Research in the design of ultra-wideband (UWB) radio systems suggests di erent kinds of signal design criteria. After an introduction to UWB radio, a variety of sequence design problems, motivated by UWB system constraints, will be presented. Design for time-hopping, for spectral atness, for rapid acquisition, and for multiple access will be discussed, and some sample designs will be presented.

A reconfigurable impulse radio ultra-wideband (UWB) pulse generator for various UWB shapes (e.g., monocycle, doublet, and triplet pulses) based on a nonlinear optical loop mirror (NOLM) and differential detection is proposed and experimentally demonstrated. The proposed approach can be used with different modulation formats and may be suitable for implementation in future low-cost, high-speed, ...

ultra-wideband (uwb) radio is a promising technology for low-cost, high-rate communications at short ranges. however, high bandwidth and low power of the uwb signals impose some difficult challenges in signal processing and implementation of the receiver. acquisition of the signal timing is the first task to be performed in a coherent receiver. the high bandwidth of uwb signals demand for fine ...

This paper presents results from co-existence measurements between multiple ultra wideband (UWB) transmitters and a UMTS mobile phone carried out at the Centre for Wireless Communications (CWC), University of Oulu, Finland. Two environments were explored with the measurements; an anechoic chamber, and inside a shelter (simulating cell boundary conditions). Large numbers of FCC compatible UWB tr...

هدف: کارآفرینی یکی از عوامل کلیدی در توسعه اقتصادی و شاخص اساسی جوامع روبه‌رشد است. آنچه که کارآفرین را به آغاز فعالیت ترغیب می‌کند، انگیزه فرایند تبدیل یک فرد عادی است می‌تواند فرصت‌هایی ایجاد کند حداکثر رساندن ثروت کمک کند. هدف این پژوهش شناسایی طبقه‌بندی انگیزه‌های کارآفرینان می­باشد.طراحی/ روش‌شناسی/ رویکرد: با رویکرد مرور نظام­مند استفاده ماتریس شش سلولی دو مؤلفه جهت (کشش یا فشار) منبع (اق...

In this Chapter, a short range radar system based on ultra-wideband (UWB) technology is presented. The radar and its applications were reserved during a long time to national defence, air security or weather services domains. Since a few years, with the emergence of new technologies, the radar applications were developed and become known in many sectors of daily life. The arrival of a new techn...

INTRODUCTION The Ultra wideband (UWB) radio communication is known as a “carrier-free”, “baseband” or “impulse” technology. The basic concept is to transmit and receive an extremely short duration burst of pulses, typically having few tens of picoseconds in duration, with the resulting waveforms extremely broadband in frequency [1]. The UWB systems send a train of pulses with a very low duty cy...

Data communications is going to wireless everywhere, from computer keyboard to Internet, from sensor networks to embedded systems. The spread of wireless communications is blocked by the fact that the radio channels have been already assigned to conventional communication systems and except a very few and crowded ISM bands there are no empty channels. Radio communications via channels already o...

This paper presents the design of a 2-16 GHz ultra wide band low noise amplifier (UWB LNA). The proposed LNA has a gain of 11.5 ± 0.85 dB with NF less than 2.82 dB. Good input and output impedance matching, good isolation and linearity are achieved over the operating frequency band. The proposed UWB LNA consumes 18.14 mW of power from 1.8V supply. This UWB LNA is designed and simulated in 0.18 ...