Bibliographies thématiques / Frequency Selective Broadband Channels

Littérature scientifique sur le sujet « Frequency Selective Broadband Channels »

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Publié le 25 mai 2024

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Articles de revues sur le sujet "Frequency Selective Broadband Channels"

Jiang, Ting, Maozhong Song, Xiaorong Zhu et Xu Liu. « Channel Estimation for Broadband Millimeter Wave MIMO Systems Based on High-Order PARALIND Model ». Wireless Communications and Mobile Computing 2021 (23 novembre 2021) : 1–12. http://dx.doi.org/10.1155/2021/6408442.

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Channel state information (CSI) is important to improve the performance of wireless transmission. However, the problems of high propagation path loss, multipath, and frequency selective fading make it difficult to obtain the CSI in broadband millimeter-wave (mmWave) system. Based on the inherent multidimensional structure of mmWave multipath channels and the correlation between channel dimensions, mmWave multiple input multiple output (MIMO) channels are modelled as high-order parallel profiles with linear dependence (PARALIND) model in this paper, and a new PARALIND-based channel estimation algorithm is proposed for broadband mmWave system. Due to the structural property of PARALIND model, the proposed algorithm firstly separates the multipath channels of different scatterers by PARALIND decomposition and then estimates the channel parameters from the factor matrices decomposed from the model based on their structures. Meanwhile, the performance of mmWave channel estimation is analysed theoretically. A necessary condition for channel parameter estimation is given based on the uniqueness principle of PARALIND model. Simulation results show that the proposed algorithm performs better than traditional compressive sensing-based channel estimation algorithms.

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Hu, Yuze, Mingyu Tong, Siyang Hu, Weibao He, Xiang’ai Cheng et Tian Jiang. « Multidimensional engineered metasurface for ultrafast terahertz switching at frequency-agile channels ». Nanophotonics 11, n^o 7 (22 février 2022) : 1367–78. http://dx.doi.org/10.1515/nanoph-2021-0774.

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Abstract The ability to actively manipulate free-space optical signals by using tunable metasurfaces is extremely appealing for many device applications. However, integrating photoactive semiconductors into terahertz metamaterials still suffers from a limited functionality. The ultrafast switching in picosecond timescale can only be operated at a single frequency channel. In the hybrid metasurface proposed here, we experimentally demonstrate a dual-optically tunable metaphotonic device for ultrafast terahertz switching at frequency-agile channels. Picosecond ultrafast photoswitching with a 100% modulation depth is realized at a controllable operational frequency of either 0.55 THz or 0.86 THz. The broadband frequency agility and ultrafast amplitude modulation are independently controlled by continuous wave light and femtosecond laser pulse, respectively. The frequency-selective, temporally tunable, and multidimensionally-driven features can empower active metamaterials in advanced multiplexing of information, dual-channel wireless communication, and several other related fields.

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Semmar, A., M. Lecours et H. T. Huynh. « Performance of coherent QPSK communications over frequency-selective fading channels for broadband PCS ». Canadian Journal of Electrical and Computer Engineering 22, n^o 2 (avril 1997) : 51–54. http://dx.doi.org/10.1109/cjece.1997.7101978.

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Boutalline, Mohammed, Belaid Bouikhalene et Said Safi. « Channel Identification and Equalization based on Kernel Methods for Downlink Multicarrier-CDMA Systems ». Journal of Electronic Commerce in Organizations 13, n^o 2 (avril 2015) : 14–29. http://dx.doi.org/10.4018/jeco.2015040102.

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In this paper the authors are focused on channel identification and equalization for Multi-Carrier Code Division Multiple Access (MC-CDMA) system. For this, they identify the impulse response of two practical selective frequency fading channels called Broadband Radio Access Network (BRAN A and BRAN B) normalized by the European Telecommunications Standards Institute (ETSI). To identify the channel parameters, they have the positive definite kernels to build on algorithm. The simulations show that the presented method confirms the good performance for different SNR values. In part of equalization, the authors use the Zero Forcing (ZF) and Minimum Mean Square Error (MMSE) equalizers.

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Perov, Sergey Yu, Olga V. Belaya, Quirino Balzano et Nina B. Rubtsova. « The problems of mobile communication electromagnetic field exposure assessment today and tomorrow ». Russian Journal of Occupational Health and Industrial Ecology 60, n^o 9 (7 octobre 2020) : 597–99. http://dx.doi.org/10.31089/1026-9428-2020-60-9-597-599.

