VLSI Implementation of OFDM Transceiver for 802.11n systemsIJERA Editor
Orthogonal Frequency Division Multiplexing (OFDM) is the most widely used modulation technique for wireless communication network. In this paper, 4 x 4 spatially multiplexed MIMO OFDM transceiver is designed using 1/2 encoder and 64 bit FFT. The implementation has been carried out in hardware using Field Programmable Gate Array (FPGA). Both the transmitter and the receiver are implemented on a single FPGA board with the channel being a wired one. The FPGA board used is Diligent Atlys Xilinx Spartan 6. We have analysed the effect of Bit Error Rate and Data rate with respect to Signal to Noise ratio.
PERFORMANCE ANALYSIS OF CLIPPED STBC CODED MIMO OFDM SYSTEMIAEME Publication
A combination of Multiple-Input Multiple-Output Spatial Division Multiplexing technology and Orthogonal Frequency Division Multiplexing technique, namely MIMO-OFDM systems, been well-known as a potential technology to provide high speed data transmission and spectrum efficiency to attain throughput of 1 Gbit/sec and beyond improves link reliability for modern wireless communications. The rising development of Internet related contents and demand of multimedia services leads to increasing curiosity to high speed communications. It has been shown that by using MIMO system, it is possible to increase that capacity considerably.
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.
VLSI Implementation of OFDM Transceiver for 802.11n systemsIJERA Editor
Orthogonal Frequency Division Multiplexing (OFDM) is the most widely used modulation technique for wireless communication network. In this paper, 4 x 4 spatially multiplexed MIMO OFDM transceiver is designed using 1/2 encoder and 64 bit FFT. The implementation has been carried out in hardware using Field Programmable Gate Array (FPGA). Both the transmitter and the receiver are implemented on a single FPGA board with the channel being a wired one. The FPGA board used is Diligent Atlys Xilinx Spartan 6. We have analysed the effect of Bit Error Rate and Data rate with respect to Signal to Noise ratio.
PERFORMANCE ANALYSIS OF CLIPPED STBC CODED MIMO OFDM SYSTEMIAEME Publication
A combination of Multiple-Input Multiple-Output Spatial Division Multiplexing technology and Orthogonal Frequency Division Multiplexing technique, namely MIMO-OFDM systems, been well-known as a potential technology to provide high speed data transmission and spectrum efficiency to attain throughput of 1 Gbit/sec and beyond improves link reliability for modern wireless communications. The rising development of Internet related contents and demand of multimedia services leads to increasing curiosity to high speed communications. It has been shown that by using MIMO system, it is possible to increase that capacity considerably.
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.
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.
SECURED TEXT MESSAGE TRANSMISSION IN PRE -CHANNEL EQUALIZATION BASED MIMO- OF...IJNSA Journal
In this paper, we made a comprehensive performance evaluative study of a secured MIMO Orthogonal Frequency-Division Multiplexing wireless communication system with implementation of two pre channel equalization techniques such as Pre-Minimum Mean Square Error (Pre-MMSE) and Pre-Zero
Forcing(Pre-ZF) under QPSK and QAM digital modulations. The simulated system deploys three channel coding techniques(1/2-rated Convolutional, CRC and BCH). In the present simulated system, text message transmission has been secured with concatenated implementation of Electronic Codebook (ECB)
and Cipher Feedback(CFB) cryptographic algorithm. It is remarked from simulation results that the MIMO OFDM system outperforms with pre-ZF channel equalization,QAM digital modulation and BCH channel coding schemes under fading channels(AWGN and Raleigh).In Pre-MMSE/pre-ZF channel
equalization scheme, the system shows comparatively worst performance in convolutional channel coding scheme with QAM/QPSK digital modulation. With increase in noise power as compared to signal power, the system is found to have shown performance deterioration
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
Overview about MIMO
Contents:
Diversity Definition
Why Diversity
Types of Diversity
Types of combining
MIMO Definition
Why MIMO ?
MIMO Advantages and disadvantages
Applications of MIMO
International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
Capacity Enhancement of MIMO-OFDM System in Rayleigh Fading ChannelIOSR Journals
MIMO-OFDM system in Rayleigh Fading Channel is very popular technique for mobile
communication now a day’s for research. Here we want increase the capacity of MIMO-OFDM of system by
using adaptive modulation, Algebraic Space-Time Codes (ASTC) encoder for MIMO Systems are based on
quaternion algebras .we found that ergodic capacity has some limitation which reduce the system’s
performance to overcome this we use ASTC code . ASTC code are full rank, full rate and non vanishing constant
minimum determinant for increasing spectral efficiency and reducing Peak to Average Power Ratio (PAPR) .
