MIMO-OFDM (Multi Input Multi Output- Orthogonal Frequency Division Multiplexing) system is very popular technique for mobile communication. We found that Ergodic channel capacity has some limitation in MIMO-OFDM system. So Ergodic channel capacity optimization is necessary to improve the performance of MIMO-OFDM System.
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
3GPP is going to finalize the 5G standard by 2018. 5G is scheduled to launch in around early 2020s. Even if it is not determined yet regarding the standard technology details, many researchers expect that 5G will transfer 1000 times more data, and thus, can connect billions of IoT (Internet of Things) devices at the same time. Massive MIMO (multiple input and multiple output) is one of the key candidate technologies that enable 5G to support IoT devices connection. Massive MIMO (MaMi) technology can address the high capacity requirement demanded by 5G exploiting many antennas both in the transmitter and the receiver.
In this presentation the effect of channel estimation errors on the energy efficiency of a down-link massive multiple-input multiple-output system is investigated and analyzed. The required down-link transmit power of the zero forcing (ZF) and maximum ratio transmission (MRT) precoding schemes are derived and analyzed under imperfect channel state information condition.
Achieving repeatable wireless throughput measurements under realistic conditions has been a monumental challenge for the wireless industry. The reason? Throughput of wireless links is a function of many variables, all of which must be controlled to get repeatable measurements. For benchmark testing, throughput has to be maximized in a manner that is repeatable and reproducible at multiple labs around the world. The challenges and methods of achieving maximum possible throughput and repeatable measurements are the subject of this talk.
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
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
3GPP is going to finalize the 5G standard by 2018. 5G is scheduled to launch in around early 2020s. Even if it is not determined yet regarding the standard technology details, many researchers expect that 5G will transfer 1000 times more data, and thus, can connect billions of IoT (Internet of Things) devices at the same time. Massive MIMO (multiple input and multiple output) is one of the key candidate technologies that enable 5G to support IoT devices connection. Massive MIMO (MaMi) technology can address the high capacity requirement demanded by 5G exploiting many antennas both in the transmitter and the receiver.
In this presentation the effect of channel estimation errors on the energy efficiency of a down-link massive multiple-input multiple-output system is investigated and analyzed. The required down-link transmit power of the zero forcing (ZF) and maximum ratio transmission (MRT) precoding schemes are derived and analyzed under imperfect channel state information condition.
Achieving repeatable wireless throughput measurements under realistic conditions has been a monumental challenge for the wireless industry. The reason? Throughput of wireless links is a function of many variables, all of which must be controlled to get repeatable measurements. For benchmark testing, throughput has to be maximized in a manner that is repeatable and reproducible at multiple labs around the world. The challenges and methods of achieving maximum possible throughput and repeatable measurements are the subject of this talk.
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
Multiuser MIMO-OFDM simulation framework in MatlabPavel Loskot
Simulation framework for multiuser MIMO-OFDM over multipath fading channels. Also created a C-like pre-processor in Matlab to add flexibility in configuring the simulation prior its run.
These slides deal with the basic problem of channel equalization and exposes the issue related to it and shows how it can be balanced by the usage of effective and robust algorithms.
This MATLAB section of source code covers MATLAB based projects.
Download free source code viz. FIR,IIR,scrambler,interleaver,FFT,convolution,correlation,interpolation,decimation,CRC,impairments,data type conversions and more.
RS encoder,convolutional encoder,viterbi decoder,OFDM,OFDMA,MIMO is also covered.WiMAX,WLAN,LTE source codes are also provided.
Min input and min output of the system can be conduct by the process of interest in the process of view of synchronisation and software Engineer at the system can be a good idea for this colour combination of view of the best part of the system can be conduct by the process of view till now I'm interested for the system based engineering and technology related issues in college and software engineer h today’s increasing demand for security, especially in public places such as
airports, train stations, supermarkets, schools, and crowded street, surveillance cameras are
used for monitoring daily activities and detecting abnormal events. This task focuses on the
localization of anomalies using both temporal and partial information in videos. Anomalies
can be defined as events deviating from normal behavior [1], e.g., fighting, sneaking,
or unattended bags at an airport. The purpose of using surveillance cameras is the early
detection of anomalous human behaviors. This is a critical task in many cases where human
intervention is necessary, e.g., for crime prevention or countering terrorism. However,
this process requires labor-intensive and continuous human attention, which is a tedious
process, since abnormal events only happen 0.01% of the time and 99.9% of the surveillance
time is wasted [2]. Moreover, a surveillance system produces a lot of redundant video data,
which require unnecessary storage space. For reducing human errors and storage costs, it
is necessary to build an efficient surveillance system for detecting any strange behaviors
that may lead to dangerous situations. This requires deep and comprehensive study of
human activity recognition, to understand the features representative of each action.
