نتایج جستجو برای: باند uwb

تعداد نتایج: 10649  

2003
Matti Hämäläinen Romeo Giuliano

This document is about the “UWB co-existence analysis” to be published as an Ultrawaves deliverable D2.2. The document covers the co-existence studies between ultra wideband and other radio systems. If UWB systems will be adopted in a common use globally, or only in Europe, an inevitable consequence is that the UWB co-existence issues will have more and more significant role in the near future ...

Journal: :IEICE Transactions 2006
Chin-Sean Sum Shigenobu Sasaki Hisakazu Kikuchi

In this paper, the impact of timing jitter in direct sequence ultra wideband (DS-UWB) system is investigated over multipath fading channel. Also, a novel hybrid direct sequence multiband UWB (DS-MBUWB) system is proposed to mitigate the impact of timing jitter. We analyze and compare the system performance for conventional DS-UWB and hybrid DS-MB-UWB with Rake receiver in the presence of timing...

Band-notch characteristic has been of great interest recently to overcome the electromagnetic interference of Ultra-wideband systems (UWB) with other existing ones. In this paper, we present a novel microstrip-fed antenna with band rejection property appropriate for UWB applications. Band-notch characteristic has been achieved by adding a rectangular resonant element to the ground section. A pr...

پایان نامه :وزارت علوم، تحقیقات و فناوری - موسسه آموزش عالی غیرانتفاعی و غیردولتی سجاد مشهد - دانشکده برق 1389

در این گزارش با معرفی مخابرات فراپهن باند بعنوان یک تکنولوژی نوظهور در سیستم های مخابراتی بی سیم، موضوع شکل دهی طیفی مورد توجه قرار گرفته و با بررسی علت و اهمیت شکل دهی طیف سیگنال فراپهن باند و روشهای مختلف شکل دهی طیفی، یک نمونه سیگنال فراپهن باند که با استفاده از تقریب چندجمله ایها بدست می آید طراحی گردیده و پارامترهای طراحی سیگنال را نیز با استفاده از الگوریتم remez بدست آورده ایم. در واقع ا...

2009
Shuyuan Yang

The paper presents a method of designing ultrawide band (UWB) pulse array beamformer in the case of nearfield. Firstly the principle of space-time processing of UWB pulse array is discussed. The radical beampattern transform based on spherical coordinates is employed to solve the nearfield beamforming of UWB pulse array. The frequency invariant technology is considered for the frequency depende...

2012
Mohamed Nabil Srifi

On February 14, 2002, the Federal Communications Commission (FCC) of the United States adopted the First Report and Order that permitted the commercial operation of ultra wideband (UWB) technology (FCC, 2002). The FCC allocated a bandwidth of 7.5GHz, i.e. from 3.1GHz to 10.6GHz, to unlicensed use for UWB applications. Ultra Wideband is defined as any communication technology that occupies great...

Journal: :IEEE Trans. Vehicular Technology 2005
Robert C. Qiu Robert A. Scholtz X. Shen

ULTRA-WIDEBAND (UWB) transmission has recently received significant attention in both academia and industry for applications in wireless communications. UWB technology has many benefits, including high-data rate, availability of low-cost transceivers, low-transmit power, and low interference. It operates with emission levels that are commensurate with common digital devices such as laptops, pal...

2012
Moez Hizem Ridha Bouallegue

UWB impulse radios (UWB-IR) have attracted increasing interest due to their potential to propose high user capacity with low-complexity and low-power transceivers (Win & Sholtz, 2000). It is approved by the Federal Communications Commission’s (FCC) Report in which the UWB spectral mask is released and published in February 2002. Most of these benefits initiate from the distinctive characteristi...

Journal: :IEICE Transactions 2010
Chin-Sean Sum Shigenobu Sasaki Hiroshi Harada

In this paper, the impact of chip duty factor (DF) on direct sequence (DS), time hopping (TH) and hybrid DS-TH ultra wideband (UWB) systems is investigated in realistic environments. Rake receivers are designed to perform energy capture (EC) on received UWB signals over multipath and multi-user environment in the presence of narrowband interference. It is found that by applying lower DF in the ...

Journal: :Tsinghua Science & Technology 2022

The Ultra-WideBand (UWB) technique, which offers good energy efficiency, flexible data rate, and high ranging accuracy, has recently been recognized as a revived wireless technology for short distance communication. This paper presents brief overview of two UWB techniques, covering Impulse-Radio (IR-UWB) Frequency-Modulation (FM-UWB) methods. link margin enhancement Very-WideBand (VWB), power c...

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