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
Deterministic MIMO Channel Capacity
• CSI is Known to the Transmitter Side
• CSI is Not Available at the Transmitter Side
Channel Capacity of Random MIMO Channels
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.
Minimize MIMO OFDM interference and noise ratio using polynomial-time algorit...IJECEIAES
In the distributed transmit antenna MIMO OFDM system, each transmitting antenna has different frequency offset between each transmitting antenna and receiver due to the use of independent crystal oscillator. This paper proposes Polynomial-time algorithm for correcting the frequency offset in a received signal by maximizing the conditional average signal. The algorithm focus on reducing to interference and noise ratio of each subcarrier on the receiving antenna by frequency offset. The simulation result shows the performance of the proposed algorithm is slightly improved compared with the existing frequency offset correction algorithm, and the complexity is reduced by 50% or more.
Deterministic MIMO Channel Capacity
• CSI is Known to the Transmitter Side
• CSI is Not Available at the Transmitter Side
Channel Capacity of Random MIMO Channels
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.
Minimize MIMO OFDM interference and noise ratio using polynomial-time algorit...IJECEIAES
In the distributed transmit antenna MIMO OFDM system, each transmitting antenna has different frequency offset between each transmitting antenna and receiver due to the use of independent crystal oscillator. This paper proposes Polynomial-time algorithm for correcting the frequency offset in a received signal by maximizing the conditional average signal. The algorithm focus on reducing to interference and noise ratio of each subcarrier on the receiving antenna by frequency offset. The simulation result shows the performance of the proposed algorithm is slightly improved compared with the existing frequency offset correction algorithm, and the complexity is reduced by 50% or more.
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 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.
PAPR REDUCTION OF OFDM SIGNAL BY USING COMBINED HADAMARD AND MODIFIED MEU-LAW...IJCNCJournal
Orthogonal frequency division multiplexing (OFDM) is a technique which gives high quality of service (QOS) to the users by mitigating the fading signals as well as high data rates in multimedia services. However, the peak-to-average power ratio (PAPR) is a technical challenge that reduces the efficiency of RF power amplifiers. In this paper, we propose the combined Hadamard transform and modified meu-law companding transform method in order to lessen the effects of the peak-to-average power ratio of the
OFDM signal. Simulation results show that the proposed scheme reduces PAPR compared to other companding techniques as well as the Hadamard transform technique when used on its own.
SLM-PTS BASED PAPR REDUCTION TECHNIQUES IN OFDM SYSTEMHariniChaganti1
Signals, which were initially sent in the analog domain, are being sent more and more in the digital domain these days. For better transmission, even single–carrier waves are being replaced by multi–carriers. Multi-carrier
systems like OFDM are now – a – days being implemented commonly. In the OFDM system,
orthogonally placed subcarriers are used to carry the data from the transmitter end to the receiver end. The presence of a guard band in this system deals with the problem of ISI and noise is minimized by a larger number of sub–carriers. But the large Peak– to –Average Power Ratio of these signal have some undesirable effects on the system. The Peak-to-Average Power Ratio is the ratio between the maximum power and average power of a complex passband signal. It causes many disadvantages like band-in and band-out variation, low signal to quantization noise ratio, low efficiency of power amplifier, etc. Hence, it is necessary to reduce PAPR in OFDM for its efficient use.
In this project, the main objective is to study the basics of an OFDM System and analyze and
simulate various methods such as clipping and filtering, selected mapping, Partial transmit sequence
to reduce the PAPR in the system and compare these techniques with and without PAPR reduction to
obtain an efficient technique so that this system can be used more commonly and effectively.
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
Optical Spatial Modulation OFDM using Micro LEDsBasil Jacob
An insight into the latest technology that could become the corner stone of Li-Fi technology. It mainly compares the OSM-OFDM with Optical Spatial Multiplexing OFDM based on the reference publications.
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.
Herbal Cures Practised By Rural Populace In Varanasi Region Of Eastern U.P.(I...IOSR Journals
A survey based study to collect information regarding use of herbs as household treatment of common ailments in rural areas of Varanasi region of eastern U.P. was undertaken .In Varanasi as in other parts of India , the people especially those residing in rural and semi-urban areas still practise herbal cures for many of their ailments. In the present investigation a total of 40 medicinally important plant species belonging to 27 families were recorded which are frequently used by local populace to cure diseases such as cold,cough,fever,snake bite,boils piles etc.As plants are easily available and sometimes the only source of healthcare available to poor therefore there is a great need for preservation of such medicinal plants.
Lipid oxidation and perceived exertion level during exercise in obese: effect...IOSR Journals
Regular exercise is one of the most used solutions to avoid obesity. In this study we compared the amounts of lipid oxidation and the level of perceived exertion in three physical exercises, one continuous and two intermittent in obese. Ten obese men (age 26.01 ± 6.0 years, weight: 104.2 ± 19.4 kg, BMI: 33.5 ± 3.6 kg / m2) performed three 45 minutes exercises during which we measured energy expenditure and the level of perceived exertion. A continuous exercise whose intensity corresponds to the intensity of Fat max, an intermittent exercise which alternate four minutes at the intensity of Fat max -10% and one minute at the fat max intensity +10% (intermittent 1/4), and a second intermittent exercise which alternate two minutes at the intensity of Fat max -10% and one minute at the Fat max intensity +20% (intermittent 1/2). While the total energy expenditure during continuous exercise (321.6 Kcal) is higher than those of the intermittent 1/4 (268.1 Kcal) and the intermittent 1/2 (268.9 Kcal), the amounts of energy from oxidized fats in the three exercises are equivalent: 34,6 Kcal, 31,8 Kcal and 36,2 Kcal respectively for the three exercises. The perceived exertion measured by the Borg scale showed that intermittent exercises causes less fatigue in obese than the continuous exercise.
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 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.
PAPR REDUCTION OF OFDM SIGNAL BY USING COMBINED HADAMARD AND MODIFIED MEU-LAW...IJCNCJournal
Orthogonal frequency division multiplexing (OFDM) is a technique which gives high quality of service (QOS) to the users by mitigating the fading signals as well as high data rates in multimedia services. However, the peak-to-average power ratio (PAPR) is a technical challenge that reduces the efficiency of RF power amplifiers. In this paper, we propose the combined Hadamard transform and modified meu-law companding transform method in order to lessen the effects of the peak-to-average power ratio of the
OFDM signal. Simulation results show that the proposed scheme reduces PAPR compared to other companding techniques as well as the Hadamard transform technique when used on its own.
SLM-PTS BASED PAPR REDUCTION TECHNIQUES IN OFDM SYSTEMHariniChaganti1
Signals, which were initially sent in the analog domain, are being sent more and more in the digital domain these days. For better transmission, even single–carrier waves are being replaced by multi–carriers. Multi-carrier
systems like OFDM are now – a – days being implemented commonly. In the OFDM system,
orthogonally placed subcarriers are used to carry the data from the transmitter end to the receiver end. The presence of a guard band in this system deals with the problem of ISI and noise is minimized by a larger number of sub–carriers. But the large Peak– to –Average Power Ratio of these signal have some undesirable effects on the system. The Peak-to-Average Power Ratio is the ratio between the maximum power and average power of a complex passband signal. It causes many disadvantages like band-in and band-out variation, low signal to quantization noise ratio, low efficiency of power amplifier, etc. Hence, it is necessary to reduce PAPR in OFDM for its efficient use.
In this project, the main objective is to study the basics of an OFDM System and analyze and
simulate various methods such as clipping and filtering, selected mapping, Partial transmit sequence
to reduce the PAPR in the system and compare these techniques with and without PAPR reduction to
obtain an efficient technique so that this system can be used more commonly and effectively.
