Orthogonal Frequency Division Multiplexing (OFDM) is an emerging field of research in the field of 4G broadband wireless communications due to its robustness against multipath fading and relatively simple implementation. Peak to Average Power Ratio (PAPR) is the limiting factor for an OFDM system as it consists of large number of independent subcarriers as a result of which the amplitude of such a signal can have high peak values which degrades the system performance. Such a signal when amplified by a Power Amplifier without processing results spectral regrowth and intermodulation among subcarrier. Hence this non linearity destroys the orthogonally of the OFDM signal and introduces out-of-band radiation and in band distortions causing significant performance degradation. The clipping and filtering method is analysed which is an efficient and simple method to reduce the PAPR. We have shown the effects of clipping and filtering on the performance of OFDM, including the power spectral density, the crest factor, and the bit-error rate.
AN OVERVIEW OF PEAK-TO-AVERAGE POWER RATIO REDUCTION TECHNIQUES FOR OFDM SIGNALSijmnct
OFDM (Orthogonal Frequency Division Multiplexing) has been widely adopted for high data rate wireless
communication systems due to its advantages such as extraordinary spectral efficiency, robustness to
channel fading and better QoS (Quality of Service) performance for multiple users. However, some
challenging issues are still unresolved in OFDM systems. One of the issues is the high PAPR (peak-toaverage
power ratio), which results in nonlinearity in power amplifiers, and causes out of band radiation
and in band distortion. This paper reviews some conventional PAPR reduction techniques and their
modifications to achieve better PAPR performance. Advantages and disadvantages of each technique are
discussed in detail. And comparisons between different techniques are also presented. Finally, this paper
makes a prospect forecast about the direction for further researches in the area of PAPR reduction for
OFDM signals
Hybrid approach to solve the problem of papr in ofdm signal a surveyeSAT Journals
“Orthogonal frequency division multiplexing
method used to achieve the today’s need of wireless communication
3GPP Association for the use of LTE. The
higher data rate, higher bit rate, mitigated delay spread, lower multipath distortion,
OFDM system has few major issues associated with
ratio (PAPR)” associated with the signal.
interleaved OFDM, selective mapping (SLM)
windowing, clipping, filtering, tone rejection(TR), tone injection(TI), compandin
A Hybrid PAPR Reduction Scheme for OFDM System ijmnct
Orthogonal frequency division multiplexing (OFDM) i
s considered as most efficient technique for future
wireless communication systems due to its higher sp
ectral bandwidth efficiency, robustness to frequenc
y
selective fading channels, etc. However, the succes
sful implementation of the OFDM system necessitates
several difficulties. The biggest disadvantage to w
ork with OFDM system is its high peak-to-average po
wer
ratio PAPR leadsto severe inter carrier interferenc
e, out-of-band radiation, and poor bit error rate
performance due to the nonlinearity of the high pow
er amplifier. In this paper, a novel hybrid techniq
ue is
proposed to reduce PAPR further and comparison has
been done with conventional techniques as well.
Simulated results are presentedconfirm theoretical
results.MATLAB 7.5 is used to simulate the results
for system parametersconsidered.
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.
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.
PAPR REDUCTION OF OFDM SIGNAL BY USING COMBINED HADAMARD AND MODIFIED MEU-LAW...IJCNCJournal
Orthogonal frequency division multiplexing (OFDM) is a technique which gives high quality of service (QOS) to the users by mitigating the fading signals as well as high data rates in multimedia services. However, the peak-to-average power ratio (PAPR) is a technical challenge that reduces the efficiency of RF power amplifiers. In this paper, we propose the combined Hadamard transform and modified meu-law companding transform method in order to lessen the effects of the peak-to-average power ratio of the
OFDM signal. Simulation results show that the proposed scheme reduces PAPR compared to other companding techniques as well as the Hadamard transform technique when used on its own.
AN OVERVIEW OF PEAK-TO-AVERAGE POWER RATIO REDUCTION TECHNIQUES FOR OFDM SIGNALSijmnct
OFDM (Orthogonal Frequency Division Multiplexing) has been widely adopted for high data rate wireless
communication systems due to its advantages such as extraordinary spectral efficiency, robustness to
channel fading and better QoS (Quality of Service) performance for multiple users. However, some
challenging issues are still unresolved in OFDM systems. One of the issues is the high PAPR (peak-toaverage
power ratio), which results in nonlinearity in power amplifiers, and causes out of band radiation
and in band distortion. This paper reviews some conventional PAPR reduction techniques and their
modifications to achieve better PAPR performance. Advantages and disadvantages of each technique are
discussed in detail. And comparisons between different techniques are also presented. Finally, this paper
makes a prospect forecast about the direction for further researches in the area of PAPR reduction for
OFDM signals
Hybrid approach to solve the problem of papr in ofdm signal a surveyeSAT Journals
“Orthogonal frequency division multiplexing
method used to achieve the today’s need of wireless communication
3GPP Association for the use of LTE. The
higher data rate, higher bit rate, mitigated delay spread, lower multipath distortion,
OFDM system has few major issues associated with
ratio (PAPR)” associated with the signal.
interleaved OFDM, selective mapping (SLM)
windowing, clipping, filtering, tone rejection(TR), tone injection(TI), compandin
A Hybrid PAPR Reduction Scheme for OFDM System ijmnct
Orthogonal frequency division multiplexing (OFDM) i
s considered as most efficient technique for future
wireless communication systems due to its higher sp
ectral bandwidth efficiency, robustness to frequenc
y
selective fading channels, etc. However, the succes
sful implementation of the OFDM system necessitates
several difficulties. The biggest disadvantage to w
ork with OFDM system is its high peak-to-average po
wer
ratio PAPR leadsto severe inter carrier interferenc
e, out-of-band radiation, and poor bit error rate
performance due to the nonlinearity of the high pow
er amplifier. In this paper, a novel hybrid techniq
ue is
proposed to reduce PAPR further and comparison has
been done with conventional techniques as well.
Simulated results are presentedconfirm theoretical
results.MATLAB 7.5 is used to simulate the results
for system parametersconsidered.
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.
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.
PAPR REDUCTION OF OFDM SIGNAL BY USING COMBINED HADAMARD AND MODIFIED MEU-LAW...IJCNCJournal
Orthogonal frequency division multiplexing (OFDM) is a technique which gives high quality of service (QOS) to the users by mitigating the fading signals as well as high data rates in multimedia services. However, the peak-to-average power ratio (PAPR) is a technical challenge that reduces the efficiency of RF power amplifiers. In this paper, we propose the combined Hadamard transform and modified meu-law companding transform method in order to lessen the effects of the peak-to-average power ratio of the
OFDM signal. Simulation results show that the proposed scheme reduces PAPR compared to other companding techniques as well as the Hadamard transform technique when used on its own.
SLM-PTS BASED PAPR REDUCTION TECHNIQUES IN OFDM SYSTEMHariniChaganti1
Signals, which were initially sent in the analog domain, are being sent more and more in the digital domain these days. For better transmission, even single–carrier waves are being replaced by multi–carriers. Multi-carrier
systems like OFDM are now – a – days being implemented commonly. In the OFDM system,
orthogonally placed subcarriers are used to carry the data from the transmitter end to the receiver end. The presence of a guard band in this system deals with the problem of ISI and noise is minimized by a larger number of sub–carriers. But the large Peak– to –Average Power Ratio of these signal have some undesirable effects on the system. The Peak-to-Average Power Ratio is the ratio between the maximum power and average power of a complex passband signal. It causes many disadvantages like band-in and band-out variation, low signal to quantization noise ratio, low efficiency of power amplifier, etc. Hence, it is necessary to reduce PAPR in OFDM for its efficient use.
In this project, the main objective is to study the basics of an OFDM System and analyze and
simulate various methods such as clipping and filtering, selected mapping, Partial transmit sequence
to reduce the PAPR in the system and compare these techniques with and without PAPR reduction to
obtain an efficient technique so that this system can be used more commonly and effectively.
