazil, for colimetric and parasitological analysis. Analyses were performed seasonally over a year and the levels of Escherichia coli were within the recommended only in the summer of 2012 and fall, and inappropriate with levels above recommended in winter, spring and summer of 2013 in both the micro basins. Through our observations, we compare the average values of the levels of total coliforms and Escherichia coli between both rivers. Initially, the samples indicate a similarity between the distributions of coliforms and Escherichia coli. However, Mann-Whitney-Wilcoxon test samples indicate that the distributions are different. In parasitological analysis it was observed that in Capivari was detected a greater presence of filarial larvae. Anthropogenic influences mainly by the presence of sewage is being able to compromise the health quality of the micro basins studied carrying a significant pollutant load to the Juturnaíba reservoir. The monitoring of the sanitary quality of the watersheds that supply the population may indicate when it is necessary to adopt more effective measures in the treatment of water supply of cities.
Ber performance of ofdm with discrete wavelet transform for time dispersive c...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
Dwpt Based FFT and Its Application to SNR Estimation in OFDM SystemsCSCJournals
In this paper, wavelet packet (WP) based FFT and its application to SNR estimation is proposed. OFDM systems demodulate data using FFT. The proposed solution computes the exact FFT using WP and its computational complexity is of the same order as FFT, i.e. O (Nlog2 N). SNR estimation is done inside wavelet packet based FFT block unlike previous SNR estimations techniques which perform SNR estimation after FFT. Wavelet packet analyzed data is used to perform SNR estimation in colored noise. The proposed estimator takes into consideration the different noise power levels of the colored noise over the OFDM sub-carriers. The OFDM band is divided into several sub-bands using wavelet packet and noise in each sub-band is considered white. The second-order statistics of the transmitted OFDM preamble are calculated in each sub-band and the power noise is estimated. The proposed estimator is compared with Reddy’s estimator for colored noise in terms of mean squared error (MSE).
FPGA Design & Simulation Modeling of Baseband Data Transmission SystemIOSR Journals
Abstract: This paper describes a study on a baseband data transmission system developed for undergraduate
students studying communication engineering. Theoretical material, developed in the lectures, is briefly
covered. A practical system is presented with pre-detection filtering being employed to improve the bit error
rate. A simulation of the complete system is carried out on a Sun work station using the MATLAB simulation
package. Simulation and theoretical results are compared.
Capacity Enhancement of MIMO-OFDM System in Rayleigh Fading ChannelIOSR Journals
Abstract: MIMO-OFDM system in Rayleigh Fading Channel is very popular technique for mobile communication now a day’s for research. Here we want increase the capacity of MIMO-OFDM of system by using adaptive modulation, Algebraic Space-Time Codes (ASTC) encoder for MIMO Systems are based on quaternion algebras .we found that ergodic capacity has some limitation which reduce the system’s performance to overcome this we use ASTC code . ASTC code are full rank, full rate and non vanishing constant minimum determinant for increasing spectral efficiency and reducing Peak to Average Power Ratio (PAPR) . Keywords— Adaptive modulation ASTC code, Capacity, BER, Ergodic capacity, PAPR, Spectral Efficiency and SNR
Investigation and Analysis of SNR Estimation in OFDM systemIOSR Journals
Estimation of signal to noise ratio (SNR) of received signal and to transmit the signal effectively for
the modern communication system. The performance of existing non-data-aided (NDA) SNR estimation methods
are substantially degraded for high level modulation scheme such as M-ary amplitude and phase shift keying
(APSK) or quadrature amplitude modulation (QAM).In this paper SNR estimation proposed method which uses
zero point auto-correlation of received signal per block and auto/cross- correlation of decision feedback signal
in orthogonal frequency division multiplexing (OFDM) system. Proposed method can be studied into two types;
Type 1 can estimate SNR by zero point auto-correlation of decision feedback signal based on the second
moment property. Type 2 uses both zero point auto-correlation and cross-correlation based on the fourth
moment property. In block-by-block reception of OFDM system, these two SNR estimation methods can be
possible for the practical implementation due to correlation based the estimation method and they show more
stable estimation performance than the earlier SNR estimation methods.
