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For its simplicity and ease of implementation, Energy detection (ED) is attractive for spectrum sensing in cognitive radio (CR) systems. In ED, the energy captured is compared against a fixed detection threshold, which is estimated as a function of the noise power. Uncertainties caused by the imperfect knowledge of the noise power, referred to as noise uncertainty, leads to a reduced performance of...
When transistor noise characterization becomes a difficult task at millimeter wave range, the accuracy on the resulting noise parameters is not or poorly discussed. Within this context, this paper aims to present a methodology to estimate the uncertainties related to the extraction of the four noise parameters when using in situ tuner techniques, in the 130–170 GHz frequency range. B9MW SiGe HBT from...
This paper describes IMPREAL 2.0, a system developed in LabVIEW which automates the acquisition of voltage impulse waveforms from digital oscilloscopes and implements the mathematical procedures described in the new standards IEC 60060/2010. The system controls Tektronix oscilloscopes and is able to automatically calculate the time and amplitude parameters of lightning impulses, switching impulses,...
Owing to their uttermost linearity, high-grade multimeters can be profitably used as voltage ratio standards. To exploit the high performances achievable, the residual nonlinearities must be evaluated with a quantum reference and particular attention is required to avoid reduction in accuracy. Differently from the resistive divider case, the ratio is obtained from actual voltage measurements, and...
An error vector magnitude (EVM) measurement method for W-CDMA source is proposed using a real time oscilloscope with traceability to SI unit. Also measurement uncertainty is evaluated based on a Monte-Carlo simulation, which takes into account the errors from the oscilloscope and signal processing. The measured EVM of a source at 900 MHz is 0.2535% ± 0.0057% at 95% confidence level.
Coordinated Multipoint (CoMP) transmission provides high theoretic gains in spectral efficiency, in particular with coherent linear Joint Transmission (JT) to multiple users. However, this requires high backhaul capacity. If the backhaul requirement cannot be met by the system, then CoMP gains decrease as the linear precoder matrix must be adjusted to include zeros. To minimize the loss of CoMP gains,...
The present paper proposes a concept for model-based sensor fault diagnosis and its application to the reference system Stuttgart SmartShell. The approach is based on the well-known Dedicated Observer Scheme and utilizes observable subsystems for residual generation. Particular attention is paid to the residual evaluation in order to account for the effects of noise, model uncertainties and external...
This paper describes an automated non-coherent sampling THD meter based on the 24 bit digitizer National Instruments PXI 5922. The THD meter is designed for a frequency range up to 1 MHz with analysis of the harmonics up to 6 MHz. Contrary to commercial devices developed THD meter displays a signal spectrum and gives user the possibility to evaluate impurities in the signal affecting THD calibration...
An ultrastable low-noise current amplifier (ULCA) is presented. The ULCA is a non-cryogenic instrument based on specially designed operational amplifiers and resistor networks. It acts as a current-to-current amplifier or a current-to-voltage converter. Its transfer coefficient is extremely stable versus time, temperature and current amplitude within the full dynamic range of ±13 nA. The concept aims...
A comprehensive uncertainty, baseline, and noise analysis in computing 3D points using a recent L1-based triangulation algorithm is presented. This method is shown to be not only faster and more accurate than its main competitor, linear triangulation, but also more stable under noise and baseline changes. A Monte Carlo analysis of covariance and a confidence ellipsoid analysis were performed over...
The dynamic range of THz Spectroscopy is limited by noise. Analysis of the data shows that alignment of the results, using windowed autocorrelation, reduced the uncertainties from 11.9% to 0.15% at 95% confidence.
This paper lists identified error sources in waveforms synthesized with a combined Josephson system of binary-divided and pulse-driven arrays. In addition, measurements to be performed for investigating its use for ac component characterization are described. Measurement results and quantified errors will be presented at the conference.
A self-validated computing (SVC) method, based on affine arithmetic (AA) is proposed in this paper to solve the optimal power flow (OPF) problem for microgrids with renewable sources of variable generation. In the AA-based OPF formulation, all the state and control variables are presented in affine form, to represent the variable load, and wind and solar generation. Hence, the OPF model becomes an...
Sensor fault detection method based on UIF (Unknown Input Filter) and minimum variance is proposed to address the real-time fault detection problem of the critical flight sensor and precise positioning the sensor fault in this literature. For aircraft flight control systems that include modeling uncertainties, the UIF method is given and the greatest decoupling between the residuals and the modeling...
A recurring theme in research employing type-2 fuzzy sets is the question of how much uncertainty in a given context warrants the application of type-2 fuzzy sets and systems over their type-1 counterparts. In this paper we provide insight into this challenging question through a detailed investigation into the ability of both types of Fuzzy Logic Systems (FLSs) to capture and model different levels...
As a result of the rapid evolution of mobile communications in the last decade many propagation models have been developed for radio planning purposes. To verify the various propagation models, accurate measurements of the received signals have to be performed especially at the edges of mobile communication cells, where the received power is at very low level and signal to noise ratio is degraded...
The key signal of the Embedded Model Control (EMC) is the model error, measured minus model output, which is used by Internal Model Control and in a more efficient way by Active Disturbance Rejection Control (ADRC). EMC extends ADRC along four lines: a generic disturbance dynamics, design of the noise layout (where uncertainty enters the model), dynamic uncertainty estimation, a design degree of freedom...
In this paper, we propose a compressive spectrum sensing method robust against noise uncertainty. The proposed scheme utilizes relative ratio of residual matrix for signal detection. Simulation results verify that the proposed scheme provides reliable detection performance regardless of noise variance estimation error.
This paper presents a comparison study of performances and characteristics of two types of state observer based state feedback control schemes, including Sliding Mode Observer (SMO) based Sliding Mode Controller (SMC) scheme and Luenberger observer (LO) based Sliding Mode Control scheme. The effectiveness of the schemes are simulated and implemented on Two Conical Tank Interacting Level System (TCTILS)...
This paper introduces a discriminative framework for the task of vehicle detection based on Hough Forest. The leaf nodes in Hough Forest framework are not discriminative enough, which means that they do not have the ability to classify whether the test patches ended up in each leaf are positive or negative. Hough votes are assigned to all test patches by Hough forest, including negative test patches,...
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