The problem of identification and mitigation of the Non Line Of Sight (NLOS) effects in Ultra Wideband (UWB) indoor localization is a very challenging ongoing topic in the research community. There are two groups of methods applied in UWB indoor localization: indirect two-step localization methods and direct one-step localization methods [1]. Two-step localization methods are widely investigate...

The Impulse Radio based Ultra Wideband (IR-UWB) system transmits data by sending pulses, each with very small time duration followed by pauses that are approximately two hundred times that length. Rake receiver improves system performance by equalizing signals from different paths. This enables the use of Rake receiver techniques in UWB systems. For high data rate ultra-wideband communication s...

Ultra-Wideband (UWB) was approved by the Federal Communications Commission (FCC) in Mar. 2002 for unlicensed operation in the 3.1-10.6 GHz band subject to modified Part 15 rules. The rule limits the emitted power spectral density (p.s.d) from a UWB source measured in a 1 MHz bandwidth at the output of an isotropic transmit antenna at a reference distance to that shown in Figure 1. Further, the ...

Ultra-wideband (UWB) signals are defined to have a band-width of at least 500 MHz and/or a relative bandwidth of more than 20%. A signal with such a large bandwidth has some very unique properties like resistance to small-scale fading, good resolution for ranging and geolocation, and resistance to narrow-band interference. These signals can be used for transmission of extremely high-speed data ...

Ultra Wide Band (UWB) wireless communications offers a radically different approach to wireless communication compared to conventional narrow band systems. Global interest in the technology is huge. This paper reports on the state of the art of UWB wireless technology and highlights key application areas, technological challenges, higher layer protocol issues, spectrum operating zones and futur...

Ultra-wideband (UWB) signals originated from research and development work on high resolution radiofrequency (RF) radar systems in the 1950-60s. The current FCC regulations in the US, define a UWB signal as having an absolute bandwidth which exceeds 500 MHz or fractional bandwidth over 20%. The FCC frequency band assigned to UWB systems extends from 3.1 GHz to 10.6 GHz, i.e. a bandwidth of 7.5 ...

This paper shows the design of a broadband low noise amplifier (LNA) for ultra-wideband (UWB) system on 0.18um CMOS process. The proposed LNA uses resistive shunt feedback technique and an inter-stage inductor as an inductive peaking to realize the flat gain throughout the UWB band. The designed UWB LNA has a noise figure lower than 3.5dB, gain above 20dB in the frequency range 3. 1-10.2GHz. It...

In order to extend the communication range of UWB systems, multi-hop transmission is essencial. However, since the number of hops increases, the packet loss increases as well. In this paper, to improve the reliability of the connection and make up for the packet loss, the retransmission scheme with code-sense for DS-UWB ad-hoc network is investigated and evaluated. key words UWB, Ad-hoc Network...

With the recent media attention on UWB and the announcements of 22 UWB based Wireless-USB (W-USB) products being certified by the WiMedia Alliance, the time has come to evaluate this exciting new wireless technology and see if it has delivered on the promise of transporting hundreds of megabits per second while delivering superior QoS. This test was organized with the cooperation of WirelessNet...

Trends in modern communication systems place high demands on low power consumption, high speed transmission and anti-interference characteristics. Therefore impulse radio ultra–wideband (IR-UWB) [1] radio systems have recently gained increased popularity. Since IR-UWB symbols are transmitted with short pulses (< 2 ns), in IR-UWB systems, energy has been spread over the frequency bands of up to ...