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4G: LTE/LTE-Advanced for Mobile Broadband

TL;DR: In this article, the authors focus on LTE with full updates including LTE-Advanced to provide a complete picture of the LTE system, including the physical layer, access procedures, broadcast, relaying, spectrum and RF characteristics, and system performance.
Abstract: Based on the bestseller "3G Evolution - HSPA and LTE for mobile broadband" and reflecting the ongoing success of LTE throughout the world, this book focuses on LTE with full updates including LTE-Advanced to provide a complete picture of the LTE system. Overview and detailed explanations are given for the latest LTE standards for radio interface architecture, the physical layer, access procedures, broadcast, relaying, spectrum and RF characteristics, and system performance. Key technologies presented include multi-carrier transmission, advanced single-carrier transmission, advanced receivers, OFDM, MIMO and adaptive antenna solutions, advanced radio resource management and protocols, and different radio network architectures. Their role and use in the context of mobile broadband access in general is explained. Both a high-level overview and more detailed step-by-step explanations of the LTE/LTE-Advanced implementation are given. An overview of other related systems such as GSM/EDGE, HSPA, CDMA2000, and WIMAX is also provided. This book is a 'must-have' resource for engineers and other professionals in the telecommunications industry, working with cellular or wireless broadband technologies, giving an understanding of how to utilize the new technology in order to stay ahead of the competition. The authors of the book all work at Ericsson Research and have been deeply involved in 3G and 4G development and standardisation since the early days of 3G research. They are leading experts in the field and are today still actively contributing to the standardisation of LTE within 3GPP. Includes full details of the latest additions to the LTE Radio Access standards and technologies up to and including 3GPP Release 10Clear explanations of the role of the underlying technologies for LTE, including OFDM and MIMO Full coverage of LTE-Advanced, including LTE carrier aggregation, extended multi-antenna transmission, relaying functionality and heterogeneous deploymentsLTE radio interface architecture, physical layer, access procedures, MBMS, RF characteristics and system performance covered in detail
Citations
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Proceedings ArticleDOI
01 Oct 2015
TL;DR: An efficient matrix-based semi-blind channel estimator (MB-SCE) is proposed for single-input multiple-output (SIMO) systems suffering from severe broadband RFI and Matlab Monte-Carlo simulations have corroborated that MBSCE and TB-S CE outperform MB-BCE and TB -BCE, respectively.
Abstract: The effect of broadband radio frequency interference(RFI) is often overlooked in the terrestrial communication literature. However, such an RFI can render very poor equalization for a reception over a frequency selective channel by making the channel estimator perform the worst. Accordingly, the paper firstly proposes an efficient matrix-based semi-blind channel estimator (MB-SCE) for single-input multiple-output(SIMO) systems suffering from severe broadband RFI. Secondly, more complex yet more performant tensor-based semi-blind channel estimator (TB-SCE) is proposed while showcasing a trade-off between performance and complexity. The paper then compares MB-SCE and TB-SCE with the existing matrix-based blind channel estimator (MB-BCE) and tensor-based blind channel estimator (TB-BCE), respectively, that ignore RFI. Eventually, Matlab Monte-Carlo simulations have corroborated that MBSCE and TB-SCE outperform MB-BCE and TB-BCE, respectively. In addition, TB-SCE outperforms MB-SCE especially for a short observation interval.

10 citations

Journal ArticleDOI
TL;DR: This article proposes a reconfigurable intelligent surface (RIS)-empowered over-the-air FL system to alleviate the dilemma between learning accuracy and privacy and develops a system optimization problem to optimize the learning accuracy while satisfying privacy and power constraints.
Abstract: Federated learning (FL), as a disruptive machine learning (ML) paradigm, enables the collaborative training of a global model over decentralized local data sets without sharing them. It spans a wide scope of applications from the Internet of Things (IoT) to biomedical engineering and drug discovery. To support low-latency and high-privacy FL over wireless networks, in this article, we propose a reconfigurable intelligent surface (RIS)-empowered over-the-air FL system to alleviate the dilemma between learning accuracy and privacy. This is achieved by simultaneously exploiting the channel propagation reconfigurability with RIS for boosting the received signal power, as well as the waveform superposition property with over-the-air computation (AirComp) for fast model aggregation. By considering a practical scenario, where high-dimensional local model updates are transmitted across multiple communication blocks, we characterize the convergence behaviors of the differentially private federated optimization algorithm. We further formulate a system optimization problem to optimize the learning accuracy while satisfying privacy and power constraints via the joint design of transmit power, artificial noise, and phase shifts at RIS, for which a two-step alternating minimization framework is developed. Simulation results validate our systematic, theoretical, and algorithmic achievements and demonstrate that RIS can achieve a better tradeoff between privacy and accuracy for over-the-air FL systems.

10 citations

Journal ArticleDOI
TL;DR: Simulation results show that the proposed asynchronous detection algorithms are able to offer descent bit error rate performances, with only a small performances loss compared to the synchronous case.
Abstract: Sparse code multiple access (SCMA) is one type of non-orthogonal multiple access techniques for the fifth-generation wireless communication networks. Existing multiuser detection algorithms for SCMA uplink systems are based on the assumption that signals are in synchronization. However, asynchrony cannot be neglected due to the propagation delays in practical environments. In this paper, we present three detection algorithms for uplink asynchronous SCMA systems, namely belief propagation message passing algorithm, belief propagation with equal gain combining message passing algorithm, and partial phase-coherent algorithms. Simulation results show that our proposed asynchronous detection algorithms are able to offer descent bit error rate performances, with only a small performances loss compared to the synchronous case. Moreover, our proposed algorithms converge well in the uplink asynchronous SCMA systems.

10 citations


Cites background or methods from "4G: LTE/LTE-Advanced for Mobile Bro..."

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  • ...The second received signal rk [2] and the penultimate received signal rk [3N + 1] consist of two users’ information....

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Journal ArticleDOI
TL;DR: The proposed scheme is more reliable than OFDM-IM, particularly for channels that have deep fading, and uses generalized prefix as a guard interval and this GP provides additional degrees of freedom, which can be optimized.

10 citations

Journal Article
TL;DR: This paper presents a survey on hybrid ARQ (HARQ) types and mechanisms which is the core feature that provides robustness in LTE and Advance LTE networks.
Abstract: Long Term Evaluation (LTE) technology is the most efficient mobile broadband technology for providing an excellent user experience. The 3rd Generation Partnership Project (3GPP), Release’8 LTE provides the next step of 3G technology. LTE offers cogent improvements over previous technologies like GSM/UMTS/HSPA. Lower latency, higher downlink & uplink speeds, and simpler network architecture are among, other new features that are provided. This paper presents a survey on hybrid ARQ (HARQ) types and mechanisms which is the core feature that provides robustness in LTE and Advance LTE networks.

10 citations