Performance 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 Massive MIMO Downlink System with Imperfect Channel S...IJRES Journal
We investigate the ergodic sum rate and required transmit power of a single-cell massive
multiple-input multiple-output (MIMO) downlink system. The system considered in this paper is based on two
linear beamforming schemes, that is, maximum ratio transmission (MRT) beamforming and zero-forcing (ZF)
beamforming. What’s more, we use minimum mean square error (MMSE) channel estimation to get imperfect
channel state information (CSI). Compared with the perfect CSI case, both theoretical analysis and simulation
results show that the system performance is different when the imperfect CSI is taken into account.
MIMO radar is introduced in presentation ,its advantage .future scope,research area.
MIMO radars represent a new generation of radars. In contrast to the traditional phased-array radar in which the transmit elements can transmit only the scaled versions of same signal, a MIMO radar allows the transmitters to transmit multiple signals. This waveform diversity offers enhanced flexibility in transmit beampattern synthesis which is an important area of MIMO radar signal processing
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.
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.
SECURED TEXT MESSAGE TRANSMISSION IN PRE -CHANNEL EQUALIZATION BASED MIMO- OF...IJNSA Journal
In this paper, we made a comprehensive performance evaluative study of a secured MIMO Orthogonal Frequency-Division Multiplexing wireless communication system with implementation of two pre channel equalization techniques such as Pre-Minimum Mean Square Error (Pre-MMSE) and Pre-Zero
Forcing(Pre-ZF) under QPSK and QAM digital modulations. The simulated system deploys three channel coding techniques(1/2-rated Convolutional, CRC and BCH). In the present simulated system, text message transmission has been secured with concatenated implementation of Electronic Codebook (ECB)
and Cipher Feedback(CFB) cryptographic algorithm. It is remarked from simulation results that the MIMO OFDM system outperforms with pre-ZF channel equalization,QAM digital modulation and BCH channel coding schemes under fading channels(AWGN and Raleigh).In Pre-MMSE/pre-ZF channel
equalization scheme, the system shows comparatively worst performance in convolutional channel coding scheme with QAM/QPSK digital modulation. With increase in noise power as compared to signal power, the system is found to have shown performance deterioration
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
Overview about MIMO
Contents:
Diversity Definition
Why Diversity
Types of Diversity
Types of combining
MIMO Definition
Why MIMO ?
MIMO Advantages and disadvantages
Applications of MIMO
International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
Capacity Enhancement of MIMO-OFDM System in Rayleigh Fading ChannelIOSR Journals
MIMO-OFDM system in Rayleigh Fading Channel is very popular technique for mobile
communication now a day’s for research. Here we want increase the capacity of MIMO-OFDM of system by
using adaptive modulation, Algebraic Space-Time Codes (ASTC) encoder for MIMO Systems are based on
quaternion algebras .we found that ergodic capacity has some limitation which reduce the system’s
performance to overcome this we use ASTC code . ASTC code are full rank, full rate and non vanishing constant
minimum determinant for increasing spectral efficiency and reducing Peak to Average Power Ratio (PAPR) .
Performance 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 Massive MIMO Downlink System with Imperfect Channel S...IJRES Journal
We investigate the ergodic sum rate and required transmit power of a single-cell massive
multiple-input multiple-output (MIMO) downlink system. The system considered in this paper is based on two
linear beamforming schemes, that is, maximum ratio transmission (MRT) beamforming and zero-forcing (ZF)
beamforming. What’s more, we use minimum mean square error (MMSE) channel estimation to get imperfect
channel state information (CSI). Compared with the perfect CSI case, both theoretical analysis and simulation
results show that the system performance is different when the imperfect CSI is taken into account.
MIMO radar is introduced in presentation ,its advantage .future scope,research area.
MIMO radars represent a new generation of radars. In contrast to the traditional phased-array radar in which the transmit elements can transmit only the scaled versions of same signal, a MIMO radar allows the transmitters to transmit multiple signals. This waveform diversity offers enhanced flexibility in transmit beampattern synthesis which is an important area of MIMO radar signal processing
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.
Nearest Adjacent Node Discovery Scheme for Routing Protocol in Wireless Senso...IOSR Journals
The broad significance of Wireless Sensor Networks is in most emergency and disaster rescue
domain. The routing process is the main challenges in the wireless sensor network due to lack of physical links.
The objective of routing is to find optimum path which is used to transferring packets from source node to
destination node. Routing should generate feasible routes between nodes and send traffic along the selected path
and also achieve high performance. This paper presents a nearest adjacent node scheme based on shortest path
routing algorithm. It is plays an important role in energy conservation. It finds the best location of nearest
adjacent nodes by involving the least number of nodes in transmission of data and set large number of nodes to
sleep in idle mode. Based on simulation result we shows the significant improvement in energy saving and
enhance the life of the network
Thorny Issues of Stakeholder Identification and Prioritization in Requirement...IOSR Journals
Abstract: Identifying the stakeholder in requirement engineering process is one of the critical issues. It
performs a remarkable part for successful project completion. The software project largely depends on several
stakeholders. Stakeholder identification and prioritization is still a challenging part in the software development
life cycle. Most of the time, the stakeholders are treated with less importance during the software deployment.
