ABSTRACT

A novel data-hiding methodology, denoted as digital invisible ink (DII), is proposed to implement secure steganography systems. Like the real-world invisible ink, secret messages will be correctly revealed only after the marked works undergo certain prenegotiated manipulations, such as lossy compression and processing. Different from conventional data-hiding schemes where content processing or compression operations are undesirable, distortions caused by prenegotiated manipulations in DII-based schemes are indispensable steps for ....etc

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1. INTRODUCTION
Code Division Spread Spectrum is one form of CDMA communication technique optimized for the cost conscious, high volume and short cycle consumer electronics market. Its primary application is in digital cordless telephony today. Meanwhile, it is being applied to wireless devices for the last 100-meter connection to the Internet, and in the wireless local loop to provide sub-$20 handset cost, tariff free mobile voice services in some third world countries.
Why is CD/SS technology suitable for consumer e ....etc

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MSK Direct Sequence Spread Spectrum System Incorporating SAW Tapped Delay Line and SAW Shaping Filter
Abstract
The present work deals with theIF section of an indoor wireless TDMA/CDMA(TCDMA) communication system operating inthe 2.45 GHz ISM band . Spreading anddespreading is done at the 361 MHz IF withan extremely wide bandwidth of 65 MHz whichis greater than the coherence bandwidth of theUHF indoor radio channel. For the modulationof the data we employ on o_ keying (OOK), andfor the spreading minimum shift keying (MSK).Two ty ....etc

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hi friends.... i have choosen seminar topic as Pseudo-chaotic PN-sequence generator circuits for spread spectrum communications.. please help me to get information regarding this topic and to prepare ppts.. ....etc

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Abstract:
Spread spectrum is a form of wireless communications in which the frequency of the transmitted signal is deliberately varied. This result in a much greater bandwidth than the signal would have if its frequency were not varied.A conventional wireless signal has a frequency, and are methods by which electromagnetic energy generated in a particular bandwidth is deliberately spread in the frequency domain, resulting in a signal with a wider bandwidth usually specified in megahertz (MHz) or gigahertz gigahertz), that doe ....etc

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PRESENTED BY:
S ADITYA THIMMA REDDY
PUSHPAVALLI R
P VENKATA KRISHNA TEJA
S PENNA OBULAMMA


Abstract
Spread-spectrum telecommunications is a signal structuring technique that employs direct sequence, frequency hopping, or a hybrid of these, which can be used for multiple access and/or multiple functions. This technique decreases the potential interference to other receivers while achieving privacy. Frequency-hopping spread spectrum (FHSS), direct-sequence spread spectrum (DSSS ....etc

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Much of the signal processing performed in modern wireless
communications systems—such as digital modulator/demodulator
applications—takes place in the digital domain and requires high
throughput. Dedicated hardware can provide the processing capability to
meet this requirement. The parallel processing capability of Altera®
programmable logic devices (PLDs) makes them ideal for
baseband/intermediate frequency (IF) digital signal processing
applications.
The direct sequence spread spectrum (DSSS) digital modem reference
design is ....etc

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1.1WHAT IS SPREAD SPECTRUM?
Spread-spectrum techniques are methods by which a signal (e.g. an electrical,electromagnetic, or acoustic signal) generated in a particular bandwidth is deliberately spread in the frequency domain, resulting in a signal with a wider bandwidth. These techniques are used for a variety of reasons, including the establishment of securecommunications, increasing resistance to natural interference and jamming, topreventdetection, and to limit power flux density (e.g. in satellite downlinks).
S ....etc

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Abstract
In this paper, we propose to embed the watermark
information in the log-2-spatio domain by means of
spread spectrum technique. In log-2-spatio domain,
the variance of the information is reduced
significantly. This improves the efficiency and
robustness of spread spectrum technique. Low
intensity and mid-band regions are selected to embed
the information in order to guarantee an invisible
watermark as well as the robustness to JPEG
compression. Simulation results show that the
embedded information still survive up to ....etc

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1. Abstract
In recent time watermarking technique becomes a potential solution for copyright protection, authentication and integrity verification of digital media. Among the widely used watermarking techniques, spread spectrum modulation based method becomes appealing due to its inherent advantage of greater robustness and is used widely for various applications. Some watermarking applications, for example, digital television broadcasting, internet protocol television (IP-TV), etc. essentially demand development of ....etc

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