Temat: sensing - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Cooperative Spectrum Sensing in Cognitive Radio Networks: A Survey on Machine Learning-based Methods
Autorzy:: Khamayseh, Sundous
Halawani, Alaa
Powiązania:: https://bibliotekanauki.pl/articles/308079.pdf
Data publikacji:: 2020
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: cognitive radio
cooperative spectrum sensing
IEEE 802.22
machine learning
spectrum sensing
Opis:: The continuous growth of demand experienced by wireless networks creates a spectrum availability challenge. Cognitive radio (CR) is a promising solution capable of overcoming spectrum scarcity. It is an intelligent radio technology that may be programmed and dynamically conﬁgured to avoid interference and congestion in cognitive radio networks (CRN). Spectrum sensing (SS) is a cognitive radio life cycle task aiming to detect spectrum holes. A number of innovative approaches are devised to monitor the spectrum and to determine when these holes are present. The purpose of this survey is to investigate some of these schemes which are constructed based on machine learning concepts and principles. In addition, this review aims to present a general classiﬁcation of these machine learningbased schemes.
Źródło:: Journal of Telecommunications and Information Technology; 2020, 3; 36-46
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Recognition of the numbers in the Polish language
Autorzy:: Plichta, A.
Gąciarz, T.
Krzywdziński, T.
Powiązania:: https://bibliotekanauki.pl/articles/308844.pdf
Data publikacji:: 2013
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: Automatic Speech Recognition
compressed sensing
Sparse Classification
Opis:: Automatic Speech Recognition is one of the hottest research and application problems in today’s ICT technologies. Huge progress in the development of the intelligent mobile systems needs an implementation of the new services, where users can communicate with devices by sending audio commands. Those systems must be additionally integrated with the highly distributed infrastructures such as computational and mobile clouds, Wireless Sensor Networks (WSNs), and many others. This paper presents the recent research results for the recognition of the separate words and words in short contexts (limited to the numbers) articulated in the Polish language. Compressed Sensing Theory (CST) is applied for the first time as a methodology of speech recognition. The effectiveness of the proposed methodology is justified in numerical tests for both separate words and short sentences.
Źródło:: Journal of Telecommunications and Information Technology; 2013, 4; 70-78
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Optimal Voting Rule and Minimization of Total Error Rate in Cooperative Spectrum Sensing for Cognitive Radio Networks
Autorzy:: Ghosh, Samit Kumar
Trankatwar, Sachin Ravikant
Bachan, P.
Powiązania:: https://bibliotekanauki.pl/articles/1839471.pdf
Data publikacji:: 2021
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: cognitive radio
energy detection
optimization
spectrum sensing
Opis:: In cognitive radio technology, spectrum sensing is essential for detecting spectrum holes which may be allotted to secondary users. In this paper, an optimal voting rule is used for cooperative spectrum sensing while minimizing the total error rate (TER). The proposed spectrum sensing method is more energy-efficient and may be implemented in practice. It is relied upon in an improved energy detector whose utilization depends on the presence or absence of the primary user. Expressions for false alarm and missed detection probabilities are derived in the paper as well. Overall performance is analyzed both for AWGN and Rayleigh fading channels, in the presence of additive white Gaussian noise (AWGN). The optimum voting rule is applied to the cooperative spectrum sensing process in order to identify the optimum number of sensing nodes and the detection threshold. Finally, an energy-efficient spectrum sensing algorithm is proposed, requiring a lower number of cognitive users for a given error bound.
Źródło:: Journal of Telecommunications and Information Technology; 2021, 1; 43-50
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Optimal Voting Rule and Minimization of Total Error Rate in Cooperative Spectrum Sensing for Cognitive Radio Networks
Autorzy:: Ghosh, Samit Kumar
Trankatwar, Sachin Ravikant
Bachan, P.
