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Journal ArticleDOI

LTE-advanced: next-generation wireless broadband technology [Invited Paper]

01 Jun 2010-IEEE Wireless Communications (IEEE Press)-Vol. 17, Iss: 3, pp 10-22
TL;DR: An overview of the techniques being considered for LTE Release 10 (aka LTEAdvanced) is discussed, which includes bandwidth extension via carrier aggregation to support deployment bandwidths up to 100 MHz, downlink spatial multiplexing including single-cell multi-user multiple-input multiple-output transmission and coordinated multi point transmission, and heterogeneous networks with emphasis on Type 1 and Type 2 relays.
Abstract: LTE Release 8 is one of the primary broadband technologies based on OFDM, which is currently being commercialized. LTE Release 8, which is mainly deployed in a macro/microcell layout, provides improved system capacity and coverage, high peak data rates, low latency, reduced operating costs, multi-antenna support, flexible bandwidth operation and seamless integration with existing systems. LTE-Advanced (also known as LTE Release 10) significantly enhances the existing LTE Release 8 and supports much higher peak rates, higher throughput and coverage, and lower latencies, resulting in a better user experience. Additionally, LTE Release 10 will support heterogeneous deployments where low-power nodes comprising picocells, femtocells, relays, remote radio heads, and so on are placed in a macrocell layout. The LTE-Advanced features enable one to meet or exceed IMT-Advanced requirements. It may also be noted that LTE Release 9 provides some minor enhancement to LTE Release 8 with respect to the air interface, and includes features like dual-layer beamforming and time-difference- of-arrival-based location techniques. In this article an overview of the techniques being considered for LTE Release 10 (aka LTEAdvanced) is discussed. This includes bandwidth extension via carrier aggregation to support deployment bandwidths up to 100 MHz, downlink spatial multiplexing including single-cell multi-user multiple-input multiple-output transmission and coordinated multi point transmission, uplink spatial multiplexing including extension to four-layer MIMO, and heterogeneous networks with emphasis on Type 1 and Type 2 relays. Finally, the performance of LTEAdvanced using IMT-A scenarios is presented and compared against IMT-A targets for full buffer and bursty traffic model.
Citations
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Journal ArticleDOI
14 Jul 2014
TL;DR: A new scheduling algorithm in downlink Long Term Evolution networks which is adoptable with fast variations in channel conditions and makes a good trade-off between throughput and fairness at the cost of small decrease in amount of system throughput.
Abstract: This paper proposes a new scheduling algorithm in downlink Long Term Evolution networks whichis adoptable with fast variations in channel conditions.It allocates resources in a fair manner among users so that it increases cell edge users’ performance. Besides, it makes a good trade-off between throughput and fairness. The proposed method is simulated and compared with three scheduling algorithms available for Long Term Evolution. The results showgood degree of fairness at the cost of small decrease in amount of system throughput.

6 citations

Proceedings ArticleDOI
01 Dec 2017
TL;DR: Simulation results reveal that the proposed NOMA networks is capable of outperforming conventional orthogonal multiple access (OMA) networks in terms of QoE; moreover, the proposed algorithms for sum-MOS maximization can achieve significant fairness improvement against the sum- rate maximization scheme.
Abstract: This paper investigates the resource allocation to enhance the users' quality of experience (QoE) for multi-cell non-orthogonal multiple access (NOMA) networks An optimization problem is formulated with the objective of maximizing the sum mean opinion score (MOS) of users in the network To solve the challenged mixed integer programming problem, we first decompose it into two subproblems A three-dimensional (3D) matching problem is proposed for modelling the relation among users, BSs and subchannels Then, a two-step approach is proposed to attain a suboptimal solution Furthermore, a low complexity suboptimal approach based on successive convex approximation (SCA) techniques is developed for optimizing power allocation among users Simulation results reveal that the proposed NOMA networks is capable of outperforming conventional orthogonal multiple access (OMA) networks in terms of QoE; moreover, the proposed algorithms for sum-MOS maximization can achieve significant fairness improvement against the sum- rate maximization scheme

6 citations


Cites background from "LTE-advanced: next-generation wirel..."

  • ...Multicarrier transmission techniques such as orthogonal frequency division multiple access (OFDMA), have been widely adopted in broadband wireless communication systems such as LTE and LTE-Advanced [1], [2]....