Additionally, there is a lack of attempt to think about the right project stakeholder by the development team. In
maximum cases, the stakeholder identification technique is performed incorrectly and there is a lack of attempt
to mark out them with priority. Besides, there are so many limitations on the existing processes which are used
for identifying stakeholders and setting their priority. These limitations pose a negative impact on the
development of software project, which should be pointed out by giving deep concern on it. We are aiming to
focus on this typical fact, so that we can figure out the actual problem and current work on identifying
stakeholders and setting their priority.
Keywords: Stakeholders, Stakeholder Identification, Stakeholder Selection, Stakeholder
Prioritization, Stakeholder Value, Software Development
Synthesis and Application of Direct Dyes Derived From Terephthalic and Isopht...IOSR Journals
Abstract: The synthesis of direct dyes derived from terephthalic and isophthalic acid using J and H- acids was
undertaken with the view of replacing benzidine moiety in the production of direct dyes. The amide derivatives
of isophthalic and terephthalic acids were used as the coupling components while aniline and its derivatives
were used as the source of diazo components. The amide derivatives were characterized by Gas
Chromatography/Mass Spectrometry and Infra-red analysis. The spectroscopic properties of the dyes in various
solvents were also examined and most of the dyes showed bathochromic shifts when the solvent was changed to
more polar solvents. The dyes also showed positive and negative halochromism with the addition of few drops of
hydrochloric acid (HCl). The synthesized dyes were applied to cotton fabrics and their performance properties
evaluated. They have good exhaustion in the presence of electrolyte and have good wash fastness properties
upon application of after-treating agents of values of 3-4, 4 and 4-5. They also had good fastness properties to
light of values between 4-7. Their resistance to rubbing and perspiration had values between 3 and 4-5. The
toxicity of the synthesized coupling components was studied using the Dietrich Lorke (LD50) method on Albino
miceand they were found to be non-toxic.
Key words: Benzidine, direct dyes, exhaustion, electrolyte, cotton, fastness.
Survey on Restful Web Services Using Open Authorization (Oauth)I01545356IOSR Journals
Abstract: Web services are application based programming interfaces (API) or web APIs that are accessed
through Hypertext Transfer Protocol (HTTP) to execute on a remote system hosting the requested services. A
RESTFUL web service is a budding technology, and a light weight approach that do not restrict the clientserver
communication. The open authorization (OAuth) 2.0 protocol enables the users to grant third-party
application access to their web resources without sharing their login credential data. The Authorization Server
includes authorization information with the Access Token and signs the Access Token. An access token can be
reused until it expires. An authentication filter is used for business services. This paper presents a secure
communication at the message level with minimum overhead and provides a fine grained authenticity using the
Jersey framework.
Keywords: Open authorization (oauth), Restful web services, HTTP protocols and uniform resource
identifier(URI).
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.
MIMO Channel Estimation Using the LS and MMSE AlgorithmIOSRJECE
Wireless Communication Technology has developed over the past few yearsfor other objectives.The Multiple InputMultiple Output (MIMO) is one of techniques that is used to enhancethe data rates, in which multiple antennas are employed both the transmitter and receiver. Multiple signals are transmitted from different antennas at the transmitter using the same frequency and separated space. Various channel estimation techniques are employed in order to judge the physical effects of the medium present. In this paper, we analyze and implementvarious estimation techniques for MIMO Systems such as Least Squares (LS), Minimum Mean Square Error (MMSE),these techniques are therefore compared to effectively estimate the channel in MIMO System. The results demonstrate that SNR required to support different values of bit error rate varies depending on different low correlation between the transmitting and the receiving antennas .In addition, it is illustrated that when the number of transmitter and receiver antennas increases, the performance of TBCE schemes significantly improves. The Same behavior isalso observed for MIMO system. Performance of both MMSE and LSestimation are the same for allkinds of modulation at small value of SNR but the more we increase the SNR value the more performance gap goes on increasing.