Anomaly detection in video has a wide range of applications, such as for traffic
accident detection, criminal activity detection, and illegal activity detection. In addition,
detecting anomalous items or abandoned objects, such as guns or knifes, is necessary in
sensitive area
Multicarrier modulation can be implemented by using Orthogonal Frequency Division Multiplexing (OFDM) to achieve utmost bandwidth exploitation and soaring alleviation attributes profile besides multipath fading. To support delay sensitive and band bandwidth demanding multimedia applications and internet services, MIMO in addition with other techniques can be used to achieve high capacity and reliability. To obtain high spatial rate by transmitting data on several antennas by using MIMO with OFDM results in reducing error recovery features and the equalization complexities arise by sending data on varying frequency levels. Three parameters frequency OFDM, Spatial (MIMO) and time (STC) can be used to achieve diversity in MIMO-OFDM. This technique is dynamic and well-known for services of wireless broadband access. MIMO if used with OFDM is highly beneficial for each scheme and provides high throughput. There are several space time block codes to exploit MIMO OFDM; one of the techniques is called Alamouti Codes. The paper investigates adaptive Alamouti Codes and their application in IEEE 802.11n.
IMPLEMENTATION OF LINEAR DETECTION TECHNIQUES TO OVERCOME CHANNEL EFFECTS IN ...IJCI JOURNAL
Spatial diversity technique enables improvement in quality and reliability of wireless link. Antenna
diversity along with understanding effects of channel on transmitted signal and methods to overcome the
channel impairment plays an important role in wireless communication where sharing of channel occurs
between users. In this paper single input single output system (SISO) is compared with multiple input
multiple output system (MIMO) in terms of bit error rate performance. Bit error rate performance is also
evaluated for MIMO with least squares (LS) and Minimum mean square error (MMSE) linear detection.
Further analysis and simulation is done to understand the effect of channel imperfections on BER.
Performance Analysis of 802.lln MIMO OFDM TransceiverIJERA Editor
The increasing demand on real time application to achieve high throughput, reliable wireless system and network capacity for fourth generation wireless local area networks is to combine MIMO wireless technology with OFDM. Orthogonal Frequency Division Multiplexing (OFDM), which offers reliable high bit rate wireless system with reasonable low complexity. OFDM does provide large data rates with sufficient robustness to radio channel impairments. OFDM is a combination of modulation and multiplexing and are able to maximize spectral efficiency without causing adjacent channel interference. This paper first focuses on 802.11n standard, MIMO-OFDM system. This paper further reviews different work done on implementation of MIMO-OFDM transceiver for 802.11n standard.
One of vital parts of the mobile wireless channel is channel estimation significantly
improve the performance of the system, especially for 4G LTE and 5G systems. The
main goal of this project is to test the time-variant channel estimation using F-OFDM
model. It investigates the Mean Square Error (MSE), the Least Squares (LS) method
and compares performance of OFDM and F-OFDM using BER vs 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.
IOSR Journal of Electronics and Communication Engineering(IOSR-JECE) is an open access international journal that provides rapid publication (within a month) of articles in all areas of electronics and communication engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electronics and communication engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
DYNAMIC OPTIMIZATION OF OVERLAP-AND-ADD LENGTH OVER MIMO MBOFDM SYSTEM BASED ...ijwmn
An important role performed by Zero Padding (ZP) in multi-band OFDM (MB-OFDM) System. This role
show for low-complexity in résistance against multipath interference by reducing inter-carrier interference
(ICI) and eliminating the inter-symbol interference (ISI) Also, zero-padded suffix can be used to eliminate
ripples in the power spectral density in order to conform to FCC requirements. At the receiver of MB-OFDM system needs to use of a technique called as overlap-and-add (OLA). Which maintain the circular convolution property and take the multipath energy of the channel.In this paper, we proposed a method of performing overlap-and-add length for zero padded suffixes. Then,we studied the effect of this method, dynamic optimization of overlap-and-add (OLA) equalization, on the performance of MIMO MBOFDM system on Bit Error Rate (BER) with AWGN channel and SalehValenzuela (S-V) Multipath channel Model.In the dynamic optimization OLA, the Length of ZP depends on length of channel impulse response (CIR).
These measures, based on SNR, insert the ZP according to the measurement.Dynamic optimization of length of ZP improves the Performance of MIMO MBOFDM system. In fact wedeveloped a technique to select the length of ZP as function of SNR and CIR estimate. In our simulation
this technique improve to 0.6 dB at BER=10-2 with a multipath channels CM4
Error Control and performance Analysis of MIMO-OFDM Over Fading ChannelsIOSR Journals
ABSTRACT: Multiple Input Multiple Output is a wireless technology that uses multiple transmitters and
receivers to transfer more data at the same time. Orthogonal Frequency Division Multiplexing, an FDM
modulation technique which splits the signal into multiple smaller sub-signals that are then transmitted
simultaneously at different frequencies to the receiver. OFDM technique spreads the data over number of
carriers which are at specific predefined frequencies. This reduces or eliminates the ISI. Forward error
correction or channel coding is a technique used for controlling errors in data transmission over unreliable or
noisy communication channels. The objective of our proposed paper is to implement the FEC into the MIMO
OFDM systems and its performance is analysed by using MATLAB over different fading channels. For
modulation it employs M-QAM which combines both ASK and PSK thereby enabling several bits to be
transmitted per symbol. The performance of MIMO-OFDM system is evaluated by BER Vs SNR when the bits
propagates through the different fading channels.