Performance improvement for papr reduction in lte downlink system with ellipt...IJCNCJournal
This paper is concerned with the performance improvement of PAPR reduction of orthogonal frequency division multiplexing (OFDM) signal using amplitude clipping & filtering based design. Note that OFDM is one of the well adept multi-carrier multiplexing transmission scheme which has been implemented in long term evolution (LTE) downlink. Nonetheless peak to average power ratio (PAPR) is the more rattling problem with OFDM, consequently in this paper a reduction procedure of the PAPR by using amplitude clipping and filtering is proposed. Here we used IIR bandpass elliptic filter after amplitude clipping to
reduce the PAPR. The performance of the system in terms of bit error rate (BER) is also canvased as a new
filter based clipping method. Our results show that the proposed methodology of clipping method with the
IIR elliptic band pass filter significantly reduces the PAPR value.
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.
Performance and Analysis of OFDM Signal Using Matlab SimulinkIJMER
Multi-carrier modulation is an attractive technique for fourth generation .OFDM is based on
multicarrier modulation technique. In OFDM system the bit stream is divided into many different sub
channels. An efficient and distortionless scheme for peak power reduction in OFDM is proposed. In this
paper, a set of mapping where the actual transmit signal is selected. From this set of signal reduced
PAPR. Simulation results are shown. The lowest PAPR is compared with conventional work. It is also
compared BER to SNR and best result is achieved.
PAPR Reduction in OFDM using Active and Non-Active ChannelsIOSR Journals
Abstract : According to the request of advance communication field there should be high data rate in addition to both power efficiency and lower bit error rate. This request of high data rate can be achieved by the multi carrier modulation scheme using the OFDM technique. But the great drawback of the OFDM technique is its high peak to average power ratio (PAPR). High PAPR reduces OFDM signals by driving the analog amplifier to work in the nonlinear region, changing this way the signal and making the amplifier to consume more power. To reduce the PAPR methods exist which adjust or present new signals to battle large signal peaks. The methods which use data carrying channels are called active channel methods and which use redundant channel are called non active channel methods. This work deals with reduction of the PAPR of OFDM signal using both Active and Non Active Channels. Clipping technique has been applied to active channels and Tone reservation has been applied to Non Active Channels. By using both channels we can get considerable reduction in PAPR. Keywords:Orthogonal Frequency Division Multiplexing (OFDM), Peak to Average Power Ratio (PAPR), Power Amplifier (PA).
Performance Analysis of Post Compensated Long Haul High Speed Coherent Optica...Yayah Zakaria
This paper addresses the performance analysis of OFDM transmission system based on coherent detection over high speed long haul optical links with high spectral efficiency modulation formats such as Quadrature Amplitude Modulation (QAM) as a mapping method prior to the OFDM multicarrier representation. Post compensation is used to compensate for
phase noise effects. Coherent detection for signal transmitted at bit rate of 40 Gbps is successfully achieved up to distance of 3200km. Performance is analyzed in terms of Symbol Error Rate and Error Vector Magnitude by varying Optical Signal to Noise Ratio (OSNR) and varying the length of the fiber i.e transmission distance. Transmission performance is also observed through constellation diagrams at different transmission distances and
different OSNRs.
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.
RF testing has remained hype for most of us. But seriously it is not so. It can be very interesting and one can develop a lot of interest in this if given an opportunity.
In this paper, authors have started with the some basic concepts of radio engineering which we studied in engineering and built upon these concepts to use in practical applications.
We have also described the basic principles of Signal Analyzer and Signal Generator which are the most common test tools used for any radio testing.
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
Effect of Compression Ratio on Performance of Combined Cycle Gas Turbineijsrd.com
It is known the performance of a gas turbine (GT) has strong dependence of climate conditions. A suitable solution to minimize this negative effect is to raise inlet turbine temperature and reduce temperature of inlet air to GT compressor. Combined cycles gas turbines (CCGT) are a lot used to acquire a high-efficiency power plant. Increases the peak compression ratio has been proposed to improve the combined-cycle gas-turbine performance. The code of the performance model for CCGT power plant was developed utilizing the MATLAB software. The simulating results show that the overall efficiency increases with the increase of the peak compression ratio. The total power output increases with the increase of the peak compression ratio. The peak overall efficiency occurs at the higher compression ratio with low ambient temperature and higher turbine inlet temperature. The overall thermal efficiencies for CCGT are higher compared to gas-turbine plants.
Software Development Life Cycle: Traditional and Agile- A Comparative Studyijsrd.com
In the field of software development, software development lifecycle is the most important component. There is a number of software development methodologies used in software industry today. The paper discussed below focuses on the modern SDLC which are traditional methods and the agile methods. It also explains the compensation and shortcomings of the traditional as well as agile methods. Along with this, it suggests some improvements which could help in improving current agile development
Cost Effective and Innovative Housing Technologyijsrd.com
Shelter is amongst the three basic human needs but now-a-days, about two-third of the total Indian population does not have their own shelter. This two-third population belongs to the middle and lower income class. These people find it difficult to construct their houses at an affordable cost by using conventional construction technology. It is found in many cases that people serve their whole life constructing their own house, but fail. The mission and dream of these people can be achieved by appropriate use of cost effective and innovative construction technology. As a whole, the housing shortage of the country can be overcome within lesser funds, without compromising with the quality control and structural stability of the structure. Note: This technology is only applicable for single or two storied buildings and can be applied in most of the soil and climatic conditions.
SLM-PTS BASED PAPR REDUCTION TECHNIQUES IN OFDM SYSTEMHariniChaganti1
Signals, which were initially sent in the analog domain, are being sent more and more in the digital domain these days. For better transmission, even single–carrier waves are being replaced by multi–carriers. Multi-carrier
systems like OFDM are now – a – days being implemented commonly. In the OFDM system,
orthogonally placed subcarriers are used to carry the data from the transmitter end to the receiver end. The presence of a guard band in this system deals with the problem of ISI and noise is minimized by a larger number of sub–carriers. But the large Peak– to –Average Power Ratio of these signal have some undesirable effects on the system. The Peak-to-Average Power Ratio is the ratio between the maximum power and average power of a complex passband signal. It causes many disadvantages like band-in and band-out variation, low signal to quantization noise ratio, low efficiency of power amplifier, etc. Hence, it is necessary to reduce PAPR in OFDM for its efficient use.
In this project, the main objective is to study the basics of an OFDM System and analyze and
simulate various methods such as clipping and filtering, selected mapping, Partial transmit sequence
to reduce the PAPR in the system and compare these techniques with and without PAPR reduction to
obtain an efficient technique so that this system can be used more commonly and effectively.
Performance improvement for papr reduction in lte downlink system with ellipt...IJCNCJournal
This paper is concerned with the performance improvement of PAPR reduction of orthogonal frequency division multiplexing (OFDM) signal using amplitude clipping & filtering based design. Note that OFDM is one of the well adept multi-carrier multiplexing transmission scheme which has been implemented in long term evolution (LTE) downlink. Nonetheless peak to average power ratio (PAPR) is the more rattling problem with OFDM, consequently in this paper a reduction procedure of the PAPR by using amplitude clipping and filtering is proposed. Here we used IIR bandpass elliptic filter after amplitude clipping to
reduce the PAPR. The performance of the system in terms of bit error rate (BER) is also canvased as a new
filter based clipping method. Our results show that the proposed methodology of clipping method with the
IIR elliptic band pass filter significantly reduces the PAPR value.
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.
Performance and Analysis of OFDM Signal Using Matlab SimulinkIJMER
Multi-carrier modulation is an attractive technique for fourth generation .OFDM is based on
multicarrier modulation technique. In OFDM system the bit stream is divided into many different sub
channels. An efficient and distortionless scheme for peak power reduction in OFDM is proposed. In this
paper, a set of mapping where the actual transmit signal is selected. From this set of signal reduced
PAPR. Simulation results are shown. The lowest PAPR is compared with conventional work. It is also
compared BER to SNR and best result is achieved.
