Fading and the Doppler effect can impact wireless communication. Fading occurs when multipath signals interfere, causing fluctuations in signal strength over time. The Doppler effect is the change in frequency of a wave due to relative motion between the source and observer. In wireless communication, the Doppler effect causes shifts in the received carrier frequency due to motion between the transmitter and receiver. This Doppler spread must be accounted for in system design through techniques like Doppler compensation.
In communication system, intersymbol interference (ISI) is a form of distortion of a signal in which one symbol interferes with subsequent symbols. This is an unwanted phenomenon as the previous symbols have similar effect as noise, thus making the communication less reliable.
In communication system, the Nyquist ISI criterion describes the conditions which when satisfied by a communication channel (including responses of transmit and receive filters), result in no intersymbol interference(ISI). It provides a method for constructing band-limited functions to overcome the effects of intersymbol interference.
This ppt contains information about concepts of wireless communication, signal propagation effects, spread spectrum, cellular systems, multiple access systems.
Loss of strength, A periodic reduction in the received strength of a radio transmission.
This is about the phenomenon of loss of signal in telecommunications.Fading refers to the
time variation of the received signal power caused by changes in the transmission medium or path.
In communication system, intersymbol interference (ISI) is a form of distortion of a signal in which one symbol interferes with subsequent symbols. This is an unwanted phenomenon as the previous symbols have similar effect as noise, thus making the communication less reliable.
In communication system, the Nyquist ISI criterion describes the conditions which when satisfied by a communication channel (including responses of transmit and receive filters), result in no intersymbol interference(ISI). It provides a method for constructing band-limited functions to overcome the effects of intersymbol interference.
This ppt contains information about concepts of wireless communication, signal propagation effects, spread spectrum, cellular systems, multiple access systems.
Loss of strength, A periodic reduction in the received strength of a radio transmission.
This is about the phenomenon of loss of signal in telecommunications.Fading refers to the
time variation of the received signal power caused by changes in the transmission medium or path.
Spread spectrum system promises several benefits, such as higher capacity, anti-jamming and the ability to resist multipath propagation in wireless communication. I hope this content will provide useful informations about this system.
introduction to pulse shaping and equalization in advanced digital communication, it's characterisation, signal design of band limited signal, design of bandlimited signal for no ISI and design of bandlimited signal with controlled ISI-partial response, linear equalization,
An overview of Doppler Effect in Ultrasonography - the medical imaging of the body using Ultrasound.
Includes Colour Doppler, Power Doppler, Spectral Doppler, Continuous Wave Doppler, Pulsed Wave Doppler, and comparisons with other Radiographic imaging modalities.
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.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible 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.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
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.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible 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.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
COLLEGE BUS MANAGEMENT SYSTEM PROJECT REPORT.pdfKamal Acharya
The College Bus Management system is completely developed by Visual Basic .NET Version. The application is connect with most secured database language MS SQL Server. The application is develop by using best combination of front-end and back-end languages. The application is totally design like flat user interface. This flat user interface is more attractive user interface in 2017. The application is gives more important to the system functionality. The application is to manage the student’s details, driver’s details, bus details, bus route details, bus fees details and more. The application has only one unit for admin. The admin can manage the entire application. The admin can login into the application by using username and password of the admin. The application is develop for big and small colleges. It is more user friendly for non-computer person. Even they can easily learn how to manage the application within hours. The application is more secure by the admin. The system will give an effective output for the VB.Net and SQL Server given as input to the system. The compiled java program given as input to the system, after scanning the program will generate different reports. The application generates the report for users. The admin can view and download the report of the data. The application deliver the excel format reports. Because, excel formatted reports is very easy to understand the income and expense of the college bus. This application is mainly develop for windows operating system users. In 2017, 73% of people enterprises are using windows operating system. So the application will easily install for all the windows operating system users. The application-developed size is very low. The application consumes very low space in disk. Therefore, the user can allocate very minimum local disk space for this application.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
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.
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/
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.
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.
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.
2. OVERVIEW
• What is Fading?
• Effect of Fading in Wireless Communication
• Doppler Effect (Principle)
• Doppler Effect in Wireless Communication
• Channel Correlation Function and Power Spectra
• Conclusion
3. FADING
• In wireless communication system, a signal experiences multipath propagation which causes rapid
signal level fluctuations in time, called fading.
• Fading effects that characterize radio communication are large scale fading and small scale fading.
• Fading is caused by interference between two or more versions of the transmitted signal which arrive at
the receiver at slightly different times.
• These waves, called multipath waves, combine at the receiver antenna to give a resultant signal which
can vary widely in amplitude and phase, depending on the distribution of the intensity and relative
propagation time of the waves and the bandwidth of the transmitted signals.
4. DOPPLER EFFECT
• The Doppler effect (or Doppler shift) is the change in frequency of a wave (or other periodic event) for
an observer moving relative to its source.
• It is commonly heard when a vehicle sounding a siren or horn approaches, passes, and recedes from an
observer. Compared to the emitted frequency, the received frequency is higher during the approach,
identical at the instant of passing by, and lower during the recession.
• When the source of the waves is moving toward the observer, each successive wave crest is emitted
from a position closer to the observer than the previous wave. Therefore, each wave takes slightly less
time to reach the observer than the previous wave. Hence, the time between the arrival of successive
wave crests at the observer is reduced, causing an increase in the frequency. While they are travelling,
the distance between successive wave fronts is reduced, so the waves "bunch together".
• Conversely, if the source of waves is moving away from the observer, each wave is emitted from a
position farther from the observer than the previous wave, so the arrival time between successive
waves is increased, reducing the frequency. The distance between successive wave fronts is then
increased, so the waves "spread out".
