It is well known that the existing spectrum licensing system results in a gross under-utilization of the frequency spectrum. Spectrum background measurements – spectrum surveys – provide useful data for spectrum regulation, planning or finding frequency niches for spectrum sharing. Dynamic spectrum sharing as a main goal of cognitive radio (CR) is the modern option on how to optimize usage of t...

We have carried out a bulk-sensitive high-resolution photoemission experiment on Mn5Si3. The measurements are performed for both core level and valence band states. The Mn core level spectra are deconvoluted into two components corresponding to different crystallographic sites. The asymmetry of each component is of noticeable magnitude. In contrast, the Si 2p spectrum shows a simple Lorentzian ...

The spectrum of the compound from V. sativa shows two bands, the more complex one, at higher field, is the AB portion of an ABX spectrum which has been further split by a single proton. The lower field band is the AB part of an ABX spectrum. The position and multiplicities of these bands in the observed spectrum are those expected of the 3and 5-protons of the proposed formula. The 2and 4proton ...

Spectrum sensing has been an active research area for the past two decades. Nonetheless, current spectrum sensing systems provide only coarse occupancy data. They lack information about the detailed signal patterns in each band and can easily miss fleeting signals like radar. This paper presents SpecInsight, a system for acquiring a detailed view of 4 GHz of spectrum in realtime. SpecInsight’s ...

Broadband access by satellite in the Ka band is currently constrained by spectrum availability. Cognitive radio has emerged as a promising paradigm to improve the spectrum usage efficiency and cope with spectrum scarcity problems through dynamically detecting and re-allocating white spaces in licensed (incumbent) radio band to unlicensed (cognitive) users. In this context, the EU FP7 project Co...

in this article, the effect of cells' radius on the behavior of wavelength switching optical filter andthe effect of the radius of the optical filters' key characteristics such as wavelength resonance onan optical filter based on photonic crystals, have been investigated. currently, the most commonapplied mechanism for designing optical filter based on photonic crystals is using twomechanisms s...

In this demo, we propose to use multiple inexpensive off-the-shelf radios to build the FAIR system that can be flexibly configured to realize (1) non-contiguous spectrum access (2) MIMO and beamforming (3) constructing wider-band radio. While non-contiguous spectrum access and MIMO/beamforming are naturally supported by the FAIR system, we further develop radio bonding technique for constructin...

This paper presents the use of a variety of lters in the temporal trajectories of frequency band spectrum to extract speech recognition features for environmental robustness. Three kind of lters for emphasizing the statistically important parts of speech are proposed. First, a bank of RASTA-like band-pass lters to t the statistical peaks of modulation frequency band spectrum of speech are used....