Powiązania:: https://bibliotekanauki.pl/articles/1839487.pdf
Data publikacji:: 2021
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: cognitive radio
energy detection
optimization
spectrum sensing
Opis:: In cognitive radio technology, spectrum sensing is essential for detecting spectrum holes which may be allotted to secondary users. In this paper, an optimal voting rule is used for cooperative spectrum sensing while minimizing the total error rate (TER). The proposed spectrum sensing method is more energy-efficient and may be implemented in practice. It is relied upon in an improved energy detector whose utilization depends on the presence or absence of the primary user. Expressions for false alarm and missed detection probabilities are derived in the paper as well. Overall performance is analyzed both for AWGN and Rayleigh fading channels, in the presence of additive white Gaussian noise (AWGN). The optimum voting rule is applied to the cooperative spectrum sensing process in order to identify the optimum number of sensing nodes and the detection threshold. Finally, an energy-efficient spectrum sensing algorithm is proposed, requiring a lower number of cognitive users for a given error bound.
Źródło:: Journal of Telecommunications and Information Technology; 2021, 1; 43-50
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Optimization of Spectrum Sensing Parameters in Cognitive Radio Using Adaptive Genetic Algorithm
Autorzy:: Chatterjee, S.
Dutta, S.
Bhattacharya, P. P.
Roy, J. S.
Powiązania:: https://bibliotekanauki.pl/articles/308511.pdf
Data publikacji:: 2017
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: adaptive genetic algorithm
bandwidth
cognitive radio
spectrum sensing
throughput
Opis:: Quality of service parameters of cognitive radio, like, bandwidth, throughput and spectral efficiency are optimized using adaptive and demand based genetic algorithm. Simulation results show that the proposed method gives better real life solution to the cognitive radio network than other known approach.
Źródło:: Journal of Telecommunications and Information Technology; 2017, 1; 21-27
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: High-resolution Direction of Arrival Estimation Method Based on Sparse Arrays with Minimum Number of Elements
Autorzy:: Mohammed, Jafar Ramadhan
Powiązania:: https://bibliotekanauki.pl/articles/1839475.pdf
Data publikacji:: 2021
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: compressed sensing
direction of arrival
DOA
estimation
sparse array
Opis:: Regular fully filled antenna arrays have been widely used in direction of arrival (DOA) estimation. However, practical implementation of these arrays is rather complex and their resolutions are limited to the beamwidth of the array pattern. Therefore, higher resolution and simpler methods are desirable. In this paper, the compressed sensing method is first applied to an initial fully filled array to randomly select the most prominent and effective elements which are used to form the sparse array. To keep the dimension of the sparse array equal to that of the fully filled array, the first and the last elements were excluded from the sparseness process. In addition, some constraints on the sparse spectrum are applied to increase estimation accuracy. The optimization problem is then solved iteratively using the iterative reweighted l1 norm. Finally, a simple searching algorithm is used to detect peaks in the spectrum solution that correspond to the directions of the arriving signals. Compared with the existing scanned beam methods, such as the minimum variance distortionless response (MVDR) technique, and with subspace approaches, such as multiple signal classification (MUSIC) and ESPIRT algorithms, the proposed sparse array method offers better performance even with a lower number of array elements and in severely noisy environments. Effectiveness of the proposed sparse array method is verified via computer simulations.