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
Optical Spatial Modulation OFDM using Micro LEDsBasil Jacob
An insight into the latest technology that could become the corner stone of Li-Fi technology. It mainly compares the OSM-OFDM with Optical Spatial Multiplexing OFDM based on the reference publications.
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.
Herbal Cures Practised By Rural Populace In Varanasi Region Of Eastern U.P.(I...IOSR Journals
A survey based study to collect information regarding use of herbs as household treatment of common ailments in rural areas of Varanasi region of eastern U.P. was undertaken .In Varanasi as in other parts of India , the people especially those residing in rural and semi-urban areas still practise herbal cures for many of their ailments. In the present investigation a total of 40 medicinally important plant species belonging to 27 families were recorded which are frequently used by local populace to cure diseases such as cold,cough,fever,snake bite,boils piles etc.As plants are easily available and sometimes the only source of healthcare available to poor therefore there is a great need for preservation of such medicinal plants.
Lipid oxidation and perceived exertion level during exercise in obese: effect...IOSR Journals
Regular exercise is one of the most used solutions to avoid obesity. In this study we compared the amounts of lipid oxidation and the level of perceived exertion in three physical exercises, one continuous and two intermittent in obese. Ten obese men (age 26.01 ± 6.0 years, weight: 104.2 ± 19.4 kg, BMI: 33.5 ± 3.6 kg / m2) performed three 45 minutes exercises during which we measured energy expenditure and the level of perceived exertion. A continuous exercise whose intensity corresponds to the intensity of Fat max, an intermittent exercise which alternate four minutes at the intensity of Fat max -10% and one minute at the fat max intensity +10% (intermittent 1/4), and a second intermittent exercise which alternate two minutes at the intensity of Fat max -10% and one minute at the Fat max intensity +20% (intermittent 1/2). While the total energy expenditure during continuous exercise (321.6 Kcal) is higher than those of the intermittent 1/4 (268.1 Kcal) and the intermittent 1/2 (268.9 Kcal), the amounts of energy from oxidized fats in the three exercises are equivalent: 34,6 Kcal, 31,8 Kcal and 36,2 Kcal respectively for the three exercises. The perceived exertion measured by the Borg scale showed that intermittent exercises causes less fatigue in obese than the continuous exercise.
Evaluation of Level of Precursors of N-Nitrosamine in Vitro in Wistar Rats Fe...IOSR Journals
This study compares the level of Nitrite in urine, protein concentration and nitrite concentration in post mitochondrial fraction of rats fed different levels of dietary protein with concurrent administration of precursors of N-nitrosamine; dimethylamine hydrochloride (DMA-HCl) and sodium nitrite (NaNO2). Thirty Male Wistar rats were divided into three groups and were kept for four weeks. Group one was given high protein diet (64%), group two was given a normal protein diet (27%) and group three was given low protein diet (3.5%). All the groups were administered with 3mg NaNO2 and 20mg DMA-HCL/kg, using the application of spectrophotometric analysis, centrifugation, as well as colorimetric methods. Following administrations of the chemicals to the test animal groups, the concentration of 24 hours urinary excretion of nitrite was 7.417μg/ml in high protein fed rats, 2.063μg/ml in normal protein fed rats and 0.569 μg/ml in low protein fed rats. There was a significant difference (p<0.05) in the nitrite concentration in the group fed high protein diet with concurrent administration of NaNO2 and DMA-HCl. The wistar rats fed with high protein diet, excreted 5.8 to 7 times more nitrite in urine than the severely protein deprived animals. The protein and nitrite concentration of the post mitochondrial fraction of liver was highest in rats that were fed high protein diet. This study has revealed that nutrition status affects metabolism of foreign compounds including nitrites and dimethylamine hydrochloride.
An Inquiry on the Effect of Knowledge Management and Strategic Leadership on ...IOSR Journals
Organizational dynamic capability and entrepreneurship strategy are two aspects that have contribution in affecting organizational performances particularly by means of knowledge management and strategic leadership. There is a need to identify this presumption, thus current research in this paper were employed in the General Public Hospitals in Makassar in the Provinces of South Sulawesi (Indonesia). Previous research has uncovered important factors of organizational performance such as knowledge management, strategic leadership, dynamic capability, entrepreneurship strategy. Nonetheless they require further conceptual depth and empirical assessment as it remains unclear how these factors holistically affects critical performances in organizational performances. In this paper, we developed the structural model including the introduction of knowledge management and strategic leadership and the more established relationship between dynamic capability and strategic entrepreneurship with organizational performances as a means to understand their interrelatedness and feasibility on improving the body of knowledge in current literature
Synthesis and Characterization O-, M- and Para-Toluyl Thiourea Substituted Pa...IOSR Journals
Abstract: Six new derivatives of carbonyl thiourea comprises of o-,m- and p-toluyl at one end of Nitrogen atom and p-methylpyridine or ethyl pyridine at another one end of Nitrogen atom has been synthesized. The compounds are, 2-methyl-N-[(4-methylpyridine-2-yl) carbamothiol] benzamide (I), 3-methyl-N-[(4-methylpyridine-2-yl) carbamothiol] benzamide (II) and 4-N-[(4-methylpyridine-2-yl) carbamothiol] benzamide (III) for Toluyl-MP while 2-methyl-N-[(2-pyridine-2-yl-ethyl) carbamothiol] benzamide (IV), 3- methyl-N-[(2-pyridine-2-yl-ethyl) carbamothiol] benzamide (V) and 4- methyl-N-[(2-pyridine-2-yl-ethyl) carbamothiol] benzamide (VI) for isomer Toluidal-AEP have been successfully synthesized and characterized by elemental analysis, Infrared Spectroscopy analysis (FT-IR), Nuclear Magnetic Resonance Spectroscopy (NMR) and Ultraviolet-visible (UV-vis). All products shown stretching modes of ν(N-H), ν(C=O), ν(C-N), and ν(C=S) around 3276 cm-1, 1671 cm-1, 1315cm-1 and 1148 cm-1 respectively. All products shown two maximum absorption around 262 nm and 290 nm respectively for carbonyl C=O and thione C=S chromophore. Those both values contributed by n -п* transition. 1H nuclear magnetic resonance spectrum showed presence of aromatic, methyl, methine and amide protons except for product III. All products showed presence of carbon thione in 13C nuclear magnetic resonance except for product III. Ionophor interpretation with acetate anion shows color changes by naked eye for compound (I) and (III).
Techniques for Face Detection & Recognition Systema Comprehensive ReviewIOSR Journals
Abstract: Face detection and Facial recognition technology has emerged as a striking solution to address
many contemporary prerequisites for identification and the verification of identity prerogatives. It brings
together the potential of supplementary biometric systems, which attempt to link identity to individually
distinctive features of the body, and the more acquainted functionality of visual surveillance systems. In current
decades face recognition has experienced significant consideration from both research communities and the
marketplace, conversely still remained very electrifying in real applications. The assignment of face detection
and recognition has been dynamically researched in current eternities. This paper offers a conversant
evaluation of foremost human face recognition research. We first present a summary of face detection, face
recognition and its solicitations. Then, a literature review of the predominantly used face recognition techniques
is accessible.
Clarification and restrictions of the performance of these face recognition algorithms are specified.
Here we present a vital assessment of the current researches concomitant with the face recognition process. In
this paper, we present a broad range review of major researches on face recognition process based on various
circumstances. In addition, we present a summarizing description of Face detection and recognition process
and development along with the techniques connected with the various influences that affects the face
recognition process.
