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Journal ArticleDOI

Ultra-wideband wireless systems

28 May 2003-IEEE Microwave Magazine (IEEE MICROWAVE MAGAZINE)-Vol. 4, Iss: 2, pp 36-47
TL;DR: In this article, two UWB multiband systems, frequency hopping and Spectral Keying, have been described, both of which meet the stringent requirements provided by IEEE 802.15.3a.
Abstract: The recent FCC frequency allocation for UWB has generated a lot of interest in UWB technologies. There is 7,500 MHz of spectrum for unlicensed use. The main limitations are provided by the low-power spectral density and by the fact that the transmit signal must occupy at least 500 MHz at whole times. IEEE 802.15.3a is being developed for high-bit-rate PAN applications, and UWB is the most promising technology to support the stringent requirements: 110, 200, and 480 Mb/s. Two UWB multiband systems, frequency hopping and Spectral Keying, have been described in this article. Both systems meet the stringent requirements provided by IEEE 802.15.
Citations
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Journal ArticleDOI
TL;DR: This tutorial overviews the state-of-the-art UWB in channel modeling, transmitters, and receivers of UWB radios, and outlines the research directions and challenges that needs to be overcome.
Abstract: Ultra-wideband (UWB) radio is a fast emerging technology with many unique attractive features that promotes major advances in wireless communications, networking, radar, imaging, and positioning systems. Research in UWB is still in its infancy stages, offering limited resources in handling the challenges facing the UWB communications. Understanding the unique properties and challenges of UWB communications as well as its application in competent signal processing techniques are vital in conquering the obstacles towards developing exciting UWB applications. UWB research and development has to cope with the challenges that limit their performance, capacity, throughput, network flexibility, implementation complexity, and cost. This tutorial focuses on UWB wireless communications at the physical layer. It overviews the state-of-the-art UWB in channel modeling, transmitters, and receivers of UWB radios, and outlines the research directions and challenges that needs to be overcome. Since a signal processing expertise is expected to have major impact in research and development of UWB systems, emphasis is placed on the DSP aspects.

1,199 citations

Journal ArticleDOI
TL;DR: The current progress of terahertz-wave technologies related to communications applications are examined and some issues that need to be considered for the future of THz communications are discussed.
Abstract: Recent changes in how people consume multimedia services are causing an explosive increase in mobile traffic. With more and more people using wireless networks, the demand for the ultra-fast wireless communications systems is increasing. To date, this demand has been accommodated with advanced modulation schemes and signal-processing technologies at microwave frequencies. However, without increasing the carrier frequencies for more spectral resources, it may be quite difficult to keep up with the needs of users. Although there are several alternative bands, recent advances in terahertz-wave (THz-wave) technologies have attracted attention due to the huge bandwidth of THz waves and its potential for use in wireless communications. The frequency band of 275 ~ 3000 GHz , which has not been allocated for specific uses yet, is especially of interest for future wireless systems with data rates of 10 Gb/s or higher. Although THz communications is still in a very early stage of development, there have been lots of reports that show its potential. In this review, we will examine the current progress of THz-wave technologies related to communications applications and discuss some issues that need to be considered for the future of THz communications.

1,072 citations

Journal ArticleDOI
TL;DR: In this article, a microstrip-line ultra-wideband (UWB) bandpass filter is proposed and implemented using a multiplemode resonator (MMR), aiming at transmitting the signals in the whole UWB passband of 3.1-10.6GHz.
Abstract: A novel microstrip-line ultra-wideband (UWB) bandpass filter is proposed and implemented using a multiple-mode resonator (MMR), aiming at transmitting the signals in the whole UWB passband of 3.1-10.6GHz. In the design, the first three resonant frequencies of this MMR are properly adjusted to be placed quasiequally within the UWB. Then, the parallel-coupled lines at the two sides are longitudinally stretched so as to raise the frequency-dispersive coupling degree with the coupling peak near the center of the UWB. After optimization of this filter, a good UWB bandpass behavior with five transmission poles is theoretically realized and experimentally confirmed. Within the whole UWB passband, the return loss is found higher than 10dB, and the group delay variation is less than 0.23ns.

990 citations

Journal ArticleDOI
TL;DR: An ultrawideband 3.1-10.6-GHz low-noise amplifier employing an input three-section band-pass Chebyshev filter using a 0.18-/spl mu/m CMOS process achieves a power gain of 9.3 dB with an input match of -10 dB over the band.
Abstract: An ultrawideband 3.1-10.6-GHz low-noise amplifier employing an input three-section band-pass Chebyshev filter is presented. Fabricated in a 0.18-/spl mu/m CMOS process, the IC prototype achieves a power gain of 9.3 dB with an input match of -10 dB over the band, a minimum noise figure of 4 dB, and an IIP3 of -6.7 dBm while consuming 9 mW.

