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.

Ultra-wideband wireless systems

This invention generally relates to networks of communications devices, in particular ultra wideband (UWB) communications devices. An ultra-wideband (UWB) network comprising a plurality of UWB devices each forming a node of said network, pairs of said UWB devices being configured for communication with one another using one of a plurality of UWB channels, each said UWB device comprising a UWB transceiver for bidirectional communication over one or more of said UWB channels with at least one other of said UWB devices; and a device controller coupled to said UWB transceiver, said controller being configured to determine a said UWB channel for use in establishing a communication link with each other UWB device; whereby said network is configured for automatic construction of a set of communications links between said nodes of said network.

Communications systems and methods

Performance evaluation of ultra wideband technology for construction resource location tracking in harsh environments

Summary Ultra-wideband (UWB) communication techniques have attracted a great interest in both academia and industry in the past few years for applications in short-range wireless mobile systems. This is due to the potential advantages of UWB transmissions such as low power, high rate, immunity to multipath propagation, less complex transceiver hardware, and low interference. However, tremendous R&D efforts are required to face various technical challenges in developing UWB wireless systems, including UWB channel characterization, transceiver design, coexistence and interworking with other narrowband wireless systems, design of the link and network layers to benefit from UWB transmission characteristics. This paper is to provide an overview of UWB communications, summarize the previous research results, and identify further research issues that need to be tackled. The emphasis is placed on the commercial wireless communications. Copyright # 2003 John Wiley & Sons, Ltd.

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Ultra-Wideband Wireless Communications

Throughput capacity is a critical parameter for the design and evaluation of ad-hoc wireless networks. Consider n identical randomly located nodes, on a unit area, forming an ad-hoc wireless network. Assuming a fixed per node transmission capability of T hits per second at a fixed range, it has been shown that the uniform throughput capacity per node r(n) is /spl otimes/(T//spl radic/nlogn). We consider an alternate communication model, with each node constrained to a maximum transmit power P/sub 0/ and capable of utilizing W Hz of bandwidth. Under the limiting case W/spl rarr//spl infin/, such as in ultra wide band networks, the uniform throughput per node is /spl otimes/((nlogn)/sup /spl alpha/-1/2/ (upper bound) and /spl Omega/(n/sup (/spl alpha/-1)/2//(logn)/sup (/spl alpha/+1)/2/) (achievable lower bound). These bounds demonstrate that throughput increases with node density n, in contrast to previously published results. This is the result of the large bandwidth, and the assumed power and rate adaptation, which alleviate interference. Thus, the significance of physical layer properties on the capacity of ad-hoc wireless networks is demonstrated.

Capacity of power constrained ad-hoc networks

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.

D. Guy

Papers

Recent advances in ultra wideband communications systems