Linear Integrated Circuits basics

To understand the basics of LIC

Op-amp basics

Wireless Communication Two mark Q&A

 Wireless Communication

UNIT I WIRELESS CHANNELS

Large scale path loss — Path loss models: Free Space and Two-Ray models -Link Budget design — Small scale fading- Parameters of mobile multipath channels — Time dispersion parameters-Coherence bandwidth — Doppler spread & Coherence time, fading due to Multipath time delay spread — flat fading — frequency selective fading — Fading due to Doppler spread — fast fading — slow fading.

UNIT II CELLULAR ARCHITECTURE

Multiple Access techniques — FDMA, TDMA, CDMA — Capacity calculations–Cellular concept- Frequency reuse — channel assignment- hand off- interference & system capacity- trunking & grade of service — Coverage and capacity improvement.

UNIT III DIGITAL SIGNALING FOR FADING CHANNELS

Structure of a wireless communication link, Principles of Offset-QPSK, p/4-DQPSK, Minimum Shift Keying, Gaussian Minimum Shift Keying, Error performance in fading channels, OFDM principle — Cyclic prefix, Windowing, PAPR.

UNIT IV MULTIPATH MITIGATION TECHNIQUES

Equalisation — Adaptive equalization, Linear and Non-Linear equalization, Zero forcing and LMS Algorithms. Diversity — Micro and Macro diversity, Diversity combining techniques, Error probability in fading channels with diversity reception, Rake receiver.

UNIT V MULTIPLE ANTENNA TECHNIQUES

MIMO systems — spatial multiplexing -System model -Pre-coding — Beam forming — transmitter diversity, receiver diversity- Channel state information-capacity in fading and non-fading channels.

OUTCOMES:

The student should be able to:

• Characterize a wireless channel and evolve the system design specifications

• Design a cellular system based on resource availability and traffic demands

• Identify suitable signaling and multipath mitigation techniques for the wireless channel and system under consideration.

TEXT BOOKS:

1. Rappaport,T.S., ―Wireless communicationsǁ, Pearson Education, Second Edition, 2010.(UNIT I, II, IV)

2. Andreas.F. Molisch, ―Wireless Communicationsǁ, John Wiley – India, 2006. (UNIT III,V) REFERENCES:

1. Wireless Communication –Andrea Goldsmith, Cambridge University Press, 2011

2. Van Nee, R. and Ramji Prasad, ―OFDM for wireless multimedia communications, Artech House, 2000

3. David Tse and Pramod Viswanath, ―Fundamentals of Wireless Communication, Cambridge University Press, 2005.

4. Upena Dalal, ―Wireless Communicationǁ, Oxford University Press, 2009.

Two mark Q&A Click to Download

Will gesture control become the future of computer interfacing?

     For many years, we interfaced with our computers using a keyboard and a mouse. But the arrival of touch screen technology has changed all that. Today, many of us will use touch as the main way to interact with our devices.

But even touch technology has its limitations; the user has to make physical contact with the device in question. Looking to address this issue, a number of companies and researchers are developing new ways to make devices understand what we want them to do – and gestures are being seen as a natural way of interaction. And some tvs are already offering just this ability. Samsung's Smart TVs, for example, support simple gesture control.   

 Fanie Duvenhage is director of Microchip's human machine interface division. He said: "We're interested in how people connect with technology and that interaction between people and machines is getting interesting." 

 Gest IC technology, which is integrated into the host device, uses thin sensing electrodes made from any conductive material. Amongst the options are pcb traces and indium tin oxide coatings. The company says this allows for visually appealing industrial designs with very low additional system costs. The technology is also said to provide 100% surface coverage, eliminating 'angle of view' blind spots found in other technologies.Microchip has also supplied capacitive touch technology for some years. Duvenhage said that, while capacitive touch is still widely used, it has limitations. "The state of the art for capacitive touch only has a range of a couple of inches “he pointed out.

 GestIC technology uses frequencies of around 100 kHz, with a wavelength of 3km. Because the electrodes are much smaller, their magnetic component is practically zero and no wave propagation takes place. Five electrodes are required by the system: right, left, up, down and centre. When a hand, for example, enters the electrical field, its distribution is distorted and the field lines intercepted by the hand are shunted to ground through the human body. The proximity of the body shifts the receiver electrode signal levels to a lower potential and this can be detected. Digital signal processing determines the exact location of the gesture and its direction. Duvenhage said: "GestIC has a detection range of 15cm and, because it has low power consumption, can be always on”.

            The first chip to enable the technology is the MGC3130. Consuming as little as 150µW in its active sensing state, the MGC3130 is suited for use in battery powered products even with it’s always on nature. 

            Gest IC technology uses the Colibri suite, an on chip library of intuitive and natural human gestures. The Colibri suite combines a stochastic Hidden Markov model and x/y/z hand position vectors to provide designers with a reliable set of recognized 3d hand and finger gestures. Examples include position tracking, flicks, circles and symbol gestures. These can be used to perform functions such as on/off, open application, point, click, and zoom and so on.