Designing and Performance Evaluation of 64 QAM OFDM SystemIOSR Journals
Abstract (11Bold) : — In this report, the performance analysis of 64 QAM-OFDM wireless communication
systems affected by AWGN in terms of Symbol Error Rate and Throughput is addressed. 64 QAM (64 ary
Quadrature Amplitude Modulation) is the one of the effective digital modulation technique as it is more power
efficient for larger values of M(64). The MATLAB script based model of the 64 QAM-OFDM system with
normal AWGN channel and Rayleigh fading channel has been made for study error performance and
throughput under different channel conditions. This simulated model maximizes the system throughput in the
presence of narrowband interference, while guaranteeing a SER below a predefined threshold. The SER
calculation is accomplished by means of modelling the decision variable at the receiver as a particular case of
quadratic form D in complex Gaussian random variables. Lastly comparative study of SER performance of 64
QAM-OFDM simulated & 64 QAM-OFDM theoretical under AWGN channel has been given. Also
performance of the system is given in terms of throughput (received bits/ofm symbol) is given in a plot for
different SNR. Keywords (11Bold) –64 QAM, BPSK, OFDM, PDF, SNR.
Designing and Performance Evaluation of 64 QAM OFDM SystemIOSR Journals
In this report, the performance analysis of 64 QAM-OFDM wireless communication
systems affected by AWGN in terms of Symbol Error Rate and Throughput is addressed. 64 QAM (64 ary
Quadrature Amplitude Modulation) is the one of the effective digital modulation technique as it is more power
efficient for larger values of M(64). The MATLAB script based model of the 64 QAM-OFDM system with
normal AWGN channel and Rayleigh fading channel has been made for study error performance and
throughput under different channel conditions. This simulated model maximizes the system throughput in the
presence of narrowband interference, while guaranteeing a SER below a predefined threshold. The SER
calculation is accomplished by means of modelling the decision variable at the receiver as a particular case of
quadratic form D in complex Gaussian random variables. Lastly comparative study of SER performance of 64
QAM-OFDM simulated & 64 QAM-OFDM theoretical under AWGN channel has been given. Also
performance of the system is given in terms of throughput (received bits/ofm symbol) is given in a plot for
different SNR
An Adaptive Approach to Switching Coded Modulation in OFDM System Under AWGN ...ijsrd.com
In this paper we have studied the OFDM for different Quadrature amplitude modulation technique (QAM) The scatter plot and their output signal to noise ratio, dependent bit error rate variation is analyzed for every type of modulation in OFDM. After observing the BER for each SNR in the system, switching threshold range has been prepared and now system is ready to face the Adaptive coded modulation (ACM).The results shows the switching of modulation technique.
Comparative evaluation of bit error rate for different ofdm subcarriers in ra...ijmnct
In the present situation, the expectation about the quality of signals in wireless communication is as high as possible. This quality issue is dependent upon the different communication parameters. One of the most important issues is to reduce the bit error rate (BER) to enhance the performance of the system. This paper provides a comparative analysis on the basis of this bit error rate. I have compared the BER for different number of subcarriers in OFDM system for BPSK modulation scheme. I have taken 6 varieties of data subcarriers to analyze this comparison. Here my target is to reach at the lowest level of BER for BPSK modulation. That is achieved at 2048 number of subcarriers.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
Low Peak to Average Power Ratio and High Spectral Efficiency Using Selective ...theijes
A low complexity peak to average power ratio (PAPR) reduction scheme for orthogonal frequency division multiplexing (OFDM) systems is proposed. All pass filters technique used PAPR is reduction but small amount of reduction, So use Selective Mapping (SLM) technique reduce PAPR and SNR increases.
A low complexity partial transmit sequence scheme for better papr reduction i...eSAT Journals
Abstract The main drawback of OFDM system is the high Peak to Average Power Ratio (PAPR) of the transmitted signals. Partial transmit sequence scheme is a promising algorithm to reduce the peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM). The Partial Transmit Sequence (PTS) consist of several inverse fast Fourier transform (IFFT) operations and complicated calculations to obtain optimum phase sequence which results in increasing the computational complexity of PTS. A phase sequence applied to the PTS Scheme reduces its complexity but at the expense of slight degradation in PAPR reduction. In this paper, for further reduction of PAPR the peak clipping of the OFDM signal is introduced along with the PTS with new phase sequence scheme. Since clipping is one of the simplest techniques of PAPR reduction, it does not increase the complexity of the system much and a better PAPR reduction is obtained with the combined effect of clipping and PTS with New Phase Sequence. But the clipping technique introduce some distortion in the signal, however peak clipping of signal below a particular threshold can maintain the BER in the tolerable range. The clipping threshold selected will be different for different OFDM systems. Index Terms: OFDM, Peak to Average Power Ratio (PAPR), Partial Transmit Sequence (PTS), Clipping.