Iterative qr decompostion channel estimation for mimo ofdm systems eSAT Journals
Abstract Channel estimation algorithms have a key role in signal detection in MIMO-OFDM systems. In this system, the number of channel components which need to be estimated is much more than conventional SISO wireless systems. Consequently, the computational process of channel estimation is highly intensive. In addition, the high performance channel estimation algorithms mostly suffer from high computational complexity. In the other words, the system undergoes intensive computations if high performance efficiency is desired. However, there is an alternative solution to achieve both high performance efficiency and relatively low level of computational complexity. In this solution, high efficient channel estimation is firstly designed, and then it is simplified using alternative mathematical expressions. In this paper, Iterative channel estimation based on QR decomposition for MIMO-OFDM systems is proposed. From simulation results, the iterative QRD channel estimation algorithm can provide better mean-square-error and bit error rate performance than conventional methods. Index Terms: MIMO, OFDM, QRD,Least squre Channel estimation
In this paper, we analyzed a numerical evaluation of the performance of MIMO radio systems in the LTE network environment. Downlink physical layer of the OFDM-MIMO based radio interface is considered for system model and a theoretical analysis of the bit error rate of the two space-time codes (SFBC 2×1 and FSTD 4×2 codes are adopted by the LTE norm as a function of the signal to noise ratio. Analytical expressions are given for transmission over a Rayleigh channel without spatial correlation which is then compared with Monte-Carlo simulations. Further evaluated channel capacity and simulation results show throughput almost reaches to the capacity limit.
Intersymbol interference caused by multipath in band limited frequency selective time dispersive channels distorts the transmitted signal, causing bit error at receiver. ISI is the major obstacle to high speed data transmission over wireless channels. Channel estimation is a technique used to combat the intersymbol interference. The objective of this paper is to improve channel estimation accuracy in MIMO-OFDM system by using modified variable step size leaky Least Mean Square (MVSSLLMS) algorithm proposed for MIMO OFDM System. So we are going to analyze Bit Error Rate for different signal to noise ratio, also compare the proposed scheme with standard LMS channel estimation method.
Analysis of Space Time Codes Using Modulation TechniquesIOSR Journals
Abstract: In this Paper, Analysis of channel codes for improving the data rate and reliability of communication over fading channels using multiple transmit antennas has been considered. The codes, namely ’Space Time Codes’ render full diversity and amend coding gain. Performance criteria for designing such codes, under this assumption that the fading is slow and nonselective frequency, is also analysed. Under this research, Study of Frame Error Rate(FER) and outage capacity is compared for different no. Of transmit and receive antennas as well as for different modulation techniques. According to theoretical results FER decreases with increasing SNR and No. Of receiving antennas. Numerical and practical result shows that FER decreases with increasing SNR and no. Of receiving antennas. Keywords: Space time Block Codes ,Space time trellis Codes,Frame Error Rate(FER),Outage capacity,Pairwise Error Probability
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).
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.
Capacity Enhancement of MIMO-OFDM System in Rayleigh Fading ChannelIOSR Journals
Abstract: MIMO-OFDM system in Rayleigh Fading Channel is very popular technique for mobile communication now a day’s for research. Here we want increase the capacity of MIMO-OFDM of system by using adaptive modulation, Algebraic Space-Time Codes (ASTC) encoder for MIMO Systems are based on quaternion algebras .we found that ergodic capacity has some limitation which reduce the system’s performance to overcome this we use ASTC code . ASTC code are full rank, full rate and non vanishing constant minimum determinant for increasing spectral efficiency and reducing Peak to Average Power Ratio (PAPR) . Keywords— Adaptive modulation ASTC code, Capacity, BER, Ergodic capacity, PAPR, Spectral Efficiency and SNR
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.
Bit Error Rate Performance of MIMO Spatial Multiplexing with MPSK Modulation ...ijsrd.com
Wireless communication is one of the most effective areas of technology development of our time. Wireless communications today covers a very wide array of applications. In this, we study the performance of general MIMO system, the general V-BLAST architecture with MPSK Modulation in Rayleigh fading channels. Based on bit error rate, we show the performance of the 2x2 schemes with MPSK Modulation in noisy environment. We also show the bit error rate performance of 2x2, 3x3, 4x4 systems with BPSK modulation. We see that the bit error rate performance of 2x2 systems with QPSK modulation gives us the best performance among other schemes analysed here.
For ease of analog or digital information transmission and reception, modulation is the foremost important technique. In the present project, we’ll discuss about different modulation scheme in digital mode done by operating a switch/ key by the digital data. As we know, by modifying basic three parameters of the carrier signal, three basic modulation schemes can be obtained; generation and detection of these three modulations are discussed and compared with respect to probability of error or bit error rate (BER).
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
Software Delivery At the Speed of AI: Inflectra Invests In AI-Powered QualityInflectra
In this insightful webinar, Inflectra explores how artificial intelligence (AI) is transforming software development and testing. Discover how AI-powered tools are revolutionizing every stage of the software development lifecycle (SDLC), from design and prototyping to testing, deployment, and monitoring.
Learn about:
• The Future of Testing: How AI is shifting testing towards verification, analysis, and higher-level skills, while reducing repetitive tasks.