PAPR Reduction in OFDM using Active and Non-Active ChannelsIOSR Journals
Abstract : According to the request of advance communication field there should be high data rate in addition to both power efficiency and lower bit error rate. This request of high data rate can be achieved by the multi carrier modulation scheme using the OFDM technique. But the great drawback of the OFDM technique is its high peak to average power ratio (PAPR). High PAPR reduces OFDM signals by driving the analog amplifier to work in the nonlinear region, changing this way the signal and making the amplifier to consume more power. To reduce the PAPR methods exist which adjust or present new signals to battle large signal peaks. The methods which use data carrying channels are called active channel methods and which use redundant channel are called non active channel methods. This work deals with reduction of the PAPR of OFDM signal using both Active and Non Active Channels. Clipping technique has been applied to active channels and Tone reservation has been applied to Non Active Channels. By using both channels we can get considerable reduction in PAPR. Keywords:Orthogonal Frequency Division Multiplexing (OFDM), Peak to Average Power Ratio (PAPR), Power Amplifier (PA).
Performance Analysis of Post Compensated Long Haul High Speed Coherent Optica...Yayah Zakaria
This paper addresses the performance analysis of OFDM transmission system based on coherent detection over high speed long haul optical links with high spectral efficiency modulation formats such as Quadrature Amplitude Modulation (QAM) as a mapping method prior to the OFDM multicarrier representation. Post compensation is used to compensate for
phase noise effects. Coherent detection for signal transmitted at bit rate of 40 Gbps is successfully achieved up to distance of 3200km. Performance is analyzed in terms of Symbol Error Rate and Error Vector Magnitude by varying Optical Signal to Noise Ratio (OSNR) and varying the length of the fiber i.e transmission distance. Transmission performance is also observed through constellation diagrams at different transmission distances and
different OSNRs.
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.
RF testing has remained hype for most of us. But seriously it is not so. It can be very interesting and one can develop a lot of interest in this if given an opportunity.
In this paper, authors have started with the some basic concepts of radio engineering which we studied in engineering and built upon these concepts to use in practical applications.
We have also described the basic principles of Signal Analyzer and Signal Generator which are the most common test tools used for any radio testing.
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
Effect of Compression Ratio on Performance of Combined Cycle Gas Turbineijsrd.com
It is known the performance of a gas turbine (GT) has strong dependence of climate conditions. A suitable solution to minimize this negative effect is to raise inlet turbine temperature and reduce temperature of inlet air to GT compressor. Combined cycles gas turbines (CCGT) are a lot used to acquire a high-efficiency power plant. Increases the peak compression ratio has been proposed to improve the combined-cycle gas-turbine performance. The code of the performance model for CCGT power plant was developed utilizing the MATLAB software. The simulating results show that the overall efficiency increases with the increase of the peak compression ratio. The total power output increases with the increase of the peak compression ratio. The peak overall efficiency occurs at the higher compression ratio with low ambient temperature and higher turbine inlet temperature. The overall thermal efficiencies for CCGT are higher compared to gas-turbine plants.
Software Development Life Cycle: Traditional and Agile- A Comparative Studyijsrd.com
In the field of software development, software development lifecycle is the most important component. There is a number of software development methodologies used in software industry today. The paper discussed below focuses on the modern SDLC which are traditional methods and the agile methods. It also explains the compensation and shortcomings of the traditional as well as agile methods. Along with this, it suggests some improvements which could help in improving current agile development
Cost Effective and Innovative Housing Technologyijsrd.com
Shelter is amongst the three basic human needs but now-a-days, about two-third of the total Indian population does not have their own shelter. This two-third population belongs to the middle and lower income class. These people find it difficult to construct their houses at an affordable cost by using conventional construction technology. It is found in many cases that people serve their whole life constructing their own house, but fail. The mission and dream of these people can be achieved by appropriate use of cost effective and innovative construction technology. As a whole, the housing shortage of the country can be overcome within lesser funds, without compromising with the quality control and structural stability of the structure. Note: This technology is only applicable for single or two storied buildings and can be applied in most of the soil and climatic conditions.
A Study of Various Projected Data Based Pattern Mining Algorithmsijsrd.com
The time required for generating frequent patterns plays an important role. Some algorithms are designed, considering only the time factor. Our study includes depth analysis of algorithms and discusses some problems of generating frequent pattern from the various algorithms. We have explored the unifying feature among the internal working of various mining algorithms. The work yields a detailed analysis of the algorithms to elucidate the performance with standard dataset like Mushroom etc. The comparative study of algorithms includes aspects like different support values, size of transactions.
Adaptive Signal Processing has been playing a key role confining itself not just to the field of communications but also had spread into the fields of embedded systems, biological instruments, astronomy, image processing and many other fields. Adaptive filters are slowly replacing traditional filters in many areas. The development of new techniques and trends of adaptation algorithms has provided us with a broader sense of understanding the adaptation phenomena. In this paper some basic algorithms such as Least-Mean-Squares, Leaky-LMS, Normalized-LMS, and Recursive-Least-Squares algorithms have been studied and the convergence of these algorithms has been studied. The study convergence of the algorithms gives us a better picture of how fast the algorithms converge to optimum values. This is an issue of consideration in real-time signal processing as the signal processor implementing these kinds of algorithms has to be converging fast enough to the optimum values to save time and memory.
Integrated Resource Adaptive On Demand Geographic Routing (IRA-ODGR) for MANETijsrd.com
It is a big challenge to develop routing protocol that can meet different application needs and optimize routing paths according to the topology change in mobile ad hoc networks. The existing work presented two self-adaptive on-demand geographic routing schemes to build efficient paths based on the needs of user applications and adapt to various scenarios for provide efficient and reliable routing. To overcome the impact due to inaccurate local topology knowledge, the topology information is updated at a node in the specific time periods. The on-demand routing mechanism reduces to control overhead made on geographic routing. The route optimization scheme adapts routing path according to the topology changes and actual data traffic requirements. Adaptive parameter setting scheme is introduced to allow each node to determine and adjust the protocol parameter values independently. However, existing work did not address resource parameters such as energy, bandwidth and data loss. The proposal presents and Integrated Resource Adaptive on Demand Geographic Routing (IRA-ODGR) for MANET. The node energy resource is optimized with path energy consumption rate and bandwidth utilization of the path is analysed. Loss rate is reduced in geographic routing with dynamic routes. The simulation conducted to demonstrate IRA-ODGR routing protocols.
Secure System based on Dynamic Features of IRIS Recognitionijsrd.com
Basically, the idea behind this system is improvement in cybernetics, the biometric person identification technique based on the pattern of the human iris is well suited to be applied to access control. The human eye is sensitive to visible light. Security systems having realized the value of biometrics for two basic purposes: to verify or identify users. In this busy world, identification should be fast and efficient. In this paper I focus on an efficient methodology for identification and verification for iris detection using Haar transform and Minimum hamming distance. I use canny operator for the edge detection. This biological phenomenon contracts and dilates the two pupils synchronously when illuminating one of the eyes by visible light .I applied the Haar wavelet compressing the data. By comparing the quantized vectors using the Hamming Distance operator, we determine finally whether two irises are similar. The result shows that system is quite effective.
A Quick Glance over the Digital Watermarkingijsrd.com
Digital watermarking is a process for modifying physical or electronic media to embed a machine-readable code into the media. The media may be modified such that the embedded code is imperceptible or nearly imperceptible to the user, yet may be detected through an automated detection process. Watermarking is the art of imperceptibly embedding a message into a work. More than 700 years ago in Fabriano (Italy), paper watermarks appeared in handmade paper, in order to identify its provenance, format, and quality. In this context, the watermark is a kind of invisible signature that allows identifying the creator or the owner of a document, and to detect possible copyright violations, and especially non-authorized copying [1]. More recently, different watermarking techniques and strategies have been proposed in order to solve a number of problems, ranging from the detection of content manipulations, to information hiding (steganography), to document usage tracing. In particular, the insertion of multiple watermarks to trace a document during its lifecycle is a very interesting and challenging application [1]. The main property of the proposed method is that it allows the insertion of multiple watermarks by different users, who sequentially come into play one after the other and do not need any extra information besides the public keys. This characteristic makes the present approach more attractive than previously available solutions.