Hardware Implementation of OFDM system to reduce PAPR using Selective Level M...IOSR Journals
Abstract : OFDM is a modulation as well as multiplexing technique which is widely used in various high speed mobile and wireless communication systems because of its capacity of ensuring high level robustness against interference. In this paper the design and implementation of OFDM system along with SLM implementation to reduce PAPR[6]is illustrated and a detailed simulation of the OFDM system with 16-QAM. OFDM transceiver is implemented using FPGA Spartan6 kit. The hardware results show a detailed study of RTL schematics and Test Bench. In this paper, the software simulation results show 2dB reduction in the peaks. Keywords - Field Programmable Gate Array, Matlab Simulink, Orthogonal Frequency Division Multiplexing , Peak-to-Average Power Ratio, Selective level Mapping and Xilinx
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.
Similar to Performance Analysis of a SIMO-OFDM System Using Different Diversity Combining Techniques and Their Comparison (20)
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
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.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Performance Analysis of a SIMO-OFDM System Using Different Diversity Combining Techniques and Their Comparison
1. The International Journal Of Engineering And Science (IJES)
|| Volume || 5 || Issue || 5 || Pages || PP -63-68 || 2016 ||
ISSN (e): 2319 – 1813 ISSN (p): 2319 – 1805
www.theijes.com The IJES Page 63
Performance Analysis of a SIMO-OFDM System Using Different
Diversity Combining Techniques and Their Comparison
Sahil Dhingra1
,Sovanjyoti Giri
1
Department Of Electronics And Communication, Dehradun Institute Of Technology
2
Department Of Electronics And Electrical Communication Engineering, IIT Kharagpur
--------------------------------------------------------ABSTRACT--------------------------------------------------
The motive of any wireless communication system is to reduce BER for the corresponding SNR. Through this
OFDM based receiver diversity system we analyze BER for different diversity combining techniques such as
EGC, MRC, SC in a rayliegh faded environment. This model serves two benefits: first noise limited system
performance is improved by combating ISI through OFDM and second use of diversity combining which helps
combat multipath fading. We also try to achieve an optimum trade-off between BER improvement and increase
in number of receiver antennas. This is just to make less-complex receiver as it requires only one DFT
processor.
KEYWORDS: BER, EGC, MRC, OFDM, Pre-DFT combining, SC, SNR.
---------------------------------------------------------------------------------------------------------------------------------------
Date of Submission: 19 April 2016 Date of Accepted: 10 May 2016
---------------------------------------------------------------------------------------------------------------------------------------
I. Introduction
Though BER can be reduced by increasing SNR of a system but most wireless equipments are power
limited i.e. we cannot go on indefinitely increasing the signal power as the power source will dry out fast rather
we need to find ways to reduce BER at low SNR values also For that we use OFDM and receiver Diversity
combining in this paper.
OFDM is a technique used for high speed data transmission. In OFDM high speed data streams are
broken into multiple low speed data streams to be carried over by different sub-carriers which are orthogonal to
each other. OFDM converts independent frequency selective fading channels into frequency flat fading
channels. Use of OFDM today is in digital data transmission and WLANs.
OFDM performs better than other techniques because it can transmit data at high rate even when
channel bandwidth is low. OFDM along with diversity combining helps in further enhancing the system
performance as the frequency flat fading problem is solved by using diversity combining techniques.
The process is to first transmit the modulated data by using OFDM technique through a wireless
rayliegh channel. At the receiver end the data received is first equalized using diversity techniques i.e. weighted
sum of each link is added to produce optimum SNR. Then the data is de-multiplexed and at last demodulated.
The idea behind diversity is to send data on independent fading paths. The combination of these paths is such
that fading of the resultant signal is reduced.
Most combining techniques are linear: the output of the combiner is just a weighted sum of the
different fading paths or branches, when more than one branch is non-zero the combiner first removes the phase
of each branch coherently by technique called co-phasing. In post-DFT combining all the receiver chains have a
separate DFT processor while in pre-DFT there is only one DFT processor for all receiver chains though in
performance post-DFT is better but it is at the cost of system complexity, increased hardware and increased size.
By using post-DFT the performance is only slightly improved[1].
