Book•
4G: LTE/LTE-Advanced for Mobile Broadband
21 Mar 2011-
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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TL;DR: The proposed architecture to improve video streaming quality of experience (QoE) in cellular networks with high user equipment (UE) density is presented and QoE awareness is employed in three aspects; cellular resource allocation, caching of video segments, and SM-assignment optimization.
Abstract: In this paper, we present an architecture to improve video streaming quality of experience (QoE) in cellular networks with high user equipment (UE) density. In the proposed architecture, video segments are progressively cached, as requested, in selected UEs called storage members (SMs). Video segments are strategically cached to be available to requesting users in the cell. Furthermore, the base-station controls the device-to-device communication between the UEs to provide collaborative peer-to-peer transmission of video segments. Dynamic adaptive streaming over HTTP is also employed to adapt the quality of video segments to network conditions. We study the improvements achieved by the proposed architecture in terms of many video streaming QoE metrics. Thereafter, we improve the operation of the proposed architecture by introducing QoE awareness to both caching and distribution of video segments. We employ QoE awareness in three aspects of the proposed architecture; cellular resource allocation, caching of video segments, and SM-assignment optimization. We analyze the improvements achieved by the prospered QoE-awareness techniques in terms of video streaming QoE metrics.
5 citations
03 Jun 2018
TL;DR: This work examines the design and implications of contention- based channel access for the lowest CBRS tier that comprises opportunistic users known as General Authorized Access (GAA) devices, and assesses the suitability of Listen-Before-Talk (LBT) for GAA channel access.
Abstract: The opening up of the 3550-3700 MHz band in the US for Citizen's Broadband Radio Service (CBRS) represents a new opportunity for deploying spectrum-sharing cellular networks The three-tier structure of the CBRS sharing regime with different interference protection constraints per tier imposes a coexistence challenge for networks based on Long-Term Evolution (LTE) As a result, contention-based channel access mechanisms can be incorporated into LTE networks as a method of sharing frequency channels assigned by the Spectrum Access System (SAS) In this work, we examine the design and implications of contention- based channel access for the lowest CBRS tier that comprises opportunistic users known as General Authorized Access (GAA) devices In particular, we assess the suitability of Listen-Before-Talk (LBT) for GAA channel access Performance evaluations for an outdoor deployment scenario show that LBT- based coexistence is effective for low-power GAA users or symmetric power situations, while a combination of LBT and channel allocation is preferred for asymmetric power situations with a mix of low and high-power GAA transmitters
5 citations
Cites background or methods from "4G: LTE/LTE-Advanced for Mobile Bro..."
...Time-Division Duplex (TDD) LTE [1], LicensedAssisted Access LTE [2][3], and MulteFire (MF) [9] are all candidate Radio Access Technologies (RATs) for certain classes of devices in the 3.5 GHz band, where LAA and MF utilize contention-based channel access mechanisms....
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...Time-Division Duplex (TDD) LTE [1], LicensedAssisted Access LTE [2][3], and MulteFire (MF) [9] are all candidate Radio Access Technologies (RATs) for certain classes of devices in the 3....
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...Keywords—Citizens Broadband Radio Service, GAA spectrum sharing, 3.5 GHz, LTE....
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...The CBRS Alliance examines coexistence aspects and network services with emphasis on LTE-based networks [11]....
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...Apart from LBT, the main difference between them is that TDD LTE adopts a fixed DL-UL frame configuration and always transmits reference signals even if there is no accompanying DL data, while LAA and MF can dynamically vary their DL-UL subframe ratio and do not transmit if there is no data to be served....
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TL;DR: A holistic framework that highlights the goals of mobile adoption is proposed, a taxonomy of enterprise mobile services capabilities is presented which if utilised should assist organisations to achieve the goalsof mobile adoption and the components of mobile solutions and mobile strategy are categorised.
5 citations
Cites background from "4G: LTE/LTE-Advanced for Mobile Bro..."
...The first release of LTE was in 2007 (Dahlman et al., 2011)....