Keywords: Face Detection, Face Recognition System, Biometric System, Review Research.
Speciation And Physicochemical Studies of Some Biospecific CompoundsIOSR Journals
Abstract: A green, safer , efficient , eco-friendly approach for the synthesis of novel compounds which reveal biological and spermicidal activity. The nature of the pharmacophore decides the physiological reactivity of the compound.
Investigating and Classifying the Applications of Flexible Manufacturing Syst...IOSR Journals
The recent manufacturing environment is characterized as having diverse products due to mass
customization, short production lead-time, and unstable customer demand. Today, the need for flexibility, quick
responsiveness, and robustness to system uncertainties in production scheduling decisions has increased
significantly. In traditional job shops, tooling is usually assumed as a fixed resource. However, when tooling
resource is shared among different machines, a greater product variety, routing flexibility with a smaller tool
inventory can be realized. Such a strategy is usually enabled by an automatic tool changing mechanism and tool
delivery system to reduce the time for tooling setup, hence allows parts to be processed in small batches. In this
research, a dynamic scheduling problem under flexible tooling resource constraints is studied. An integrated
approach is proposed to allow two levels of hierarchical, dynamic decision making for job scheduling and tool
flow control in Automated Manufacturing Systems. It decomposes the overall problem into a series of static subproblems
for each scheduling window, handles random disruptions by updating job ready time, completion
time, and machine status on a rolling horizon basis, and considers the machine availability explicitly in
generating schedules. Two types of manufacturing system models are used in simulation studies to test the
effectiveness of the proposed dynamic scheduling approach. First, hypothetical models are generated using
some generic shop flow structures (e.g. flexible flow shops, job shops, and single-stage systems) and
configurations(Insup,Um.,et al.,2009).They are tested to provide the empirical evidence about how well the
proposed approach performs for the general automated manufacturing systems where parts have alternative
routings. Second, a model based on a real industrial flexible manufacturing system was used to test the
effectiveness of the proposed approach when machine types, part routing, tooling, and other production
parameters closely mimic to the real flexible manufacturing operations.
Biomimetic Materials in Our World: A Review.IOSR Journals
The study of biomineralization offers valuable and incredible insights into the scope and nature of material chemistry at the inorganic and organic surfaces. Biological systems (architecture) are replete with examples of organic supramolecular assemblies (double and triplet helices, multisubunit proteins, membrane-bound reaction centres, vesicle, tubules e. t. c.), some of which (collagen, cellulose and chitin) extend to microscopic dimensions in the form of hierarchical structure, There are ample opportunities of lessons from the biological (on growth and functional adaptation), and physical (properties and compositions) world. This review explores the field of biomimetic material chemistry as it relates to fibres with respect to their historical perspective, the use of the products of biomimetic material, the progressive efforts and a general overview. Conclusively, biomimetic materials research is indeed a rapidly growing and enormously promising field that needs to be explored.
Effect of Fermentation on the Nutritional and Antinutritional Composition of ...IOSR Journals
The dehulled seeds of three varieties of Lagenaria siceraria were subjected to control fermentation process. The fermented and unfermented seeds were analysed for their nutritional and anti-nutritional compositions using AOAC 1998. The fermented seeds were found to contain high amount of crude protein (48.12%) and crude fibre (4.11%) compared to 27.42% and 0.67% for unfermented seeds respectively. Similarly, crude lipid content of the seeds decreased by about 75%. The process also results in decrease in phytate, oxalate, tannins and cyanide content with consequent increase in nitrate and Vitamin C. Hence fermenting the seeds is an important way of exposing its protein content and reducing the antinutritional content. The seeds were found to have good potentials for preparation of condiments which are commonly used in the preparation of soup.
A New Lupan type Triterpene Butilinol from Viburnum grandiflorumIOSR Journals
The isolation and structural studies on the chemical constituents of Viburnum grandiflorum are described. The medicinal properties of the plant are also described. The mentholic extract was subjected to the preparative thin layer chromatography (PTLC) test experiments to investigate the isolation pattern. Based on the PTLC test experiments, the extract was subjected to the silica gel column chromatography. The column was eluted with increasing polarities of organic solvents. This afforded several fractions. The fractions were re-chromatographed on silica gel column to afford a new lupan type triterpene butilinol (1) with several known compounds i. e. oleanolic acid (2), ursolic acid (3), β-sitosterol (4), butilinic acid (5), butilin (6), α-amyrin (7) and germanicol (8). The compound (6) was not reported previously from the genus Viburnum. This therefore represents its first report from Viburnum grandiflorum. The compounds (2) and (4) have been previously reported from Viburnum pronifolium while the compounds (3) and (8) from Viburnum opulus and Viburnum erubescens, respectively. This represents the first report of the presence of these compounds in Viburnum grandiflorum. The structures of the above compounds were identified on the basis of spectral data (UV, IR, Mass, 1NMR, 13C-NMR) and literature evidences. The hexane and ethyl acetate soluble portions of the methanolic extract showed significant antifungal activity, while the chloroform soluble portion and the remaining methanol extract showed moderate activity.
Complexation, Spectroscopic, Thermal, Magnetic And Conductimetric Studies On ...IOSR Journals
7-hydroxy-4-methyl-8-(phenylazo) coumarin (L1)and 7-hydroxy-4-methyl-8-(o-carboxyphenylazo) coumarin (L2) have been prepared and characterized by elemental analysis, infrared (IR), proton nuclear magnetic resonance (1H NMR) and Mass spectra. The important infrared (IR) spectral bands corresponding to the active groups in the two ligands and the solid complexes under investigation were studied. Also the important fragments in the ligands and the complexes were done using mass spectra and the main peaks were corresponding to the molecular weights of the ligands and complexes. The solid complexes have been synthesized and studied by elemental and thermal analyses (TG and DTA) as well as by IR, 1H NMR, magnetic measurements, electronic transition, molar conductance, mass spectra and electron spin resonance (ESR) spectra. The proposed steriochemical structures for the investigated metal complexes suggest octahedral geometry with respect to Mn, Co, Ni, Cu and Zn metal ions and all of the formed complexes contain coordinated and hydrated water molecules. All of the prepared solid complexes behave as non-electrolytes in chloroform.
Eleven (11) composites, are unfilled and five each filled with varying contents of charcoal and wood dust separating bonded with melted spent thermoplastics have been compounded and their compressive strength, density, specific gravity, percentage shrinkage and percentage absorption determined.Composite density ranges (0.83-0.94)g/cm3, compressive strength from (6.92-16.14)n/mm2, percentage shrinkage from (1.01-4.76)% and percentage water absorption from (1.75-15.75)%. These results suggest that these composites (i) meet the allowable American standard for test and measurement (ASTM) for ceramic floor and wall tiles in compressor strength (0.2-22.1)minimum, % shrinkage (maximum 15%) and water absorption (maximum 16%) (ii)are appreciably strong compare to the gmelina-wood/cement composite and (iii) if comprehensively examined, composites may be useful in the building industry for the manufacture of tiles and boards and even compete favorably with the wood cement composites.