714 citations

Journal ArticleDOI
TL;DR: An extensive literature review over the period 2002-2013 of machine learning methods that were used to address common issues in WSNs is presented and a comparative guide is provided to aid WSN designers in developing suitable machine learning solutions for their specific application challenges.
Abstract: Wireless sensor networks (WSNs) monitor dynamic environments that change rapidly over time. This dynamic behavior is either caused by external factors or initiated by the system designers themselves. To adapt to such conditions, sensor networks often adopt machine learning techniques to eliminate the need for unnecessary redesign. Machine learning also inspires many practical solutions that maximize resource utilization and prolong the lifespan of the network. In this paper, we present an extensive literature review over the period 2002–2013 of machine learning methods that were used to address common issues in WSNs. The advantages and disadvantages of each proposed algorithm are evaluated against the corresponding problem. We also provide a comparative guide to aid WSN designers in developing suitable machine learning solutions for their specific application challenges.

704 citations

References
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Proceedings ArticleDOI
21 May 2002
TL;DR: This work has developed a method of rapid acquisition that allows two nodes to acquire each other in a fraction of the time afforded by other methods, utilizing a beacon/listener technique using Kasami sequences and divide-and-conquer algorithms.
Abstract: Ultra-wideband (UWB) signals as implemented in our localizers provide a foundation for highly accurate methods of 3D position determination using precise ranging between any two nodes. In a large, distributed network of nodes, the time required for all nodes to acquire each other is of paramount importance. We have developed a method of rapid acquisition that allows two nodes to acquire each other in a fraction of the time afforded by other methods. We utilize a beacon/listener technique using Kasami sequences and divide-and-conquer algorithms to effect acquisitions in less than a second. We discuss our rapid acquisition process in this paper.

125 citations

Proceedings ArticleDOI
21 May 2002
TL;DR: Three recent system developments are described: an ad hoc wireless UWB communications network for tactical voice and high-speed data communications; a long range UWB system for over-the-water and non line-of-sight voice, data and video communications.
Abstract: The last compilation of ultra wideband (UWB) communications systems is nearly two years old (see Fontana, R.J., Ultra-Wideband, Short-Pulse Electromagnetics, EuroEM 2000). This paper is intended as an update and illustrates recent trends in UWB communications for multi-user networking applications. More specifically, the paper describes three recent system developments: an ad hoc wireless UWB communications network for tactical voice and high-speed data communications; a long range UWB system for over-the-water and non line-of-sight voice, data and video communications; a wireless UWB communications network for support of both tactical and strategic (long haul) communications.

105 citations

Proceedings ArticleDOI
19 Jun 2001
TL;DR: The characteristics and the advantages of ultra-wideband (UWB) radio technology when combined with a decentralized, priority-driven network architecture for wireless video networking in the home are described.
Abstract: The proliferation of consumer electronic devices that provide streams of video, such as digital-video disk (DVD) players, high-definition television (HDTV) sets, digital cameras, and digital camcorders, has given rise to significant interest in broadband home entertainment networks. Wireless home networks are particularly attractive because of ease of installation or relocation. However, many existing wireless networks do not satisfy the demands of the home-networking environment, nor do they provide the necessary performance to support multiple audio-video streams. This paper describes the characteristics and the advantages of ultra-wideband (UWB) radio technology when combined with a decentralized, priority-driven network architecture for wireless video networking in the home.

38 citations

Proceedings ArticleDOI
21 May 2002
TL;DR: In this article, the authors provide an overview of multiplexing techniques and suggest ways in which they can be applied to UWB networks and relative advantages and challenges of each technique are identified in order to understand the suitabilitability of each for use in a multi-piconet WPAN system.
Abstract: Ultra-wideband technology provides robust high data rate networks that can be used to meet the needs of wireless personal area network (WPAN) applications. An essential part of this design is the selection of a multiplexing technique to provide multiple physical channels (piconets) from the single shared UWB band. This paper provides an overview of multiplexing techniques and suggests ways in which they can be applied to UWB networks. Relative advantages and challenges of each technique are identified in order to understand the suitabilitity of each for use in a multi-piconet WPAN system.

36 citations