            The MGC3130 supports a resolution of 150point/in and samples at 200Hz sampling rate to detect the fastest motions. It

features automated self-calibration for high accuracy and has integrated flash to support product upgrades. Interference from other RF sources are avoided by a frequency hopping approach which shifts the detection frequency within the range from 70 to 130 kHz.

Microchip claims it is working with input device and other product manufacturers to implement efficient user input controls. Example applications include taking advantage of the interface capabilities in Windows 8, using hovering motions and free space gesture controls, instead of touchscreen interaction. Duvenhage believes Gest IC technology will be suited to a range of markets. "Alongside consumer input devices," he said, "we also see potential in automotive and medical applications." Microchip is supporting developers with the Sabrewing single zone evaluation kit. Working with the MGC3130, the kit provides a choice of 5 or 7in electrode sizes and comes with the Aurea graphical user interface. This allow designers to match their system commands to Microchip's ColibriSuite. 
Sounds good 

            According to Microsoft Research, gestures are becoming an increasingly popular way to interact with computers. However, it says deploying robust gesture recognition sensors in existing mobile platforms can be expensive. In a paper which describes its work, the team note that vision based gesture recognition systems can be affected by variables such as lighting conditions, while requiring reasonable amounts of processing power. The team also points to Microsoft's Kinecttechnology, but suggests miniaturising this is not likely in the near future. Looking to solve this problem, a team of researchers has developed a system called SoundWave, which takes advantage of the speakers and microphone found in most commodity devices. 
 Sidhant Gupta, a ubiquitous computing researcher, is part of the team, whose approach is based on the Doppler effect. "Sound Wave is a real time technique," said Gupta, "which uses speakers and a microphone to detect a range of gestures without the use of any special sensors." Sound Wave generates frequencies in the range between 18 and 22 kHz, which are frequency shifted when they reflect off  moving objects, including the hand. "We use a microphone on the same device to pick up the frequency shifted signal and recognize the gesture," he continued. The system is also capable of detecting differences between gestures. For example, when the hand moves faster, the frequency shift is greater. And SoundWave can also understand when the user walks away from their laptop, for example, and can be set up to lock the device. Because Sound Wave uses frequencies above the range of human hearing, it can work alongside audible music. "The user can have music playing on their laptop while using Sound  Wave,"Gupta  Noted.

In flight application 

            Researchers from Thales are working on a gesture control system for in-flight entertainment systems. According to the company, passengers will be able to interact with a large screen, with the camera recognizing their motions and the system responding much as if they were using a touch screen. The idea is based on technology used in the Xbox games console, but Thales says the design goes beyond games and to address many aspects of in flight entertainment content: movies, music, gesture games and e-readers. But don't expect to find gesture control towards the rear of the plane. This system is intended for use by those who 'turn left' when they board.. 

NEXI - Robot with facial expressions

A latest invention by MIT Media Lab is a new robot that is able to show various facial expressions such as 'slanting its eyebrows in anger', or 'raise them in surprise', and show a wide assortment of facial expressions while communicating with people. This latest achievement in the field of Robotics is named NEXI as it is framed as the next generation robots which are aimed for a range of applications for personal robots and human- robot teamwork.

DESIGNING:

             The head and face of NEXI were designed by Xitome Design .The expressive robotics started with a neck mechanism sporting 4 degrees of freedom (DoF) at the base, plus pan-tilt-yaw of the head itself. The mechanism has been constructed to time the movements so they mimic human speed. The face of NEXI has been specially designed to use gaze, eyebrows, eyelids and an articulate mandible which helps in expressing a wide range of different emotions. The chassis of NEXI is also advanced. It has been developed by the Laboratory for Perceptual Robotics UMASS (University of Massachusetts), Amherst. This chassis is based on the uBot5 mobile manipulator. The mobile base can balance dynamically on two wheels. The arms of NEXI can pick up a weight of up to 10 pounds and the plastic covering of the chassis can detect any kind of human touch.

CYNTHIA BREAZEAL: HEAD OF THE PROJECT

            This project was headed by Media Lab's Cynthia Breazeal, a well-known robotics expert famous for earlier expressive robots such as Kismet. She is an Associate Professor of Media Arts and Sciences at the MIT. She named her new product as an MDS (mobile, dextrous, social).

FEATURES OF NEXI

            Nexi has self-balancing wheels like the Segway transporter, to ultimately ride on. Currently it uses an additional set of supportive wheels to operate as a statically stable platform in its early stage of development. It has hands which can be used to manipulate objects, eyes (video cameras), ears (an array of microphones), and a 3-D infrared camera and laser rangefinder which support real-time tracking of objects, people and voices as well as indoor navigation.