Area Time Efficient Scaling Free Rotation Mode Cordic Using Circular TrajectoryIOSR Journals
Abstract: This paper presents an area-time efficient Coordinate Rotation Digital Computer (CORDIC) algorithm that completely eliminates the scale-factor. Besides we have proposed an algorithm to reduce the number of CORDIC iterations by increasing the number of stages. The efficient scale factor compensation techniques are proposed which adversely effect the latency/throughput of computation. The proposed CORDIC algorithm provides the flexibility to manipulate the number of iterations depending on the accuracy, area and latency requirements. The CORDIC is an iterative arithmetic algorithm for computing generalized vector rotations without performing multiplications. Index Terms: coordinate rotation digital computer (CORDIC), cosine/sine, field-programmable gate array (FPGA), most-significant-1, recursive architecture, Discrete Fourier Transform (DFT), Discrete Cosine transform (DCT), Iterative CORDIC, Pipelined CORDIC.
Survey on Single image Super Resolution TechniquesIOSR Journals
Super-resolution is the process of recovering a high-resolution image from multiple lowresolutionimages
of the same scene. The key objective of super-resolution (SR) imaging is to reconstruct a
higher-resolution image based on a set of images, acquired from the same scene and denoted as ‘lowresolution’
images, to overcome the limitation and/or ill-posed conditions of the image acquisition process for
facilitating better content visualization and scene recognition. In this paper, we provide a comprehensive review
of existing super-resolution techniques and highlight the future research challenges. This includes the
formulation of an observation model and coverage of the dominant algorithm – Iterative back projection.We
critique these methods and identify areas which promise performance improvements. In this paper, future
directions for super-resolution algorithms are discussed. Finally results of available methods are given.
Performance Comparison of Uncoded OFDM & Uncoded Adaptive OFDM System Over AW...IOSR Journals
Adaptive OFDM (AOFDM) is the important approach to fourth generation of mobile
communication. Adaptive modulating scheme is employed according to channel fading condition for improving
the performance of OFDM. This gives improved data rate, spectral efficiency & throughput. OFDM is flexible
to adapt modulation schemes on subcarriers according instantaneous signal-to-noise ratio (SNR). In this paper,
we compare Bit Error Rate (BER),Mean Square Error(MSE), Spectral Efficiency, Throughput performance of
uncoded OFDM & uncoded adaptive OFDM with BPSK,QPSK & QAM modulation over AWGN channel.
Promoting Industrial Training through Macro Economic Approach (The Importance...IOSR Journals
Libya is blessed with many factories but regrettably these factories failed due to lack of skills and experiences. Often Libya due to their uncoordinated, unregulated and fragmented nature delivery systems and policies are the challenges faced by the state. It is difficult to design a training system that ensures demand driven skills provision and involves stakeholders from key relevant sectors and this requires a study to identify problems and prosper solution for sustainable future development. Hence, the report adopted the approach which combines the results of studies being reviewed. I utilized analytical techniques to estimate the strength of a given set of findings across many different studies and sometime compare and draw conclusion. This has allowed the creation of a context from which this report emerged The report data solely rely on the empirical source which classified in primary and secondary source.The reported found out that the number of trainee dropped from 2000 to 2005 by an average of 26 students, in comparison to 1999. However, in 2006 and 2007, the number of trainee showed increased (by an average of 25 students). Due to this increased in trainee, oil production also increased at the beginning of the new millennium. This Indicate that training increase productivity and productivity growth can raise incomes and reduce poverty in a virtuous circle. Productivity growth reduces production costs and increases returns on investments, some of which turn into income for business owners and investors and some of which are turned into higher wages and national growth.
Comparison of Sports Anxiety in three different Stages between Team and Indiv...IOSR Journals
Abstract: To find out the degrees of anxieties experienced by both the individual and team sports persons of
Manipur at three different stages of sports such as prior to the actual play, during the progress of the play and
after the conclusion of the play over the period of five years beginning from 1995 to 2000 A.D. The researchers
mainly adopted the simple and easy methods of questionnaires, personal visits to national and state level
sportspersons of Manipur at their residence, hostels and other sports complexes. The subjects of the study were
173 teams’ sportspersons and 173 individual sportspersons of Manipur over the span of five years starting form
1995 to 2000. The team sports persons were form the field of hockey, handball, kabaddi, sepak-takraw and
volleyball, on the other hand the individual team sportspersons were from the disciplines of Archery, cycling,
table-tennis, wrestling, fencing, athletics, weight lifting, judo, boxing and tae-kwondo respectively. Data were
collected by using “Anxiety test questionnaire” tools.
Comparing the sport anxiety before, during and after the play, both the individual and team sportsperson were
found significantly higher in anxiety level during the play than the before and after the play situation. The sports
anxiety between the individuals and teams sports found no significant difference before the play and after the
play. But there is significant different found during the play i.e., individuals sportspersons were found
significantly higher in sports anxiety then the team sportspersons.
Key wards: Sports anxiety, individual and team sportspersons, STAI Form Y-I, comparative t test.
Transformational Leadership at Muhammadiyah Primary Schoolson Emotional Intel...IOSR Journals
The aim of this research are examines the influence of Authentic Transformational Leadership behavior on Emotional Intelligence with intervening variables: Value CongruenceandTrust of the teachers and employees at MuhammadiyahPrimary Schools forward Bass &Avolio Theory. Quantitative approach used on this research. The samples in this study were 55 employees and 110 teachers. The finding indicate that Authentic Transformational Leadership behavior have significant direct effect on Emotional Intelligence. The significant influence was also shown by intervening variables: Value Congruence (positive), andTrust (negative). For further studies there is recommended to conduct similar studies in high school Muhammadiyah, considering there are differences in the curriculum and the emotional maturity of students and teachers
Transmit antenna subset selection in mimo ofdm system using adaptive mutuatio...ijmnct
Multiple input multiple output techniques are considered attractive for future wireless communication
systems, due to the continuing demand for high data rates, spectral efficiency, suppress interference ability
and robustness of transmission. MIMO-OFDM is very helpful to transmit high data rate in wireless
transmission and provides good maximum system capacity by getting the advantages of both MIMO and
OFDM. The main problem in this system is that increase in number of transmit and receive antennas lead
to hardware complexity. To tackle this issue, an effective optimal transmit antenna subset selection method
is proposed in paper with the aid of Adaptive Mutation Genetic Algorithm (AGA). Here, the selection of
transmit antenna subsets are done by the adaptive mutation of Genetic Algorithm in MIMO-OFDM system.
For all the mutation points, the fitness function are evaluated and from that value, best fitness based
mutation points are chosen. After the selection of best mutation points, the mutation process is carried out,
accordingly. The implementation of proposed work is done in the working platform MATLAB and the
performance are evaluated with various selection of transmit antenna subsets. Moreover, the comparison
results between the existing GA with mutation and the proposed GA with adaptive mutation are discussed.
Hence, using the proposed work, the selection of transmit antenna with the maximum capacity is made and
which leads to the reduced hardware complexity and undisturbed data rate in the MIMO-OFDM system
Designing and Performance Evaluation of 64 QAM OFDM SystemIOSR Journals
Abstract (11Bold) : — In this report, the performance analysis of 64 QAM-OFDM wireless communication
systems affected by AWGN in terms of Symbol Error Rate and Throughput is addressed. 64 QAM (64 ary
Quadrature Amplitude Modulation) is the one of the effective digital modulation technique as it is more power
efficient for larger values of M(64). The MATLAB script based model of the 64 QAM-OFDM system with
normal AWGN channel and Rayleigh fading channel has been made for study error performance and
throughput under different channel conditions. This simulated model maximizes the system throughput in the
presence of narrowband interference, while guaranteeing a SER below a predefined threshold. The SER
calculation is accomplished by means of modelling the decision variable at the receiver as a particular case of
quadratic form D in complex Gaussian random variables. Lastly comparative study of SER performance of 64
QAM-OFDM simulated & 64 QAM-OFDM theoretical under AWGN channel has been given. Also
performance of the system is given in terms of throughput (received bits/ofm symbol) is given in a plot for
different SNR. Keywords (11Bold) –64 QAM, BPSK, OFDM, PDF, SNR.