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New and necessary improvements of electromagnetic exposure assessment principles and methods are considered and presented. The electromagnetic field exposure assessment is the physical basis for hygienic and biological research and needs s to consider the new technological features of emerging 5G mobile systems in addition to existing 2-4G systems. The new generation of telecommunication networks will cause significantly novel electromagnetic field exposure, in particular for time-frequency and spatial parameters. A complex exposure assessment based on refined broadband measurements seems to be the proper and necessary approach to the enhancement of Russian EMF assessment guidelines. Simple broadband EMF measurements are the common approach for present exposure assessment and cannot be used any longer as the only measure for multiple 5G sources exposure evaluation. Then again broadband measurements are the simple and practical approach for mm wave in-situ exposure assessment. Frequency-selective and code-selective measurements provide detailed EMF level distribution in separate frequency channels, telecommunication services or sources and are a promising approach for objective exposure assessment.

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Fateh, Rachid, Anouar Darif, Ahmed Boumezzough, Said Safi et Miloud Frikel. « A Novel Kernel Algorithm for Finite Impulse Response Channel Identiﬁcation ». Journal of Telecommunications and Information Technology, n^o 2 (29 juin 2023) : 84–93. http://dx.doi.org/10.26636/jtit.2023.169823.

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Over the last few years, kernel adaptive ﬁlters have gained in importance as the kernel trick started to be used in classic linear adaptive ﬁlters in order to address various regression and time-series prediction issues in nonlinear environments.In this paper, we study a recursive method for identifying ﬁnite impulse response (FIR) nonlinear systems based on binary-value observation systems. We also apply the kernel trick to the recursive projection (RP) algorithm, yielding a novel recursive algorithm based on a positive deﬁnite kernel. For purposes, our approach is compared with the recursive projection (RP) algorithm in the process of identifying the parameters of two channels, with the ﬁrst of them being a frequency-selective fading channel, called a broadband radio access network (BRAN B) channel, and the other being a a theoretical frequency-selective channel, known as the Macchi channel. Monte Carlo simulation results are presented to show the performance of the proposed algorithm.

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Zidane, Mohammed, Said Safi, Mohamed Sabri et Ahmed Boumezzough. « Bit Error Rate Analysis of MC-CDMA Systems with Channel Identification Using Higher Order Cumulants ». Indonesian Journal of Electrical Engineering and Computer Science 1, n^o 1 (1 janvier 2016) : 138. http://dx.doi.org/10.11591/ijeecs.v1.i1.pp138-152.

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The aim of this paper is to contribute to study the problems of the blind identification and equalization using Higher Order Cumulants (HOC) in downlink Multi-Carrier Code Division Multiple Access (MC-CDMA) systems. For this problem, two blind algorithms based on HOC for Broadband Radio Access Network (BRAN) channel are proposed. In the one hand, to assess the performance of these approaches to identify the parameters of non minimum phase channels, we have considered two theoretical channels, and one practical frequency selective fading channel called BRAN C, driven by non gaussian signal. In the other hand, we use the Minimum Mean Square Error (MMSE) equalizer technique after the channel identification to correct the channel distortion. Theoretical analysis and numerical simulation results, in noisy environment and for different signal to noise ratio (SNR), are presented to illustrate the performance of the proposed methods.

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Fateh, Rachid, Anouar Darif et Said Safi. « Performance Evaluation of MC-CDMA Systems with Single User Detection Technique using Kernel and Linear Adaptive Method ». Journal of Telecommunictions and Information Technology 4, n^o 2021 (30 décembre 2021) : 1–11. http://dx.doi.org/10.26636/jtit.2021.151621.

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Among all the techniques combining multi-carrier modulation and spread spectrum, the multi-carrier code division multiple access (MC-CDMA) system is by far the most widely studied. In this paper, we present the performance of the MC-CDMA system associated with key single-user detection techniques. We are interested in problems related to identification and equalization of mobile radio channels, using the kernel method in Hilbert space with a reproducing kernel, and a linear adaptive algorithm, for MC-CDMA systems. In this context, we tested the efficiency of these algorithms, considering practical frequency selective fading channels, called broadband radio access network (BRAN), standardized for MC-CDMA systems. As far as the equalization problem encountered after channel identification is concerned, we use the orthogonality restoration combination (ORC) and the minimum mean square error (MMSE) equalizer techniques to correct the distortion of the channel. Simulation results demonstrate that the kernel algorithm is efficient for practical channels.

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Yan, Qiuna, Yu Sun et Dian-Wu Yue. « LOS-Based Equal Gain Transmission and Combining in General Frequency-Selective Ricean Massive MIMO Channels ». Electronics 8, n^o 1 (10 janvier 2019) : 79. http://dx.doi.org/10.3390/electronics8010079.