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Dissertation•
08 Nov 2016
TL;DR: In this paper, a schema inter-couches PHY 1 APPL, associe a un systeme MIMO-OFDM mono-utilisateur, which transmet a video H.264/SVC.
Abstract: Cette these s'interesse aux strategies de transmission de contenu multimedia des reseaux sans fil. L'interet d'une strategie repose sur sa capacite a gerer les ressources selon les objectifs des applications visees. On propose ainsi un schema de transmission, qui garantit la qualite de service (QdS), quelles que soient les conditions du canal et suivant les specificites du contenu multimedia. On exploite pour cela les diversites (spatiales, frequentielles, etc.) du canal radio. A ce titre, l'association MIMO-OFDM apparait comme une solution ideale pour accroitre les performances du systeme. On propose ainsi un systeme MIMO-OFDMA, qui integre des strategies inter-couches. Celles-ci se basent sur des techniques d'adaptation de lien pour regler dynamiquement les parametres du systeme. On developpe en premier un schema inter-couches PHY 1 APPL, associe a un systeme MIMO-OFDM mono-utilisateur, qui transmet une video H.264/SVC. L'adaptation de lien permet de definir le jeu de parametres optimaux, qui minimise la distorsion de la video recue. On introduit ainsi une politique d'optimisation sous contraintes de puissance et de taux d'erreurs binaires. Pour tenir compte d'aspects de transmission realistes, on propose un schema inter-couches PHY/MAC, dedie a un systeme MIMO-OFDMA, multi-utilisateurs et multi-services. Ce dernier associe un algorithme d'ordonnancement, au parametrage optimal, pour fournir au maximum d'utilisateurs des debits utiles respectant les exigences des services demandes. Enfin, on combine les deux premieres solutions pour definir les parametres optimaux minimisant la distorsion de la video recue par utilisateur, tout en garantissant la QdS des autres services.
5 citations
Additional excerpts
...1.1 Grandeurs des mesures de QdS en LTE-A . . . . . . . . . . . . . . . . . . . . . . . . . 28 2.1 Paramètres principaux de la couche APPL . . . . . . . . . . . . . . . . . . . . . . . . . 64 2.2 Paramètres principaux de la couche PHY . . . . . . . . . . . . . . . . . . . . . . . . . 65 2.3 Distorsion par niveau de qualité transmis sur les sous-canaux SISO hiérarchiques . . . . 66 2.4 Comparaison des PSNR de la vidéo transmise avec la méthode LKT et notre stratégie ....
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...Par exemple, les technologies WIMAX [3] et LTE-A [9] répondent aisément aux attentes des utilisateurs....
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...50 2.4.2 Description du schéma de transmission basé sur la technologie LTE-A . . . . . ....
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26 Jun 2019
TL;DR: This paper proposes an alternative OFDM-based waveform adopted from wireless communication systems, which employs a pre-spreading stage by means of a discrete Fourier transform (DFT), and shows that DFT-spread OFDM has similar radar properties as OFDM, while crest factors can be reduced considerably.
Abstract: Multiple-input multiple-output radar has been recognized as an interesting option for near- to medium-range radar applications, since its virtual antenna array concept offers increased angular resolutions at a compact installation size. Orthogonal frequency-division multiplexing (OFDM) – which is widely employed in wireless communications – has been shown to provide an efficient means to establish the required orthogonal transmit signals. Despite its many advantages, a well-known drawback of OFDM is that transmit signals are typically characterized by relatively high crest factors. This requires corresponding power back-offs at the transmitter side or power amplifiers with highly linear characteristics, so as to avoid undesired signal distortions. In this paper, we propose an alternative OFDM-based waveform adopted from wireless communication systems, which employs a pre-spreading stage by means of a discrete Fourier transform (DFT). By means of computer simulation results, we show that DFT-spread OFDM has similar radar properties as OFDM, while crest factors can be reduced considerably. This renders DFT-spread OFDM a particularly “hardware-friendly” modulation scheme.
5 citations