Keywords– OFDM, MIMO, QAM, FEC, BER.
A survey on Energy Efficient ProtocolsLEACH, Fuzzy-based approach and Neural ...IJEEE
Wireless Sensor Networks (WSN) plays a very important role in transmitting the data from source to destination but energy consumption is one of the major challenges in these networks. WSN consists of hundreds to thousands of nodes which consume energy while transmitting the information and with a span of time whole energy get consumed and network life time gets reduced. Clustering and Cluster head (CH) selection are important parameters used to enhance the lifetime of the WSN. Clustering use two methods: rotating CH periodically in every round to distribute the energy consumption among nodes and the node with more residual energy becomes CH.This research paper is focused on the performance of the techniques used to enhance the energy efficiency in Wireless Sensor Networks (WSNs). Low- Energy Adaptive Clustering Hierarchy (LEACH), Fuzzy- Based and Neural Network are some of the important techniques used. MATLAB simulation tool is considered in this paper.
Implementation of Back-Propagation Neural Network using Scilab and its Conver...IJEEE
Artificial neural network has been widely used for solving non-linear complex tasks. With the development of computer technology, machine learning techniques are becoming good choice. The selection of the machine learning technique depends upon the viability for particular application. Most of the non-linear problems have been solved using back propagation based neural network. The training time of neural network is directly affected by convergence speed. Several efforts are done to improve the convergence speed of back propagation algorithm. This paper focuses on the implementation of back-propagation algorithm and an effort to improve its convergence speed. The algorithm is written in SCILAB. UCI standard data set is used for analysis purposes. Proposed modification in standard backpropagation algorithm provides substantial improvement in the convergence speed.
Automated Air Cooled Three Level Inverter system using ArduinoIJEEE
The output voltage of a three level inverter is stepped voltage in which the output voltage have three possible values. Such systems can be used to interface renewable energy sources with the grid. Temperature has significant effect on performance of power MOSFETs. Typically, the MOSFETs used as power switches in such applications are a significant source of heat, and the heat energy dissipated by these components must be carefully controlled if operating temperatures are to be maintained. So for the system to work efficiently cooling of MOSFETs is required. This paper proposed an automated air cooled 3 level H-bridge inverter. The system consists of MOSFETs, LM 35 temperature sensor, Optocouplers for isolation. Arduino is used to control the on-off operation of fan. When temperature rises above certain level fan turns on to cool the MOSFETs.
In this work, a Split Ring Resonator (SRR) unit cell is simulated in a waveguide with electromagnetic field solver High Frequency Structure Simulator (HFSS). Analytical calculations of the inductance and capacitance have been also carried out to obtain the resonant frequencies for SRR dimensions. A comparison between calculated and simulated resonance frequencies)) is done. A good correlation between simulated and measured resonance frequencies is achieved.
In this paper, we provide the average bit error probabilities of MQAM and MPSK in the presence of log normal shadowing using Maximal Ratio Combining technique for L diversity branches. We have derived probability of density function (PDF) of received signal to noise ratio (SNR) for L diversity branches in Log Normal fadingfor Maximal Ratio Combining (MRC). We have used Fenton-Wilkinson method to estimate the parameters for a single log-normal distribution that approximates the sum of log-normal random variables (RVs). The results that we provide in this paper are an important tool for measuring the performance ofcommunication links in a log-normal shadowing.
An Approach to Speech and Iris based Multimodal Biometric SystemIJEEE
Biometrics is the science and technology of human identification and verification through the use of feature set extracted from the biological data of the individual to be recognized. Unimodal and Multimodal systems are the two modal systems which have been developed so far. Unimodal biometric systems use a single biometric trait but they face limitations in the system performance due to the presence of noise in data, interclass variations and spoof attacks. These problems can be resolved by using multimodal biometrics which rely on more than one biometric information to produce better recognition results. This paper presents an overview of the multimodal biometrics, various fusion levels used in them and suggests the use of iris and speech using score level fusion for a multimodal biometric system.
An Overview of EDFA Gain Flattening by Using Hybrid AmplifierIJEEE
Data communication systems are increasingly engrossing optical fiber communication system as the transmission paths for the information, the information is in the form of light pulses sending from one place to another through the optical fiber. Several types of optical amplifiers have been developed in optical fiber communication system to amplify the optical signals. The erbium doped fiber amplifier is one of the optical fiber amplifiers which are used for long distance communication. The most significant points in any optical amplifier design are gain and noise figure. They are connected to one another. The other optical amplifier, Raman amplifier has wide gain bandwidth. The EDFA gain spectrum has variations over 1536 to 1552 nm, therefore the gain flattening is a research issue in recent years with the development of high capacity DWDM. The gain variation becomes a problem as the number of channels increases. The gain of EDFA depends on large number of device parameters such as, Erbium ion concentration, amplifier length, core radius, pump power. Raman amplifiers can be combined with EDFAs to expand the optical gain flattened bandwidth. This paper focuses on different methods used for the gain flattening.