Energy-Efficient Image Transmission over OFDM Channel Using Huffman Codingijsrd.com
In this paper, Energy efficient image transmission using Huffman coding over OFDM channel has been proposed, which combines wavelet-based image decomposition and Huffman coding. Wavelet image transform provides data decomposition in multiple levels of resolution, so the image can be divided into packets with different priorities. The consumed energy when DWT is applied is clearly lower compared to the case without DWT. Using Huffman coding scheme, compress the low frequency band. In the proposed scheme, lower-resolution version of the compressed image obtained via discrete wavelet transform (DWT) is used. And show that the proposed strategy (DWT with Huffman coding)is more energy efficient than previous work (DWT without Huffman coding).In addition show that error rate(BER) is low compared to existing system(DWT without Huffman coding).
Earthquakes are very serious problems since they affect human life in various ways. The Earthquakes are mainly prevented by two methods namely Base Isolation Methods and Seismic Dampers. The present paper deals with 1.Increase natural period of structure by "Base Isolation Techniques".2.Increase damping of the system by "Energy Dissipation Devices". In brief manner. This paper explains the main theme of the above methods and their preventive methods about Earthquakes. The present paper deals with structures which resist Earthquakes. It explains the frames which help in resisting Earthquakes. In total, this present paper deals with Methods of resisting Earthquakes and Frames resisting them and also the prominent techniques followed to resist Earthquakes.
Classification of Malware based on Data Mining Approachijsrd.com
In recent years, the number of malware families/variants has exploded dramatically. Automatic malware classification is becoming an important research area. Using data mining, we identify seven key features within the Microsoft PE file format that can be fed to machine learning algorithms to classify malware. In this paper, resting on the analysis of Windows API execution sequences called by PE files, we develop the Intelligent Malware Detection System (IMDS) using Objective- Oriented Association (OOA) mining based classification. IMDS is an integrated system consisting of three major modules: PE parser, OOA rule generator, and rule based classifier. An OOA_Fast_FP Growth algorithm is adapted to efficiently generate OOA rules for classification. Promising experimental results demonstrate that the accuracy and efficiency of our IMDS system outperform popular anti-virus software such as Norton Antivirus and McAfee Virus Scan, as well as previous data mining based detection systems which employed Naive Bayes, Support Vector Machine (SVM) and Decision Tree techniques.
Comparative Analysis of Power System Stabilizer using Artificial Intelligence...ijsrd.com
Power system stabilizers (PSSs) are used to enhance the damping during low frequency oscillations. The paper presents study of power system stabilizer using fuzzy logic and neural network to enhance stability of single machine infinite bus system. In this paper basic problem of conventional power system stabilizer for stability enhancement is defined which is traditionally used. Artificial intelligence techniques provide one alternative for stability enhancement and speed deviation (Δw). The proposed method using Artificial intelligence techniques achieves better improvement than conventional power system stabilizer. Fuzzy logic rules were developed for triangular membership function of input and output variables. Neuro controller is implemented and it is compared with reference model. The system is simulated in SIMULINK environment and the performances of conventional, Fuzzy based and Neural network based power system stabilizers are compared.
Pressure swing adsorption a Cleaner techniques to reduce emissionijsrd.com
Reduction of the absorber size of a medical oxygen concentrator (MOC) employing a generic pressure swing adsorption (PSA) technology is an ongoing research and development activity. The MOC typically produces a 90_93% O2-enriched product gas from ambient air at a rate of e10 L/minute (LPM) for individual use. Adsorbent columns packed with very small adsorbent particles are used to enhance the adsorption kinetics for rapid PSA cycle operation. An experimental mini-PSA set up was used to measure the performance of a simulated Skarstrom-like PSA cycle using a commercial sample of LiX Zeolite as the air separation sorbent
Simulation Study of FIR Filter based on MATLABijsrd.com
First, the rapid design of FIR digital filter was completed by using the Signal Processing Toolbox FDA Tool, the case filter design of a composite signal by filtering, to prove that the content filter designed for filtering. MATLAB and Simulink programs of the filter were used to verify the performance of the filter in MATLAB. Experimental results show that the low-pass filter filters the high frequency component of input signals mixed. Comparison of two types of simulation, the latter method was more convenient quickly, and reduces the workload.
Boiler Efficiency Improvement through Analysis of Lossesijsrd.com
Thermal is the main source for power generation in India. The percentage of thermal power generation as compare to other sources is 65 %. The main objective of thermal power plant is to fulfill the energy demands of the market and to achieve these demands; plant requires technical availability with the parts reliability and maintenance strategy. This paper deals with the determination of current operating efficiency of Boiler and calculates major losses for Vindhyachal Super thermal power plant (India) of 210 MW units. Then identify the causes of performance degradation. Also find the major causes of heat losses by Fault Tree Analysis (FTA) and recommends its appropriate strategy to reduce major losses. The aim of performance monitoring is continuous evaluation of degradation i.e. decrease in performance of the steam boiler. These data enable additional information which is helpful in problem identification, improvement of boiler performance and making economic decisions about maintenance schedule.
Comparative Analysis of PAPR Reduction Techniques in OFDM Using Precoding Tec...IJSRD
In this modern era, Orthogonal Frequency Division Multiplexing (OFDM) has been proved to be an explicit promising technique for wired and wireless systems because of its several advantages like high spectral efficiency, robustness against frequency selective fading, relatively simple receiver implementation etc. Besides having a number of advantages OFDM suffers from few disadvantages like high Peak to Average Power Ratio (PAPR), Intercarrier Interference (ICI), Intersymbol Interference (ISI) etc. These detrimental effects, if not compensated properly and timely, can result in system performance degradation. This paper mainly concentrates on reduction of PAPR.A comparisons have been made between various precoding techniques against conventional OFDM.
Comparative Analysis of PAPR Reduction Techniques in OFDM Using Precoding Tec...IJSRD
In this modern era, Orthogonal Frequency Division Multiplexing (OFDM) has been proved to be an explicit promising technique for wired and wireless systems because of its several advantages like high spectral efficiency, robustness against frequency selective fading, relatively simple receiver implementation etc. Besides having a number of advantages OFDM suffers from few disadvantages like high Peak to Average Power Ratio (PAPR), Intercarrier Interference (ICI), Intersymbol Interference (ISI) etc. These detrimental effects, if not compensated properly and timely, can result in system performance degradation. This paper mainly concentrates on reduction of PAPR.A comparisons have been made between various precoding techniques against conventional OFDM.
Adaptive Clipping for PAPR Reduction in OFDMIJERA Editor
A new Technique “Adaptive Clipping” is introduced to reduce the Peak to Average Power Ratio (PAPR) of OFDM system efficiently for wireless applications. In this technique, the threshold for clipping the signal is decided according to the peak size and number of peaks in the OFDM burst signal. A comparison is done between selective clipping and adaptive clipping and the results are shown in terms of Bit error rate (BER) and PAPR. Adaptive clipping offers nearly half a dB reduction in PAPR compared to selective clipping. With proposed adaptive clipping, PAPR of 3 dB is obtained with BER of 10-4 . For a particular set of signals where there are large number of peak variations, adaptive clipping is more efficient in terms of BER compared to selective clipping. The simulation of adaptive clipping is done with the MATLAB software and the BER is plotted. An IEEE 806.11 standard is used for OFDM signal Transmission.
A modified design of acf operation for reducing papr of ofdm signalijngnjournal
Next generation wireless communication technology long term evolution (LTE) has implemented
orthogonal frequency division multiplexing (OFDM) technique as a strong candidate for radio access
systems. It has several attributes such as providing robustness to multipath fading & impulse noise,
eliminating intersymbol interference (ISI), inter carrier interference (ICI) & the need for equalizers. The
major challenging issue of OFDM technique is the high peak to average power ratio (PAPR) which is
defined as the ratio of the peak power to the average power of the OFDM signal. A trade-off is
necessary for reducing PAPR with increasing bit error rate (BER), computational complexity or data rate
loss etc. In this paper, a moderately modified design of amplitude clipping & filtering operation (ACF) is
proposed and implemented which shows the significant improvement in case of PAPR reduction for both
quadrature phase shift keying (QPSK) & quadrature amplitude modulation (QAM) while increasing slight
BER match up to to an existing method.