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In general frequency-selective Ricean fading environments with doubly-ended spatial correlation, this paper investigates the spectral efficiency of a broadband massive multiple-input multiple-output (MIMO) system. In particular, in order to reduce overhead of channel estimation effectively, it proposes a scheme of equal gain transmission and combining, which is only based on line- of-sight (LOS) component and has low hardware complexity. With the scheme, several interesting transmit power scaling properties without and with spatial correlation are derived when the number of antennas at the transmitter or the number of antennas at the receiver grows in an unlimited way. Furthermore, the asymptotical rate analysis is extended to the cooperative relaying scenarios with decode-and-forward and amplify-and-forward protocols, respectively, and then two novel power scaling laws are given.

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Fateh, Rachid, Anouar Darif et Said Safi. « An Extended Version of the Proportional Adaptive Algorithm Based on Kernel Methods for Channel Identification with Binary Measurements ». Journal of Telecommunications and Information Technology 3, n^o 2022 (29 septembre 2022) : 47–58. http://dx.doi.org/10.26636/jtit.2022.161122.

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In recent years, kernel methods have provided an important alternative solution, as they offer a simple way of expanding linear algorithms to cover the non-linear mode as well. In this paper, we propose a novel recursive kernel approach allowing to identify the finite impulse response (FIR) in non-linear systems, with binary value output observations. This approach employs a kernel function to perform implicit data mapping. The transformation is performed by changing the basis of the data In a high-dimensional feature space in which the relations between the different variables become linearized. To assess the performance of the proposed approach, we have compared it with two other algorithms, such as proportionate normalized least-meansquare (PNLMS) and improved PNLMS (IPNLMS). For this purpose, we used three measurable frequency-selective fading radio channels, known as the broadband radio access Network (BRAN C, BRAN D, and BRAN E), which are standardized by the European Telecommunications Standards Institute (ETSI), and one theoretical frequency selective channel, known as the Macchi’s channel. Simulation results show that the proposed algorithm offers better results, even in high noise environments, and generates a lower mean square error (MSE) compared with PNLMS and IPNLMS.

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Thèses sur le sujet "Frequency Selective Broadband Channels"

Kosa, Irfan. « Performance of IEEE 802.11a wireless LAN standard over frequency-selective, slowly fading Nakagami channels in a pulsed jamming environment ». Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02Dec%5FKosa.pdf.

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Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, December 2002.
Thesis advisor(s): R. Clark Robertson, Tri Ha. Includes bibliographical references (p. 107-108). Also available online.

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Bemani, Ali. « Affine Frequency Division Multiplexing (AFDM) for Wireless Communications ». Electronic Thesis or Diss., Sorbonne université, 2023. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2023SORUS610.pdf.