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  • ...I. INTRODUCTION Multicarrier transmission techniques such as orthogonal frequency division multiple access (OFDMA), have been widely adopted in broadband wireless communication systems such as LTE and LTE-Advanced [1], [2]....

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Dissertation
01 Jan 2017
TL;DR: This thesis examines efficient solutions to overcome three key challenges: mechanisms to guarantee QoS levels when smart meters use public communications networks to transport their data, approaches to guarantee the scalable deployment of the complex smart meter based applications, and a platform to efficiently simulate smart grid networks along with its control and communication operations in order to assess smart grid applications.
Abstract: The smart grid is an interconnected electricity network. It integrates the electricity grid with powerful control and communications networks that can dynamically respond to customer demands and energy supply scenarios with increased reliability. One of the key components of the smart grid is the smart meter, which is the main sensor in the electricity distribution grid. As of today, the introduction of the smart meter has transformed manual electricity billing system to an automated meter reading system. In the future, the capabilities of smart meters will not only be limited to meter-readings but are expected to facilitate outage detections and demand side management, allowing the grid to respond dynamically to both customer demands and energy market pricing signals. However, these smart meters based applications face many challenges in implementing them in the network including provisioning adequate resources for smart metering traffic to guarantee the required quality of service (QoS) level, maintaining scalability of applications that require complex computations, ensuring the security of the smart metering data, and providing a platform to identify the effect of communications networks on smart meter applications. This thesis investigates approaches to overcome the challenges in implementing smart meter based applications to achieve a reliable and cost-efficient electricity network. In particular, this thesis examines efficient solutions to overcome three key challenges: mechanisms to guarantee QoS levels when smart meters use public communications networks to transport their data, approaches to guarantee the scalable deployment of the complex smart meter based applications, and a platform to efficiently simulate smart grid networks along with its control and communication operations in order to assess smart grid applications. For the smart meter communications network, the public telecommunications network is considered as a cost-effective solution as it does not involve any separate installation or maintenance costs. However, when sharing network resources with both public traffic and smart metering traffic, required QoS levels of essential broadband services along with those of smart meters should be satisfied. To this end, this thesis explores

6 citations


Cites methods from "LTE-advanced: next-generation wirel..."

  • ...Orthogonal frequency-division multiplexing (OFDM) is used as the multiple access technology in the downlink of the LTE network while the single-carrier frequency division multiple access (SC-FDMA) scheme is used in uplink [139]....

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Dissertation
28 Jun 2016
TL;DR: This Thesis firstly focuses on energy-efficient transmission schemes and introduces a scheme for alleviating the power loss experienced by the Tomlinson-Harashima precoder, by aligning the interference of a number of users with the symbols to transmit.
Abstract: The exponential growth of wireless data traffic has caused a significant increase in the power consumption of wireless communications systems due to the higher complexity of the transceiver structures required to establish the communication links. For this reason, in this Thesis we propose and characterize technologies for improving the energy efficiency of multiple-antenna wireless communications. This Thesis firstly focuses on energy-efficient transmission schemes and commences by introducing a scheme for alleviating the power loss experienced by the Tomlinson-Harashima precoder, by aligning the interference of a number of users with the symbols to transmit. Subsequently, a strategy for improving the performance of space shift keying transmission via symbol pre-scaling is presented. This scheme re-formulates complex optimization problems via semidefinite relaxation to yield problem formulations that can be efficiently solved. In a similar line, this Thesis designs a signal detection scheme based on compressive sensing to improve the energy efficiency of spatial modulation systems in multiple access channels. The proposed technique relies on exploiting the particular structure and sparsity that spatial modulation systems inherently possess to enhance performance. This Thesis also presents research carried out with the aim of reducing the hardware complexity and associated power consumption of large scale multiple-antenna base stations. In this context, the employment of incomplete channel state information is proposed to achieve the above-mentioned objective in correlated communication channels. The candidate’s work developed in Bell Labs is also presented, where the feasibility of simplified hardware architectures for massive antenna systems is assessed with real channel measurements. Moreover, a strategy for reducing the hardware complexity of antenna selection schemes by simplifying the design of the switching procedure is also analyzed. Overall, extensive theoretical and simulation results support the improved energy efficiency and complexity of the proposed schemes, towards green wireless communications systems.