The use of pre-DFT combining to reduce computational complexity as seen in the works of Minoru
okada in space diversity assisted COFDM[1], the work of H. Hamazumi on application of OFDM to create a
OFDM and diversity assisted technique for wideband mobile radio reception[5],
The work of S. Hara, M. Mouri, M. Okada, and N. Morinaga on Transmission performance analysis of
multi-carrier modulation in frequency selective fast Rayleigh fading channel[4] . all these works have inspired
me to develop this system which performs better even at low SNR values and has reduced system complexity
due to the innovative use of pre-DFT combining which requires only one DFT processor at receiver end. The
goal of wireless system design is to reduce BER on this principle this whole paper is centered. Rest of the paper
is sequentially organized as:
Section-II describes the block diagram of the system and functions of each block.
2. Performance Analysis Of A SIMO-OFDM System Using Different Diversity Combining …
www.theijes.com The IJES Page 64
Section-III simulation includes system parameters and various graphical results obtained for each combining
technique plus an approach on receiver optimization.
Section-IV is conclusion where we discuss the best technique of all and its implementation.
II. System Description
Fig1: Block Diagram of system
In the above figure Data generation is in the form of bits 1’s and 0’s. These data bits are modulated
using binary phase shift keying where the signal output corresponding to 1’s and 0’s is 180 degree apart. These
modulated bits are then converted serial to parallel for assignment to the orthogonal carriers generated by IFFT
operation. These data streams are then concatenated with cyclic prefix added after each stream.
Data is transmitted through a rayliegh channel and same copies of data are sent to multiple receivers.
The pre-DFT processor then by using diversity combining techniques which can be selection combining, equal
gain combining, maximal ratio combining generates an optimum SNR signal.
Further, FFT(Fast Fourier Transform) of the data stream is taken and cyclic prefix is removed. After
demodulation the data generated at output is compared with the input data to calculate the number of errors.
These errors are then further used in evaluation of BER. The BER corresponding to different number of receiver
antennas is plotted on a BER vs SNR plot.
1. Orthogonal Frequency Division Multiplexing:
High speed Data streams broken into low speed data streams.
Each stream assigned a sub-carrier which is orthogonal to other sub-carriers.
Cyclic prefix added to avoid interference and data loss.
IFFT,FFT, cyclic prefix addition, serial to parallel conversion, concatenation of multiple parallel streams
for data transmission and the reverse process on receiver side combined make the OFDM block
2. Receiver Diversity:
Multiple antennas at the receiver end employed as the probability of a single link to go into deep fade is
high than probability of multiple links. Different combining techniques ensure better optimization of all the
receiver chains.
2.1 Selection Combining:
in this approach the link with the maximum SNR is chosen at the combiner output. This is the most
simplified method and is least efficient.
𝐸 =
𝐸𝑏
𝑁𝑜
1
𝑖
𝑁
𝑖=1
Where i is the ith receiver chain and N is the total number of receiver chains, E is the average bit energy to noise
ratio, Eb is bit energy and No noise.
2.2 Equal Gain Combining:
A simpler technique which co-phases the signals on each branch and then combines them with equal
weight. The SNR of the combiner output, assuming equal noise power N in each branch.
𝐸 =
𝐸𝑏
𝑁𝑜
1
𝑁
ℎ𝑖
2
𝑁
𝑖=1
E is the effective (Eb/No) after combination of all receiver chains, N is the number of antennas, h is the
channel complex number, I is the ith receiver antenna.
3. Performance Analysis Of A SIMO-OFDM System Using Different Diversity Combining …
www.theijes.com The IJES Page 65
2.3 Maximal Ratio Combining:
The output is a weighted sum of all branches. the signals are cophased ,𝛼 = 𝑎𝑒−𝑗𝜃
, where ϴ is the
phase of the incoming signal on the ith branch.
𝐸 =
ℎ𝑖
2
𝑁𝑜
𝑁
𝑖=1
𝐸𝑏
E is the effective (Eb/No) after combination of all receiver chains, N is the number of antennas, h is the channel
complex number, i is the ith receiver antenna.
III. Simulation
To start with simulation we define number of antennas as a variable and see how BER changes with
increase in SNR and number of antennas for all the diversity techniques SC, EGC, MRC. As the system also
uses OFDM we also check how system responds with and without diversity combining.
3.1. System Parameters:
These include various variables that define the system as modulation order, number of bits, size of FFT
etc.
