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.
Performance Analysis of MIMO-OFDM System Using QOSTBC Code Structure for M-PSKCSCJournals
MIMO-OFDM system has been currently recognized as one of the most competitive technology for 4G mobile wireless systems. MIMO-OFDM system can compensate for the lacks of MIMO systems and give play to the advantages of OFDM system. In this paper, a general Quasi orthogonal space time block code (QOSTBC) structure is proposed for multiple-input multiple-output–orthogonal frequency-division multiplexing (MIMO-OFDM) systems for 4X4 antenna configuration. The signal detection technology used in this paper for MIMO-OFDM system is Zero-Forcing Equalization (linear detection technique). In this paper the analysis of high level of modulations (i.e. M-PSK for different values of M) on MIMO-OFDM system is presented. Here AWGN and Rayleigh channels have been used for analysis purpose and their effect on BER for high data rates have been presented. The proposed MIMO-OFDM system with QOSTBC using 4X4 antenna configuration has better performance in terms of BER vs SNR than the other systems.
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.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
IMPROVEMENT OF LTE DOWNLINK SYSTEM PERFORMANCES USING THE LAGRANGE POLYNOMIAL...IJCNCJournal
To achieve a high speed data rate, higher spectral efficiency, improved services and low latency the 3rd
generation partnership project designed LTE standard (Long Term Evolution).the LTE system employs
specific technical as well the technical HARQ, MIMO transmission, OFDM Access or estimation technical.
In this paper we focus our study on downlink LTE channel estimation and specially the interpolation which
is the basis of the estimation of the channel coefficients. Thus, we propose an adaptive method for polynomial interpolation based on Lagrange polynomial. We perform the Downlink LTE system MIMO transmission then compare the obtained results with linear, Sinus Cardinal and polynomial Newton Interpolations. The simulation results show that the Lagrange method outperforms system performance in term of Block Error Rate (BLER) , throughput and EVN(%)vs. Signal to Noise Ratio (SNR).
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
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.
Performance Analysis of MIMO-OFDM System Using QOSTBC Code Structure for M-PSKCSCJournals
MIMO-OFDM system has been currently recognized as one of the most competitive technology for 4G mobile wireless systems. MIMO-OFDM system can compensate for the lacks of MIMO systems and give play to the advantages of OFDM system. In this paper, a general Quasi orthogonal space time block code (QOSTBC) structure is proposed for multiple-input multiple-output–orthogonal frequency-division multiplexing (MIMO-OFDM) systems for 4X4 antenna configuration. The signal detection technology used in this paper for MIMO-OFDM system is Zero-Forcing Equalization (linear detection technique). In this paper the analysis of high level of modulations (i.e. M-PSK for different values of M) on MIMO-OFDM system is presented. Here AWGN and Rayleigh channels have been used for analysis purpose and their effect on BER for high data rates have been presented. The proposed MIMO-OFDM system with QOSTBC using 4X4 antenna configuration has better performance in terms of BER vs SNR than the other systems.
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.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
IMPROVEMENT OF LTE DOWNLINK SYSTEM PERFORMANCES USING THE LAGRANGE POLYNOMIAL...IJCNCJournal
To achieve a high speed data rate, higher spectral efficiency, improved services and low latency the 3rd
generation partnership project designed LTE standard (Long Term Evolution).the LTE system employs
specific technical as well the technical HARQ, MIMO transmission, OFDM Access or estimation technical.
In this paper we focus our study on downlink LTE channel estimation and specially the interpolation which
is the basis of the estimation of the channel coefficients. Thus, we propose an adaptive method for polynomial interpolation based on Lagrange polynomial. We perform the Downlink LTE system MIMO transmission then compare the obtained results with linear, Sinus Cardinal and polynomial Newton Interpolations. The simulation results show that the Lagrange method outperforms system performance in term of Block Error Rate (BLER) , throughput and EVN(%)vs. Signal to Noise Ratio (SNR).
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
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.
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.
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.
Blind Channel Shortening for MIMO-OFDM System Using Zero Padding and Eigen De...ijsrd.com
This paper deals with multiple-input multiple-output (MIMO) broadband wireless communication systems, employing orthogonal frequency-division multiplexing (OFDM). In order to exploit the benefits of OFDM in highly frequency-selective channels, without any significant increase in receiver complexity, a channel shortening prefilter is inserted at the receiver. The main aim of inserting channel shorteners is to shorten the channel so that the main energy of the composite channel is concentrated within a duration smaller than the guard interval inserted while transmission. Thus by including channel shortening equalizers at the receiver the inter symbol interference or the inter block interference can be suppressed. The new approach proposed in this thesis is zero padding approach with Eigen decomposition approach. The advantages of the proposed approaches include immunity to delay spread, resistance to frequency selective fading and simple equalization. This shortening design is a blind one, i.e., a priori knowledge of the MIMO channel impulse response to be shortened is not required, and can be carried out in closed-form.
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).