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La recherche de nouvelles formes d'onde robustes, lorsque utilisées sur des canaux doublement sélectifs, est primordiale. De telles formes d'onde permettraient donc d'assurer des communications fiables pour les réseaux sans fil de nouvelle génération dans les scénarios de haute mobilité. Dans cette thèse, une nouvelle solution, le affine frequency division multiplexing (AFDM), est proposée. Cette nouvelle forme d'onde de type multichirps est basée sur la transformée de Fourier affine discrète (DAFT), une variante de la transformée de Fourier discrète caractérisée par deux paramètres pouvant être adaptés pour mieux faire face aux canaux doublement dispersifs. Cette thèse offre une enquête complète sur les principes de l'AFDM au sein des communications à haute mobilité. Elle fournit un aperçu de la relation explicite entrée-sortie dans le domaine DAFT, révélant l'impact conséquent des paramètres de l'AFDM. Le manuscrit détaille le réglage précis des paramètres DAFT qui permette d'assurer une représentation complète délai-Doppler du canal de propagation sans fil. À travers des démonstrations analytiques, il est affirmé que l'AFDM atteint de manière optimale l'ordre de diversité des canaux doublement dispersifs en raison de la représentation complète délai-Doppler du canal qu'il permet d'obtenir. La thèse propose également deux algorithmes de détection à faible complexité pour l'AFDM, tirant parti de la parcimonie inhérente du canal. Le premier est un détecteur de type minimum mean squared error (MMSE) à faible complexité basé sur la factorisation LDL. Le deuxième est un égaliseur de type decision feedback equalizer (DFE) à faible complexité basé sur la combinaison cohérente, grace à la méthode maximum ratio combining (MRC), de différentes copies des symboles d'entrée du canal ayant été altérés par différents trajets de ce dernier. De plus, la thèse présente une technique de type embedded d'estimation de canal pour les systèmes AFDM, exploitant la capacité de l'AFDM à obtenir une représentation complète délai-Doppler du canal. Dans cette approche, un seul symbole pilote est inséré dans le domain DAFT du symbole AFDM, et les interférences que ce pilote pourrait générer pour les symboles de donnée sont évitées par des intervalles de garde. Un algorithme pratique d'estimation de canal, compatible avec ce schéma de transmission de pilote et basé sur une approche de type approximate maximum likelihood (ML), est aussi proposé. La thèse est conclue en se penchant sur de possibles applications de l'AFDM au delà de celles conçues pour les environnements marqués par une haute mobilité, spécifiquement les applications de type integrated sensing and communication (ISAC) et les communications dans les bandes de hautes fréquences. Il est démontré que pour identifier tous les composants de délai et de Doppler liés au milieu de propagation, on peut utiliser soit le signal AFDM complet, soit seulement sa partie pilote constituée d'un symbole de domaine DAFT et de son intervalle de garde. De plus, la nature chirp de l'AFDM permet une annulation simple de l'auto-interférence, éliminant ainsi le besoin de méthodes coûteuses normalement nécessaires dans les systèmes full duplex. La thèse met également en évidence les bonnes performances de l'AFDM pour les communications sans fil dans les bandes de hautes fréquences sans ou avec mobilité, grâce à la répartition maximale du signal AFDM en temps et en fréquences, assurant un gain de couverture. Contrairement à d'autres formes d'onde, l'AFDM ne fournit pas seulement une répartition maximale temps-fréquences mais assure également une détection robuste et efficace et une résilience au décalage de fréquence de porteuse et au bruit de phase
In the realm of next-generation wireless systems (beyond 5G/6G), the vision is clear: to support a broad range of services and applications. This includes ensuring reliable communications in environments marked by high mobility, such as high-speed railway systems and various vehicular communications. Despite the deployment of various multicarrier techniques like orthogonal frequency division multiplexing (OFDM) and single-carrier frequency division multiple access (SC-FDMA) in standardized communication systems, the challenge persists. These techniques, while effective in time-invariant frequency selective channels, face performance degradation in high mobility scenarios due to the destruction of orthogonality among subcarriers caused by significant Doppler frequency shifts. Addressing this, the search for new, robust modulation techniques is paramount. It stands as a key area of investigation aiming to resolve the reliable communications issue for next-generation wireless networks within doubly-selective wireless channels. In this thesis, a novel solution, affine frequency division multiplexing (AFDM), is proposed. This new chirp-based multicarrier waveform is based on the discrete affine Fourier transform (DAFT), a variant of the discrete Fourier transform characterized with two parameters that can be adapted to better cope with doubly dispersive channels. This thesis provides a comprehensive investigation into the principles of AFDM within high mobility communications. It provides insight into the explicit input-output relation in the DAFT domain, unveiling the consequential impact of AFDM parameters. The manuscript details the precise setting of DAFT parameters, ensuring a full delay-Doppler representation of the channel. Through analytical demonstrations, it asserts that AFDM optimally achieves the diversity order in doubly dispersive channels due to its full delay-Doppler representation. The thesis also proposes two low-complexity detection algorithms for AFDM, taking advantage of its inherent channel sparsity. The first is a low complexity MMSE detector based on LDL factorization. The second is a low complexity iterative decision feedback equalizer (DFE) based on weighted maximal ratio combining (MRC) of the channel impaired input symbols received from different paths. Additionally, the thesis presents an embedded channel estimation strategy for AFDM systems, leveraging AFDM's ability to achieve full delay-Doppler representation of the channel. In this approach, an AFDM frame contains a pilot symbol and data symbols, with zero-padded symbols employed as guard intervals to prevent interference. A practical channel estimation algorithm based on an approximate maximum likelihood (ML) approach and compatible with this pilot scheme is also provided. The thesis concludes by delving into the expanded applications of AFDM, specifically in integrated sensing and communication (ISAC) and extremely high frequency (EHF) band communications. It is demonstrated that to identify all delay and Doppler components linked with the propagation medium, one can use either the full AFDM signal or only its pilot part consisting of one DAFT domain symbol and its guard interval. Furthermore, the chirp nature of AFDM allows for unique and simple self-interference cancellation with a single pilot, eliminating the need for costly full-duplex methods. The thesis also highlights AFDM's efficient performance in high-frequency bands (with or without mobility), where the maximal spreading of its signal in time and frequency ensures a coverage gain. Unlike other waveforms, AFDM not only provides maximal time-frequency spreading but also ensures robust and efficient detection, characterized by one-tap equalization and resilience to carrier frequency offset (CFO) and phase noise

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Qin, Tianrui. « Over-the-air computation via broadband channels ». Thesis, The University of Sydney, 2021. https://hdl.handle.net/2123/26460.