These are enlisted in the following table
S.No. Parameter value
1. Modulation Type BPSK
2. FFT size 64
3. Number of subcarriers 52
4. Number of symbols 104
5. Number of bits/symbol 52
6. SNR range(dB) 0-20
7. Number of receiver antennas Variable (1-4)
Table 1: System Parameters
3.2. Selection Combining Simulation:
The logic of selection combining is to choose the best signal out of all the receiver chains i.e. the chain with the
maximum SNR.
Fig 2: BER vs. SNR plot for selection combining
The blue line indicates that number of receiver antenna is equal to one which means that there is no
diversity logic used the system behaves purely as OFDM implemented. But as it is evidently clear that with use
of space diversity or multiple antennas the BER for a particular SNR goes on decreasing with increase in
number of antennas.
SNR value No. Of antenna BER
5 dB 1 0.1750
5 dB 2 0.0200
5 dB 3 0.0036
5 dB 4 0.0012
Table 2: values of BER for different number of antennas (SC).
3.3. Equal Gain Combining:
It is a sub-optimal technique in which only co-phasing is required. In this all the branches are given
equal weight.
0 5 10 15 20
10
-4
10
-3
10
-2
10
-1
10
0
Eb/No, dB
BitErrorRate
Bit error for SC with OFDM
No of receiver-1
No of receiver-2
No of receiver-3
No of receiver-4
4. Performance Analysis Of A SIMO-OFDM System Using Different Diversity Combining …
www.theijes.com The IJES Page 66
Fig 3: BER vs. SNR plot for Equal Gain Combining.
The EGC logic further enhances the system performance following the same trend of decrease in BER
for a particular SNR with increase in number of antennas
.
SNR value No. Of antennas BER
5 dB 1 0.17500
5 dB 2 0.01000
5 dB 3 0.00060
5 dB 4 0.00006
Table 3: values of BER for different number of antennas (EGC).
3.4. Maximal Ratio Combining:
It is the most optimum technique of the three. It considers all the receiver chains in both amplitude and
phase and after co-phasing assigns different weights to different chains to produce the best SNR at combiner
output.
Fig 4: BER vs. SNR plot for Maximal Ratio Combining
As seen in the graph the OFDM and MRC combination has reduced BER to a considerably low level even at
low SNR. BER is reaching around 10−6
at SNR value just above 5 dB.
SNR value No. Of antennas BER
5 dB 1 0.175000
5 dB 2 0.008000
5 dB 3 0.000200
5 dB 4 0.000004
Table 4: values of BER for different number of antennas (MRC).
It is evident from the graph that slope of MRC logic is very steep that is with increase in number of
antennas the fall in BER is very high.
3.5. Comparative Study:
In this section we compare all the three techniques to find the best suitable technique for use in wireless
communication.
Taking the values from the above three tables:
0 5 10 15 20
10
-6
10
-5
10
-4
10
-3
10
-2
10
-1
10
0
Eb/No, dB
BitErrorRate
Bit error for EGC with OFDM
No of receiver-1
No of receiver-2
No of receiver-3
No of receiver-4
0 5 10 15 20
10
-6
10
-5
10
-4
10
-3
10
-2
10
-1
10
0
Eb/No, dB
BitErrorRate
Bit error for MRC with OFDM
No of receiver-1
No of receiver-2
No of receiver-3
No of receiver-4
5. Performance Analysis Of A SIMO-OFDM System Using Different Diversity Combining …
www.theijes.com The IJES Page 67
SNR antennas SC EGC MRC
5 dB 4 0.00120 0.000060 0.0000040
6 dB 4 0.00030 0.000005 0.0000010
Table 5: Comparative Study of SC,EGC,MRC.
With single unit rise in SNR the values for each technique change drastically and the table clearly
shows that OFDM with MRC produces the best result. For further evaluation we will use MRC as the most
optimum technique.
3.6. Number of Receiver antenna optimization:
The last part of simulation is the trade-off between BER reduction and number of antennas that can be put to
use.
Fig 5: Receiver optimization
In the graph we can see that slope goes on decreasing with increase in number of antennas. Using the
above data, systems that work on very low SNR values to have BER performance of around 10−6
need to
increase the number of receiver antennas considerably. At 1 dB if a system requires BER of 10−5.9
there need to
be around 10 receiver antennas. Factors of cost, hardware, complexity, size all come into picture in trade-off
with system performance. If the system can work at 8-10dB range then only 3 receiver antennas can give a BER
of 10−5.9
. so, optimization of number of receiver antennas is very application specific or system requirement
dependent.