Orthogonal Frequency Division Multiplexing with Offset Quadrature Amplitude Modulation
(OFDM / OQAM) is a multicarrier modulation scheme that can be considered as an alternative
to the conventional Orthogonal Frequency Division Multiplexing (OFDM) with Cyclic Prefix
(CP) for transmission over multipath fading channels. In this paper, we investigate the
combination of the OFDM/OQAM with Alamouti system with Time Reversal (TR) technique.
TR can be viewed as a precoding scheme which can be combined with OFDM/OQAM and
easily carried out in a Multiple Input Single Output (MISO) context such as Alamouti system.
We present the simulation results of the performance of OFDM/OQAM system in SISO case
compared with the conventional CP-OFDM system and the performance of the combination
Alamouti OFDM / OQAM with TR compared to Alamouti CP-OFDM. The performance is
derived by computing the Bit Error Rate (BER) as a function of the transmit signal-to-noise
ratio (SNR).
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.
Multi carrier equalization by restoration of redundanc y (merry) for adaptive...IJNSA Journal
This paper proposes a new blind adaptive channel shortening approach for multi-carrier systems. The
performance of the discrete Fourier transform-DMT (DFT-DMT) system is investigated with the proposed
DST-DMT system over the standard carrier serving area (CSA) loop1. Enhanced bit rates demonstrated
and less complexity also involved by the simulation of the DST-DMT system.
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
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.
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.
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.
Blind Channel Shortening for MIMO-OFDM System Using Zero Padding and Eigen De...ijsrd.com
This paper deals with multiple-input multiple-output (MIMO) broadband wireless communication systems, employing orthogonal frequency-division multiplexing (OFDM). In order to exploit the benefits of OFDM in highly frequency-selective channels, without any significant increase in receiver complexity, a channel shortening prefilter is inserted at the receiver. The main aim of inserting channel shorteners is to shorten the channel so that the main energy of the composite channel is concentrated within a duration smaller than the guard interval inserted while transmission. Thus by including channel shortening equalizers at the receiver the inter symbol interference or the inter block interference can be suppressed. The new approach proposed in this thesis is zero padding approach with Eigen decomposition approach. The advantages of the proposed approaches include immunity to delay spread, resistance to frequency selective fading and simple equalization. This shortening design is a blind one, i.e., a priori knowledge of the MIMO channel impulse response to be shortened is not required, and can be carried out in closed-form.
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).
Orthogonal Frequency Division Multiplexing with Offset Quadrature Amplitude Modulation
(OFDM / OQAM) is a multicarrier modulation scheme that can be considered as an alternative
to the conventional Orthogonal Frequency Division Multiplexing (OFDM) with Cyclic Prefix
(CP) for transmission over multipath fading channels. In this paper, we investigate the
combination of the OFDM/OQAM with Alamouti system with Time Reversal (TR) technique.
TR can be viewed as a precoding scheme which can be combined with OFDM/OQAM and
easily carried out in a Multiple Input Single Output (MISO) context such as Alamouti system.
We present the simulation results of the performance of OFDM/OQAM system in SISO case
compared with the conventional CP-OFDM system and the performance of the combination
Alamouti OFDM / OQAM with TR compared to Alamouti CP-OFDM. The performance is
derived by computing the Bit Error Rate (BER) as a function of the transmit signal-to-noise
ratio (SNR).
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.
Multi carrier equalization by restoration of redundanc y (merry) for adaptive...IJNSA Journal
This paper proposes a new blind adaptive channel shortening approach for multi-carrier systems. The
performance of the discrete Fourier transform-DMT (DFT-DMT) system is investigated with the proposed
DST-DMT system over the standard carrier serving area (CSA) loop1. Enhanced bit rates demonstrated
and less complexity also involved by the simulation of the DST-DMT system.
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
Blackphone is a secured mobile phone, based on Android OS called PrivateOS. For serious people who are looking for privacy and security.
بلاكفون جوال آمن بنظام تشغيل أندرويد اسمه برايفت أو إس، وهو للمستخدمين الجادين والمهتمين بالخصوصية والأمان
Analyses and performance of techniques papr reduction for stbc mimo ofdm syst...ijwmn
An OFDM system is combined with multiple-input mult
iple-output (MIMO) in order to increase the
diversity gain and system capacity over the time va
riant frequency-selective channels. However, a maj
or
drawback of MIMO-OFDM system is that the transmitte
d signals on different antennas might exhibit high
peak-to-average power ratio (PAPR).In this paper, w
e present a PAPR analysis reduction of space-time-
block-coded (STBC) MIMO-OFDM system for 4G wireless
networks. Several techniques have been used to
reduce the PAPR of the (STBC) MIMOOFDM system: clip
ping and filtering, partial transmit sequence
(PTS) and selected mapping (SLM). Simulation result
s show that clipping and filtering provides a bette
r
PAPR reduction than the others methods and only SLM
technique conserve the PAPR reduction in
reception part of signal.