A Modified Design Of Acf Operation For Reducing Papr Of Ofdm Signaljosephjonse
Next generation wireless communication technology long term evolution (LTE) has implemented orthogonal frequency division multiplexing (OFDM) technique as a strong candidate for radio access systems. It has several attributes such as providing robustness to multipath fading & impulse noise, eliminating intersymbol interference (ISI), inter carrier interference (ICI) & the need for equalizers. The major challenging issue of OFDM technique is the high peak to average power ratio (PAPR) which is defined as the ratio of the peak power to the average power of the OFDM signal. A trade-off is necessary for reducing PAPR with increasing bit error rate (BER), computational complexity or data rate loss etc. In this paper, a moderately modified design of amplitude clipping & filtering operation (ACF) is proposed and implemented which shows the significant improvement in case of PAPR reduction for both quadrature phase shift keying (QPSK) & quadrature amplitude modulation (QAM) while increasing slight BER match up to to an existing method.
Peak to Average Power Ratio (PAPR) Reduction in OFDM-OQAM Signalspaperpublications3
Abstract: The Orthogonal Frequency Division Multiplexing (OFDM) is a type of modulation that is being used for many of the latest wireless, telecommunication and broadcasting standards. OFDM is considered to be complicated than other signals but also it possess high data rate transmissions with relatively wide bandwidths. The major disadvantage included in OFDM signal is Peak-to-Average Power Ratio (PAPR) in higher level and Sensitive to Carrier offset. Hence there were found to be many reduction techniques for PAPR have been proposed where in need to reduction in high PAPR and carrier sensitivity still more to make it efficient for future optical domain standards. This paper not only makes the OFDM system advantageous but also suitable for fast data transmission and reduces the complication at receiver side, because all the transmitting data are cleared out of signal noise, interferences, etc. The technique which is going to get implemented for PAPR reduction is Optimized Iterative Clipping and Filtering (OICF).The OFDM is provided with the subcarrier of N=256 and the modulation of Offset Quadrature Amplitude Modulation (OQAM). The OQAM-OFDM provides the higher spectral efficiency and also the inter-symbol interference is avoided since not using Cyclic Prefix (CP) in OQAM-OFDM signal. The main reason for reducing PAPR is that to avoid non- linearity at the receiving end in high speed wireless communication.
Ofdm-cpm Ber Performance and FOBP Under IEEE802.16 ScenarioCSCJournals
The application of Orthogonal frequency domain modulation-Continuous Phase Modulation (OFDM-CPM) in multipath Stanford University Interim (SUI) channels is presented in this paper. OFDM-CPM is proposed for IEEE 802.16 standards as an alternative technique of orthogonal frequency division multiplexing (OFDM) in physical layer. It is shown that, in addition to 0dB Peak to Average Power Ratio (PAPR) and power efficiency, un-coded OFDM-CPM exploits the frequency diversity of multipath channel. Taking into account the Input Power Back off (IBO), OFDM-CPM is shown to outperform OFDM at high bit energy-to-noise density ratios (Eb/N0). However, at low Signal to Noise Ratio (SNR), the OFDM-CPM phase demodulator receiver suffers from a threshold effect. In addition, this paper compares the spectral fractional out of band power of OFDM-CPM for different modulation indices.
Riemann Sequence based SLM with nonlinear effects of HPAiosrjce
Orthogonal frequency division multiplexing (OFDM) has been considered as a promising technique
to achieve high data rate transmission in mobile environment. However, it is very sensitive to nonlinear effects
due to high peak to average power ratio (PAPR). In this paper firstly the nonlinear effect of high power
amplifier in the form of inband & outband distortion caused by high PAPR is analyzed and then Riemann
sequence and normalized Riemann sequence based SLM is applied to reduce the effect of high PAPR. All the
simulation results are obtained in presence of Rapp’s SSPA model.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
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Performance Evaluation of CE-OFDM in PLC ChannelCSCJournals
One major drawback associated with an OFDM system is that the transmitter’s output signal may have a high peak-to-average ratio (PAPR). High levels of PAR may be a limiting factor for power line communication (PLC) where regulatory bodies have fixed the maximum amount of transmit power. To overcome this problem, many approaches have been presented in the literature. One potential solution for reducing the peak-to-average power ratio (PAPR) in an OFDM system is to utilize a constant envelope OFDM (CE-OFDM) system. This paper describes a CE-OFDM based modem for Power Line Communications (PLC) over the low voltage distribution network. The impact of the electrical appliances on the signal transmission is investigated. The good performances of the BER have been checked by the simulation platform of real PLC channel using Matlab. Finally, CE-OFDM-CPM is compared with conventional OFDM under HomePlug AV.
The peer-reviewed International Journal of Engineering Inventions (IJEI) is started with a mission to encourage contribution to research in Science and Technology. Encourage and motivate researchers in challenging areas of Sciences and Technology.
Performance comparison of two clipping based filtering methods for papr reduc...ijmnct
The growth of wireless communication technologies has been producing the intense demand for high-speed,
efficient, reliable voice & data communication. As a result, third generation partnership project (3GPP)
has implemented next generation wireless communication technology long term evolution (LTE) which is
designed to increase the capacity and speed of existing mobile telephone & data networks. LTE has
adopted a multicarrier transmission technique known as orthogonal frequency division multiplexing
(OFDM). OFDM meets the LTE requirement for spectrum flexibility and enables cost-efficient solutions for
very wide carriers. One major generic problem of OFDM technique is high peak to average power ratio
(PAPR) which is defined as the ratio of the peak power to the average power of the OFDM signal. A
trade-off is necessary for reducing PAPR with increasing bit error rate (BER), computational complexity or
data rate loss etc. In this paper, two clipping based filtering methods have been implemented & also
analyzed their modulation effects on reducing PAPR.
A Hybrid VLM Preceded SLM Technique Using Clipping and Filtering Method for P...IJERA Editor
MIMO-OFDM is an attractive interface for the next generation WLANs, WMAN, 4G and 5G mobile cellular
systems. However the performance of the MIMO-OFDM systems is affected by Peak to Average Power Ratio
(PAPR). PAPR is the main disadvantage associated with the MIMO-OFDM systems. So far, many techniques
have been proposed to reduce the value of PAPR but high PAPR for MIMO-OFDM systems is still a demanding
area and a different issue.In this paper, a hybrid VLM precoded SLM scheme using Clipping & Filtering has
been proposed to reduce PAPR in MIMO-OFDM systems. And it has been observed that the proposed scheme
has achieved a significant gain in PAPR reduction without increasing the system complexity and affecting the
error performance of the system.
Peak-to-Average Power Ratio Reduction in NC-OFDM based Cognitive Radio.CSCJournals
This paper presents a novel technique for reducing the peak-to-average power ratio (PAPR) in non-contiguous bands spectrum of Orthogonal Frequency Division Multiplexing (OFDM) based Cognitive Radio (CR). The proposed system exposed to carry the past channel information and the spectrum sensing to utilize the radio spectrum as well as achieving an appropriate PAPR reduction and maintaining end-to-end throughput performance by using a set of approaches in the current CR environment. The simulation results for PAPR reduction has shown that higher constellation modulation schemes are better compared to lower constellation modulation schemes.
Similar to Impact of Clipping and Filtering on Peak to Average Power Ratio of OFDM System (20)
Due to availability of internet and evolution of embedded devices, Internet of things can be useful to contribute in energy domain. The Internet of Things (IoT) will deliver a smarter grid to enable more information and connectivity throughout the infrastructure and to homes. Through the IoT, consumers, manufacturers and utility providers will come across new ways to manage devices and ultimately conserve resources and save money by using smart meters, home gateways, smart plugs and connected appliances. The future smart home, various devices will be able to measure and share their energy consumption, and actively participate in house-wide or building wide energy management systems. This paper discusses the different approaches being taken worldwide to connect the smart grid. Full system solutions can be developed by combining hardware and software to address some of the challenges in building a smarter and more connected smart grid.
