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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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Journal ArticleDOI
TL;DR: In the proposed ranging method, the base station does not need to send a timing-adjustment message, and the overhead associated with ranging in the downlink resources, and computational complexity can be significantly reduced without degrading the timing-offset-estimation performance.
Abstract: In this study, a decentralised ranging method for uplink orthogonal frequency division multiple access (OFDMA) systems with half-duplex (HD) amplify-and-forward (AF) relay stations (RSs) is proposed. In the OFDMA systems with HD AF RSs, twice more resources and delays are required as ranging without RS. To reduce the required resources and delays for ranging, the authors propose a two-phase ranging scheme based on the decentralised timing-offset estimation at each ranging mobile station (MS). At the first phase, RS occasionally broadcasts timing reference signal, and at the second phase RS retransmits the collected ranging signals from the MSs. Then, each ranging MSs can individually estimate its own timing offset from the received signals. In the proposed ranging method, the base station does not need to send a timing-adjustment message, and the overhead associated with ranging in the downlink resources, and computational complexity can be significantly reduced without degrading the timing-offset-estimation performance. Moreover, the delay associated with ranging can be maintained as same as ranging without RS.

5 citations

Proceedings ArticleDOI
01 Jun 2017
TL;DR: A solution that uses the radio parameters measured by a mobile terminal to determine the best Application Protocol (APPP) for a service, so as it could adapt to the varying network conditions is presented.
Abstract: With the 5G technology, data traffic is going to grow by a factor of 1000, while the number of connected devices is likely going to be two orders of magnitude higher. With smartphones being cornerstone in our daily lives, understanding mobile network performance is critical for providing a superior user experience and, consequently, determining the success of an application. This paper presents a solution that uses the radio parameters measured by a mobile terminal to determine the best Application Protocol (APPP) for a service, so as it could adapt to the varying network conditions. From the training of an inference system with actual Mean Opinion Score (MOS) data, it will be possible to discern which radio Key Performance Indicators (KPIs) are best suited to characterize the state of the network and make the best possible decision. Results show how the decision system based on only three radio KPI is able to determine the user application experience with a success of up to 83%. Thanks to the use of this approach, application developers may fill the gap of knowledge between network KPIs and user experience.

5 citations


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

  • ...In this figure, it is observed the different protocol entities of the Radio Access Network (RAN) user plane, which are [16]: Physical (PHY), Medium Access Control (MAC), Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP), Internet Protocol (IP), TCP, plus the multiple-option application layer protocols, which will be selected as a function of the varying network conditions....

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Proceedings ArticleDOI
01 Jan 2016
TL;DR: System level simulation performance for the downlink, based upon current LTE systems, provides an indication of the achievable potential system performance improvement by employing massive MIMO in future (5G) cellular networks.
Abstract: Massive MIMO (multiple-input multiple-output) antenna technology can provide significant performance improvement for cellular systems in terms of both throughput and energy efficiency. It is widely recognized that inter-user interference can be eliminated with a large number of antennas because of the asymptotical orthogonality among users when linear MF (Matched Filter) downlink precoding is used in the eNodeB. In this paper, system level simulation performance for the downlink, based upon current LTE systems, provides an indication of the achievable potential system performance improvement by employing massive MIMO in future (5G) cellular networks. System simulations consider various performance limiting factors including non-ideal asymptotical orthogonality, transmit channel correlation, imperfect channel estimation and pilot contamination. It is demonstrated that even as the number of transmit antennas is increased to a large number, the accumulative effects of the non-ideal asymptotical orthogonality among different users constitute a significant limiting degradation to the system performance. Likewise, a significant performance decrease is also incurred due to transmit channel correlation, imperfect channel estimation, and pilot contamination.

5 citations


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

  • ...Since the user terminals are typically equipped with a small number of transmit antennas, the required number of uplink pilot resources will be small and similar to that of classical MIMO systems....

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Proceedings ArticleDOI
01 Sep 2013
TL;DR: In the proposed algorithm, an energy efficiency scaling factor is introduced into the criteria when selecting the target cell in load balance to achieve the joint optimization of both load balance and energy saving.
Abstract: Energy efficiency of wireless networks is becoming more and more important because of the steadily rising energy cost and environmental concerns. In a real network with unequal traffic load distributions among cells, by offloading some edge users in a heavily-loaded cell to neighboring lightly-loaded cell, load balance, aims to utilize the radio resource more efficiently and consequently can improve the end-user performance. In this paper an energy efficient load balancing algorithm is proposed. In the proposed algorithm, the target cell in load balance is selected based on the prediction of the possible performance. Furthermore, an energy efficiency scaling factor is introduced into the criteria when selecting the target cell in load balance to achieve the joint optimization of both load balance and energy saving. Simulation results show that the proposed algorithm can reduce the power consumption in the network and at the same time improve the cell throughput.

5 citations

Journal ArticleDOI
TL;DR: This paper demonstrates an alternative approach that directly exploits the differences between coherence bandwidth and coherence time of users under frequency-selective conditions, showing that it can lead to significant new efficiencies and gains.
Abstract: Downlink transmission into frequency-selective links experiencing different coherence bandwidths and coherence times has obvious practical relevance, but is often addressed via assuming for all users the coherence conditions corresponding to the fastest, most dispersive user. This paper demonstrates an alternative approach that directly exploits the differences between coherence bandwidth and coherence time of users under frequency-selective conditions, showing that it can lead to significant new efficiencies and gains. More specifically, we study a two-user downlink frequency-selective channel under three broad conditions of disparity between the link qualities: when the disparity is in coherence time, in coherence bandwidth, and in both coherence time and coherence bandwidth. Each of the coherence scenarios calls for a distinct treatment; for each, we provide an analysis demonstrating the gains in achievable rates due to exploiting coherence disparity. Numerical simulations demonstrate the advantages of the proposed schemes.

5 citations