Wyniki wyszukiwania - BazTech

1

Wyznaczenie wartości mocy sygnału maskującego, chroniącego sieć przed namierzeniem przy wykorzystaniu algorytmu MUSIC

Gajewski Jaromir, Łopatka Jerzy

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

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2023

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nr 4

369--372

PL

W artykule przedstawiono wyznaczone wartości mocy sygnału uniemożliwiającego wyznaczenie lokalizacji węzłów sieci radiowej przy pomocy algorytmu MUSIC. Omówiono sposób przeprowadzania pomiarów mocy sygnału maskującego oraz przedstawiono otrzymane wyniki. Wszystkie przedstawione symulacje i obliczenia wykonano w środowisku MATLAB.

EN

The paper presents the determined values of the power of a signal that prevents the localization of radio network nodes using the MUSIC algorithm. The method of measuring the power of the masking signal was discussed, and the obtained results were presented. All presented simulations and calculations were performed in the MATLAB environment.

2

Passive localization for mixed-field moving sources

Gao C., Liu H.

Polish Maritime Research

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2018

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S 2

69--74

EN

Due to the mobility of underwater equipment, high-precision underwater positioning technology will face two technical challenges: dealing with mixed-field signals composed of near-field signals and far-field signals; adapting to variable component of mixed-field signals considering the mobility of equipment. Under this condition, an effective method based on MUSIC is addressed in this paper. After distinguishing far-field signal subspace from mixed-field signal subspace, estimations of DOAs and powers of far-field sources are carried out. Then the corresponding far-field and noise signal components can be eliminated from the signal subspace. After that, based on path-following algorithm, modified 2D-MUSIC is performed for DOA and range estimations of near-field sources. The performance of the proposed method is verified and compared with the other methods through computer simulations. Reasonable classification of source types and accurate localization estimation can be achieved by using the proposed method.

3

Calculating surface current distribution in antenna array in the presence of mutual coupling by analytical solving of Pocklington’s integral equation

Parhizgar N.

Archives of Electrical Engineering

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2018

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Vol. 67, nr 1

65--79

EN

In this article, the current distribution of an antenna array in the presence of mutual coupling is calculated analytically by solving Pocklington’s integral equation. Blockpulse and Galerkin’s functions are used for numerical solving of Pocklington’s integral equation. In this work, the surface current distribution can be achieved for an antenna array in receiving mode, with any arbitrary structure and various numbers of elements. In all previous works, the authors have been tried to solve Pocklington’s integral equation for a single half dipole antenna in transmitting mode. Pocklington’s equation is somehow difficult to work with because of the singularity and existence of a sharp peak for a small value of wire’s radius. In order to calculate surface current distribution, for thin wires, singularity part is extracted from the kernel in aforementioned integral. Hence, the kernel is decomposed into singular and nonsingular parts. An inter-element mutual coupling effect between array elements and self-coupling for each element are assumed in this case. The validity of the proposed methodology is tested by numerical simulation results. The accuracy of the proposed method is evaluated by the multiple signal classification (MUSIC) algorithm for different scenarios to direction of arrival (DOA) estimation.

4

A new mutual coupling compensation method for receiving antenna array-based DOA estimation

Parhizgar N.

Archives of Electrical Engineering

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2018

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Vol. 67, nr 2

419–-431

EN

Most receiving antenna arrays suffer from the mutual coupling problem between antenna elements, which can critically influence the performance of the array. In this work, a novel and accurate form of compensation matrix is applied to compensate the mutual coupling in a uniform linear array (ULA). This is achieved by applying a new method based on solving a boundary value problem for the whole ULA. In this method, both self and mutual impedances are exploited in an accurate characterization of mutual impedance matrix which results in a perfect mutual coupling compensation method, and hence a very accurate direction of arrival (DOA) estimation. In the new scheme, the compensation matrix is obtained by using the relationship between measured voltage and theoretical coupled voltage based on the MOM. Numerical results show that using DOA estimation algorithms to the decoupled voltage obtained by using this method leads to an excellent performance of DOA estimation with higher accuracy and resolution.

5

An Application of Canonical Decomposition to TDOA Estimation for 3D Wireless Sensor Network Node Localization

Jiang H., Liu C., Sun X.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 9b

92-95

EN

In this paper, a time difference of arrival (TDOA) estimation algorithm is proposed by extending canonical correlation decomposition (CCD) to measure multipath delays for determining node positions in Ultra-wideband wireless sensor networks (WSNs). Multilateral localization based on 3D Chan algorithm is employed to solve the non-linear problems for performance improvement. The method can perform well in the environment with unknown noise. The effectiveness is validated by simulations and the effects of noise and the number of anchor nodes are analyzed.

PL

Przedstawiono algorytm TDOA (time difference of arrival) do określania wielościeżkowych opóźnień w szerokopasmowej bezprzewodowej sieci czujników. Metoda jest przydatna w środowisku o nieznanych szumach.

6

Photoacoustic detection of sentinel lymph node with sensor arrays

Haraszczuk R., Nurzyńska K.

Journal of Medical Informatics & Technologies

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2011

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Vol. 17

233--238

EN

Cancer is one of the diseases which cause the highest death rate in XXI century. However, through years techniques and equipment used to fight with this disease improved there are still many opportunity to get better results. Nowadays, the attention is focused on precise cancerous cells place estimation. It is important for effective cancer treatment, but also it allows diminishing the unwanted effects as destruction of healthy cells. One of the promising techniques in obtaining better spatial and temporal resolution of the internal of the human body is the photoacoustic imaging. Combination of the acoustics, ultrasounds or microwaves by the set of ultrasonic detectors can lead to estimation of the localization of the sources of the waves. The work presents the utilization of the multiple signal classification (MUSIC) algorithm in estimation of angle and distance of microwave or photoacoustic waves sources. The technique presented in the work allows for better prediction of localization of the sources of the detected waves by the sensors array. The proposed application of his technique is detection of sentinel lymph nodes.

7

Zastosowanie algorytmu MUSIC do detekcji tonów DTMF

Izydorczyk J., Kamiński S.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

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2004

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nr 11

443-446

PL

Celem niniejszego artykułu jest prezentacja podprzestrzennej metody estymacji sygnałów MUSIC na przykładzie detektora DTMF. Detektor został zaimplementowany w systemie uruchomieniowym z procesorem ADSP21061. Opis algorytmu w artykule wsparty został symulacjami w środowisku MATLABŽ. Zawarte wyniki doświadczeń laboratoryjnych skupiają się na wysokiej odporności detektora na obecność szumu białego w kanale transmisyjnym.

EN

The article id devoted to a subspace method of signal estimation called MUSIC. The method have been used to implement DTMF tones detector. The detector is based on ADSP21061 evaluation kit from Analog Devices. The algorithm description taken in the article are supported by simulations made in the MATLABŽ environment. The detector is very resistant to the influence of the white Gaussian noise added to DTMF sinusoids.