Źródło:: Journal of Telecommunications and Information Technology; 2021, 1; 8-14
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: High-resolution Direction of Arrival Estimation Method Based on Sparse Arrays with Minimum Number of Elements
Autorzy:: Mohammed, Jafar Ramadhan
Powiązania:: https://bibliotekanauki.pl/articles/1839489.pdf
Data publikacji:: 2021
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: compressed sensing
direction of arrival
DOA
estimation
sparse array
Opis:: Regular fully filled antenna arrays have been widely used in direction of arrival (DOA) estimation. However, practical implementation of these arrays is rather complex and their resolutions are limited to the beamwidth of the array pattern. Therefore, higher resolution and simpler methods are desirable. In this paper, the compressed sensing method is first applied to an initial fully filled array to randomly select the most prominent and effective elements which are used to form the sparse array. To keep the dimension of the sparse array equal to that of the fully filled array, the first and the last elements were excluded from the sparseness process. In addition, some constraints on the sparse spectrum are applied to increase estimation accuracy. The optimization problem is then solved iteratively using the iterative reweighted l1 norm. Finally, a simple searching algorithm is used to detect peaks in the spectrum solution that correspond to the directions of the arriving signals. Compared with the existing scanned beam methods, such as the minimum variance distortionless response (MVDR) technique, and with subspace approaches, such as multiple signal classification (MUSIC) and ESPIRT algorithms, the proposed sparse array method offers better performance even with a lower number of array elements and in severely noisy environments. Effectiveness of the proposed sparse array method is verified via computer simulations.
Źródło:: Journal of Telecommunications and Information Technology; 2021, 1; 8-14
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Suboptimal Approach to Distributed Detection in Cognitive Radio Networks
Autorzy:: Kumari, Shweta
Praveena, Sirimilla
Powiązania:: https://bibliotekanauki.pl/articles/1839486.pdf
Data publikacji:: 2021
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: cognitive radio
distributed detection
energy detector
myopic policy
spectrum sensing
Opis:: In this paper a dynamic spectrum access (DSA) concept is explored for mitigating the paucity of spectral bandwidth in cognitive radio (CR) for opportunistic, dynamic access of the spectrum without any interference. Dynamic spectrum access schemes are proposed for a distributed cognitive radio network consisting of one secondary user (SU) and many primary users (PUs). The SU has to make decisions for accessing PU channels within discrete time slots. The design of sensing and access strategies that govern channel choice in each slot for near-optimal throughput performance of the SU may be formulated as a partially observable Markov decision process (POMDP). Furthermore, it is considered that the SU incurs a cost whenever it switches to a different channel. The switching cost is expressed in terms of delay, packet loss and packet overhead. In this work, the SU access policy based on a myopic approach is proposed and evaluated.
Źródło:: Journal of Telecommunications and Information Technology; 2021, 1; 32-36
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: An Efficient Cooperative Spectrum Sensing Method Using Renyi Entropy Weighted Optimal Likelihood Ratio for CRN
Autorzy:: Shrote, Sandip B.
Poshattiwa, Sadhana D.
Powiązania:: https://bibliotekanauki.pl/articles/24200748.pdf
Data publikacji:: 2023
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: cognitive radio
eigen statistics
optimal weight
signal energy
spectrum sensing
Opis:: The main concept behind employing cognitive radio is to enable secondary users (SUs) or unlicensed users to utilize the available spectrum. Spectrum sensing methods detect the existence of primary users (PUs) and have become the main topic of research in the CRN industry and in academia. This paper proposes a new framework based on the Adam gradient descent (Adam GD) algorithm to develop a spectrum sensing mechanism used in CRNs and detecting the availability of free channels. The signal's components are extracted from the received signal and the spectrum is searched for availability which is detected through a fusion center using the proposed algorithm. The proposed Adam GD algorithm attains the maximum detection probability rate and the minimum false alarm probability of 0.71 and 0.39, respectively, for a Rayleigh channel.
Źródło:: Journal of Telecommunications and Information Technology; 2023, 3; 41--48
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Mobility-Aware, Correlation-Based Node Grouping and Selection for Cooperative Spectrum Sensing
Autorzy:: Cichoń, K.
De Nardis, L.
Bogucka, H.
Di Benedetto, M. G.
