المؤلفون: Golmohammadi, Ahmad, Mitchell, David G. M., Kliewer, Jorg, Costello, Daniel J.

المصدر: IEEE Transactions on Communications. Nov2018, Vol. 66 Issue 11, p5691-5703. 13p.

مصطلحات موضوعية: *COMPUTER programming, LOSSY data compression, RADIO wave propagation, DECODING algorithms, BANDWIDTH allocation

مستخلص: It has been shown that a class of spatially coupled low-density generator-matrix (SC-LDGM) code ensembles displays distortion saturation for the lossy binary symmetric source coding problem with the belief propagation guided decimation (BPGD) algorithm, i.e., the BPGD distortion approaches the optimal expected distortion of the underlying ensemble asymptotically in code length. We investigate the distortion performance of a practical class of protograph-based SC-LDGM code ensembles and demonstrate distortion saturation numerically. Moreover, taking advantage of the convolutional structure of the SC-LDGM codes, we propose an efficient windowed encoding (WE) algorithm with two decimation techniques for lowering the WE complexity that maintain distortion performance close to the rate-distortion bound. [ABSTRACT FROM AUTHOR]

: Copyright of IEEE Transactions on Communications is the property of IEEE and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المؤلفون: Zeng, Huacheng¹, Hou, Y. Thomas², Shi, Yi², Lou, Wenjing², Kompella, Sastry³, Midkiff, Scott F.²

المصدر: IEEE Transactions on Communications. Mar2017, Vol. 65 Issue 3, p1131-1145. 15p.

مصطلحات موضوعية: *DATA transmission systems, *MANAGEMENT, ELASTIC wave propagation, OCEANOGRAPHIC observations, MATHEMATICAL models of underwater acoustics, DISTRIBUTED algorithms

مستخلص: Underwater acoustic (UWA) networks are a key form of communications for human exploration and activities in the oceanographic space of the earth. A fundamental issue of UWA communications is large propagation delays due to water medium, which has posed a grand challenge in UWA network protocol design. Conventional wisdom of addressing this issue is to live with this disadvantage by inserting a guard interval to introduce immunity to propagation delays. Recent advances in interference alignment (IA) open up a new direction to address this issue and promise a great potential to improve network throughput by exploiting large propagation delays. In this paper, we investigate propagation delay-based IA (PD-IA) in multi-hop UWA networks. We first develop a set of simple constraints to characterize PD-IA feasible region at the physical layer. Based on the set of PD-IA constraints, we develop a distributed PD-IA scheduling algorithm to greedily maximize interference overlapping possibilities in a multi-hop UWA network. Simulation results show that the proposed PD-IA algorithm yields higher throughput than an idealized benchmark algorithm without propagation delays, indicating that large propagation delays are not adversarial but beneficial for network throughput performance. [ABSTRACT FROM AUTHOR]

: Copyright of IEEE Transactions on Communications is the property of IEEE and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المؤلفون: Xu, Kaizhe, Zhang, Jun, Yang, Xi, Ma, Shaodan, Yang, Guanghua

المصدر: IEEE Transactions on Communications; Dec2021, Vol. 69 Issue 12, p8228-8241, 14p

مصطلحات موضوعية: PHASE-shifting interferometry, STATISTICAL physics, ELECTROMAGNETIC wave propagation, COVARIANCE matrices, MIMO systems, RICIAN channels, CHANNEL estimation

مستخلص: Reconfigurable intelligent surface (RIS) stands out as a promising technology by enhancing the electromagnetic wave propagation environment with its passive reflecting elements. In this paper, we focus on the ergodic sum-rate analysis and maximization of the RIS-assisted uplink multiuser multiple-input multiple-output (MIMO) multiple-access channel (MAC) under Rician fading by exploiting full statistical channel state information (CSI). The spatial correlations at the base station, the users, and the RIS are also considered. By using the replica method originated in statistical physics, the closed-form asymptotic ergodic sum-rate of the system is first derived in the large-system regime on the account of the unique channel structure of the RIS-assisted MIMO-MAC system. Then, based on the derived asymptotic ergodic sum-rate, we propose an alternating optimization (AO) algorithm to jointly design the transmit covariance matrix of users and the phase-shifting matrix of RIS with full statistical CSI. Simulation results are also demonstrated to verify the accuracy of the derived asymptotic ergodic sum-rate and the superiority of the proposed AO algorithm. The results reveal that the derived closed-form asymptotic ergodic sum-rate matches very well with the Monte Carlo results even for a small number of antennas, and the proposed AO algorithm can achieve up to 10 bps/Hz gain at high signal-to-noise (SNR) regime, which is therefore valuable for future RIS-assisted MIMO-MAC system designs. [ABSTRACT FROM AUTHOR]

: Copyright of IEEE Transactions on Communications is the property of IEEE and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المؤلفون: Drougas, Athanasios E.¹, Panagopoulos, Athanasios D.¹ thpanag@cc.ece.ntua.gr, Cottis, Panayotis G.¹

المصدر: IEEE Transactions on Communications. Jan2009, Vol. 57 Issue 1, p22-25. 4p.

مصطلحات موضوعية: *BROADBAND communication systems, *WIRELESS communications, *INFORMATION theory, *TELECOMMUNICATION systems, *TELECOMMUNICATION, RADIO wave propagation, OPTICAL communications, ELECTRONICS

مستخلص: In broadband fixed wireless access (BFWA) networks mainly operating above 20 GHz, a clear line-of-sight (LOS) path is necessary between the base stations (BS) and the subscribers (S). In this letter, a Markov-based method to estimate the packet loss rate (PLR) statistical characteristics over a dynamically, due to propagation, varying LOS BFWA channel is presented. The method is verified by means of information theoretic metrics and tested against simulation results. [ABSTRACT FROM AUTHOR]

: Copyright of IEEE Transactions on Communications is the property of IEEE and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المؤلفون: Saeedi, Hamid¹, Banihashemi, Amir H.¹

المصدر: IEEE Transactions on Communications. Jan2009, Vol. 57 Issue 1, p6-11. 6p. 1 Graph.