• Test Automation: How AI-powered test case generation, optimization, and self-healing tests are making testing more efficient and effective.
• Visual Testing: Explore the emerging capabilities of AI in visual testing and how it's set to revolutionize UI verification.
• Inflectra's AI Solutions: See demonstrations of Inflectra's cutting-edge AI tools like the ChatGPT plugin and Azure Open AI platform, designed to streamline your testing process.
Whether you're a developer, tester, or QA professional, this webinar will give you valuable insights into how AI is shaping the future of software delivery.
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
Transcript: Selling digital books in 2024: Insights from industry leaders - T...BookNet Canada
The publishing industry has been selling digital audiobooks and ebooks for over a decade and has found its groove. What’s changed? What has stayed the same? Where do we go from here? Join a group of leading sales peers from across the industry for a conversation about the lessons learned since the popularization of digital books, best practices, digital book supply chain management, and more.
Link to video recording: https://bnctechforum.ca/sessions/selling-digital-books-in-2024-insights-from-industry-leaders/
Presented by BookNet Canada on May 28, 2024, with support from the Department of Canadian Heritage.
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Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overview
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During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
To view the webinar recording, go to:
https://www.rttsweb.com/jmeter-integration-webinar
"Impact of front-end architecture on development cost", Viktor TurskyiFwdays
I have heard many times that architecture is not important for the front-end. Also, many times I have seen how developers implement features on the front-end just following the standard rules for a framework and think that this is enough to successfully launch the project, and then the project fails. How to prevent this and what approach to choose? I have launched dozens of complex projects and during the talk we will analyze which approaches have worked for me and which have not.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
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In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
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https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
State of ICS and IoT Cyber Threat Landscape Report 2024 preview
I010125056
1. IOSR Journal of Electronics and Communication Engineering (IOSR-JECE)
e-ISSN: 2278-2834,p- ISSN: 2278-8735.Volume 10, Issue 1, Ver. II (Jan - Feb. 2015), PP 50-56
www.iosrjournals.org
DOI: 10.9790/2834-10125056 www.iosrjournals.org 50 | Page
Channel Estimation In The STTC For OFDM Using MIMO With
4G System
Anshu Jaiswal, Asst. Prof. Ashish Dubey, Prof. Manish Gurjar
Dept. Of Electronics & Communication, TIT College, RGPV University, Bhopal, India
Abstract: This paper presents performance of the STTC based MIMO-OFDM system. The goal was to reach
10-5
Bit error rate & achieve high Signal to noise ratio (SNR) to evaluate the performances of the system. The
results of this dissertation are based on PSK modulation technique over fast Channel Estimation. We have
simulated the proposed approach for 2-PSK, 4-PSK, 8-PSK, 16-PSK and the number of OFDM subcarriers. In
our result we have considered that is transmitter and receiver so that maximum illustrates the noise reduction in
balanced STTC for OFDM based MIMO channel with 2-PSK, 4-PSK, 8-PSK and 16-PSK modulation schemes
in terms of Bits error rate and signal to noise ratio(SNR) gain. We simulate the result with 2 x 2 antennas and
decoding of the signal STTC codes are simulated by using three different techniques, these are MMES(minimum
mean square error), ZF(zero forcing), and ML(maximum likelihood) with viterbi algorithm.
Keywords: Channel Estimation, STTC, OFDM, MIMO, MATLAB, PSK Modulation.
I. Introduction
In Recent year, the wireless communication industry is facing new challenges due to constant evolution
of new standards (2.5G,3G, and4G). Wireless system are expected to require high data rates with low delay and
low bit-error-rate (BER). In addition, high data rate transmission and high mobility of transmitter and/or
receivers usually result in frequency-selective and time-selective, i.e., doubly selective, fading channels for
future mobile broadband wireless system.
Orthogonal frequency division multiplexing (OFDM) is a method of encoding digital data on multiple
carrier frequencies. OFDM has developed into a popular scheme for wideband digital communication, whether
wireless or over copper wires, used applications such as digital television & audio broadcasting, DSL Internet
access, wireless networks, power-line network, and 4G mobile communication [4]. An orthogonal frequency
division multiplexing(OFDM) is an efficient high data-rate, having advantages of high spectrum efficiency,
simple & efficient implementation by using the fast Fourier transform(FFT) & the inverse FFT(IFFT),
mitigation of inter symbol Interference by inserting a cyclic prefix (CP) and robustness to frequency selective
fading channels transmission technique for wireless communication[3].