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As the scale of the current network keeps increasing at a dramatic rate, the future Internet-of-Things applications will need to connect billions of sensor nodes. This brings great challenges to the traditional "transmit then compute" mode, as communication latency will be excessive for a large-scale communication network. The massive access points will also exhaust bandwidth resources in a conventional multiple-access scheme. By exploiting the superposition property of a multi-access channel, Over-the-Air Computation (AirComp) has been recognized as a low-latency solution for wireless sensor data fusion, where multiple sensors simultaneously send their measurement signals to a receiver for computation. Most existing work only considered performing AirComp over a single frequency channel. However, for a sensor network with a massive number of nodes, a single frequency channel may not be sufficient to accommodate the large number of sensors, and the AirComp performance will be very limited. So it is highly desirable to have more frequency channels for large-scale AirComp systems to benefit from multi-channel diversity. In this thesis, we propose an M-frequency AirComp system where each sensor selects a subset of the M frequencies and broadcasts its signal over these channels under a certain power constraint. We derive the optimal sensors' transmission and receiver's signal processing methods separately, and develop an algorithm for joint design to achieve the best AirComp performance. We further investigate the property of the optimal design problem to reduce its complexity. Numerical results show that increasing one frequency channel can improve the AirComp performance threefold compared to the single-frequency case.

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Ekinci, Umut Utku. « Code Aided Frame Synchronization For Frequency Selective Channels ». Thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/2/12611951/index.pdf.

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Frame synchronization is an important problem in digital communication systems. In frame synchronization, the main task is to find the frame start given the flow of the communication symbols. In this thesis, frame synchronization problem is investigated for both additive white Gaussian noise (AWGN) channels and frequency selective channels. Most of the previous works on frame synchronization consider the simple case of AWGN channels. The algorithms developed for this purpose fail in frequency selective channels. There is limited number of algorithms proposed for the frequency selective channels. In this thesis, existing frame synchronization techniques are investigated for both AWGN and frequency selective channels. Code-aided frame synchronization techniques are combined with the methods for frequency selective channels. Mainly two types of code-aided frame synchronization schemes are considered and two new system structures are proposed for frame synchronization. One of the proposed structures performs better than the alternative methods for frequency selective channels. The overall system for this new synchronizer is composed of a list synchronizer which generates the possible frame starts, a channel estimator, a soft output MLSE equalizer, and a soft output Viterbi decoder. A mode separation algorithm is used to generate the statistics for the selection of the true frame start. Several experiments are done and the performance is outlined for a variety of scenarios.

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Chen, Xuan. « Adaptive equalization of frequency selective indoor wireless channels ». Thesis, University of Ottawa (Canada), 1995. http://hdl.handle.net/10393/10132.

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In this thesis, we examine the performance of adaptive linear, T/2 fractionally spaced, and decision feedback equalizers (LE, FSE and DFE) for digital communication systems over indoor wireless channels affected by frequency selective fading. The channel is modeled as both fixed and time varying channels, and the data transmission rate is 10 M bits/s. The simulation results show that, with differential encoding, the quadrature phase shift keying (DQPSK) modulation scheme outperforms 4-state and 8-state 8PSK-based trellis coded modulations (D8PTCM4 and D8PTCM8), when the DFE with the least-mean-square (LMS) algorithm (DFELMS) is used. While D8PTCM4 has better BER performance than D8PTCM8 with the DFELMS over time varying channels, the reverse conclusion can be obtained over fixed channels. When the recursive least-square (RLS) algorithm is applied instead of the LMS algorithm, the systems with the DFERLS can achieve slightly better bit error rate (BER) performance than those with the DFELMS.

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So, Daniel Ka Chun. « MIMO wireless communications in frequency selective fading channels / ». View Abstract or Full-Text, 2003. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202003%20SO.

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Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2003.
Includes bibliographical references (leaves 136-144). Also available in electronic version. Access restricted to campus users.

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Liu, Shoumin. « Soft-decision equalization techniques for frequency selective MIMO channels / ». Available online. Click here, 2005. http://sunshine.lib.mtu.edu/ETD/DISS/lius/Dissertation.pdf.

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Xu, Ying Lin 1975. « OFDMA schemes with diversity in frequency-selective fading channels ». Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=81577.

