نتایج جستجو برای: selcote ultra
تعداد نتایج: 58116 فیلتر نتایج به سال:
In this paper, Multiband-OFDM UWB system based on IEEE 802.15.3a standard is studied and simulated with spatial, time and frequency (STF)coding scheme. The using of STF coding method can guarantee both full symbol rate and full diversity advantages. The simulation results show that the STF code uses multipath-rich and random-clustering characteristics of UWB channel environment on the performan...
The emergence of commercial wireless devices based on ultra-wideband radio technology (UWB-RT) is widely awaited and anticipated. UWB-RT is not only applicable to communications, imaging and ranging, it also promises to alleviate the problem of increasingly scarce spectrum resources while enabling new wireless applications and business opportunities. These prospects have caught the early attent...
In ultra-wideband (UWB) channels, the signal energy in the acquisition receiver spreads over correlator outputs due to rich multipaths, making the output of each correlator have only a small portion of the total energy. To enhance the acquisition performance for UWB signals by exploiting the signals spread over a number of correlator outputs, this paper proposes a two-stage acquisition scheme. ...
This paper presents a theoretical analysis of the structure of wide angle, ultra-wideband SAR images formed by a constant integration angle backprojection image former. It is shown that the effects of the image former can be modeled as a filtering operation on the original data. Furthermore, SAR images for different squint angles can be obtained from the original images by directional filtering...
In this paper, on-body radio channel performance of a compact ultra wideband (UWB) antenna is investigated for body-centric wireless communications. Measurement campaigns were first done in the chamber and then repeated in an indoor environment for comparison. The path loss parameter for eight different on-body radio channels has been characterized and analyzed. In addition, the path loss was m...
Impulse radio, a form of ultra-wide band signaling, has properties that make it a viable candidate for short range communications in dense multipath environments. This paper describes the characteristics of impulse radio, gives analytical estimates of its multiple access capability, and presents propagation test results and their implications for the design of the radio receiver.
........................................................................................................................ ii List of Figures .............................................................................................................. iv List of Tables ................................................................................................................ vi Acknowledgem...
We tested an off-ground ground-penetrating radar (GPR) system at a fixed location over a bare agricultural field to monitor the soil freeze-thaw cycles over a snow-covered surface. The GPR system consisted of a monostatic horn antenna combined with a vector network analyzer, providing an ultra-wideband stepped-frequency continuous-wave radar. An antenna calibration experiment was performed to f...
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