A Survey Report on : Security & Challenges in Internet of Thingsijsrd.com
In the era of computing technology, Internet of Things (IoT) devices are now popular in each and every domains like e-governance, e-Health, e-Home, e-Commerce, and e-Trafficking etc. Iot is spreading from small to large applications in all fields like Smart Cities, Smart Grids, Smart Transportation. As on one side IoT provide facilities and services for the society. On the other hand, IoT security is also a crucial issues.IoT security is an area which totally concerned for giving security to connected devices and networks in the IoT .As, IoT is vast area with usability, performance, security, and reliability as a major challenges in it. The growth of the IoT is exponentially increases as driven by market pressures, which proportionally increases the security threats involved in IoT The relationship between the security and billions of devices connecting to the Internet cannot be described with existing mathematical methods. In this paper, we explore the opportunities possible in the IoT with security threats and challenges associated with it.
In today’s emerging world of Internet, each and every thing is supposed to be in connected mode with the help of billions of smart devices. By connecting all the devises used in our day to day life, make our life trouble less and easy. We are incorporated in a world where we are used to have smart phones, smart cars, smart gadgets, smart homes and smart cities. Different institutes and researchers are working for creating a smart world for us but real question which we need to emphasis on is how to make dumb devises talk with uncommon hardware and communication technology. For the same what kind of mechanism to use with various protocols and less human interaction. The purpose is to provide the key area for application of IoT and a platform on which various devices having different mechanism and protocols can communicate with an integrated architecture.
Study on Issues in Managing and Protecting Data of IOTijsrd.com
This paper discusses variety of issues for preserving and managing data produced by IoT. Every second large amount of data are added or updated in the IoT databases across the heterogeneous environment. While managing the data each phase of data processing for IoT data is exigent like storing data, querying, indexing, transaction management and failure handling. We also refer to the problem of data integration and protection as data requires to be fit in single layout and travel securely as they arrive in the pool from diversified sources in different structure. Finally, we confer a standardized pathway to manage and to defend data in consistent manner.
Interactive Technologies for Improving Quality of Education to Build Collabor...ijsrd.com
Today with advancement in Information Communication Technology (ICT) the way the education is being delivered is seeing a paradigm shift from boring classroom lectures to interactive applications such as 2-D and 3-D learning content, animations, live videos, response systems, interactive panels, education games, virtual laboratories and collaborative research (data gathering and analysis) etc. Engineering is emerging with more innovative solutions in the field of education and bringing out their innovative products to improve education delivery. The academic institutes which were once hesitant to use such technology are now looking forward to such innovations. They are adopting the new ways as they are realizing the vast benefits of using such methods and technology. The benefits are better comprehensibility, improved learning efficiency of students, and access to vast knowledge resources, geographical reach, quick feedback, accountability and quality research. This paper focuses on how engineering can leverage the latest technology and build a collaborative learning environment which can then be integrated with the national e-learning grid.
Internet of Things - Paradigm Shift of Future Internet Application for Specia...ijsrd.com
In the world more than 15% people are living with disability that also include children below age of 10 years. Due to lack of independent support services specially abled (handicap) people overly rely on other people for their basic needs, that excludes them from being financially and socially active. The Internet of Things (IoT) can give support system and a better quality of life as well as participation in routine and day to day life. For this purpose, the future solutions for current problems has been introduced in this paper. Daunting challenges have been considered as future research and glimpse of the IoT for specially abled person is given in the paper.
A Study of the Adverse Effects of IoT on Student's Lifeijsrd.com
Internet of things (IoT) is the most powerful invention and if used in the positive direction, internet can prove to be very productive. But, now a days, due to the social networking sites such as Face book, WhatsApp, twitter, hike etc. internet is producing adverse effects on the student life, especially those students studying at college Level. As it is rightly said, something which has some positive effects also has some of the negative effects on the other hand. In this article, we are discussing some adverse effects of IoT on student’s life.
Pedagogy for Effective use of ICT in English Language Learningijsrd.com
The use of information and communications technology (ICT) in education is a relatively new phenomenon and it has been the educational researchers' focus of attention for more than two decades. Educators and researchers examine the challenges of using ICT and think of new ways to integrate ICT into the curriculum. However, there are some barriers for the teachers that prevent them to use ICT in the classroom and develop supporting materials through ICT. The purpose of this study is to examine the high school English teachers’ perceptions of the factors discouraging teachers to use ICT in the classroom.
In recent years usage of private vehicles create urban traffic more and more crowded. As result traffic becomes one of the important problems in big cities in all over the world. Some of the traffic concerns are traffic jam and accidents which have caused a huge waste of time, more fuel consumption and more pollution. Time is very important parameter in routine life. The main problem faced by the people is real time routing. Our solution Virtual Eye will provide the current updates as in the real time scenario of the specific route. This research paper presents smart traffic navigation system, based on Internet of Things, which is featured by low cost, high compatibility, easy to upgrade, to replace traditional traffic management system and the proposed system can improve road traffic tremendously.
Ontological Model of Educational Programs in Computer Science (Bachelor and M...ijsrd.com
In this work there is illustrated an ontological model of educational programs in computer science for bachelor and master degrees in Computer science and for master educational program “Computer science as second competence†by Tempus project PROMIS.
Understanding IoT Management for Smart Refrigeratorijsrd.com
Lately the concept of Internet of Things (IoT) is being more elaborated and devices and databases are proposed thereby to meet the need of an Internet of Things scenario. IoT is being considered to be an integral part of smart house where devices will be connected to each other and also react upon certain environmental input. This will eventually include the home refrigerator, air conditioner, lights, heater and such other home appliances. Therefore, we focus our research on the database part for such an IoT’ fridge which we called as smart Fridge. We describe the potentials achievable through a database for an IoT refrigerator to manage the refrigerator food and also aid the creation of a monthly budget of the house for a family. The paper aims at the data management issue based on a proposed design for an intelligent refrigerator leveraging the sensor technology and the wireless communication technology. The refrigerator which identifies products by reading the barcodes or RFID tags is proposed to order the required products by connecting to the Internet. Thus the goal of this paper is to minimize human interaction to maintain the daily life events.
DESIGN AND ANALYSIS OF DOUBLE WISHBONE SUSPENSION SYSTEM USING FINITE ELEMENT...ijsrd.com
Double wishbone designs allow the engineer to carefully control the motion of the wheel throughout suspension travel. 3-D model of the Lower Wishbone Arm is prepared by using CAD software for modal and stress analysis. The forces and moments are used as the boundary conditions for finite element model of the wishbone arm. By using these boundary conditions static analysis is carried out. Then making the load as a function of time; quasi-static analysis of the wishbone arm is carried out. A finite element based optimization is used to optimize the design of lower wishbone arm. Topology optimization and material optimization techniques are used to optimize lower wishbone arm design.
A Review: Microwave Energy for materials processingijsrd.com
Microwave energy is a latest largest growing technique for material processing. This paper presents a review of microwave technologies used for material processing and its use for industrial applications. Advantages in using microwave energy for processing material include rapid heating, high heating efficiency, heating uniformity and clean energy. The microwave heating has various characteristics and due to which it has been become popular for heating low temperature applications to high temperature applications. In recent years this novel technique has been successfully utilized for the processing of metallic materials. Many researchers have reported microwave energy for sintering, joining and cladding of metallic materials. The aim of this paper is to show the use of microwave energy not only for non-metallic materials but also the metallic materials. The ability to process metals with microwave could assist in the manufacturing of high performance metal parts desired in many industries, for example in automotive and aeronautical industries.
Web Usage Mining: A Survey on User's Navigation Pattern from Web Logsijsrd.com
With an expontial growth of World Wide Web, there are so many information overloaded and it became hard to find out data according to need. Web usage mining is a part of web mining, which deal with automatic discovery of user navigation pattern from web log. This paper presents an overview of web mining and also provide navigation pattern from classification and clustering algorithm for web usage mining. Web usage mining contain three important task namely data preprocessing, pattern discovery and pattern analysis based on discovered pattern. And also contain the comparative study of web mining techniques.