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By using sufficiently long prefix and orthogonal narrow-band sub-carriers with adaptive bit loading, orthogonal frequency-division multiple-access (OFDMA) can offer high bandwidth efficiency required for broadband wireless access communications in frequency-selective fading channels. However, when deep fading occurs in a frequency slot, it can create data loss in one or more sub-carriers. Diversity techniques could be used to enhance the performance of OFDMA in the presence of deep fades.
The research presented in this thesis aims to provide diversity in OFDMA for broadband wireless access communications in frequency-selective fading channels. First, the diversity characteristics in OFDMA are examined to establish the diversity equivalence in the time and frequency domains. Based on these characteristics, suitable techniques to achieve the full diversity gain in OFDMA are developed. When channel information is available to transmitters, a group-optimal adaptive-tone-diversity OFDMA (GO-ATD-OFDMA) scheme that combines adaptive diversity gain and bit loading, is proposed. It is shown that the GO-ATD-OFDMA can offer a better performance than the conventional time-domain Rake receiver. In the case of unavailable channel information, spreading is combined with diversity in the proposed group-spreading OFDMA (GS-OFDMA) scheme to provide both diversity protection and interference suppression. The GS-OFDMA has a comparable performance to the group-orthogonal multi-carrier code-division multiple-access (GO-MC-CDMA) scheme but with a reduced transmitted peak-to-average power ratio (PAR). Performance of the proposed schemes in terms of error rates, spectral efficiency, achievable system throughput, and computational complexity is investigated by analysis and simulations.

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Davies, Martin. « Polynomial matrix decomposition techniques for frequency selective MIMO channels ». Thesis, Loughborough University, 2010. https://dspace.lboro.ac.uk/2134/6047.

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For a narrowband, instantaneous mixing multi-input, multi-output (MIMO) communications system, the channel is represented as a scalar matrix. In this scenario, singular value decomposition (SVD) provides a number of independent spatial subchannels which can be used to enhance data rates or to increase diversity. Alternatively, a QR decomposition can be used to reduce the MIMO channel equalization problem to a set of single channel equalization problems. In the case of a frequency selective MIMO system, the multipath channel is represented as a polynomial matrix. Thus conventional matrix decomposition techniques can no longer be applied. The traditional solution to this broadband problem is to reduce it to narrowband form by using a discrete Fourier transform (DFT) to split the broadband channel into N narrow uniformly spaced frequency bands and applying scalar decomposition techniques within each band. This describes an orthogonal frequency division multiplexing (OFDM) based system. However, a novel algorithm has been developed for calculating the eigenvalue decomposition of a para-Hermitian polynomial matrix, known as the sequential best rotation (SBR2) algorithm. SBR2 and its QR based derivatives allow a true polynomial singular value and QR decomposition to be formulated. The application of these algorithms within frequency selective MIMO systems results in a fundamentally new approach to exploiting spatial diversity. Polynomial matrix decomposition and OFDM based solutions are compared for a wide variety of broadband MIMO communication systems. SVD is used to create a robust, high gain communications channel for ultra low signal-to-noise ratio (SNR) environments. Due to the frequency selective nature of the channels produced by polynomial matrix decomposition, additional processing is required at the receiver resulting in two distinct equalization techniques based around turbo and Viterbi equalization. The proposed approach is found to provide identical performance to that of an existing OFDM scheme while supporting a wider range of access schemes. This work is then extended to QR decomposition based communications systems, where the proposed polynomial approach is found to not only provide superior bit-error-rate (BER) performance but significantly reduce the complexity of transmitter design. Finally both techniques are combined to create a nulti-user MIMO system that provides superior BER performance over an OFDM based scheme. Throughout the work the robustness of the proposed scheme to channel state information (CSI) error is considered, resulting in a rigorous demonstration of the capabilities of the polynomial approach.

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Litchfield, Charan. « Single user diversity receivers for frequency selective WCDMA channels ». Thesis, University of Kent, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.443772.

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Livres sur le sujet "Frequency Selective Broadband Channels"

Arijon, Ignacio M. Performance of an orthogonal frequency division multiplexing (OFDM) system in frequency selective channels. Manchester : University of Manchester, 1996.

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Silva, Fabio, Rui Dinis et Paulo Montezuma. Frequency-Domain Receiver Design for Doubly Selective Channels. Taylor & Francis Group, 2017.

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Frequency-Domain Receiver Design for Doubly Selective Channels. Taylor & Francis Group, 2017.

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Silva, Fabio, Rui Dinis et Paulo Montezuma. Frequency-Domain Receiver Design for Doubly Selective Channels. Taylor & Francis Group, 2017.