6 citations

Journal ArticleDOI
01 Mar 2015
TL;DR: The design and the physical implementation of a power aware FFT core for OFDM-based, dynamic spectrum access (DSA) enabled cognitive radios is presented, equipped with a pruning engine that allows the run-time removal of dummy operations related to the pruning of sub-carriers of the communication systems.
Abstract: This research work presents the design and the physical implementation of a power aware FFT core for OFDM-based, dynamic spectrum access (DSA) enabled cognitive radios. The FFT core is equipped with a pruning engine that allows the run-time removal of dummy operations (e.g. multiplications by a zero term) related to the pruning of sub-carriers of the communication systems. The pruning algorithm introduced by this research work utilizes a reduced size configuration matrix, which limits the memory requirements' overhead. Finally, the physical implementation of the FFT on a 45 nm technology node showed that, for a 8 % area overhead, the total power saving settles around 10 % when in the presence of a medium to high pruning level, justifying the silicon area overhead introduced by the pruning unit.

6 citations


Cites background from "LTE-advanced: next-generation wirel..."

  • ...To cope with these demands, different solutions have been proposed by the wireless communications community: newer standards (e.g. LTE-A [13] and Wi-Max [14]) provide communication links in the order of hundreds of megabits per seconds; Flexible radios and in particular Software Defined Radios (SDRs) laid down the basis for the integration of different radio standards on a single platform [1, 7]; Cognitive radios (CRs) built on top of flexible radios, providing communication systems with an even higher degrees of flexibility, optimizing communication parameters according to the environment and run-time operating conditions [16, 18]....

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  • ...LTE-A [13] and Wi-Max [14]) provide communication links in the order of hundreds of megabits per seconds; Flexible radios and in particular Software Defined Radios (SDRs) laid down the basis for the integration of different radio standards on a single platform [1, 7]; Cognitive radios (CRs) built on top of flexible radios, providing communication systems with an even higher degrees of flexibility, optimizing communication parameters according to the environment and run-time operating conditions [16, 18]....

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References
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Proceedings ArticleDOI
01 Sep 2006
TL;DR: A preliminary look at the air interface for Evolved UTRA (E-UTRA) and associated key technologies required to reach its design objectives are provided.
Abstract: With the emergence of packet-based wireless broadband systems such as 802.16e, it is evident that a comprehensive evolution of the universal mobile telecommunications system specifications is required to remain competitive. As a result, work has begun on long term evolution (LTE) of the UMTS terrestrial radio access and radio access network aimed for commercial deployment in 2010. Goals for the evolved system include support for improved system capacity and coverage, high peak data rates, low latency, reduced operating costs, multi-antenna support, flexible bandwidth operations and seamless integration with existing systems. To reach these goals, a new design for the air interface is envisioned. This paper provides a preliminary look at the air interface for Evolved UTRA (E-UTRA) and associated key technologies required to reach its design objectives. Initial E-UTRA system performance results show a 2 to 3x improvement over a reference Rel-6 UMTS system configuration [1, 2] for both uplink and downlink.

30 citations

Proceedings ArticleDOI
24 Oct 2008
TL;DR: The proposed channel estimation technique is shown to have significant gains in performance compared to other well known channel estimation techniques such as the maximum-likelihood (ML) and the inverse fast Fourier transform (IFFT) channel estimation methods.
Abstract: The performance of the uplink physical channel of the 3GPP LTE system is considered in this paper. Assuming a single user spatial division multiple access transmission scheme, where users' signals are transmitted over different subcarriers, a low complexity channel estimation technique is proposed for the physical uplink shared channel (PUSCH). The proposed channel estimation technique is shown to have significant gains in performance compared to other well known channel estimation techniques such as the maximum-likelihood (ML) and the inverse fast Fourier transform (IFFT) channel estimation methods [5]. Simulation results for different channel models and modulation and coding schemes (MCS) using incremental redundancy (IR) based hybrid automatic repeat request (HARQ) operation are also shown. Finally, a robust detection scheme is proposed for the physical uplink control channel (PUCCH) and simulation results are summarized.

10 citations


"LTE-advanced: next-generation wirel..." refers methods in this paper

  • ...The DFT precoding operation is performed to reduce the cubic metric (CM) of the signal, leading to higher maximum transmit power [2]....

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Trending Questions (1)
What is the difference between LTE and FIOS Internet?

LTE-Advanced (also known as LTE Release 10) significantly enhances the existing LTE Release 8 and supports much higher peak rates, higher throughput and coverage, and lower latencies, resulting in a better user experience.