 

The Hacker Crackdown-by Bruce Sterling

 

The Hacker Crackdown-by Bruce Sterling

 

 

This is a book about cops, and wild teenage whiz- kids, and lawyers, and

hairy-eyed anarchists, and industrial technicians, and hippies, and

high-tech millionaires, and game hobbyists, and computer security

experts, and Secret Service agents, and grifters, and thieves.

This book is about the electronic frontier of the 1990s. It concerns

activities that take place inside computers and over telephone lines.

A science fiction writer coined the useful term "cyberspace" in 1982.

But the territory in question, the electronic frontier, is about a hundred

and thirty years old. Cyberspace is the "place" where a telephone conversation

appears to occur. Not inside your actual phone, the plastic

device on your desk. Not inside the other person's phone, in some other

city. *The place between* the phones. The indefinite place *out there,*

where the two of you, two human beings, actually meet and communicate.

Although it is not exactly "real," "cyberspace" is a genuine place.

Things happen there that have very genuine consequences. This "place"

is not "real," but it is serious, it is earnest. Tens of thousands of people

have dedicated their lives to it, to the public service of public communication

by wire and electronics.

People have worked on this "frontier" for generations now. Some people

became rich and famous from their efforts there. Some just played in

it, as hobbyists. Others soberly pondered it, and wrote about it, and

regulated it, and negotiated over it in international forums, and sued one

another about it, in gigantic, epic court battles that lasted for years.

And almost since the beginning, some people have committed crimes in

this place.

But in the past twenty years, this electrical "space," which was once

thin and dark and one-dimensional — little more than a narrow speaking-

tube, stretching from phone to phone — has flung itself open like a

gigantic jack-in- the- box. Light has flooded upon it, the eerie light of

the glowing computer screen. This dark electric netherworld has

become a vast flowering electronic landscape. Since the 1960s, the

world of the telephone has cross-bred itself with computers and television,

and though there is still no substance to cyberspace, nothing you

can handle, it has a strange kind of physicality now. It makes good sense

today to talk of cyberspace as a place all its own.

Because people live in it now. Not just a few people, not just a few

technicians and eccentrics, but thousands of people, quite normal people.

And not just for a little while, either, but for hours straight, over

weeks, and months, and years. Cyberspace today is a "Net," a

"Matrix," international in scope and growing swiftly and steadily. It's

growing in size, and wealth, and political importance.

People are making entire careers in modern cyberspace. Scientists and

technicians, of course; they've been there for twenty years now. But

increasingly, cyberspace is filling with journalists and doctors and

lawyers and artists and clerks. Civil servants make their careers

there now, "on-line" in vast government data- banks; and so do spies,

industrial, political, and just plain snoops; and so do police, at least a

few of them. And there are children living there now.

People have met there and been married there. There are entire living

communities in cyberspace today; chattering, gossipping, planning,

conferring and scheming, leaving one another voice-mail and electronic

mail, giving one another big weightless chunks of valuable data, both

legitimate and illegitimate. They busily pass one another computer

software and the occasional festering computer virus.

We do not really understand how to live in cyberspace yet. We are feeling

our way into it, blundering about. That is not surprising. Our lives

in the physical world, the "real" world, are also far from perfect,

despite a lot more practice. Human lives, real lives, are imperfect by

their nature, and there are human beings in cyberspace. The way we

live in cyberspace is a funhouse mirror of the way we live in the real

world. We take both our advantages and our troubles with us.

This book is about trouble in cyberspace. Specifically, this book is about

certain strange events in the year 1990, an unprecedented and startling

year for the the growing world of computerized communications.

In 1990 there came a nationwide crackdown on illicit computer hackers,

with arrests, criminal charges, one dramatic show-trial, several

guilty pleas, and huge confiscations of data and equipment all over the

USA.

The Hacker Crackdown of 1990 was larger, better organized, more

deliberate, and more resolute than any previous effort in the brave new

world of computer crime. The U.S. Secret Service, private telephone

security, and state and local law enforcement groups across the country

all joined forces in a determined attempt to break the back of America's

electronic underground. It was a fascinating effort, with very mixed

results.

The Hacker Crackdown had another unprecedented effect; it spurred the

creation, within "the computer community," of the Electronic Frontier

Foundation, a new and very odd interest group, fiercely dedicated to the

establishment and preservation of electronic civil liberties. The crackdown,

remarkable in itself, has created a melee of debate over electronic

crime, punishment, freedom of the press, and issues of search and

seizure. Politics has entered cyberspace. Where people go, politics

follow.

This is the story of the people of cyberspace.

Click to download EC2207 Lab manual

EVOMOUSE

Easy and convenient

Setting up evoMouse is quick and simple and requires very little space. It connects via standard USB port or Bluetooth without installing software.

Multi-touch feature

In addition to common mouse operations, evoMouse recognizes multiple gestures when connected to supported devices.

Ergonomic

Because it allows natural movements and doesn’t require pushing around a physical object, evoMouse® may help reduce repetitive stress injuries.

*Picture shown evoMouse Plus (Bluetooth) model

                                                                                All the best:)

                                                                        Believed goal never fails:)