Designing and Performance Evaluation of 64 QAM OFDM SystemIOSR Journals
In this report, the performance analysis of 64 QAM-OFDM wireless communication
systems affected by AWGN in terms of Symbol Error Rate and Throughput is addressed. 64 QAM (64 ary
Quadrature Amplitude Modulation) is the one of the effective digital modulation technique as it is more power
efficient for larger values of M(64). The MATLAB script based model of the 64 QAM-OFDM system with
normal AWGN channel and Rayleigh fading channel has been made for study error performance and
throughput under different channel conditions. This simulated model maximizes the system throughput in the
presence of narrowband interference, while guaranteeing a SER below a predefined threshold. The SER
calculation is accomplished by means of modelling the decision variable at the receiver as a particular case of
quadratic form D in complex Gaussian random variables. Lastly comparative study of SER performance of 64
QAM-OFDM simulated & 64 QAM-OFDM theoretical under AWGN channel has been given. Also
performance of the system is given in terms of throughput (received bits/ofm symbol) is given in a plot for
different SNR
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.
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.
Performance Analysis of PAPR Reduction in MIMO-OFDMIJARBEST JOURNAL
Authors: Jayaraman.G1, VeeraKumar K2, Selvakani.S3
Abstract— In communication system, it is aimed to provide highest possible
transmission rate at the lowest possible power and with the least possible noise. MIMOOFDM
has been chosen for high data rate communications and widely deployed in many
wireless communication standards. The major drawback in OFDM signal transmission is
high PAPR. In previous, use clipping technique to tackle this problem. In this paper, use
EM-GAMP algorithm to reduce PAPR in considerable amount.
Performance analysis of adaptive filter channel estimated MIMO OFDM communica...IJECEIAES
Advanced Communication Systems are wideband systems to support multiple applications such as audio, video and data so and so forth. These systems require high spectral efficiency and data rates. In addition, they should provide multipath fading and inter-symbol interference (ISI) free transmission. Multiple input multiple output orthogonal frequency division multiplexing (MIMO OFDM) meets these requirements Hence, MIMOOFDM is the most preferable technique for long term evaluation advanced (LTEA). The primary objective of this paper is to control bit error rate (BER) by proper channel coding, pilot carriers, adaptive filter channel estimation schemes and space time coding (STC). A combination of any of these schemes results in better BER performance over individual schemes. System performance is analyzed for various digital modulation schemes. In this paper, adaptive filter channel estimated MIMO OFDM system is proposed by integrating channel coding, adaptive filter channel estimation, digital modulation and space time coding. From the simulation results, channel estimated 2×2 MIMO OFDM system shows superior performance over individual schemes.
At this present scenario, the demand of the system capacity is very high in wireless network. MIMO
technology is used from the last decade to provide this requirement for wireless network antenna
technology. MIMO channels are mostly used for advanced antenna array technology. But it is most
important to control the error rate with enhanced system capacity in MIMO for present-day progressive
wireless communication. This paper explores the frame error rate with respect to different path gain of
MIMO channel. This work has been done in different fading scenario and produces a comparative analysis
of MIMO on the basis of those fading models in various conditions. Here, it is to be considered that
modulation technique as QPSK to observe these comparative evaluations for different Doppler frequencies.
From the comparative analysis, minimum amount of frame error rate is viewed for Rician distribution at
LOS path Doppler shift of 0 Hz. At last, this work is concluded with a comparative bit error rate study on
the basis of singular parameters at different SNR levels to produce the system performance for uncoded
QPSK modulation.
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
Reduction of PAPR and Efficient detection ordering scheme for MIMO Transmissi...IJERA Editor
The technical challenges for communication engineers is the development of best performance wireless
networks with negligible amount of distortions. We have to consider multipath propagation attenuation and
radio spectrum inefficiency. Now a days, In MIMO (Multi Input Multi Output) systems there is a huge demand
for the networks with the high transmission rates and better quality of service which are having low PAPR ratio.
Instead of OFDMA, filter banks are used in massive MIMO to reduce the complexity. But they are error prone
to noise. This base paper discusses about PAPR reduction in MIMO systems using different precoding based
OFDM systems. Mainly, minimization of multi-antenna systems by controlling the transmission power and
reduction of PAPR using ZC (Zadoff-Chu) matrix transform.
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.
Investigation and Analysis of SNR Estimation in OFDM systemIOSR Journals
Estimation of signal to noise ratio (SNR) of received signal and to transmit the signal effectively for
the modern communication system. The performance of existing non-data-aided (NDA) SNR estimation methods
are substantially degraded for high level modulation scheme such as M-ary amplitude and phase shift keying
(APSK) or quadrature amplitude modulation (QAM).In this paper SNR estimation proposed method which uses
zero point auto-correlation of received signal per block and auto/cross- correlation of decision feedback signal
in orthogonal frequency division multiplexing (OFDM) system. Proposed method can be studied into two types;
Type 1 can estimate SNR by zero point auto-correlation of decision feedback signal based on the second
moment property. Type 2 uses both zero point auto-correlation and cross-correlation based on the fourth
moment property. In block-by-block reception of OFDM system, these two SNR estimation methods can be
possible for the practical implementation due to correlation based the estimation method and they show more
stable estimation performance than the earlier SNR estimation methods.
Study and Analysis Capacity of MIMO Systems for AWGN Channel Model ScenariosIJERA Editor
Future wireless communication systems can utilize the spatial properties of the wireless channel to enhance the spectral efficiency and therefore increases its channel capacity. This can be designed by deploying multiple antennas at both the transmitter side and receiver side. The basic measure of performance is the capacity of a channel; the maximum rate of communication for which arbitrarily small error probability can be achieved. The AWGN (additive white Gaussian noise) channel introduces the notion of capacity through a heuristic argument. The AWGN channel is then used as a basic building block to check the capacity of wireless fading channels in contrast to the AWGN channel. There is no single definition of capacity for fading channels that is applicable in all situations. Several notions of capacity are developed, and together they form a systematic study of performance limits of fading channels. The various capacity measures allow us to observe clearly the various types of resources available in fading channels: degrees of freedom, power and diversity. The MIMO systems capacity can be enhanced linearly with large the number of antennas. This paper elaborates the study of MIMO system capacity using the AWGN Channel Model, Channel Capacity, Channel Fast Fading, Spatial Autocorrelation and Power delay profile for various channel environments.
Computationally Efficient Multi-Antenna Techniques for Multi-User Two-Way Wire...IJECEIAES
In this work, we are interested in implementing, developing and evaluating multi-antenna techniques used for multi-user two-way wireless relay networks that provide a good tradeoff between the computational complexity and performance in terms of symbol error rate and achievable data rate. In particular, a variety of newly multi-antenna techniques is proposed and studied. Some techniques based on orthogonal projection enjoy low computational complexity. However, the performance penalty associated with them is high. Other techniques based on maximum likelihood strategy enjoy high performance, however, they suffer from very high computational complexity. The Other techniques based on randomization strategy provide a good trade-off between the computational complexity and performance where they enjoy low computational complexity with almost the same performance as compared to the techniques based on maximum likelihood strategy.