Powiązania:: https://bibliotekanauki.pl/articles/307964.pdf
Data publikacji:: 2014
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: cognitive radio
cooperative spectrum sensing
mobility
node grouping
node selection
Opis:: Cooperative spectrum sensing has been proposed as a solution to increase the sensing function accuracy in cognitive radio networks, but the research has, so far, mainly focused on static scenarios, all but neglecting the impact of mobility on spectrum sensing. In this work a novel cooperative spectrum sensing scheme for mobile cognitive networks, based on a correlation-based, mobility-aware node selection algorithm is proposed. Correlation among sensing decisions is used to divide nodes into groups, and mobility is taken into account in the group leaders selection by means of a node selection metric that considers both sensing performance and mobility. Performance of the proposed algorithm is evaluated by computer simulations taking into account mobility and a detailed modeling of temporal and spatial correlation of fading and shadowing components in the channel path loss, going way beyond the performance evaluation carried out in previous works on correlation-based cooperative sensing schemes. Simulation results highlight that the proposed metric leads to a signicant increase of the update period required to maintain acceptable sensing performance, and correspondingly to a strong reduction in the overhead caused by the grouping and node selection procedure.
Źródło:: Journal of Telecommunications and Information Technology; 2014, 2; 90-102
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 11.

Tytuł:: Pilot Design for Sparse Channel Estimation in Orthogonal Frequency Division Multiplexing Systems
Autorzy:: Vimala, P.
Yamuna, G.
Powiązania:: https://bibliotekanauki.pl/articles/309257.pdf
Data publikacji:: 2018
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: channel estimation
compressive sensing
minimum coherence
minimum variance
pilot pattern
Opis:: Orthogonal Frequency Division Multiplexing (OFDM) is a well-known technique used in modern wide band wireless communication systems. Coherent OFDM systems achieve its advantages over a multipath fading channel, if channel impulse response is estimated precisely at the receiver. Pilot-aided channel estimation in wide band OFDM systems adopts the recently explored compressive sensing technique to decrease the transmission overhead of pilot subcarriers, since it exploits the inherent sparsity of the wireless fading channel. The accuracy of compressive sensing techniques in sparse channel estimation is based on the location of pilots among OFDM subcarriers. A sufficient condition for the optimal pilot selection from Sylow subgroups is derived. A Sylow subgroup does not exist for most practical OFDM systems. Therefore, a deterministic pilot search algorithm is described to select pilot locations based on minimizing coherence, along with minimum variance. Simulation results reveal the effectiveness of the proposed algorithm in terms of bit error rate, compared to the existing solutions.
Źródło:: Journal of Telecommunications and Information Technology; 2018, 2; 60-68
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 12.

Tytuł:: Suboptimal Approach to Distributed Detection in Cognitive Radio Networks
Autorzy:: Kumari, Shweta
Praveena, Sirimilla
Powiązania:: https://bibliotekanauki.pl/articles/1839473.pdf
Data publikacji:: 2021
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: cognitive radio
distributed detection
energy detector
myopic policy
spectrum sensing
Opis:: In this paper a dynamic spectrum access (DSA) concept is explored for mitigating the paucity of spectral bandwidth in cognitive radio (CR) for opportunistic, dynamic access of the spectrum without any interference. Dynamic spectrum access schemes are proposed for a distributed cognitive radio network consisting of one secondary user (SU) and many primary users (PUs). The SU has to make decisions for accessing PU channels within discrete time slots. The design of sensing and access strategies that govern channel choice in each slot for near-optimal throughput performance of the SU may be formulated as a partially observable Markov decision process (POMDP). Furthermore, it is considered that the SU incurs a cost whenever it switches to a different channel. The switching cost is expressed in terms of delay, packet loss and packet overhead. In this work, the SU access policy based on a myopic approach is proposed and evaluated.
Źródło:: Journal of Telecommunications and Information Technology; 2021, 1; 32-36
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 13.

Tytuł:: Microwave radiometry in monitoring and emergency mapping of water seepage and dangerously high groundwaters
Autorzy:: Shutko, A. M.
Haldin, A.
Krapivin, V.
Novichikhin, E.
