نتایج جستجو برای: uwb

تعداد نتایج: 4839  

Journal: :JNW 2012
Jun Wang Weiru Chen

The UWB (Ultra Wide Band) technology can play an effective role in FCS (Fieldbus Control System). But the channel acquisition time of UWB is high, and a lot of packets are short in FCS. So the efficiency of FCS based on UWB will significantly reduce. In this paper, a CSMA/CA protocol with D-UF (Dynamic Length Mechanism for Unite Frame) is proposed. The characteristics of UWB and size of data pa...

2005
Dongsong Zeng

Ultra wideband (UWB) is a promising technology for short range and high-speed wireless communications such as home entertainment, wireless video downloading, wireless LAN, wireless USB and so on. This dissertation studied several important issues in the application of UWB technology and its contributions are summarized as follows. First, a 2-stage optimal UWB pulse shaping filter design procedu...

Journal: :IEICE Transactions 2009
Chin-Sean Sum Mohammad Azizur Rahman Shigenobu Sasaki Hiroshi Harada Shuzo Kato

This paper proposes a hybrid multiband (MB) ultra wideband (UWB) system with direct sequence (DS) spreading. The theoretical error analysis for the DS-MB-UWB multiple access system with Rake receiver in the presence of multipath and narrowband interference is developed. The developed theoretical framework models the multiple access interference (MAI), multipath interference (MI) and narrowband ...

Journal: :IACR Cryptology ePrint Archive 2017
Mridula Singh Patrick Leu Srdjan Capkun

Physical layer attacks allow attackers to manipulate (spoof) ranging and positioning. These attacks had real world impact and allowed car thefts, executions of unauthorised payments and manipulation of navigation. UWB impulse radio (UWB-IR) has emerged as a prominent technique for precise ranging that allows high operating distances despite power constraints by transmitting multi-pulse symbols....

2000
Matti Hämäläinen Jari Iinatti Ian Oppermann Matti Latva-aho Jani Saloranta Ari Isola

The paper presents results of a co-existence measurement study between multiple ultra wideband (UWB) transmitters and a Universal Mobile Telecommunications System (UMTS) mobile phone. Two environments were explored: an anechoic chamber with one operating UMTS link and a true operational UMTS network. A large number of FCC compatible UWB transmitters were used to generate interference for an act...

Journal: :IEEE Journal on Selected Areas in Communications 2002
Lie-Liang Yang Lajos Hanzo

Ultra-wideband (UWB) systems having a bandwidth on the order of gigahertz have recently received wide attention both in the U.S. and in Europe. The family of UWB systems may communicate either by generating ultra-wideband signals or with the aid of innovatively combining conventional narrowband, wideband, or broadband signals. At the time of writing, UWB systems have only been implemented using...

2009
Ramu Pillalamarri Jyoti Ranjan Panda Rakhesh Singh Kshetrimayum

In this paper, we have investigated printed monopole antennas, which is basically printed microstrip antenna with etched ground plane for UWB applications. In particular, we have simulated two types of UWB printed monopole antennas: circular and modified circular disk monopole antennas. Simple rectangular microstrip lines are used for feeding the printed monopole antennas. This UWB monopole ant...

2002
Gopal Racherla

Ultra-Wideband1 (UWB) is a radio transmission scheme that uses extremely low power pulses of radio energy spread across a wide spectrum of frequencies. UWB has several advantages over conventional continuous wave radio communications including potential support for high data rates, robustness to multipath interference and fading. We present an overview of UWB technology and its use in data comm...

2011
G Tsao

An experimental testbed is described for the characterization of indoor channels with sufficient spatial resolution and sufficient bandwidth to study the practical capacities of MIMOUWB systems. UWB measurements have been made in both frequency and time domains for mutual validation. The opportunity has been taken in this paper to extract narrowband transmission loss models from the resulting U...

2004
Idnin Pasya Atsushi Tomiki Takehiko Kobayashi

−This paper studies the interference effects from 4 types of ultra wide band (UWB) sources on a narrowband π/4-shift differential quadrature phase keying (DQPSK) transmission system by simulation. The culprit UWB sources were: multi-band orthogonal frequency-division multiple-access (MB-OFDM), direct-sequence code-division multiple-access (DS-CDMA), DS spread spectrum UWB (DS-SS UWB), and addit...

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