Design and Implementation of FPGA Based Low Power Pipelined 64 Bit Risc Proce...IJEEE
This paper presents an efficient design and implementation of a 64 bit RISC Processor for Data Logging System. RISC is a design mechanism to reduce the amount of space, time, cost, power and heat etc. reduces the complexity of instruction. The processor is designed for both fixed and floating point number arithmetic calculation. A Data Logger is an electronic instrument that records environmental parameters such as temperature, Humidity, Wind Speed light intensity, water level and water quality. Data Loggers find its key application where automation and control is required. The necessary code written in the hardware description language Verilog HDL.
Design of Image Segmentation Algorithm for Autonomous Vehicle Navigationusing...IJEEE
In the past few years Autonomous vehicles have gained importance due to its widespread applications in the field of civilian and military applications. On-board camera on autonomous vehicles captures the images which need to be processed in real time using the image segmentation algorithm. On board processing of video(frames)in real time is a big challenging task as it involves extracting the information and performing the required operations for navigation.This paper proposes an approach for vision based autonomous vehicle navigation in indoor environment using the designed image segmentation algorithm. The vision based navigation is applied to autonomous vehicle and it is implemented using the Raspberry Pi camera module on Raspberry Pi Model-B+ with the designed image segmentation algorithm. The image segmentation algorithm has been built using smoothing,thresholding, morpho- logical operations, and edge detection. The reference images of directions in the path are detected by the vehicle and accordingly it moves in right or left directions or stops at destination. The vehicle finds the path from source to destination using reference directions. It first captures the video,segments the video(frame by frame), finds the edges in the segmented frame and moves accordingly. The Raspberry Pi also transmits the capture video and segmented results using the Wi-Fi to the remote system for monitoring. The autonomous vehicle is also capable of finding obstacle in its path and the detection is done using the ultrasonic sensors.
Performance Analysis of GSM Network for Different Types of Antennas IJEEE
Today, in metro cities BTSs are increasing day by day and interference is also increasing. This paper shows the received power of the cell depends on a number of factors. Antenna gain and antenna type are one of the important parameters for this. This paper reveals the effect of signal received power by changing the antenna gain and antenna type.The antenna used is omnidirectional and switched beam and gain varies from 5 to 15 dB.The GSM network is simulated for 6 users in Qualnet software.
On the Performance Analysis of Composite Multipath/Shadowing (Weibull-Log Nor...IJEEE
Composite multipath/shadowing fading environments are frequently encountered in different mobile realistic scenarios. These channels are generally modeled differentComposite multipath/shadowing fading. In this paper wepresent the performance analysis of composite (Weibull-Lognormal shadowed) fading. We adopt efficient toolproposed by Holtzman to approximate composite (Weibull-Lognormal shadowed) fading. The performance measures offading communication systems such as Probability densityfunction (PDF) of Signal to Noise ratio (SNR), Amount offading (AF), Outage probability (Pout) and ChannelCapacity(C/B) will be calculated. Graphical results will bepresented for different signals and fading parameters. Thedifferent expressions that will be provided are of greatimportance in assessing the performance of communicationsystems in composite channels.
Design Analysis of Delay Register with PTL Logic using 90 nm TechnologyIJEEE
This paper presents low area and power efficient delay register using CMOS transistors. The proposed register has reduced area than the conventional register. This resistor design consists of 6 NMOS and 6 PMOS. The proposed delay register has been designed in logic editor and simulated using 90nm technology. Also the layout simulation and parametric analysis has been done to find out the results. In this paper register has been designed using full automatic layout design and semicustom layout design. Then the performance of these different designs has been analyzed and compared in terms of power, delay and area. The simulation result shows that circuit design of delay register using PTL techniques improved by power 0.05% and 61.8% area.
Carbon Nanotubes Based Sensor for Detection of Traces of Gas Molecules- A ReviewIJEEE
In this review paper, we discuss various gas sensors based on technique and sensing materials used in there fabrication. Various sensors are designed making use of salient features of carbon nanotubes and its electrical, mechanical, and electromechanical properties. Effect of using nano-composites on sensitivity and selectivity of gas sensor have been studied.
Routing Protocols in Zigbee Based networks: A SurveyIJEEE
ZigBee is the new standard developed wireless personal area network (WPAN) based on IEEE 802.15.4 for low cost, low data rate and low power consumption wireless network. In present times, zigbee has become a hot topic for research and development all over the world. This paper briefly describes various ZigBee network topologies including star, cluster tree and mesh topology and further introduces different ZigBee routing protocols such as AODV, AODVjr, Hierarchical, Integrated and Enhanced hierarchical routing protocol (EHRP).
