نتایج جستجو برای: ultra-wideband (UWB)

تعداد نتایج: 66975  

A. Sahebalam Gh. Abed Hodtani M. Osmani-Bojd,

In this paper, Ultra-wideband (UWB) multiple access relay channel with correlated noises at the relay and receiver is investigated. We obtain outer and inner bounds for the IEEE 802.15.3a UWB multiple access relay channel, and also, a diversity gain bound. Finally, we evaluate some results numerically and show that noise correlation coefficients play important role in determining relay position.

2004
A. Muqaibel A. Safaai-Jazi S. Riad

Ultra wideband (UWB) wireless communication has been the subject of extensive research in recent years due to its potential applications and unique capabilities. However, many important aspects of UWB-based communication systems have not yet been thoroughly examined. The area of narrow band communication is well developed. The objective of this paper is to present Ultra Wideband (UWB) communica...

2014
N. Vignesh G. A. Sathish Kumar R. Brindha

Ultra Wideband (UWB) has a number of applications that make it attractive for a variety of applications such as microwave imaging, wireless communications, ground penetrating radars, remote sensing and phased arrays. This paper offered the design of a tapered slot Vivaldi antenna for ultra-wideband application using FR4 substrate which has relative permittivity of 4.4. The Vivaldi Antenna is de...

2009
F. Thiel

With the ambitious aim to exploit the specific advantages of ultra-wideband (UWB) radio sensors for medical applications the project ultraMEDIS has been designed. The project focuses on the combination of UWB radar with magnetic resonance imaging, UWB radar based breast cancer detection, identification of various physiological signatures and the development of appropriate UWB antennas to accomp...

2015
Vikas Goyal B. S. Dhaliwal

Ultra-wideband (UWB) uses narrow band pulses of nano-seconds to provide high data rate communications .These narrow pulses spread the energy across a wide frequency band that is why it is called ultra-wideband. In this paper, we will discuss the UWB pulse modulation and multiple access modulation schemes using Pulse Position Modulation technique .The simulations are done in MATLAB software.

Journal: :IEICE Transactions 2012
Dau-Chyrh Chang Chao-Hsiang Liao Powen Hsu

Power patterns in the frequency domain are usually used to describe the antenna performance in narrowband communication systems; however, they are not sufficient for ultra wideband (UWB) antennas in wideband communication systems. In this paper, energy pattern and energy gain are introduced to describe the performance of UWB antennas. Numerical simulations and measurements are used to demonstra...

2013
Rasha El-Khamy Shawky Shaaban Ibrahim Ghaleb Hassan Nadir Kheirallah

-In ultra-wideband (UWB) impulse radio (IR) technology, it is important that the pulse shape be adjusted such that the power spectral characteristics not only satisfy the standard limits, but also be characterized by deep nulls at the locations of existing narrowband primary users. Cognitive Radio Technology (CR) is presented as a viable solution for UWB systems for narrowband interference supp...

Journal: :رادار 0
نرگس زرنقی نقش ایاز قربانی حمیدرضا امین داور

in ultra-wideband (uwb) multistatic microwave breast cancer imaging, the long imaging time is an important issue. in this paper, a novel imaging method for multistatic uwb radarbased microwave breast cancer imaging using sparse sampling has been proposed that significantly reduces the amount of data and imaging time. in this method, instead of measuring multistatic radar signals conventionally,...

2010
Bikramaditya Das

For high data rate ultra wideband communication system, performance study of mutual interference such as suppression of interference signal by performing pulse shaping from UWB to other narrowband system using wavelet technique and reduction of interference from other narrowband system to UWB system in conjunction with Transmitted-Reference (TR-UWB) signaling scheme with adaptive receivers is a...

2013
M. S. I. M. Zin A. A. M. Isa M. S. M. Isa

In this paper, we consider the possibility of developing an optimal medium access control (MAC) layer for high data rate ultra-wideband (UWB) transmission systems that transmit minimal power. MAC in UWB wireless networks is required to coordinate channel access among competing devices. The unique UWB characteristics offer great challenges and opportunities in effective UWB MAC design. We first ...

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