مصطلحات موضوعية: *INFORMATION theory, RADIO wave propagation, RANDOM noise theory, SIGNAL-to-noise ratio, SIGNAL processing, STOCHASTIC information theory

مستخلص: Belief propagation (BP) algorithm for decoding low- density parity-check (LDPC) codes over a binary input additive white Gaussian noise (BIAWGN) channel requires the knowledge of the signal-to-noise ratio (SNR) at the receiver to achieve its ultimate performance. An erroneous estimation or the absence of a perfect knowledge of the SNR at the decoder is referred to as "SNR mismatch". SNR mismatch can significantly degrade the performance of LDPC codes decoded by the BP algorithm. In this paper, using extrinsic information transfer (EXIT) charts, we design irregular LDPC codes that perform better (have a lower SNR threshold) in the presence of mismatch compared to the conventionally designed irregular LDPC codes that are optimized for zero mismatch. Considering that mm-sum (MS) algorithm is the limit of BP with infinite SNR over-estimation, the EXIT functions generated in this work can also be used for the efficient analysis and design of LDPC codes under the MS algorithm. [ABSTRACT FROM AUTHOR]

: Copyright of IEEE Transactions on Communications is the property of IEEE and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المؤلفون: Piechoki, Robert J., McGeehan, Joe P., Tsoulos, George V.

المصدر: IEEE Transactions on Communications. May2001, Vol. 49 Issue 5, p855. 8p. 3 Black and White Photographs, 3 Diagrams, 1 Chart, 4 Graphs.

مصطلحات موضوعية: *MOBILE communication systems, RADIO wave propagation

مستخلص: Features a study which proposed a stochastic spatio-temporal propagation model for third generation mobile communication systems with antenna arrays. Classification of spatio-temporal models; Description of the radio channel model and its employed parameters; Numerical examples; Conclusions.

المؤلفون: Pop, Marius F., Beaulieu, Norman C.

المصدر: IEEE Transactions on Communications. Apr2001, Vol. 49 Issue 4, p699. 10p. 2 Black and White Photographs, 3 Diagrams, 6 Graphs.

مصطلحات موضوعية: RADIO transmitter fading, RADIO wave propagation

مستخلص: Presents a study which examined the extent to which a simulator by W.C. Jakes adequately models the multipath Rayleigh fading radio wave propagation environment. Overview of Jakes' simulator design; Why the signal produced by Jakes' fading channel simulator is not wide-sense stationary; Conclusion.

المؤلفون: Schutt-Aine, Jose E.

المصدر: IEEE Transactions on Communications. Apr2001, Vol. 49 Issue 4, p598. 4p. 2 Charts, 7 Graphs.

مصطلحات موضوعية: RADIO wave propagation, RADIO waves, TWISTED pair cables

مستخلص: Presents a study which proposed a wave propagation method model for the extraction of propagation parameters of high-bit rate digital subscriber twisted-pair cables. Scattering parameters of twisted-pair cables; Conclusions.

المؤلفون: Parkvall, Stefan, Strom, Erik G.

المصدر: IEEE Transactions on Communications. Jan99, Vol. 47 Issue 1, p78. 11p. 6 Black and White Photographs, 5 Graphs.

مصطلحات موضوعية: *CODE division multiple access, RADIO wave propagation, MICROWAVE receivers

مستخلص: Proposes several receivers for data demodulation in an asynchromous direct-sequence code-division multiple access (DS-CDMA) system operating without prior knowledge of the propagation delays. Model of the system; Structure of the proposed receivers; Error probability of the system.

المؤلفون: Faouzi Bellili, Mohamed Akrout, Robert W. Heath, Volodymyr Shyianov, Amine Mezghani

المصدر: IEEE Transactions on Communications. 70:2010-2024

مصطلحات موضوعية: FOS: Computer and information sciences, business.industry, Computer science, Computer Science - Information Theory, Information Theory (cs.IT), 05 social sciences, Bandwidth (signal processing), Impedance matching, 050801 communication & media studies, Topology, Interference (wave propagation), Communications system, Channel capacity, 0508 media and communications, Wireless, Electrical and Electronic Engineering, Antenna (radio), business, Performance metric, Computer Science::Information Theory

الوصف: Using ideas from Chu and Bode/Fano theories, we characterize the maximum achievable rate over the single-input single-output wireless communication channels under a restriction on the antenna size at the receiver. By employing circuit-theoretic multiport models for radio communication systems, we derive the information-theoretic limits of compact antennas. We first describe an equivalent Chu's antenna circuit under the physical realizability conditions of its reflection coefficient. Such a design allows us to subsequently compute the achievable rate for a given receive antenna size thereby providing a physical bound on the system performance that we compare to the standard size-unconstrained Shannon capacity. We also determine the effective signal-to-noise ratio (SNR) which strongly depends on the antenna size and experiences an apparent finite-size performance degradation where only a fraction of Shannon capacity can be achieved. We further determine the optimal signaling bandwidth which shows that impedance matching is essential in both narrowband and broadband scenarios. We also examine the achievable rate in presence of interference showing that the size constraint is immaterial in interference-limited scenarios. Finally, our numerical results of the derived achievable rate as function of the antenna size and the SNR reveal new insights for the physically consistent design of radio systems.
Comment: accepted to IEEE Transactions on Communications

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::adb4d772978a9d0be4fdc3f26ea492adTest
https://doi.org/10.1109/tcomm.2021.3099842Test