5.
6. DOPPLER EFFECT IN WIRELESS COMMUNICATION
• The relative motion between the transmitter and the receiver causes Doppler shifts. Local scattering
typically comes from many angles around the mobile. This scenario causes a range of Doppler shifts,
known as the Doppler spectrum. The maximum Doppler shift corresponds to the local scattering
components whose direction exactly opposes the mobile trajectory.
• Due to Doppler spread, fading effects can also be classified as fast fading and slow fading.
• There is always a relative motion between the cell-site transmitter and the mobile receiver. As a result
Doppler effect occurs in the shift of the received carrier frequency. Doppler spectrum is the spectrum of
the fluctuations of the received signal strength.
• Doppler effect results in the inaccurate operation of the system. Proper compensation technique needs
to be implemented to minimise this effect.
7. • Doppler frequency or Doppler shift is given by:
𝑓𝑑 =
𝑉𝑚
𝛌 𝑐
cos 𝜃
• The maximum Doppler frequency will be obtained when the mobile unit is moving in line with the
direction of the received signal, that is, 𝜃 = 0° or cos 𝜃 = 1. The maximum Doppler frequency is given
by:
𝑓𝑑𝑚 =
𝑉𝑚
𝛌 𝑐
• When a pure sinusoidal carrier signal having frequency 𝑓𝑐 is transmitted, the received signal spectrum,
called the Doppler spectrum, will have components in the range 𝑓𝑐 − 𝑓𝑑 to 𝑓𝑐 + 𝑓𝑑, corresponding to
whether the direction of motion of the mobile is away from or towards the direction of the received
signal respectively.
• This simply means that Doppler shift will be positive or negative depending on whether the mobile
receiver is moving toward or away from the base station transmitter.
8. CHANNEL CORRELATION FUNCTION AND POWER
SPECTRA
• Consider ∅ 𝑐(∆𝑓; ∆𝑡) which is known as the spaced-frequency, spaced time correlation function of the
channel.
• Focussing on the time variations of the channel as measured by the parameter ∆𝑡 𝑖𝑛 ∅ 𝑐(∆𝑓; ∆𝑡). The
time variations in the channel are evidenced as a Doppler broadening and, perhaps, in addition as a
Doppler shift of a spectral line.
• In order to relate the Doppler effects to the time variations of the channel, we define the Fourier
transform of ∅ 𝑐 ∆𝑓; ∆𝑡 with respect to the variable ∆𝑡 to be the function 𝑆𝑐 ∆𝑓; 𝛌 .
𝑆𝑐 ∆𝑓; 𝛌 =
−∞
∞
∅ 𝑐(∆𝑓; ∆𝑡)𝑒−𝑗2𝜋𝛌∆𝑡
𝑑∆𝑡
• With ∆𝑓 set to zero and 𝑆𝑐 0; 𝛌 ≡ 𝑆𝑐(𝛌), the relation becomes
𝑆𝑐 𝛌 =
−∞
∞
∅ 𝑐(0; ∆𝑡)𝑒−𝑗2𝜋𝛌∆𝑡
𝑑∆𝑡
9. • The function 𝑆𝑐(𝛌) is a power spectrum that gives the signal intensity as a function of the Doppler
frequency 𝛌. Hence, we call 𝑆𝑐(𝛌) the Doppler power spectrum of the channel.
• From the equation, we observe that if the channel is time invariant, ∅ 𝑐 ∆𝑡 = 1 and 𝑆𝑐(𝛌) becomes
equal to the delta function 𝛿 𝛌 . Therefore, when there are no time variations in the channel, there is
no spectral broadening observed in the transmission of a pure frequency tone.
• The range of values of 𝛌 over which 𝑆𝑐(𝛌) is essentially nonzero is called the Doppler spread 𝐵 𝑑 of the
channel. Since 𝑆𝑐(𝛌) is related to ∅ 𝑐 ∆𝑡 by the Fourier transform, the reciprocal of 𝐵 𝑑 is measure of
the coherence of the channel. That is,
(∆𝑡) 𝑐 ≈
1
𝐵 𝑑
• Clearly, a slow changing channel has a large coherence time or, equivalently, a small Doppler spread.
10. • Now consider the autocorrelation function ∅ 𝑐(𝜏; ∆𝑡) in time domain. Its Fourier transform is given as
𝑆𝑐 𝜏; 𝛌 =
−∞
∞
∅ 𝑐(𝜏; ∆𝑡)𝑒−𝑗2𝜋𝛌∆𝑡
𝑑∆𝑡
• It follows that 𝑆𝑐 𝜏; 𝛌 and 𝑆𝑐 ∆𝑓; 𝛌 are a Fourier transform pair. That is,
𝑆𝑐 𝜏; 𝛌 =
−∞
∞
𝑆𝑐 ∆𝑓; 𝛌 𝑒 𝑗2𝜋𝜏∆𝑓
𝑑∆𝑓
• Furthermore, 𝑆𝑐 𝜏; 𝛌 and ∅ 𝑐(∆𝑓; ∆𝑡) are related by the double Fourier transform
𝑆𝑐 𝜏; 𝛌 =
−∞
∞
−∞
∞
∅ 𝑐(∆𝑓; ∆𝑡)𝑒−𝑗2𝜋𝛌∆𝑡
𝑒 𝑗2𝜋𝜏∆𝑓
𝑑∆𝑡𝑑∆𝑓
• This new function 𝑆𝑐 𝜏; 𝛌 is called the scattering function of the channel. It provides us with a measure
of the average power output of the channel as a function of the time delay and Doppler frequency.
11. CONCLUSION
The intent of this presentation was to discuss the concept of fading in the
context of Doppler effect.