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...

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...

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...

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...

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 ...

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...

In this paper a new UWB textile slot antenna has been designed with high precision. This work aimed to makecloser steps towards real wearability by investigating the possibilities of designing wearable UWB antenna wheretextile materials are used for the substrate as well as the conducting parts of the designed antenna. The antenna iscomposed of three textile layers: the top and bottom are condu...

This paper presents a review of Ultra Wide Band (UWB) communication system and its application for the indoor environment, in general, and in underground mine environment. It shows that, to improve the UWB system performance many researcher proposed the modification in transmitting and receiving schemes of UWB system. Literature survey given in this paper, gives brief idea on the techniques whi...

This paper evaluates the level of interference caused by different ultra-wideband (UWB) signals to other various radio systems, as well as the performance degradation of UWB systems in the presence of narrowband interference and pulsed jamming. The in-band interference caused by a selection of UWB signals is calculated at GSM900, UMTS/wideband code-division multiple-access (WCDMA), and global p...

Multiband Orthogonal Frequency Division Multiplexing (MB-OFDM) approach using UWB signals with short duration of pulses provide unique advantages in short-range high data rate wireless applications which include easy penetration through obstacles, high precision ranging and low processing power. In this paper a performance study on MB-OFDM is attempted for high data rate ultra wideband (UWB) WP...