IV. Conclusion
To achieve a BER of (0.0001) with use of 3 antennas the SNR values for each technique vary as SC
achieves it at SNR of around 10 dB, EGC at around 7 dB and MRC at around 6dB. We can see the SNR
improvement with improvement in diversity combining logic. In each of the graphs the blue line is the system
performance only with OFDM and no use of diversity. But, we see that with use of diversity system
performance drastically improves. Out of all the three diversity combining MRC technique gave the least BER
at a particular SNR level. Further the use of OFDM-MRC in optimizing the number of receivers displayed that
trade-off between system performance at low SNR and cost, hardware usage were system requirement
dependent. Achieving 1 bit error in every 10^6 bits sent is very useful in wireless communication as with the
advent of new technologies every device is becoming wireless and there is an exponential increase in the
number of smartphone users. Data efficient technologies find application in military, high speed internet,
satellite D2H connections..
References
[1]. Minoru Okada, Shozo Komaki, Pre-DFT Combining Space Diversity Assisted COFDM, IEEE Transaction on vehicular
technology, Vol. 50 NO. 2,MARCH 2001.
[2]. Anis Charrada, Abdelaziz Samet ,SIMO-OFDM Channel Estimation based on Nonlinear Complex LS-SVM, IJCA(0975-8887)
VOLUME42-NO.3,MARCH 2012.
[3]. Ripan Kumar Roy, Tushar Kanti Roy ,BER analysis of MIMO-OFDM system using Alamouti STBC and MRC Diversity scheme
over Rayleigh multipath channel, GJRE Vol. 13 Issue 13 Print ISSN-0975-5861
[4]. S. Hara, M. Mouri, M. Okada, and N. Morinaga, Transmission performance analysis of multi-carrier modulation in frequency
selective fast Rayleigh fading channel, Wireless Personal Commun. Vol.2 no. 4, pp 335-356,1996
[5]. H. Hamazumi, Y. Ito and H. Miyazawa, Performance of frequency domain sub-band diversity combination technique for
wideband mobile radio reception-an application to OFDM ,Trans. IEICE, vol. J80-B-II, no.-6, pp. 466-474, june1997.
[6]. M.Mṻnster, T. Keller, and L.Hanzo, Co-channel interference suppression assisted adaptive OFDM in interference limited
environments.,In Proc. 50th
Vehicular Technology Conf(VTC 1000, vol. 1, Amsterdam, the Netherlands, Sept. 1999 pp. 284-288.
[7]. Andrea Goldsmith, Wireless Communications (Cambridge University Press,2005)
[8]. R. W. Chang and R. A. Gibby, A theoretical study of performance of an orthogonal multiplexing data transmission scheme, IEEE
Trans. Commun. Vol. COM-16, pp. 529-540, Aug. 1968.
0 2 4 6 8 10
10
-6
10
-5
10
-4
10
-3
10
-2
10
-1
10
0
Eb/No, dB
BitErrorRate
Bit error for MRC
6. Performance Analysis Of A SIMO-OFDM System Using Different Diversity Combining …
www.theijes.com The IJES Page 68
[9]. http://www.dsplog.com/2008/09/28/maximal-ratio-combining/,Krishna Sankar , Sept 28,2008.
[10]. Yong Soo Cho, Jaekwon Kim, Won Young Yang and Chung-Gu Kang, MIMO-OFDM Wireless Communications with
MATLAB. (Wiley publications, IEEE press, 2010)
Biographies and Photographs
Sahil Dhingra pursuing B.Tech from Dehradun Institute of Technology, Dehradun in Electronics and
Communication engineering. His areas of interest include work on SIMO systems, fixed wing UAV design and
control.
Sovanjyoti Giri received the B.Tech degree in Electronics and Communication Engineering from Kalyani
Government Engineering College (W.B.U.T.), Kalyani, India, in 2012. He received his M.Tech. degree in
Communication Systems from M.N.N.I.T. Allahabad, Allahabad, India, in 2014. He worked as an assistant professor
in the Department of Electronics and Communication Engineering at D.I.T. University, Dehradun, India from July
2014 to June 2015. Since July 2015, he is a Ph.D. research scholar in the Department of Electronics and Electrical
Communication Engineering, IIT Kharagpur, Kharagpur India. His research areas include relayed and co-operative
communication, turbo code performance over fading channels, MIMO-OFDM systems, system network coding,
complex communication networks.