Multiple-input & multiple-output or MIMO is the use of multiple antennas at both the transmitter &
receiver to improve communication performance. It is one of several forms of smart antenna technology. MIMO
technology has attracted attention in wireless communications, because it offers significant increases in data
throughput and link range without adding bandwidth or increased transmit power. It achieves this goal by
spreading the same total transmit power over the antennas to achieve an array gain that improves the spectral
efficiency and/or to achieve a diversity gain that improves the link reliability (reduced fading)[6]. Because of
these properties MIMO is an important part of modern wireless communication standards.
Space-time-trellis-coding(STTC) is an attractive & promising solution, which achieves bandwidth
efficient transmit diversity by using specially designed channel codes at the transmitter end in combination with
some additional signal processing at the receiver. Use with MIMO-OFDM for improves the data-rate and the
reliability of wireless communication. The decoding of signal STTC codes are simulated by using three different
decoding techniques, these are MMES (minimum mean square error), ZF(zero forcing), ML(maximum
likelihood) using soft decision decoding with viterbi algorithm.
II. MIMO-OFDM System Model
Multiple antennas can be used at the transmitter and receiver, an arrangement called a multiple-input
multiple- output (MIMO) system. A MIMO system takes advantage of the spatial diversity that is obtained by
spatially separated antennas in a dense multipath scattering environment. MIMO systems may be implemented
in a number of different ways to obtain either a diversity gain to combat signal fading or to obtain a capacity
gain. Generally, there are three categories of MIMO techniques. The first aims to improve the power efficiency
by maximizing spatial diversity. Such techniques include delay diversity, space–time block codes (STBC) and
space–time trellis codes (STTC). The second class uses a layered approach to increase capacity. One popular
example of such a system is V-BLAST where full spatial diversity is usually not achieved. Finally, the third
type exploits the knowledge of channel at the transmitter. It decomposes the channel coefficient matrix using
2. Channel Estimation In The STTC For OFDM Using MIMO With 4G System
DOI: 10.9790/2834-10125056 www.iosrjournals.org 51 | Page
singular value decomposition (SVD) and uses these decomposed unitary matrices as pre- and post-filters at the
transmitter and the receiver to achieve near capacity.
Fig 1 MIMO-OFDM
Assuming that the channel characteristics remain constant over two consecutive OFDM symbols, the received
signals are expressed by
r1(t) = h11(q-1
)x1(t) + h21(q-1
)x2(t)
r2(t) = h21(q-1
) x1(t) +h22(q-1
) x2(t)
r3(t) = h11(q-1
)x3(t) + h21(q-1
)x4(t)
r4(t) = h21(q-1
) x3(t) + h22(q-1
) x4(t)
Where hi,j(q-1
), i = 1,2 and j = 1,2 are the discrete-time filter representations of the channel from the j-th transmit
antenna to the i-th the receive antenna.
III. STTC And Channel Estimation
A. Space Time Trellis Coded
Space Time Trellis Coded Modulation (STTCM) is obtained by combining channel coding with the
Multiple Input Multiple Output (MIMO) concept to improve the data rate and the reliability of wireless
communications. Many performance criteria have been established to maximize both diversity and coding gain
of STTC. The rank and determinant criteria for slow fading channels and the Euclidian distance and the product
distance criteria for fast fading channels.Convolution encoders with the same structure but with different
weighting coefficients are assigned to transmitting multiple branches in STTC [2]. The state transitions of the
encoders are therefore the same, but their outputs differ, according to the past inputs. A maximum-likelihood
series estimator (i.e., a Viterbi decoder) can be applied at the receiving side. We consider the case of 2n
-PSK
space-time trellis encoder as shown on Fig 2
Fig 2 ST trellis encoder with 4-PSK and nT Transmit antennas
3. Channel Estimation In The STTC For OFDM Using MIMO With 4G System
DOI: 10.9790/2834-10125056 www.iosrjournals.org 52 | Page
This encoder is composed of one input block of n bits and ν memory blocks of n bits. At each time t, all
the bits of a block are replaced by the n bits of the previous block. The ith
bit bt−j+1
i, i = 1. .... . n, of the jth
block,
j = 1. … . ν + 1, is associated to nT multiplier coefficients ck
i,j, k = 1. ... . nT where nT is the number of
transmit antennas. A ST trellis encoder is thus classically defined by its generator matrix C of nT × n(ν + 1)
coefficients
C =
c1,1
1
cn,1
1
… … … cn,v+1
1
c1,1
k
cn,1
k
… … … cn,v+1
k
⋮
c1,1
nT
⋮
cn,1
nT … … … .
⋮
cn,v+1
nT
The encoder outputs for the kth
antenna are computed
yt
k
= bt
t−j+1v+1
j=1 ci,j
kn
i=1 mod 2n
……..4.6
A typical S'TTC based wireless system has an encoder, pulse shaper, modulator and multiple transmit
antennas at the transmitter, and the receiver has one or more receive antennas, demodulator, channel estimator
and STTC decoder. We consider a mobile communication system with nT transmit antennas and nR receive
antennas. The space-time trellis encoder encodes the data s(t) coming from the information source and the
encoded data is divided into nT streams of data.
