Wireless LAN is currently enjoying rapid deployment in University departments, business offices, hospitals and homes. It becomes an inexpensive technology and allows multiple numbers of the households to simultaneously access the internet while roaming about the house. In the present work , the design and development of a wireless LAN is highlighted which utilizes direct sequence spread spectru...

Digital watermarking is a way to provide the facility of secure multimedia data communication besides its copyright protection approach. The Spread Spectrum modulation principle is widely used in digital watermarking to satisfy the robustness of multimedia signals against various signal-processing operations. Several SS watermarking algorithms have been proposed for multimedia signals but very ...

1. ABSTRACT: Data transmission through power lines has received increasing attention in recent years. In fact the electrical energy distribution system is a big back bone that can be use for data communication. The interest for this medium includes automatic reading of energy meter, management of electrical distribution system, automation of buildings, and high speed data rate connection within...

Acquisition of the code timing in DS/SS systems is addressed for time-varying frequency-selective underwater acoustic channels. Acquisition algorithm based on adaptive channel estimation and fitlering is proposed. The algorithm employs feedback of pre-cursor and post-cursor inter-chip interference to provide a channel estimate from which the code timing is acquired. The channel estimate is also...

We propose a scheme to generate binary code for baseband spread-spectrum communication by using a chain of coupled chaotic maps. We compare the performances of this type of spatiotemporal chaotic code with those of a conventional code used frequently in digital communication, the Gold code, and demonstrate that our code is comparable or even superior to the Gold code in several key aspects: sec...

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As the Internet becomes more and more populous, people concern more about the copyright protection issue for digital data such as images and audio. Digital watermarking technique can hide data in images or audio to indicate the data owner or recipient. Therefore, it can protect the copyright. There were a lot of papers discussing how to embed watermark into images in recent years. However, few ...

Detection of weak signals in a special v-mixing noise class isthe signals are weak, asymptotic performance is of interest.considered. The detector structure is restricted to sums of memorylessnonl inear transformations of the observat ions, correlated with the dataA common measure of asymptotic performance is the sequenceand compared to a f ixed threshold. Using the efficacy...

Spread spectrum (SS) communication systems are now commonly used in civilian applications such as cellular systems and GPS and are fast becoming one of the most commonly used systems. Very low power SS systems such as Global Positioning Systems are extremely vulnerable to high power jammers. A vast array of techniques are available to resolve this problem and this paper attempts to review some ...

At present, with the progress and innovation of technology, the radar communication dual function wave has become a hot research at home and abroad. Excellent integrated waveform can make full use resources of combat platform, reduce the size of equipment, and realize the actual functionality of the reality of the battle-field without affecting the radar communication function. The MSK-LFM dual...