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
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01 Nov 2013
TL;DR: Two different channel estimation schemes are used to calculate Channel Quality Indicator and Precoding Matrix Indicator in the 3GPP-LTE fast fading channel and it is found that, by using a low-complexity ALMMSE, the estimation error is reduced with relatively small reduction in throughput.
Abstract: The fast fading channel produced by the fast user mobility requires a powerful channel estimation to report the most accurate channel status Such estimation techniques are usualy suffer from large number of computational processes, and thus, their complexity needs to be minimized However, the calculation reliability of channel coefficients depends mainly on the accuracy of the channel estimation model Therefore, obtaining a joint optimized solution for channel estimation error, feedback overhead, and complexity is very crucial In this paper, two different channel estimation schemes; Linear Minimum Mean Square Error (LMMSE) and Approximate Linear Minimum Mean Square Error (ALMMSE) are used to calculate Channel Quality Indicator (CQI) and Precoding Matrix Indicator (PMI) in the 3GPP-LTE fast fading channel It is found that, by using a low-complexity ALMMSE, the estimation error is reduced with relatively small reduction in throughput Therefore, the proposed method is recommended to be used when the network is not fully loaded for better tradeoff concerning MSE and throughput taking into account the fixed and mobility scenarios, and thus, reliable transmission will be targeted
8 citations
Cites background from "4G: LTE/LTE-Advanced for Mobile Bro..."
...It is already known that when the pilot reference occupies a certain location in the time- frequency resource grid, it will never reoccupy it [14]....
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TL;DR: A low-complexity iterative algorithm is developed to solve the problem with low complexity based on a well-known machine learning approach, i.e., variational inference to detect the indices of active transmit antennas.
Abstract: In this paper, we consider a simple coding scheme for spatial modulation, where the same set of active transmit antennas is repeatedly used over consecutive multiple transmissions. Based on a Gaussian approximation, an approximate maximum likelihood (ML) detection problem is formulated to detect the indices of active transmit antennas. We show that the solution to the approximate ML detection problem can achieve a full coding gain. Furthermore, we develop a low-complexity iterative algorithm to solve the problem with low complexity based on a well-known machine learning approach, i.e., variational inference. Simulation results show that the proposed algorithm can have a near ML performance. A salient feature of the proposed algorithm is that its complexity is independent of the number of active transmit antennas, whereas an exhaustive search for the ML problem requires a complexity that grows exponentially with the number of active transmit antennas.
8 citations
Cites background from "4G: LTE/LTE-Advanced for Mobile Bro..."
...Index Terms—Spatial Modulation; Index Modulation; Repeated Transmit Diversity; Variational Inference I. INTRODUCTION In wireless communications, multiple-input multiple-output (MIMO) systems play a crucial role in improving the spectral efficiency by exploiting multiple antennas [1], [2] and have been actively considered for cellular systems, e.g., long-term evolution (LTE) [3] and fifth generation (5G) systems [4]....
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..., long-term evolution (LTE) [3] and fifth generation (5G) systems [4]....
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TL;DR: It is concluded that the linear equalizers have higher frame error rates (FER) than DFE, however, blind equalizer have higher FERs compared to conventional equalizers with better spectral efficiency as they need no training sequence.
Abstract: WiMAX is a coming forth broadband wireless technology that considered as one of the most prominent solution to provide high speed data services. This paper addresses the design of WiMAX end to end physical layer (PHY) in Simulink with channel equalization and space time block coding techniques. The authors analyzed the performance of WiMAX PHY with decision feedback equalizers (DFE), linear equalizers and blind equalizers over AWGN and multipath faded channels. Results include MISO channel power spectral density (PSD), antenna amplitude/PSD/phase difference, multipath faded and AWGN channel's effect on the transmitted signal and the performance of proposed equalizers on the received signals. This paper concluded that the linear equalizers have higher frame error rates (FER) than DFE. However, blind equalizers have higher FERs compared to conventional equalizers with better spectral efficiency as they need no training sequence.
8 citations
25 Nov 2013
TL;DR: System level simulations indicate that adaptive base station hardware, cell DTX, antenna muting, and adaptive sectorization together can provide energy savings in the order of 75% with only minor impact on quality of service.
Abstract: This paper focuses on energy saving techniques for LTE, and what overall energy savings they can achieve. The considered techniques are adaptive base station hardware, cell DTX, antenna muting, and adaptive sectorization. The paper discusses how these can be integrated and jointly save energy, and evaluates the energy savings as well as the quality of service impact by means of extensive system level evaluations of a radio access network. The system level simulations, which are carried out over 24 hours in a country-wide LTE network, indicate that these techniques together can provide energy savings in the order of 75% with only minor impact on quality of service.
8 citations
25 Jun 2014
TL;DR: A capacity enhancement approach using user-deployed shared-access small cells in the dense informal settlements is presented, leveraging macro Long Term Evolution networks to backhaul High Speed Packet Access (HSPA) small cells and introducing of traffic steering across HSPA and LTE layers.
Abstract: Urban (and suburban) informal settlements in emerging markets will be the fastest growing population hotspots in the next few decades This presents a significant challenge in delivery of services, including affordable mobile Internet access Operator-led upgrades through network densification (rollout of additional operator-maintained sites) are difficult to sustain in those areas due to low revenues, lack of fixed lines, energy scarcity, insecurity, and so on This calls for alternative approaches in mobile network upgrades and operation In this paper, we present capacity enhancement approach using user-deployed shared-access small cells in the dense informal settlements To that end, we consider leveraging macro Long Term Evolution (LTE) networks to backhaul High Speed Packet Access (HSPA) small cells As a case study, we present comparative network simulations based on an example informal settlement The results of the study highlight the possibilities for cost-effective capacity upgrades for users in dense settlements for even a limited number of unplanned end-user small deployments and self-backhauling via existing macro sites In the study, we also note possible system performance enhancements of the small cell backhaul link through improved antenna design, scaling of carrier bandwidth and introduction of traffic steering across HSPA and LTE layers
8 citations
Cites background or methods from "4G: LTE/LTE-Advanced for Mobile Bro..."
...In this study we consider 2x2 and 4x4 configurations for LTE Release 8 and additional gains obtained by Release 10 (LTE-Advanced) extensions to 8x8 configurations in the downlink [13]....
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...For LTE Release 8 transmission bandwidth scalability is possible up to 20 MHz, while Release 10 carrier aggregation enables LTEUEs and small cell LTE backhaul connections are scheduled over multiple 20 MHz component carriers [13]....
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