A Survey of Routing Protocols for Structural Health MonitoringIJEEE
Wireless sensor networks have emerged in recent years as a promising technology that can impact the field of structural monitoring and infrastructure asset management. Various routing protocols are used to define communication among sensor nodes of the wireless sensor network for purpose of disseminating information. These routing protocols can be designed to improve the network performance in terms of energy consumption, delay and security issues. This paper discusses the requirements of routing protocol for Structural health monitoring and presents summary of various routing protocols used for WSNs for Structural health monitoring.
Layout Design Analysis of SR Flip Flop using CMOS TechnologyIJEEE
This paper presents an area, delay and power efficient design of SR flip flop. As the chip manufacturing technology is on the threshold of evaluation, which shrinks a chip in size and enhances its performance, here the flip flop is implemented in a layout level which develops an optimized design using recent CMOS layout tools. The proposed SR flip flop has been designed and simulated using 45nm technology. After that, parametric analysis has been done. In this paper, flip flop has been developed using full automatic design flow and semi-custom design flow. The performance of SR flip flop layouts using different design flows has been analyzed and compared in terms of area, delay and power consumption. The simulation results show that the design of SR flip flop using semi-custom design flow improved the area occupied by 46.9% and power consumption is reduced by 38.4%.
Codec Scheme for Power Optimization in VLSI InterconnectsIJEEE
This paper presents a codec scheme for optimizing power in VLSI Interconnects. It is based on the traditional bus encoding method which is considered to be one of the most effective ways of power and delay reduction. The work done aims at optimizing power by designing the scheme using Full-Custom design approach. The model has been designed and implemented using Cadence Virtuoso Analog Design Suite in 0.18µm CMOS technology. Power has been computed for different possible combinations of input data. Delay has been reckoned for the maximum power consuming input combination. Layout editor has been used to generate the physical description of the circuit. The 4 bit input data combination consuming maximum dynamic power of 6.44µW and propagation delay of 722.7ps is “1000” with previously transmitted 4 bit data being “0111”. A significant power reduction of 38.89% has been observed by designing the scheme using Full-Custom approach as compared to the conventional Semi-Custom approach of design.
Design of Planar Inverted F-Antenna for Multiband Applications IJEEE
Planar Inverted F- Antenna (PIFA) is widely used in handheld devices because of its various advantages like compact size, good bandwidth and moderate radiation patterns. In this paper, a design of Planar Inverted F- Antenna(PIFA) is proposed that resonates at the frequency of 2.5 GHz with a bandwidth of 300MHz. The relative permittivity of the substrate used is 2.2. The antenna is fed by coaxial feed. Also, gain, VSWR and radiation pattern of the antenna are studied.
Layout Design Analysis of CMOS Comparator using 180nm TechnologyIJEEE
Comparator is a very useful and basic arithmetic component of digital system. In the world of technology the demand of portable devices are increasing day by day. This paper presents CMOS design of 1-bit comparator on 180nm technology. The layout of 1-bit comparator has been developed using Automatic and semi-custom techniques. Both the layouts are compared and analyzed in terms of their Power and Area consumption. Automatic layout is generated from its equivalent schematic whereas semi-custom layout is developed manually. The result shows that semi-custom consumes less power as compared to Automatic.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
Event Management System Vb Net Project Report.pdfKamal Acharya
In present era, the scopes of information technology growing with a very fast .We do not see any are untouched from this industry. The scope of information technology has become wider includes: Business and industry. Household Business, Communication, Education, Entertainment, Science, Medicine, Engineering, Distance Learning, Weather Forecasting. Carrier Searching and so on.
My project named “Event Management System” is software that store and maintained all events coordinated in college. It also helpful to print related reports. My project will help to record the events coordinated by faculties with their Name, Event subject, date & details in an efficient & effective ways.
In my system we have to make a system by which a user can record all events coordinated by a particular faculty. In our proposed system some more featured are added which differs it from the existing system such as security.
Quality defects in TMT Bars, Possible causes and Potential Solutions.PrashantGoswami42
Maintaining high-quality standards in the production of TMT bars is crucial for ensuring structural integrity in construction. Addressing common defects through careful monitoring, standardized processes, and advanced technology can significantly improve the quality of TMT bars. Continuous training and adherence to quality control measures will also play a pivotal role in minimizing these defects.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Democratizing Fuzzing at Scale by Abhishek Aryaabh.arya
Presented at NUS: Fuzzing and Software Security Summer School 2024
This keynote talks about the democratization of fuzzing at scale, highlighting the collaboration between open source communities, academia, and industry to advance the field of fuzzing. It delves into the history of fuzzing, the development of scalable fuzzing platforms, and the empowerment of community-driven research. The talk will further discuss recent advancements leveraging AI/ML and offer insights into the future evolution of the fuzzing landscape.