APPLICATION OF STATCOM to IMPROVED DYNAMIC PERFORMANCE OF POWER SYSTEMijsrd.com
Application of FACTS controller called Static Synchronous Compensator STATCOM to improve the performance of power grid with Wind Farms is investigated .The essential feature of the STATCOM is that it has the ability to absorb or inject fastly the reactive power with power grid . Therefore the voltage regulation of the power grid with STATCOM FACTS device is achieved. Moreover restoring the stability of the power system having wind farm after occurring severe disturbance such as faults or wind farm mechanical power variation is obtained with STATCOM controller . The dynamic model of the power system having wind farm controlled by proposed STATCOM is developed . To validate the powerful of the STATCOM FACTS controller, the studied power system is simulated and subjected to different severe disturbances. The results prove the effectiveness of the proposed STATCOM controller in terms of fast damping the power system oscillations and restoring the power system stability.
Making model of dual axis solar tracking with Maximum Power Point Trackingijsrd.com
Now a days solar harvesting is more popular. As the popularity become higher the material quality and solar tracking methods are more improved. There are several factors affecting the solar system. Major influence on solar cell, intensity of source radiation and storage techniques The materials used in solar cell manufacturing limit the efficiency of solar cell. This makes it particularly difficult to make considerable improvements in the performance of the cell, and hence restricts the efficiency of the overall collection process. Therefore, the most attainable maximum power point tracking method of improving the performance of solar power collection is to increase the mean intensity of radiation received from the source used. The purposed of tracking system controls elevation and orientation angles of solar panels such that the panels always maintain perpendicular to the sunlight. The measured variables of our automatic system were compared with those of a fixed angle PV system. As a result of the experiment, the voltage generated by the proposed tracking system has an overall of about 28.11% more than the fixed angle PV system. There are three major approaches for maximizing power extraction in medium and large scale systems. They are sun tracking, maximum power point (MPP) tracking or both.
A REVIEW PAPER ON PERFORMANCE AND EMISSION TEST OF 4 STROKE DIESEL ENGINE USI...ijsrd.com
In day today's relevance, it is mandatory to device the usage of diesel in an economic way. In present scenario, the very low combustion efficiency of CI engine leads to poor performance of engine and produces emission due to incomplete combustion. Study of research papers is focused on the improvement in efficiency of the engine and reduction in emissions by adding ethanol in a diesel with different blends like 5%, 10%, 15%, 20%, 25% and 30% by volume. The performance and emission characteristics of the engine are tested observed using blended fuels and comparative assessment is done with the performance and emission characteristics of engine using pure diesel.
Study and Review on Various Current Comparatorsijsrd.com
This paper presents study and review on various current comparators. It also describes low voltage current comparator using flipped voltage follower (FVF) to obtain the single supply voltage. This circuit has short propagation delay and occupies a small chip area as compare to other current comparators. The results of this circuit has obtained using PSpice simulator for 0.18 μm CMOS technology and a comparison has been performed with its non FVF counterpart to contrast its effectiveness, simplicity, compactness and low power consumption.
Reducing Silicon Real Estate and Switching Activity Using Low Power Test Patt...ijsrd.com
Power dissipation is a challenging problem for today's system-on-chip design and test. This paper presents a novel architecture which generates the test patterns with reduced switching activities; it has the advantage of low test power and low hardware overhead. The proposed LP-TPG (test pattern generator) structure consists of modified low power linear feedback shift register (LP-LFSR), m-bit counter, gray counter, NOR-gate structure and XOR-array. The seed generated from LP-LFSR is EXCLUSIVE-OR ed with the data generated from gray code generator. The XOR result of the sequence is single input changing (SIC) sequence, in turn reduces the switching activity and so power dissipation will be very less. The proposed architecture is simulated using Modelsim and synthesized using Xilinx ISE9.2.The Xilinx chip scope tool will be used to test the logic running on FPGA.
Defending Reactive Jammers in WSN using a Trigger Identification Service.ijsrd.com
In the last decade, the greatest threat to the wireless sensor network has been Reactive Jamming Attack because it is difficult to be disclosed and defend as well as due to its mass destruction to legitimate sensor communications. As discussed above about the Reactive Jammers Nodes, a new scheme to deactivate them efficiently is by identifying all trigger nodes, where transmissions invoke the jammer nodes, which has been proposed and developed. Due to this identification mechanism, many existing reactive jamming defending schemes can be benefited. This Trigger Identification can also work as an application layer .In this paper, on one side we provide the several optimization problems to provide complete trigger identification service framework for unreliable wireless sensor networks and on the other side we also provide an improved algorithm with regard to two sophisticated jamming models, in order to enhance its robustness for various network scenarios.
Vaccine management system project report documentation..pdfKamal Acharya
The Division of Vaccine and Immunization is facing increasing difficulty monitoring vaccines and other commodities distribution once they have been distributed from the national stores. With the introduction of new vaccines, more challenges have been anticipated with this additions posing serious threat to the already over strained vaccine supply chain system in Kenya.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
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.
Event Management System Vb Net Project Report.pdfKamal Acharya
In present era, the scopes of information technology growing with a very fast .We do not see any are untouched from this industry. The scope of information technology has become wider includes: Business and industry. Household Business, Communication, Education, Entertainment, Science, Medicine, Engineering, Distance Learning, Weather Forecasting. Carrier Searching and so on.
My project named “Event Management System” is software that store and maintained all events coordinated in college. It also helpful to print related reports. My project will help to record the events coordinated by faculties with their Name, Event subject, date & details in an efficient & effective ways.
In my system we have to make a system by which a user can record all events coordinated by a particular faculty. In our proposed system some more featured are added which differs it from the existing system such as security.
Quality defects in TMT Bars, Possible causes and Potential Solutions.PrashantGoswami42
Maintaining high-quality standards in the production of TMT bars is crucial for ensuring structural integrity in construction. Addressing common defects through careful monitoring, standardized processes, and advanced technology can significantly improve the quality of TMT bars. Continuous training and adherence to quality control measures will also play a pivotal role in minimizing these defects.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Final project report on grocery store management system..pdf
Impact of Clipping and Filtering on Peak to Average Power Ratio of OFDM System
1. IJSRD - International Journal for Scientific Research & Development| Vol. 1, Issue 7, 2013 | ISSN (online): 2321-0613
All rights reserved by www.ijsrd.com 1467
Abstract— Orthogonal Frequency Division Multiplexing
(OFDM) is an emerging field of research in the field of 4G
broadband wireless communications due to its robustness
against multipath fading and relatively simple
implementation. Peak to Average Power Ratio (PAPR) is
the limiting factor for an OFDM system as it consists of
large number of independent subcarriers as a result of which
the amplitude of such a signal can have high peak values
which degrades the system performance. Such a signal when
amplified by a Power Amplifier without processing results
spectral regrowth and intermodulation among subcarrier.
Hence this non linearity destroys the orthogonally of the
OFDM signal and introduces out-of-band radiation and in
band distortions causing significant performance
degradation. The clipping and filtering method is analysed
which is an efficient and simple method to reduce the
PAPR. We have shown the effects of clipping and filtering
on the performance of OFDM, including the power spectral
density, the crest factor, and the bit-error rate.
Keywords: OFDM, PAPR, clipping, filtering, crest factor
I. INTRODUCTION
OFDM is a multi-carrier modulation (MCM) technique with
densely spaced sub-carriers in which data-transmission is
done by dividing a high-bit rate data stream is several
parallel low bit-rate data streams and using these low bit-
rate data streams to modulate several carriers. So
multicarrier transmission combat with selective fading and
has delay-spread tolerance and spectrum efficiency that
encourage their use in untethered broadband
communications. OFDM eliminates inter symbol
interference through use of a cyclic prefix and by using
adequate channel coding and interleaving one can recover
symbols lost due to the frequency selectivity of the channel.
It is computationally efficient by using FFT techniques to
implement the modulation and demodulation functions and
provides good protection against co-channel interference
and impulsive parasitic noise. So recent communication
systems such as IEEE 802.11 wireless LAN, Integrated
Services Digital Broadcasting for Terrestrial (ISDB-T) uses
OFDM in order to satisfy the demand for high data rate
transmission.
One of the major drawbacks of multicarrier signals with a
large number of subchannels is its waveform with a very
high peak-to-average power ratio (PAPR).OFDM signals
therefore cause problems such as a extra power penalty at
the transmitter, which is prohibitive for use in portable
wireless systems where the terminals are powered by
battery. The high PAPR limits its capacity due to the
distortion caused by the nonlinear characteristics of both the
Analog-to-digital converter (ADC) and high-power
amplifier (HPA).