Reduction of Outage Probability in Fast Rayleigh Fading MIMO Channels Using OFDMIJERA Editor
Multiple-input multiple-output (MIMO) techniques are used in wireless communications for achieving high spectral efficiency; however, a fast fading spatial channel can increase the outage probability of a MIMO system if not taken care of. This paper investigates the use of orthogonal frequency division multiplexing (OFDM) modulation technique for a MIMO system operating in fast Rayleigh fading channels with the aim of eliminating outage probabilities in the MIMO systems. Simulation results show that the MIMO-OFDM system gives significant reduction in outage probabilities compared to the conventional MIMO system.
A JOINT TIMING OFFSET AND CHANNEL ESTIMATION USING FRACTIONAL FOURIER TRANSFO...IJCNCJournal
This paper deals with symbol timing offset and channel estimation in OFDM (orthogonal frequency
division multiplexing) system in fast varying channel. Symbol timing offset (STO) estimation is a major task
in OFDM. Most of existing methods for estimating STO used cyclic prefix or training sequences. In this
paper, we consider a new system for STO estimation using constant amplitude zero autocorrelation
(CAZAC) sequences as pilot sequences in conjunction with fractional Fourier transform (FRFT). After STO
estimation is done, timing compensation is made. Thereafter, channel is estimated to well recover the
original transmitted signal. This method gives good results in terms of MSE in comparison with other
known techniques, it estimated well the channel and it is important for fast varying channel. MATLAB
Monte-Carlo simulations are used to evaluate the performance of the proposed estimator.
Study of timing synchronization in mimoofdm systems using dvb tijitjournal
OFDM (Orthogonal Frequency Division Multiplexing)provides the promising physical layer for 4G and
3GPP LTE Systems in terms of efficient use of bandwidth and data rates. This paper highlights the
implementation of OFDM in Digital Video Broadcasting-Terrestrial (DVB-T). It mainly focuses on the
timing offset problem present in OFDM systems and its proposed solution using Cyclic Prefix (CP) as a
modified SC (Schmidl and COX) algorithm. It also highlights the timing synchronization as well as
performance comparison through bit error rate. Synchronization issues in OFDM are important and can
lead to information loss if not properly addressed. Simulations were performed to implement DVB-T system
and to compare different synchronization methods under certain distribution model.
Analysis of cyclic prefix length effect on ISI limitation in OFDM system over...IJECEIAES
In this work, the influence of the cyclic prefix on the performance of the OFDM system is studied. We worked out an OFDM transceiver using a 16 QAM modulation scheme, a comparison of the BER for various lengths of the cyclic prefix has been achieved, and the influence of the noise introduced in the channel has been highlighted, for both a Gaussian and Rayleigh noise. The simulation was carried out on MATLAB where the curves of the BER for various lengths of the cyclic prefix are given and compared. We also adopted as a metric the QAM constellation to show the dispersion of the carriers as a consequence of the transmission channel, the mitigation of this effect by the CP is noticeable.
COMPARISON OF BER AND NUMBER OF ERRORS WITH DIFFERENT MODULATION TECHNIQUES I...Sukhvinder Singh Malik
This paper provides analysis of BER and Number of Errors for MIMO-OFDM wireless communication system by using different modulation techniques. Wireless designers constantly seek to improve the spectrum efficiency/capacity, coverage of wireless networks, and link reliability. So the performances of the wireless communication systems can be enhanced by using multiple transmit and receive antennas, which is generally referred to as the MIMO technique. Here analysis will be carried out for an OFDM wireless communication system using different modulation techniques and considering the effect and the wireless channel like AWGN, fading. Performance results will be evaluated numerically and graphically using the plots of BER versus SNR and plots of number of errors versus SNR.
BER Analysis of OFDM Systems with Varying Frequency Offset Factor over AWGN a...rahulmonikasharma
The progressively escalating demand for tremendously high rate data transmission over wireless mediums needsresourcefulconcord of electromagnetic resources considering restrictions like power incorporation, spectrum proficiency, robustness in disparity to multipath propagation and implementation complication. Orthogonal frequency division multiplexing (OFDM) is a favorable approach for upcoming generation wireless communication systems. However its susceptibility to the frequency offset triggered by frequency difference between local oscillator of transmitter and receiver or due to Doppler shift results to Inter Carrier Interference. This delinquent of ICI results inworsening performance of the wireless systems as bit error rate increaseswith increase in value of frequency offset. In this paper simulation results aredemonstratedfor analyzing the effect of varying frequency offset factor on system’s error rate performance.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
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.
Multi-carrier Equalization by Restoration of RedundancY (MERRY) for Adaptive ...IJNSA Journal
This paper proposes a new blind adaptive channel shortening approach for multi-carrier systems. The performance of the discrete Fourier transform-DMT (DFT-DMT) system is investigated with the proposed DST-DMT system over the standard carrier serving area (CSA) loop1. Enhanced bit rates demonstrated and less complexity also involved by the simulation of the DST-DMT system.
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.