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Silva, Fabio, Rui Dinis et Paulo Montezuma. Frequency-Domain Receiver Design for Doubly Selective Channels. Taylor & Francis Group, 2017.

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Silva, Fabio, Rui Dinis et Paulo Montezuma. Frequency-Domain Receiver Design for Doubly Selective Channels. Taylor & Francis Group, 2019.

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Montezuma, Paulo, Fabio Silva et Rui Dinis. Frequency-Domain Receiver Design for Doubly Selective Channels. CRC Press, 2017. http://dx.doi.org/10.1201/9781315169576.

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Silva, Fabio, Rui Dinis et Paulo Montezuma. Frequency-Domain Receiver Design for Doubly Selective Channels. Taylor & Francis Group, 2017.

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Performance Analysis of OFDM in Frequency Selective, Slowly Fading Nakagami Channels. Storming Media, 2001.

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Performance of the IEEE 802.11a Wireless Lan Standard Over Frequency- Selective, Slow, Ricean Fading Channels. Storming Media, 2002.

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Chapitres de livres sur le sujet "Frequency Selective Broadband Channels"

Chang, Kapseok, et Youngnam Han. « Throughput Enhancement Scheme in an OFCDM System over Slowly-Varying Frequency-Selective Channels ». Dans Information Networking. Convergence in Broadband and Mobile Networking, 697–706. Berlin, Heidelberg : Springer Berlin Heidelberg, 2005. http://dx.doi.org/10.1007/978-3-540-30582-8_73.

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Dörpinghaus, Meik. « Frequency-Selective Channels ». Dans On the Achievable Rate of Stationary Fading Channels, 189–224. Berlin, Heidelberg : Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-19780-2_9.

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Hara, Shinsuke, Shuichi Hane et Yoshitaka Hara. « Does OFDM Really Prefer Frequency Selective Fading Channels ? » Dans Multi-Carrier Spread-Spectrum & ; Related Topics, 35–42. Boston, MA : Springer US, 2002. http://dx.doi.org/10.1007/978-1-4757-3569-7_4.

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Garg, Shweta, et Sanjeev Yadav. « A Triple Band-Reject Frequency Selective Surface for Broadband Applications ». Dans Lecture Notes in Electrical Engineering, 437–46. Singapore : Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-10-7395-3_49.

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Hoeher, Peter. « An Adaptive Channel Estimator for Frequency-Selective Fading Channels ». Dans ASST ’90 7. Aachener Symposium für Signaltheorie, 168–73. Berlin, Heidelberg : Springer Berlin Heidelberg, 1990. http://dx.doi.org/10.1007/978-3-642-76062-4_28.

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Swaminathan, Shriram, Suraj Krishnan et Prabagarane Nagaradjane. « Transmitter Preprocessing Assisted MIMO SDMA Systems over Frequency-Selective Channels ». Dans Advances in Computing and Communications, 374–82. Berlin, Heidelberg : Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-22720-2_39.

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Weikert, Oomke, Christian Klünder et Udo Zölzer. « Semi-blind Equalization of Wireless MIMO Frequency Selective Communication Channels ». Dans Independent Component Analysis and Blind Signal Separation, 422–29. Berlin, Heidelberg : Springer Berlin Heidelberg, 2006. http://dx.doi.org/10.1007/11679363_53.

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Yuan, Weijie, Nan Wu et Jingming Kuang. « FTN Data Detection and Channel Estimation over Frequency Selective Channels ». Dans Receiver Design for High Spectral Efficiency Communication Systems in Beyond 5G, 59–75. Singapore : Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-8090-9_4.

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Punnoose, Sonu, Xu Zhu et Asoke K. Nandi. « Layered Space Frequency Equalisation for MIMO-MC-CDMA Systems in Frequency Selective Fading Channels ». Dans Independent Component Analysis and Blind Signal Separation, 1181–88. Berlin, Heidelberg : Springer Berlin Heidelberg, 2004. http://dx.doi.org/10.1007/978-3-540-30110-3_149.

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Bao, Yupeng, et Yanfei Lu. « The Block-Wise Adaptive Modulation Technique for Frequency-Selective Fading Channels ». Dans LISS2019, 15–28. Singapore : Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-5682-1_2.

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Actes de conférences sur le sujet "Frequency Selective Broadband Channels"

Li, Qian, Kwok H. Li et Kah C. Teh. « Noncoherent Space-Frequency Codes for Broadband MIMO Systems over Frequency-Selective Fading Channels ». Dans 2008 IEEE Vehicular Technology Conference (VTC 2008-Spring). IEEE, 2008. http://dx.doi.org/10.1109/vetecs.2008.125.