Clipping of the OFDM signal is a simple and efficient way
of controlling the PAPR. The large peaks occur with a low
probability so clipping could be an effective technique for
the reduction of the PAPR. Clipping is a non-linear
operation, and may cause significant in-band distortion
which degrades the bit-error-rate (BER) performance, and
out-of-band noise, which reduces the spectral efficiency.
The out-of-band radiation and spectral splatter is reduced by
filtering but may also cause some peak regrowth. we
investigate, through extensive computer simulations, the
effects of clipping and filtering on the performance of an
OFDM system. In this paper, we present a theoretical
analysis of clipping noise caused by the clipping technique
used to reduce the PAPR of OFDM signals.
Clipping ratio (CR) is often used as a measure of clipping
defined as the ratio of the maximum signal amplitude that is
allowed to pass unclipped to the root-mean-square power of
the unclipped signal. The study is focused to reduce PAPR
by simplified clipping and filtering method applied for
AWGN channel.
II. MATHEMATICAL MODEL
Mathematical definition of the OFDM modulation system:
An OFDM carrier signal is the sum of a number of
orthogonal sub-carriers with each sub-carrier being
independently modulated commonly using some type of
quadrature amplitude modulation (QAM) or phase-shift
keying (PSK).
If N sub-carriers are used, and each sub-carrier is modulated
using M alternative symbols, the OFDM symbol alphabet
consists of MN
symbols.
Each carrier can be presented as a complex waveform like:
Sc(t)=Ac(t) (1)
Ac(t) is amplitude of signal Sc(t)
Φc(t) is phase of signal Sc(t)
The complex signal can be described by
Ss(t)= ∑ (2)
n is the number of OFDM block.
Ss(kt)= ∑ (3)
At ω0=0
Ss(kt)= ∑ (4)
The signal is compared with general Inverse Fourier
Transform (IFT):
g(kt)= ∑ (5)
Both are equivalent if
Δf = = =
Where τ is the symbol duration period
The OFDM signal can be defined by Fourier Transform.
The Fast Fourier Transform (FFT) can obtained frequency
Impact of Clipping and Filtering on Peak to Average Power Ratio of
OFDM System
Smita Jolania1
Sandeep Toshniwal2
2. Impact of Clipping and Filtering on Peak to Average Power Ratio of OFDM System
(IJSRD/Vol. 1/Issue 7/2013/0021)
All rights reserved by www.ijsrd.com 1468
domain OFDM symbols and Inverse Fast Fourier Transform
(IFFT) can obtain time domain symbols. They can be
written as:
Fast Fourier Transform
X(k)=∑ (6)
IFFT
X(n)= ∑ (7)
0≤n≤N-1
Fig. 1: OFDM System
III. PAPR PROBLEM
The input symbol stream of the IFFT should possess a
uniform power spectrum, but the output of the IFFT may
result in a non-uniform or spiky power spectrum. Most of
transmission energy would be allocated for a few instead of
the majority subcarriers. This problem can be quantified as
the PAPR measure of the transmitted waveform.
PAPR is defined as the ratio of peak signal power and
average signal power, mathematically
PAPR=
| |
| |
(8)
Where t є [0,T]
The above power characteristics can also be described in
terms of their magnitudes (not power) by defining the crest
factor (CF) as Pass band condition: CF=√PAPR.
PAPR is best described by its statistical parameter;
complementary cumulative distribution function (CCDF).A
CCDF curve shows how much time the signal spends at or
above a given power level. The power level is expressed in
dB relative to the average power. A CCDF curve is basically
a plot of relative power levels versus probability. [5,6]
Mathematically CCDF can be explained with a set of data
having the probability density function (PDF). To obtain the
Cumulative Distribution Function (CDF), the integral of the
PDF is computed, then inverting the CDF results in the
CCDF. It concludes that the CCDF is the complement of the
CDF or CCDF = 1 – CDF.
CCDF (PAPR(X)) = prob(PAPR(X)>PAPR(0))
IV. CLIPPING AND FILTERING
The simplest approach to limit the amplitude peaks in a
multicarrier wave-form is to deliberately clip the signal
before amplification. Filtering after clipping can reduce out
of band radiation to maximum extent. So Clipping and
filtering technique is effective in removing components of
the expanded spectrum. Although filtering can decrease the
spectrum growth, filtering after clipping can reduce the out-
of-band radiation, but may also cause some peak re-growth,
which the peak signal exceeds in the clip level. The
technique of iterative clipping and filtering reduces the
PAPR without spectrum expansion. However, the iterative
signal takes long time and it will increase the computational
complexity of an OFDM transmitter.
Fig. 2: Transmitter with clipping and filtering
V. PROPOSED METHOD
With this method ,in order to suppress the frequency
components of the peak reduction signal both in band and
out-of-band a peak reduction component is introduced just
before the IFFT processing section where a time domain
signal is generated using IFFT and peaks in the time domain
signal are extracted using a signal peak detector. Certain
threshold limits the amplitude of time domain samples.The
algorithm is based on clipping the amplitude of OFDM
signal that exceeds threshold value. The amplitude of signals
exceeding clipping threshold value is clipped and the signals
having amplitudes less than amplification threshold value is
amplified to threshold level. PAPR is calculated for clipped
signal and compared with that of the original PAPR of
OFDM signal.
The amplitude of the time domain signals samples are
limited by a threshold. Let Sc clipped time sample with the
phase left unchanged. Then
Sc = Sn , if Sn ≤ A
Sc = Amax eΨ(n)
, if Sn > A
ψ(n) = arg[x(n)] represents phase of x(n). The phase of
signal is preserved whenever signal exceeds clipping
threshold Amax.
The clipping severity is quantified by clipping ratio ζ which
is defined as the ratio of the threshold to the average signal
power Pi (that of before clipping),
ζ = A2
max /Pi
Note that clipping always reduces the average power of the
signal. It results in PAPR reduction, clipping also introduces
signal distortions resulting in emissions in adjacent channels
and in increased bit error rate. This undesirable effect can be
suppressed by low pass filtering of clipped signal, which
results in a new growth of the PAPR.
Without filtering, clipping causes out-of-band radiation.
Digital filtering is present to control out-of-band radiation.
Time domain signal is obtained by IFFT. Then clipping is
applied and frequency domain signal is obtained by FFT.
Then filtering is used.
VI. RESULT AND ANALYSIS
PAPR is very sensitive to the choice of modulation in a
particular OFDM system. PAPR increases if we deal with
the modulations in which amplitude of basic functions
changes as in QAM. But same amplitude basis functions
correspond to low PAPR. But this clipping expands the
signal and thus ISI occurs. Here the trade-off is made then
by passing the clipped signal through the filter. Now the
3. Impact of Clipping and Filtering on Peak to Average Power Ratio of OFDM System
(IJSRD/Vol. 1/Issue 7/2013/0021)
All rights reserved by www.ijsrd.com 1469
PAPR is a bit increased but on the brighter side interference
is minimized.
PAPR=7.1642, No of iterations =0
PAPR=6.526, No of iterations=5
Fig. 3: PAPER vs. CCCF WITH AND WITHOUT ICF
Fig. 4: SNR vs. SER
VII. CONCLUSION
Thus, the developed model can be used as a research tool (or
educational tool) to perform deepens study and investigation
to improve OFDM systems performance.
REFERENCES
[1] X. Li and L. J. Cimini, Jr., “Effects of Clipping and
Filtering on the Performance of OFDM,” IEEE
Communications Letters, vol. 2, no. 5, pp. 131-133,
May 1998.
[2] J. Armstrong, “Peak-to-average power reduction for
OFDM by repeated clipping and frequency domain
filtering,” IEE Electronics Letters, vol. 38, pp. 246-
247, February 2002.
[3] Shang-Kang Deng and Mao-Chao Lin, 2005. OFDM.
PAPR reduction using clipping with distortion
control. IEEE International Conference of
Communications, Taipei, Taiwan, 4: 2563-2567.