Courier management system project report.pdfKamal Acharya
It is now-a-days very important for the people to send or receive articles like imported furniture, electronic items, gifts, business goods and the like. People depend vastly on different transport systems which mostly use the manual way of receiving and delivering the articles. There is no way to track the articles till they are received and there is no way to let the customer know what happened in transit, once he booked some articles. In such a situation, we need a system which completely computerizes the cargo activities including time to time tracking of the articles sent. This need is fulfilled by Courier Management System software which is online software for the cargo management people that enables them to receive the goods from a source and send them to a required destination and track their status from time to time.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
1. International Journal of Electrical & Electronics Engineering 4 www.ijeee-apm.com
IJEEE, Vol. 1, Issue 2 (April 2014) e-ISSN: 1694-2310 | p-ISSN: 1694-2426
MIMO-OFDM SYSTEM IN RAYLEIGH
FADDING CHANNEL
Maninder Singh 1
, Dr. Hardeep Singh Saini2
1,2
Indo Global College of Engineering, Punjab, India
1
md_singh1989@yahoo.com, 2
hardeep_saini17@yahoo.co.in
Abstract- MIMO-OFDM (Multi Input Multi Output-
Orthogonal Frequency Division Multiplexing) system is
very popular technique for mobile communication. We
found that Ergodic channel capacity has some limitation in
MIMO-OFDM system. So Ergodic channel capacity
optimization is necessary to improve the performance of
MIMO-OFDM System. We have that analyze MIMO-
OFDM system deeply and various algorithms to improve
Ergodic channel capacity and more over that the cost and
complexity of system will not increase. In future work we
will describes the new method that improve the performance
of system by reducing the BER (bit error rate) removing ISI
(Inter symbol interference).
Index Terms- MIMO-OFDM, SISO, SIMO, MISO
I INTRODUCTION
1.1 MIMO System:-
In order to facilitate the understanding of multiple-input
multiple-output systems (MIMO), single-input single-output
(SISO) systems, single-input multiple-output (SIMO)
systems and multiple-input single-output (MISO) systems
models are discussed briefly:
1.1.1 SISO
The simplest form of radio link can be defined in MIMO
terms as SISO - Single Input Single Output (Fig.1). This is
effectively a standard radio channel - this transmitter
operates with one antenna as does the receiver. There is no
diversity and no additional processing required.
Fig.1 SISO - Single Input Single Output
The advantage of a SISO system is its simplicity. SISO
requires no processing in terms of the various forms of
diversity that may be used. However the SISO channel is
limited in its performance. Interference and fading will
impact the system more than a MIMO system using some
form of diversity, and the channel bandwidth is limited by
Shannon's law - the throughput being dependent upon the
channel bandwidth and the signal to noise ratio.
1.1.2 SIMO
The SIMO or Single Input Multiple Output version of
MIMO occurs where the transmitter has a single antenna and
the receiver has multiple antennas as shown in Fig.2. This is
also known as received diversity. It is often used to enable a
receiver system that receives signals from a number of
independent sources to combat the effects of fading. It has
been used for many years with short wave listening /
receiving stations to combat the effects of ionospheric fading
and interference.
SIMO has the advantage that it is relatively easy to
implement although it does have
Fig. 2 SIMO– Single Input Multiple Output
some disadvantages in that the processing is required in the
receiver.The use of SIMO may be quite acceptable in many
applications, but where the receiver is located in a mobile
device such as a cellphone handset, the levels of processing
may be limited by size, cost and battery drain.
There are two forms of SIMO that can be used:
Switched diversity SIMO: This form of SIMO
looks for the strongest signal and switches to that
antenna.
Maximum ratio combining SIMO: This form of
SIMO takes both signals and sums them to give a
combination. In this way, the signals from both
antennas contribute to the overall signal.
1.1.2 MISO:-
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MISO is also termed transmit diversity. In this case, the
same data is transmitted redundantly from the two
transmitter antennas. The receiver is then able to receive the
optimum signal which it can then use to receive extract the
required data (Fig.3).
Fig. 3 MISO - Multiple Input Single Output
The advantage of using MISO is that the multiple antennas
and the redundancy coding processing is moved from the
receiver to the transmitter. In instances such as cellphone
UEs, this can be a significant advantage in terms of space for
the antennas and reducing the level of processing required in
the receiver for the redundancy coding. This has a positive
impact on size, cost and battery life as the lower level of
processing requires less battery consumption.
1.1.3 MIMO
There are more than one antenna at either end of the radio
link, this is termed MIMO - Multiple Input Multiple Output
(Fig.4). MIMO can be used to provide improvements in both
channel robustness as well as channel throughput.
Fig.4 MIMO - Multiple Input Multiple Output
In order to be able to benefit from MIMO fully it is
necessary to be able to utilise coding on the channels to
separate the data from the different paths. This requires
processing, but provides additional channel robustness / data
throughput capacity.There are many formats of MIMO that
can be used from SISO, through SIMO and MISO to the full
MIMO systems. These are all able to provide significant
improvements of performance, but generally at the cost of
additional processing and the number of antennas used.
Balances of performance against costs, size, processing
available and the resulting battery life need to be made when
choosing he correct option [1].
II OVERVIEW OF OFDM
OFDM is becoming a very popular multi-carrier modulation
technique for transmission of signals over wireless channels.