CT
1
CT
2
…………CT
nT
Each of these streams of data passes through a pulse shaper before being modulated. The output of modulator i
at time slot t is the signal , which is transmitted through transmit antenna i . Here nT 1< i < nT. The
transmitted symbols have energy ET. We assume that the nT signals are transmitted simultaneously from the
antennas. The signals have transmission period T. In the receiver, each antenna receives a superposition of nT
transmitted signals corrupted by noise and multipath fading. Let the complex channel coefficient between
transmit antenna i and receive antenna j have a value of hij(t) at time t, where 1< i < nR. The received signal at
antenna j, j=1,2,......., nR is
rt = √Es hi,j
n
i=1 (t)ct
i
(t) + nt
j
…………4.7
Where ηt
j
is additive white Gaussian noise (AWGN) at receive antenna j , which has zero mean and
power spectral density N0 and, hij(t) channel coefficient between transmit and receive antennas. Time,
frequency and spatial diversity are the traditional strategies to combat multipath fading, which is a major
obstacle to high data rates over mobile communication channels. STTCs are represented in a number of ways,
such as the trellis form or generator matrix form most codes are presented in trellis form but for a systematic
code search, the generator matrix form is preferable. The generator matrix representation is also used for
convolution codes. However the generator matrix notation of space time trellis codes (STTC) is little different
than that used for convolution codes. Two input bits enter the encoder every symbol period.
Let the input symbol stream to the encoder is [2 3 2 1 0 1 ……..]. Initially the encoder is in state “0”.
Thus “0” will be transmitted from the first antenna, the second antenna transmits “2” and the encoder goes into
state “2” In this way for this input symbol stream the output for the 4-PSK STTC is as follows in table 1.
Table 1: PSK 4-State STTC
Output symbols
State Input
0
Input
1
Input
2
Input
3
0 00 01 02 03
1 10 11 12 13
2 20 21 22 23
3 30 31 32 33
It is assumed that the STTC codeword is given by
C = (C1
1
C1
2
……C1
nt
C2
1
C2
2
…….C2
n
……….CL
1
CL
2
……… CL
nt
) ………………4.8
4. Channel Estimation In The STTC For OFDM Using MIMO With 4G System
DOI: 10.9790/2834-10125056 www.iosrjournals.org 53 | Page
Where l is the frame length. We consider a maximum likelihood receiver, which may possibly decide on an
erroneous code word e, given by
e=(e1
1
e1
2
……e1
nt
e2
1
e2
2
…….e2
n
……….eL
1
eL
2
……eL
nt
) ........4.9
We can write the difference code matrix, the difference between the erroneous codeword and the transmitted
codeword as follows [5]
The difference matrix B(c, e) has dimension nt x l. we know that to achieve the maximum diversity
order nTnR ( nR receive antennas, nT transmit antennas) matrix B(c,e)must have full rank for all possible
codewords c and e . If B(c,e) has minimum rank r over the set of pairs of distinct codewords then the diversity
will be r nR .
B. Channel Model for MIMO-OFDM
The channel model of MOMO-OFDM can be represented by following discrete time model
Or simply it can be represented as
y=H x + n
Where Nt is the total number of transmitted antennas and Nr is the total number of receiving antennas.
here x represents the Nt dimensional transmitted symbol, n is the Nr dimensional noise vector, and H is the Nt Nr
matrix of channel gains. h11 is the gain from transmit antenna 1 to receive antenna1 and x is the space time
coded signal. The channel bandwidth is assumed to be B and complex Gaussian noise with zero mean. In the
system design, both discrete Rayleigh and Nakagami fast fading MIMO channel models are assumed, where Nt
and Nr are the number of transmit and receive antennas respectively. In the transmitter, a data stream is
demultiplexed into Nt independent sub streams. Each sub stream is encoded into transmit symbols using a
modulation scheme (e.g. BPSK, QPSK, M-QAM, etc.) at symbol rate 1/T symbol/sec with synchronized symbol
timing.
The baseband Nr dimensional received signal vector
r(k) = [r1(k),r2(k),……..rNR (K)T
]
At sampling instant k may be expressed as
r(k) = H.x(k) + n(k)
Where
5. Channel Estimation In The STTC For OFDM Using MIMO With 4G System
DOI: 10.9790/2834-10125056 www.iosrjournals.org 54 | Page
X(K) = [X1(K),X2(K),…….,XNT (K)T
]
The transmit symbol vector with equally distributed transmitted power across the transmitted signal.