Comparative performance analysis of different modulation techniques for papr ...IJCNCJournal
One of the most important multi-carrier tran
smission techniques used in the latest wireless com
munication
arena is known as Orthogonal Frequency Division Mul
tiplexing (OFDM). It has several characteristics
such as providing greater immunity to multipath fad
ing & impulse noise, eliminating Inter Symbol
Interference (ISI) & Inter Carrier Interference (IC
I) using a guard interval known as Cyclic Prefix (C
P). A
regular difficulty of OFDM signal is high peak to a
verage power ratio (PAPR) which is defined as the r
atio
of the peak power to the average power of OFDM Sign
al. An improved design of amplitude clipping &
filtering technique of us previously reduced signif
icant amount of PAPR with slightly increase bit err
or rate
(BER) compare to an existing method in case of Quad
rature Phase Shift Keying (QPSK) & Quadrature
Amplitude Modulation (QAM). This paper investigates
a comparative performance analysis of the differen
t
higher order modulation techniques on that design.
Similar to Capacity Enhancement of MIMO-OFDM System in Rayleigh Fading Channel (20)
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
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Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
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• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
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• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
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Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
Capacity Enhancement of MIMO-OFDM System in Rayleigh Fading Channel
1. IOSR Journal of Electronics and Communication Engineering (IOSR-JECE)
e-ISSN: 2278-2834,p- ISSN: 2278-8735.Volume 6, Issue 1 (May. - Jun. 2013), PP 49-58
www.iosrjournals.org
www.iosrjournals.org 49 | Page
Capacity Enhancement of MIMO-OFDM System in
Rayleigh Fading Channel
Atul Gautam1
, Manisha Sharma2
1
Department of Electronics & Communication, M.Tech Scholar, Lovely professional university, Punjab, India
2
Department of Electronics & Communication, Faculty of Electronics & Communication Engineering, Punjab,
India
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
I. INTRODUCTION
NOW A day’s integration of Orthogonal Frequency di vi si on Multiplexing (OFDM) technique
with Multiple Input Multiple Output (MIMO) systems has been an area of interesting and challenging
research in the field of broadband wireless communication. Multiple input multiple output (MIMO)
system using multiple transmit and receive antennas are widely recognized as the vital
breakthrough that will allow future wireless systems to achieve higher data rates with lim it ed
bandwidth and power resources, provided the propagation medium is rich scattering or Rayleigh
fading[1].On the other hand, traditionally, multiple antennas have been used to increase diversity to combat
channel fading. Hence, A MIMO system can provide two types of gains: spatial multiplexing or capacity gain
and diversity gain. If we need to use the advantage of MIMO diversity to overcome the fading then we need to
send the same signals through the different MIMO antennae. If we want to use MIMO concept for increasing
capacity then we need to send different set of data at the same time through the different MIMO antennae
without the automatic-repeat request of the transmission [2]. OFDM has many advantages, which make it an
attractive scheme for high-speed transmission links. However, one major difficulty is OFDM’s large Peak to
Average Power Ratio (PAPR). Those are created by the coherent summation of the OFDM subcarriers. When
N signals are added with the same phase, they produce a peak power that is N times the average power. These
large peaks cause saturation in the power amplifiers, leading to inter modulation products among the subcarrier
and disturbing out of band energy. Hence, it becomes worth while reducing PAPR. Towards this end there are
several proposals such as clipping, coding and peak windowing. Respectively, reduction of PAPR comes at a
price of performance degradation, mainly in terms of rate and BER. This paper proposes to use the ASTC
codes as powerful coding techniques for IEEE 802.11x OFDM standard combined with PAPR scheme [7].
ASTC codes can for out a good solution first to overcome the disadvantage of OFDM modulations and second
to keep a robustness regarding the BER performances. ASTC encoder is shaped from two well known algebraic
space time codes. The first one is called the Golden code (GC), which was proposed in 2004. It is a 2×2STBC
obtained using a division algebra, which is full rate, full diversity, and has a nonzero lower bound on its coding
gain, which does not depend on the constellation size. The second code is the TAST code (TC) a2×2space time
algebraic code obtained using the integer algebra, with rate R=nt =2 Symbol/uc, and diversity D= nt × nr =4,
where uc denotes the used code word [6].Adaptive modulation is a promising technique to increase the spectral
efficiency of a wireless communication system. In this paper we investigate the effectiveness of adaptive
modulation in maximizing the spectral efficiency of a MIMO multiuser downlink channel [11].Under an
average transmit power and instantaneous bit error rate (BER) constraint, the transmit parameters including the
sub channel transmit power and/or spectral efficiency are optimally adapted in the spatial and/or temporal
domain to maximize the average spectral efficiency (ASE). Two categories, the continuous rate and discrete
rate, of adaptive systems were considered. In the continuous rate category, we first consider the ASE
optimization problem with both power and spectral efficiency to be jointly adapted, which is referred to as a
variable rate variable power (VRVP) system. The optimal power and rate adaptation policy, as well as the ASE
expression, are derived. Following that, two special cases are studied, the variable rate (VR) system and the
2. Capacity Enhancement of MIMO-OFDM System in Rayleigh Fading Channel
www.iosrjournals.org 50 | Page
variable power (VP) system. The VR system fixes the power as constant while the VP system fixes the rate.
The closed form asymptotic expressions for the ASEs of these three adaptive systems are derived. The
asymptotic ASEs for VRVP and VR systems are the same and both achieve a full multiplexing gain. Compared
with the VRVP and VR systems, the asymptotic ASE for a VP system with different numbers of transmit and
receive antennas shows a constant signal-to-noise ratio (SNR) penalty, while a VP system equipped with the
same number of transmit and receive antennas is unable to achieve the full multiplexing gain. In the discrete
rate category, the power and rate adaptation policy and the ASE are also derived for VRVP, VR, and VP
systems. It is shown that the ASE results for the continuous rate systems act as tight upper bounds for their
discrete rate counterparts. In particular, for the discrete rate VR system, we obtained a closed form expression
for the ASE and show that there is a 2–3 dB SNR penalty compared to the continuous rate counterpart.
However, the advantages include a much simpler adaptation rule, a better BER performance, and a preserved
full multiplexing gain [6].We will refer to this class of schemes as adaptive QAM (A-QAM) with the following
nomenclature. We say an A-QAM scheme is XY-Z-L for X and Y representing the type of variation for rate
(equivalently, constellation size) and power, respectively .Three options are possible for this variation: ’C’
(Continuous), ’D’ (Discrete) and ’K’ (Constant). The Z corresponds to the type of BER constraint, which can
be ’I’ (Instantaneous) or A’ (Average). Finally, for discrete-power schemes, L is the allowed number of power
levels per constellation [11].The paper is organized as follows. Section II, system model is described. Section
III, ASTC encoder is described. Section IV, frequency-selective correlated rayleigh fading channel .Section V,
Adaptive modulation is described. In section VI, we present simulation result for different scenarios. Finally, a
conclusion is given in section VII.
II. System Model
A model of MIMO-OFDM system with NTx transmit antennas and NRx receive antennas is depicted in
the Figure 1. Let, xi, yi and ri be the transmitted signal, received signal and the Additive White Gaussian Noise
(AWGN) for the Ith
. The sub-carrier respectively and the system uses frequency selective channel. Then the
received signal can be given as,
Yi=HiSi+ri ; 0 ≤ i ≤ N S (1)
In Eq. (1), Ns represent the number of sub -carriers Hi is the channel response matrix of Ith
the sub-carrier that is
of size NTx*NRx. The Hi is a Gaussian random matrix whose realization is known at the receiver and it is given
as
1
0
exp( j*2 *i*1/ N )
L
i l S
l
H h
(2)
In Eq. (2) hl is assumed to be an uncorrelated channel matrix where each element of the matrix follows the
independently and identically distributed (IID) complex Gaussian distribution and L represents the tap of the
chosen channel (i.e. L-tap frequency selective channel) .It is assumed that a perfect channel state information
(CSI) is available at the receiver but not at the transmitter. The total available power is also assumed to be
allocated uniformly across all space-frequency sub-channels.