It converts a frequency-selective fading channel into a
collection of parallel at fading sub channels, which greatly
simplifies the structure of the receiver. The time domain
waveform of the subcarriers are orthogonal (sub channel and
subcarrier will be used interchangeably hereinafter), yet the
signal spectral corresponding to different subcarriers overlap
in frequency domain as shown in the fig.5. Hence, the
available bandwidth is utilized very efficiently in OFDM
systems without causing the ICI (inter-carrier interference).
By combining multiple low-data-rate subcarriers, OFDM
systems can provide a composite high-data-rate with a long
symbol duration. That helps to eliminate the ISI (inter-
symbol interference), which often occurs along with signals
of a short symbol duration in a multipath channel.
Fig. 5. OFDM Carrier
Advantage of OFDM systems are:-
High spectral efficiency;
Simple implementation by FFT (fast Fourier
transform);
Low receiver complexity;
Robustability for high-data-rate transmission
over multipath fading channel
Highflexibility in terms of link adaptation;
Disadvantages of OFDM systems are:-
Sensitive to frequency offsets, timing errors
and phase noise
Relatively higher peak-to-average power ratio
compared to single carrier system[2]
III OVERVIEW OF MIMO-OFDM SYSTEM
MIMO uses multiple antenna to transmit and receive
multiple wireless signal at a time causing better wireless
system performance to improve all the three parameter i.e.
speed, range and reliability compare to other conventional
system domain as shown in the fig.6. It well known that the
performance degradation takes place due to multipath fading
channel. Different equalization techniques are used to
combat effect of Inter Symbol Interference (ISI), but this can
be done at the cost of complexity. An alternative to these
equalizers is OFDM. Orthogonal frequency division
multiplexing is a modulation technique to carry a data on
different frequency channels. OFDM can provide simplicity
on both side i.e. transmitter and receiver, and also improve
the spectral efficiency of wireless system. Existing research
is mainly focused on obtaining the capacity and performance
analysis curves for various MIMO configurations, assuming
Rayleigh fading and independent and identically distributed
MIMO-OFDM sub-channel. So far, the capacity of MIMO-
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OFDM systems in the case of the channel being known at
the transmitter and receiver and in the more practical case of
the channel known at the receiver only has been developed
for Rayleigh fading channel [3].
(a) Transmitter Section
(b)Receiver Section
Fig. 6. MIMO-OFDM system
Combining OFDM with multiple input multiple output
(MIMO) technique increases spectral efficiency to attain
throughput of 1 Gbit/sec and beyond, and improves link
reliability. MIMO concept can be implemented in various
ways, 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, and at the receiver
end, the different antennae will receive the same signals
travelled through diverse paths. 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[4].
The solution to obtaining significantly higher data rate and
increasing the range of performance at the same time is by
MIMO-OFDM application. MIMO-OFDM increase the link
capacity by simultaneously transmitting multiple data stream
using multiple transmit and receive antenna.
It make it possible to reach the data rate that are several time
larger than current highest 802.11 a/g rate of 54mbps
without having employ a larger bandwidth or less robust
QAM cancellation.
IV RAYLEIGH FADING
It is a statistical model for the effect of
a propagation environment on a radio signal, such as that
used by wireless devices. Rayleigh fading models assume
that the magnitude of a signal that has passed through such
a transmission medium (also called a communications
channel) will vary randomly, or fade, according to
a Rayleigh distribution. Rayleigh fading is viewed as a
reasonable model for tropospheric and ionospheric signal
propagation as well as the effect of heavily built-up urban
environments on radio signalsdomain as shown in the
fig.7. Rayleigh fading is most applicable when there is no
dominant propagation along a line of sight between the
transmitter and receiver In this section, we will examine the
impact that the movement on the mobile receiver (or
transmitter) causes on the received signal. The resulting
effect (typically called fading) has a significant impact on
the received signal strength which can be severely degraded
as we will show in the following sections [5].
Fig. 7.Rayleigh Fading
1.Doppler Effect-:
Fading is caused by a phenomenon known as the Doppler
Effect. When dealing with any sort of waves, a receiver’s
movement in relation to the source of the wave will distort
the perceived frequency of that wave.
Fig. 8. Illustration of Doppler Effect
Consider Fig.8, where a user is at point X, moving toward
point Y at velocity v. We make the approximation that the
angle of arrival of the received signal is the same at all
points during transmission (i.e., the source is very far away).
The difference in distance that the transmission must travel
between the receiver at points X and Y is:
∆l =v∆t cosq
The maximum Doppler shift is v/l and this is in units of Hz.
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2. Multipath channel:-
In addition to Doppler, our channel model will include
multipath distortion. What we mean by this is that there will
be several copies of the same signal being picked up by the
receiver coming from different angles. This is common in
environments such as metropolitan areas, where
electromagnetic waves can bounce off buildings or in indoor
environments where signals reflect off walls, etc. as shown
in the fig.9 Each of these components will have their own
Doppler shift and phase offset due to different angles-of-
arrival and time delays. The combination of these paths will
be constructive and destructive due to the different phases
causing the signal strength to change with mobile
movement. It is this multipath factor that produces the gains
and fades in power [6].
