Improved detection scheme for chipless RFIDs using prolate spheroidal wave function-based noise filtering

A novel, highly sensitive scheme to detect the resonance peaks in the spectrum of chipless RFID signals is presented. The detection is based on finding the zeros in the derivative of the group delay of the received signal. In order to be able to accurately detect these zeros in the presence of noise, the received signal is filtered using a prolate spheroidal wave function-based model. This allows great increases in the distance at which chipless RFIDs can be accurately read. The detection method can be used standalone or in addition to traditional amplitude-based detection schemes

Advantages of PSWF-based models for UWB systems

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Novel compact model for the radiation pattern of UWB antennas using vector spherical and Slepian decomposition

A new compact model is described for the 3D radiation pattern of an ultrawideband antenna, using a vector spherical and Slepian decomposition. Vector spherical modes are known to provide a good basis for the angular dependency of the radiation pattern. This paper is the first to extend such a model to also incorporate the frequency dependency of a radiation pattern. This is achieved by using a Slepian mode expansion. It is shown that this model requires considerably less coefficients than traditional sampling to accurately describe a frequency-dependent 3D radiation pattern. Also, generating the Slepian modes is computationally more efficient than comparable techniques, such as the singularity expansion method ( SEM). The coefficients can then directly be used to efficiently calculate performance measures such as the antenna Fidelity Factor for all angles (phi, theta) without reconstructing the radiation pattern, or to reduce the noise contribution

Compression of measured 2D UWB antenna transfer functions

Rules of thumb are derived for compressing transfer functions of UWB antennas using a phase-mode/Slepian-mode based model. These are applied to measured 2D UWB radiation patterns of bowtie, log-periodic and Vivaldi antennas. A compression ratio of 5.8 with a maximal error of 10% is achieved

A Scalable Consent, Transparency and Compliance Architecture

In this demo we present the SPECIAL consent, transparency and compliance system. The objective of the system is to afford data subjects more control over personal data processing and sharing, while at the same time enabling data controllers and processors to comply with consent and transparency obligations mandated by the European General Data Protection Regulation. A short promotional video can be found at https://purl.com/specialprivacy/demos/ESWC2018

Compact modeling of ultra wideband systems

In an ever connected world, there is an ever growing need for faster wireless communication links. Unfortunately, the frequency spectrum is a heavily used, scarce good. Ultra Wideband (UWB) communication systems promise to solve both issues. They have very wide bandwidth (larger than 500 MHz, or alternatively, larger than 0.2 times the center frequency), allowing fast data transmissions, combined with a very low spectral mask (smaller than -41 dBm/MHz). This low spectral mask allows UWB systems to coexist with current communications systems, in the same frequency range. In 2002, the Federal Communication Commission (FCC) of the United States of America, gave a large boost to UWB research, both academic and commercial, by allowing unlicensed use of these systems between 3.1 GHz and 10.6 GHz. While the benefits of UWB systems are clear, their large bandwidths make the system design much more complicated than the more traditional smallband systems. In smallband systems, all parameters can be considered independent of frequency, while in UWB systems, the frequency dependency should be considered for every component of the communication link. In order to make the design of these systems more manageable, this work proposes to model the frequency dependency of the various link components by projecting them on discrete prolate spheroidal sequences (DPSSs), or improving upon this, prolate spheroidal wave functions (PSWFs). It is shown that these functions can provide a very compact and accurate representation of the frequency dependency of various components of the system, such as antenna radiation patterns. Various applications of this model are also provided in this work. First, it is shown that the model can be used to remove measurement noise. Second, this noise filtering property is also exploited in a detection scheme for chipless passive radio frequency identification tags (RFIDs), based on the second derivative of their phase response. Finally the compactness of the model can be exploited, by using the PSWFs as a basis function of a compressive sensing framework, which allows the accurate reconstruction of the frequency dependent function from a random set of sub-Nyquist rate samples

Modeling of the frequency dependency of a measured 2D UWB radiation pattern

A model to describe the frequency dependency of a radiation pattern, using discrete prolate spheroidal sequences (DPSSs), is applied to a measured radiation pattern of a UWB antenna

Een wekedelentumor als oorzaak van heuppijn

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