3. Capacity Enhancement of MIMO-OFDM System in Rayleigh Fading Channel
www.iosrjournals.org 51 | Page
In MIMO-OFDM system Ergodic capacity is define as this is the time average capacity of a channel. It is
found by taking the mean of the capacity values obtained from a number of independent channel realizations.
Ergodic capacity is define by equation
Where
1
0
1
log( .Q )
S
Rx
N
N
iS
Tx
H
i i
c E I
N
n
Q H H
(3)
In above equation E (.) denotes the Ergodic capacity and INRx is identity matrix of NRx*NRx. Ρ is SNR per sub
carrier NTx is number of transmit antenna .figure 1 shows the block diagram of MIMO-OFDM system. We use
ASTC Encoder and Adaptive QAM (Quaderature Amplitude Modulation) for transmission. CP (Control
Programming) is an operating system originally created for 8 bit processor. FFT is an efficient algorithm to
compute the discrete Forier transform and its inverse.RF switch generally called Radio Frequency switch. PIN
Diode is generally used to make it operate at very high frequency. In this switch input signal is fed at one end
then this signal is split in no of output signal by demux. [1, 3]
III. ASTC CODES IN A FREQUENCY-SELECTIVE CHANNEL CONTEXT
We consider a coherent system over a frequency-selective correlated Rayleigh fading MIMO channel.
The overall schematic diagram of ASTC-MIMO-OFDM transceiver is depicted in Fig.1.The transmitted binary
source sequence bi of length L is modulated using the adaptive QAM-4 modulator. Each information sequence
at time ni.
1, (2n 1) (2n 1) (2n 1) (2n 1)3, 2, 1,i i i i i i
T
n n S S S S
(4)
Is encoded
by the ASTC encoder into two stream constellations represented by the code word XNc*Nt where Nt refers to
number of transmitted antennas and Nc is the number of used subcarriers. By their construction the channel was
under the Quasi-Static
Assumption, and does take into account neither the time variation nor the selectivity channel case. To spread
their power regarding the bit rate and the BER performance into the selective channel case with time variation,
we introduce the best perfect algebraic code known as Golden codes with other tow well famous algebraic space
time codes, TAST and DAST [6].
A. Golden Encoder
The code was proposed in 2004 by a STBC obtained using a division algebra, which is full rate, full
diversity, and has a nonzero lower bound on its coding gain, which does not depend on the constellation size.
The code word is written as:
( (1) (2)) ( (3) (4))1
( (3) (4)) ( (1) (2))5
i i i i
i
i i i i
n n n n
n
n n n n
X
(5)
Where
1 5
2
And
1 5
2
,
1
1
i i
i i
B. TAST Encoder
As shown in [7] [9], the TAST code is a space time algebraic code obtained using the integer algebra,
with rate R = Nt = 2 Symbole/uc (used code word), and diversity D = Nt × Nr = 4. Each space time layer is
associated with his proper algebraic space ' in order to alleviate the problem of ISI (Inter-Symbol-Interferences).
The code word is expressed as:
( (1) (2)) ( (3) (4))1
( (3) (4)) ( (1) (2))2inX
(6)
Where,
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2
exp(i )
C. DAST Encoder
The DAST code is a diagonal space time algebraic code obtained using the turned constellations of integer
algebra, with rate 1 Symbole/uc, and full diversity. The code word is described as’
. (M )
11
M
12
exp(i / 4)
Dast nt ntX H diag
(7)
M is the rotation matrix of nt =2 degree. [7, 8]
IV. Frequency-Selective Correlated Rayleigh Fading Channel
Wide-Band systems are commonly a Frequency-Selective Correlated Rayleigh Fading Channels.
However the ASTC requires a nonselective flat fading channels belonging to narrow-band systems. To alleviate
this problem let focus on lattice representation of a Frequency-Selective Correlated Rayleigh Fading Channels.
We adopt here the Clarke channel model. The received signal is the sum of q waves; we take into account the
Doppler shifts effect. To obtain a correlated Rayleigh fading channel, the autocorrelation function of {hk
j
}
process is given by:
2
0
[h h ]
(j2 f q) j (2 f qT )
i j
h k k q
h c m s
r E
r exp
(8)
Where Jo is the Bessel function with zero order, fm is the maximum Doppler shift and j is the antenna’s number.
If we guess that we have Nt (Nc+Ng) subcarrier used and the channel length is L ≤ Nt(Nc+Ng) we can represent
the channel in function of the correlated Rayleigh taps hk, where Ng refers to the number of guard subcarrier and
Nt to the number of transmitted antennas as follows
(9)
In order to use the ASTC codes properly, we need to convert the channel H into Nt × (Nc + Ng) non selective
sub-channels, The core idea is that the wide-band frequency selective MIMO channel by means of the MIMO-
OFDM processing is transferred to a number of parallel flat fading MIMO channels. In fact each code word xp
ni will be modulated within the NcNt sub-channels, without loss of generality, now we are assuming that all
subcarriers are used:
1
,1( )xp
c Nt c tz N F I N N
(10)
This transforms the frequency domain vector xNcNt, 1 into the time domain. Where x represents the Kronecker
product and F−1 represent the IFFT Matrix defined as:
(11)
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Where,
Second, to shelter the signal from the ISI (Inter-Symbol Interference) we add the cyclic prefix (CP) or what are
commonly called the guard interval, we can express this step mathematically by multiplying the signal z
0 Ng
Nt
NC
I
I
I
(12)
Where I is i.i.d matrix.
Eventually we transmit a OFDM symbol xp NcNt,1 over a selective correlated Rayleigh fading channel H, thus:
1
1 ,1. . .(F ). c t
p
c Nt N Ny H N I x
(13)
Where w is an Nt (Nc + Ng) white Gaussian noise vector. This calculation fits either with Joint Coding (JC) or
Per Antenna Coding (PAC) technique. In fact, in the (JC) method, the information bit stream is first encoded
and then converted into Nt parallel sub-streams of which each is modulated and mapped onto corresponding
antenna. Fig 1 illustrates the (JC) scheme. However in (PAC) scheme, the incoming bit stream is first
transformed to Nt parallel sub-streams and then encoding is performed per sub-stream. So, basically, the
transmitter consists of Nt OFDM transmitters among which the information bits are multiplexed. At the receiver
we consider the system is coherent over a selective correlated Rayleigh fading MIMO channel. First, the cyclic
prefix is removed. This is done by discarding the first NgNr samples of y,
2
1
(F I )rN
c
y y
N
(14)
Where £2 is defined as [0NcNgINg ] matrix. Second, the FFT is performed. Together, give results as
1 1
,1 3{(F I ) (F I )}c t t r t r
p
N N N N N Nx y
(15)
Where £3 is commonly called the circulant matrix defined as:
3 2 1H
(16)
The decision vector for each four symbols is then decoded at time (ni, ni+1) using a sub-optimum
decoder like a Zero Forcing or MMSE decoder. In the optimum decoder for the algebraic space time code was
the Shnorr-Echnerr or Sphere-Decoder, but the the ZF or the MMSE still a good candidate for such codes,
because they reduce the computational load regarding the Shnorr-Echnerr or the Sphere-Decoder without
significant performance loss:
1
4,1
p
p x
(17)
Where,
In this case we decode each 2 symbols together, thus we slice the received x4,1
Dast
into x2, 1
Dast
[7,9,10].