Here, the superscript T is transposition. H denotes the NtNr channel matrix, whose elements h m n at the mth
row
and nth column is the channel gain from the mth
transmit antenna to the nth
receive antenna and they are assumed
to be independent and identically distributed (I.I.D) circularly symmetric complex Gaussian random variables
with zero-mean and unit-variance, having uniformly distributed phase and Rayleigh or Nakagami distributed
magnitude or amplitude. A commonly used channel model in MIMO wireless communication systems is a block
fading (also known as quasi-static) channel model where the channel matrix elements, which are I.I.D complex
Gaussian (Rayleigh or Nakagami fading) random variables, are constant over a block and change independently
from block to block. The index k for the channel gain. The elements of the additive noise vector,
n(K) = [n1(K),n2(K),……..,nNT(K)]T
are assumed to be also white I.I.D complex Gaussian random variables with zero-mean and unit-variance. From
this normalization of noise power and channel loss, the averaged transmitted power which is equal to the
average SNR at each receiver antenna and is to be not greater than Nt .
B. Simulations
The main goal was improve the Signal to Noise Ratio at 10-5
Bit Error Rate (BER) for improve the
performance of the system. Therefore for each SNR information bits were simulated for each system. The
modulation technique used in system is Phase Shift Key (PSK). For simulation process the 2-PSK, 4-PSK, 8-
PSK and 16-PSK modulation are used and number of OFDM subcarriers are assumed to be 124. The following
simulation parameters are shown in table 2.
Table 2: various simulation parameters
Modulation scheme 2-PSK, 4-PSK, 8PSK, 16-PSK
Number of subcarrier for OFDM 124
Symbol length 64
Channel estimation Perfect
Signal estimation Correlated
Channel Fast channel
Decoding techniques MMSE, ZF, ML
C. Simulation Result
Fig.3. Channel estimation in the STTC for OFDM- MIMO with fourth Generation wireless system with 2-PSK
6. Channel Estimation In The STTC For OFDM Using MIMO With 4G System
DOI: 10.9790/2834-10125056 www.iosrjournals.org 55 | Page
Fig.4. Channel estimation in the STTC for OFDM-MIMO with fourth Generation wireless system with 4-PSK
Fig.5. Channel estimation in the STTC for OFDM-MIMO with fourth Generation wireless system with 8-PSK
Fig.6. Channel estimation in the STTC for OFDM-MIMO with fourth Generation wireless system with 16-PSK
IV. Conclusion
In this paper, the channel estimation based on Space-time-trellis-code (STTC). The STTC are used
three different decoding techniques for reduce the Bit Error Rate (BER) and improve the Signal to Noise Ratio
(SNR). These techniques are Minimum Mean Square Error (MMSE), Zero Forcing (ZF), and Maximum
Likelihood (ML). After observing all simulation result that the value of SNR are improve.
Algorithm BER SNR
Least Mean Square (LMS)
algorithm 10-3
30dB
Space time trellis code
(STTC) & Viterbi
Algorithm
10-5
30dB
7. Channel Estimation In The STTC For OFDM Using MIMO With 4G System
DOI: 10.9790/2834-10125056 www.iosrjournals.org 56 | Page
V. Future Work
In wireless system the most important part is channel estimation, which is increase by reduced to BER
and increase the SNR values. These both value can be more decrease and increase by the use of more different
technique and algorithms, which provide more reliable system and high accuracy for data transmission.
Technique which is used in future will be more accurate and provide the high performance of the system.
References
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by LMS algorithm”, IJCSI International Journal of Computer Science Issues, Vol. 9, Issue 3, No 3, May 2012,pp. 188-192.
[2]. Jitendra Kumar Daksh, Ravi Mohan, Sumit Sharma, “ Performance Analysis with Space-Time coding in MIMO-OFDM Systes with
Multiple Antennas”, International Journal of Advanced Computer Research, Vol. 3, No. 2, June 2013, pp 2249-7277.
[3]. A. v. Z. a. T. C. W. Schenk, "Implementation of MIMO OFDM –based Wireless Lan System," IEEE transmission on signal
processing, vol. 52, februray 2004.
[4]. Baoguo Yang, Khaled Ben Letaief, Roger S. Cheng And Zhigang Cao, “Channel Estimation For OFDM Transmission In Multipath
Fading Channels Based On Parametric Channel Modeling”, IEEE Transactions On Communications, Vol. 49, No. 3, March 2001.
[5]. V. Tarokh, H. Jafarkhami, and A.R, Calderbank, “Space-time block codes from orthogonal designs”, IEEE Transactions on
information theory, Vol. 45, No. 5, July 1999, pp 1456-1467.
[6]. Zimran Rafique and Boon-Chong Seet, “Energy Efficient MIMO-OFDM Systems”, handbook on green information and
coomunication.