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Poikonen, Jussi. « A finite-state simulation model for OFDM over frequency-selective fast fading channels ». Dans 2009 IEEE International Symposium on Broadband Multimedia Systems and Broadcasting (BMSB). IEEE, 2009. http://dx.doi.org/10.1109/isbmsb.2009.5133766.

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Hwang, Soon Up, Jinyong Choi, Sungho Jeon, Ho Jin Ryu et Jongsoo Seo. « Performance evaluation of MIMO-OFDM with signal space diversity over frequency selective channels ». Dans 2009 IEEE International Symposium on Broadband Multimedia Systems and Broadcasting (BMSB). IEEE, 2009. http://dx.doi.org/10.1109/isbmsb.2009.5133821.

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Davies, Martin, Sangarapillai Lambotharan, Jonathon Chambers et John McWhirter. « Broadband MIMO Beamforming for Frequency Selective Channels using the Sequential Best Rotation Algorithm ». Dans 2008 IEEE Vehicular Technology Conference (VTC 2008-Spring). IEEE, 2008. http://dx.doi.org/10.1109/vetecs.2008.243.

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Monfet, F., T. Le-Ngoc et Qing Zhang. « Turbo equalization using frequency-domain shortening filter for broadband single-carrier transmission over frequency-selective fading channels ». Dans 2004 IEEE 59th Vehicular Technology Conference. VTC 2004-Spring. IEEE, 2004. http://dx.doi.org/10.1109/vetecs.2004.1388993.

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Giuliano, Romeo, Pierpaolo Loreti et Franco Mazzenga. « Planning of multi-carrier broadband wireless systems with ideal power control over frequency selective channels ». Dans 2008 IEEE 19th International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC). IEEE, 2008. http://dx.doi.org/10.1109/pimrc.2008.4699719.

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Lerner, I. M., A. N. Khairullin, R. R. Fayzullin, D. V. Shushpanov et V. I. Il’in. « Resolution Time Theory Broadband Communications in Problem of Data Dependent Jitter in Frequency Selective Channels with PAM-n-Signals ». Dans 2023 Systems of Signals Generating and Processing in the Field of on Board Communications. IEEE, 2023. http://dx.doi.org/10.1109/ieeeconf56737.2023.10092097.

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Taniguchi, Tetsuki, et Yoshio Karasawa. « Broadband Channel Inversion and Vector Perturbation for MU-MIMO System Under Frequency Selective Fading ». Dans International Conference. New York, New York, USA : ACM Press, 2013. http://dx.doi.org/10.1145/2536853.2536920.

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Palma, D. A., et W. C. Wong. « Broadband Frequency Selective Surface ». Dans IEEE Military Communications Conference MILCOM 1986. IEEE, 1986. http://dx.doi.org/10.1109/milcom.1986.4805759.

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Wu, Qun, Guohui Yang, Jiahui Fu, Fanyi Meng, Kuang Zhang, Weidong Kong et Xumin Ding. « Miniaturized frequency selective surface and broadband frequency selective surface design ». Dans 2016 International Conference on Electromagnetics in Advanced Applications (ICEAA). IEEE, 2016. http://dx.doi.org/10.1109/iceaa.2016.7731437.

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Rapports d'organisations sur le sujet "Frequency Selective Broadband Channels"

Rice, Michael, et Erik Perrins. On Frequency Offset Estimation Using the iNET Preamble in Frequency Selective Fading Channels. Fort Belvoir, VA : Defense Technical Information Center, mars 2014. http://dx.doi.org/10.21236/ada622041.

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Deryabin, I. V. Noise-absorbing panel with bypass channels. FORGING AND STAMPING PRODUCTION. MATERIAL WORKING BY PRESSURE, août 2023. http://dx.doi.org/10.12731/kshpomd62023-deryabin.

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Résumé :

Noise, having a harmful effect on humans and the environment, forces us to search and conduct research on the development of new methods and means of noise protection. Currently, with an increasing increase in the flow of vehicles in residential areas, with the development of industrial production, the issue of noise control is becoming particularly relevant. A well-known and effective technical solution for blocking the transmission of acoustic energy is the use of noise-absorbing panels, both as part of various soundproof structures, and in the form of separate acoustic elements installed in noisy rooms. The article discusses the design of a noise-absorbing panel containing through bypass channels. Such a panel has a broadband sound absorption effect in frequency composition due to the use of porous sound-absorbing structures of structural materials with the integration of bypass channels into their composition.

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