V. Adaptive Modulation
A. Continuous Policy
To obtain the optimum CC-A adaptation policy for MIMO multiplexing we have to tackle a calculus of
variations problem with two isoperimetric constraints. We denote by fRi(ˆλ), fSi(ˆλ) : Rm
→ R any nonnegative
rate and power candidate adaptation laws for the ith eigen channel and by Ri(ˆλ) and Si(ˆλ) the optimum laws i.e.
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those that maximize the ASE. The power laws are normalized to the target average power. ST. Mathematically,
the MIMO multiplexing design problem is expressed as follows.
{f },{f }
1
max [ ( )]
Ri Si
m
Ri
i
E f
(ASE) (18)
Subject to
1
1 1
1
1 [ ( )] 0
[ ( )(1 ( , ,......., , ,......., ))] 0
m
Si
i
m
Ri i R Rm S Sm
i
E f
E f f f f f
(19)
Where the conditional BER (normalized to the target BER, BERT) for the ith Eigen channel is defined as
1
[BER ( ,H) | ]H i
T
i E
BER
(20)
With BERi (ˆλ, H) the instantaneous BER given the predicted and the true CSI. Under the Gaussian
approximation the conditional BER can be computed from the signal-to-noise plus interference ratio (SINR),
thus, using the usual exponential expression for MQAM,
( )
( ,H)1 8
exp( )
55 2 1Ri
i
i H
f
T
SINR
E
BER
(21)
It will be shown at the end of this section that this Gaussian approximation is quite accurate due to the particular
form of the optimum adaptive policy. Introduction and after some algebra it is straightforward to obtain
2
2
( )
( ,H)
( ) 1/
i ii Si
i
ij Sj
j i
f
SINR
f
(22)
With ˆΥ ∼ ˆΞ and the average SNR defined as y=ST /σ2n.According to Appendix A, the conditional BER
expression in (6) can be accurately computed by (8) at the top of the page, where xk are the zeros of the NP the-
order Laguerre polynomial and Lxk the associated weight factors used for Gauss-Laguerre quadrature
integration. Specifically, in expression Λj = 1 for m = 2 and for m > 2
1, ,
( )
( ) ( )
m
sj
j
l l i j
sj sl
f
f f
(23)
Which must be interpreted as a limit1 when fSl = fSj . To perform expectation over the predicted channel gain
ˆλ, note that ˆλ = (1 − χ)ξ with ξ the m-dimensional vector ξ = (ξi) of unordered eigen values of 1/(1 − χ)ˆH ˆH
H ∼ HHH. Consequently, the joint probability density function (pdf) pˆλ(ˆλ) is easily obtained from the Wishart
pdf pξ(ξ) given in which can be expressed as:
2
(a) per(b)
,
1
( ) ( 1) (a ,b )
!
i ia b d
per j i
j i i i
a b j di
p A e
m
(24)
Where d.= |NT − NR|, a = (ai) and b = (bi ) represent permutation vectors of {1, . . . , m}, the function per(·) is 0
or 1, respectively, depending on whether the permutation is even or odd, and Aj(ai, bi) is defined as the (j + 1)th
coefficient of the following polynomial:
1 1
(a 1)!(b 1)!
(x)L (x)
(a 1 d)!(b 1 d)! i i
d d di i
a b
i i
x L
(25)
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Where Ldn (x) is the generalized Laguerre polynomial. It is shown in that the marginal pdf pξ (ξ) can be
represented as follows:
2(m 1) d
( ) e j
j
j d
p B
(26)
With Bj defined as the (j + 1) Th coefficient of the following polynomial
2
1
1
1 (i 1)!
(L (x))
(i 1 )!
m
d d
i
i
x
m d
(27)
In general, solving the problem stated is hard due to the coupling between Eigen channels introduced through
both the conditional BER (imperfect CSI induced interference) and the statistical dependence between the
components of ˆλ. However, under certain approximations it is possible to find an accurate closed-form
adaptation policy for MIMO multiplexing with an average BER constraint and imperfect CSI. To analyze the
behavior of optimum A-QAM MIMO multiplexing we distinguish two scenarios according to the quality of the
available CSI: good quality (χ relatively small) and bad quality (χ relatively high). [11, 12]
VI. Results And Disscussions
As Fig 2 show how ergodic capacity change with respect to SNR value and number of transmitting
antenna (nt). here we use MATLAB SIMULINK R2010 for calculating Ergodic capacity. If we compare our
result with first reference paper result than there is good improvement in Ergodic capacity when using less
number of antenna but when we using more number of transmit antenna then at very small value of SNR ,
ergodic capacity increase rapidly. Hence we are able to overcome the limitation of ergodic capacity with small
number of antenna by using ASTC encoder. We see that at nt =1 when we increase SNR the value of ergodic
capacity also increase w.r.t. SNR. It does not come study state as in the result of first reference paper. Fig
number 3 shows the individual variation of ergodic capacity with number of transmit antenna. When number of
transmit antenna nt=30 its value above the 120 which mean that we enhance the channel capacity by using
ASTC encoder and adaptive QAM
Fig. 2 SNR versus Ergodic Capacity
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Fig. 3: Ergodic capacity versus no. of transmit antenna
In Fig 4. The y axis vertices variable 10-0 actually represent the 10-0
BER and so on. If we increases the SNR
then BER is reduce .it also shows in figure when SNR increases the value of BER decrease. At the 20 SNR the
value our BER is below the 10-30
which tell us that we improve the system performance. In Figure 5, we have a
plot of the spectral efficiency of adaptive modulation versus average SNR in dB. We do not take into account
whether or not the bits are the correct ones that were sent or not. Because we have set the target BER to a value
that we believe the system must operate under, the adaptation system will try to achieve that level of
performance Note that at low SNR value, the system achieves 2 bits per symbol, and QPSK is primarily used.
However, when the SNR increases, the throughput also improve steadily, which indicates that we are beginning
to use more spectrally efficient modulation schemes. The curve begins to level out at close to 30 dB, as 64QAM
becomes the modulation scheme used most often and QPSK is rarely used. when SNR improves, the system is
more able to choose more efficient modulation schemes by using adaptive QAM. Fig. 6 shows the performance
of system by using ASTC encoder and without also tell that by using ASTC encoder we increase our system
capacity w.r.t. SNR vs BER graph analysis.
Fig. 4 System performance w.r.t. SNR vs. BER
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Fig. 5 Spectral Efficiency for Perfect Adaptive Modulation vs. Average SNR for a Rayleigh Channel
Fig. 6 System performance by using ASTC encoder w.r.t. SNR vs BER
VII. Conclusion
Ergodic channel capacity has some limitation in MIMO OFDM system therefore it is necessary to
improve this because it affects the system performance. To improve this we use ASTC encoder because it has
properties full rank full, full rate, and non vanishing determinant for increasing rate. ASTC is also able to reduce
the major difficulty of OFDM’s Large Peak to Average Power Ratio (PAPR).As a result we find that the ASTC
codes like a good compromise between a PAPR reduction scheme and BER performance. Our results also show
that adaptive modulation for MIMO OFDM system is much more sensitive to imperfect CSI that MIMO beam
forming. We can analyze MIMO-OFDM system and use various algorithms to optimize channel capacity.
Acknowldgement
I would like to thank my friends Anupam Kumar ,Amandeep , Ajay Sharma , Manoj Kumar , Kapil
Sharma , Pankaj Sharma , Abhradip Paul and all my family member and my teachers who help me.
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