Sidorov, I.
Tishchenko, Y.
Haarbrink, R.
Georgiev, G.
Kancheva, R.
Nikolov, H.
Coleman, T.
Archer, F.
Pampaloni, P.
Paloscia, S.
Krissilov, A.
Camps Carmona, A.
Powiązania:: https://bibliotekanauki.pl/articles/307666.pdf
Data publikacji:: 2007
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: remote sensing
passive microwave radiometry
soil moisture
water seepage
risk assessment
Opis:: Detailed and geo-referenced maps identifying the locations of saturated and dry levees can be produced using microwave radiometric measurements from a light aircraft or helicopter, and integrated with GPS for positioning and orientation. The development of synergetic remote sensing technology for raised groundwater and seepage detection by the joint use of microwave and optical data along with GIS databases is an effective and most contemporary way of supporting risk assessment and facilitating disaster prevention and management. In this paper we present a remote sensing microwave technology for monitoring and detection of areas of water seepage through irrigation constructions, levees and dykes as well as for revealing areas with dangerously high groundwater level. The possibility for emergency response mapping, integrated with GPS and GIS data, facilitates the risk assessment and management services. The passive microwave radiometry (PMR) is based on spectral measurements in the millimetre to decimetre range of wavelengths. Compared to other remote sensing techniques, such as colour and infrared photography, thermal images and lidar, PMR is the only technology taking measurements under the earth's surface and therefore is very well suited for water seepage and underground water monitoring in a fast and reliable way.
Źródło:: Journal of Telecommunications and Information Technology; 2007, 1; 76-82
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 14.

Tytuł:: Doppler polarimetric ground clutter identification and suppression for atmospheric radars based on co-polar correlation
Autorzy:: Moisseev, D.
Unal, C.
Russchenberg, H.
Ligthart, L.P.
Powiązania:: https://bibliotekanauki.pl/articles/309106.pdf
Data publikacji:: 2001
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: radar polarimetry
ground clutter suppression
Doppler radar
atmospheric radar remote sensing
Opis:: A new clutter suppression technique that uses both Doppler and polarimetric information is presented. Polarimetric properties of the target and clutter are calculated per Doppler frequency cell and based on this information clutter suppression is performed. This new clutter suppression technique is demonstrated with radar measurements of precipitation made by the Delft atmospheric research radar (DARR).
Źródło:: Journal of Telecommunications and Information Technology; 2001, 4; 3-6
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 15.

Tytuł:: Deep Learning-based SNR Estimation for Multistage Spectrum Sensing in Cognitive Radio Networks
Autorzy:: Jeevangi, Sanjeevkumar
Jawaligi, Shivkumar
Patil, Vilaskumar
Powiązania:: https://bibliotekanauki.pl/articles/2174451.pdf
Data publikacji:: 2022
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: cognitive radio
improved NMF
LU-SLNO system
optimized CNN
spectrum sensing
Opis:: Vacant frequency bands are used in cognitive radio (CR) by incorporating the spectrum sensing (SS) technique. Spectrum sharing plays a central role in ensuring the effectiveness of CR applications. Therefore, a new multi-stage detector for robust signal and spectrum sensing applications is introduced here. Initially, the sampled signal is subjected to SNR estimation by using a convolutional neural network (CNN). Next, the detection strategy is selected in accordance with the predicted SNR levels of the received signal. Energy detector (ED) and singular value-based detector (SVD) are the solutions utilized in the event of high SNR, whilst refined non-negative matrix factorization (MNMF) is employed in the case of low SNR. CNN weights are chosen via the Levy updated sea lion optimization (LU-SLNO) algorithm inspired by the traditional sea lion optimization (SLNO) approach. Finally, the outcomes of the selected detectors are added, offering a precise decision on spectrum tenancy and existence of the signal.
Źródło:: Journal of Telecommunications and Information Technology; 2022, 4; 21--32
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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