Fig. 9.Multipath Channel
V EQUALIZER
In digital communications, its purpose is to reduce inter
symbol interference to allow recovery of the transmit
symbols. It may be a simple linear filter or a complex
algorithm. This approach to remove ISI is usually known as
equalization. The main advantage of this approach is that a
digital filter is easy to build and is easy to alter for different
equalization schemes. The following equalizer types are
commonly used in digital communications:
MMSE (Minimum Mean Square Equalizer )
ZFE (Zero Feedback Equalizer )
DFE (Decision Feedback Equalizer)
Adaptive Equalizer
Blind Equalizer
Viterbi Equalizer
BCJR Equalizer
But we explain only one i.e. Minimum Mean Square
Equalizer (MMSE) which we will use in our work.
1.Minimum Mean Square Equalizer (MMSE):
The zero-forcing equalizer, although removes ISI, may not
give the best error performance for thecommunication
system because it does not take into account noises in the
system. A different equalizer that takes noises into account
is the minimum mean square error (MMSE) equalizer. It is
based on the mean square error (MSE) criterion. Without
knowing the values of the information symbols Ik
beforehand, they model each symbol Ik as a random variable.
Assume that the information sequence {Ik} is WSS. Choose
a linear equalizer HE(Z) to minimize the MSE between the
original information symbols Ik and the output of the
equalizer ^Ik:
MSE = E[ek
2
] = E[(Ik - ^
Ik)2
]
The linear MMSE equalizer can also be found iteratively.
First, notice that the MSE is a quadraticfunction of hE. The
gradient of the MSE with respect to hE gives the direction to
change hE for the largest increase of the MSE. To decrease
the MSE, we can update hE in the direction opposite to the
gradient. This is the steepest descent algorithm. This is a
stochastic steepest descent algorithm called the least mean
square (LMS) algorithm [7].
VI REVIEW OF LITERATURE
A.P.Singh et.al.[8] proposed in their paper the performance
of MIMO-OFDM system in Rayleigh fading channel. They
compares ergodic and outage capacity with taking various
number of transmitting and receiving antennas and various
measures such SNR , BER etc So channel capacity
optimization is necessary to improve the performance of
MIMO-OFDM system. B.Gupta.et.al.[7] analyzed OFDM
with two equalizer i.e. zero forcing (ZF) and minimum
mean square equalizers (MMSE) along with different
modulations are used. The modulation with multicarrier is
employed, which provides advantages like inter symbol
interference (ISI) reduction, high reliability, and better
performance in multi- path fading. These equalizers are
adopted to remove the ISI generated in the transmitted data
under various fading environments. The results show that,
with MMSE and ZFE equalizers, the bit error rate (BER)
performance is improved. Further, the BER performance of
MMSE is superior to ZFE equalizer. K. N et.al. (2007)
design efficient method for layered MIMO-OFDM system
with channel equalization temporal variation due Doppler
spread use Recursive least square (RLS) algorithm for
channel equalization. Horizontal and Vertical layered
structure is applied on MIMO-OFDM SYSTEM and their
performance is evaluated. Here we use turbo codes. A
technique for layered MIMO OFDM was proposed with
low complexity on basis of the simulated results, concluded
that the layered structure has low bit error rate . Mohamed-
slim Alouini and Andrea J. Goldsmith [9] study the
Rayleigh fading channel capacity under three adaptive
policies:
1. Optimal power and rate adaptation
2. Constant power with optimal rate adaptation.
3. Channel inversion with fixed rate.
Here they use two diversity combining technique i.e. MRC
and SC (selective combining).They investigate the relative
impact of MRC and selective combining (SC) diversity
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AUTHORS
First Author – Maninder Singh is following
M.Tech from Indo Global College of
Engineering, India. He has completed B.Tech
from IGCE, Mohali (Punjab), India in the year
2011. He has two year of educational
expertise. Working as Assistant Professor (ECE) at indo
global college of Engineering, Abhipur (Mohali) since June-
2012.His areas of interest are wireless and mobile
communication, Optical communication.
E-mail address: md_singh1989@yahoo.com
Second Author– Hardeep Singh Saini
obtained his Doctorate degree in Electronics
and communication Engineering in 2012. He
holds Master’s degree in Electronic and
communication from Punjab technical
university, jalandhar passed in 2007. His
total experience is 14 year, presently,
working as Professor (ECE) and Associate Dean Academic at
indo global college of Engineering, Abhipur (Mohali) and
PUNJAB(INDIA) since June-2007. He is author of 5 books in
the field of communication Engineering. He has presented 21
papers in international /national conferences and published 23
paper in international journals. He is a fellow and senior
member of various prestigious societies like IETE (India),
IEEE and he is also editorial member of various in
international journal.
E-mail address: hardeep_saini17@yahoo.co.in
.