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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
TL;DR: Simulation results demonstrate that the proposed low-complexity online Lyapunov optimization algorithm combined with a constrained concave-convex procedure (CCCP) performs better than the greedy algorithm and the orthogonal multiple access (OMA) scheme.
Abstract: In this paper, a multiple-cluster downlink multiple-input single-output (MISO) nonorthogonal multiple access (NOMA) system is considered. In each cluster, there are one central user and one cell-edge user. The central user has a data buffer with finite storage units, which will decode the cell-edge user’s message and store it at the data buffer. To enhance the performance of the cell-edge user, the central user operates as a relay and helps forward the message to the cell-edge user. Our objective is to maximize the long-term average sum rates for the cell-edge users by designing the beamforming vectors and online power control, under the constraints of the data buffer causality, required information rates for central users, and transmit power at the base station and central users. Based on the current buffer state and the channel state information, we propose a low-complexity online Lyapunov optimization algorithm combined with a constrained concave-convex procedure (CCCP) to solve the causal and nonconvex problem. Furthermore, we verify the asymptotic optimality of the proposed online Lyapunov optimization algorithm. Simulation results demonstrate that our proposed scheme performs better than the greedy algorithm and the orthogonal multiple access (OMA) scheme.

1 citations

Journal ArticleDOI
TL;DR: This work includes the details of Downlink LTE Advanced System Model and thereby all the performance analysis of Non Contiguous Carrier Aggregation are done and an overview of LTE-Advanced CA scenarios is discussed.
Abstract: Long Term Evolution-Advanced (LTE-A) has brought revolution in the field of wireless communication technology by providing high data rates of up to 1Gbps. One key enhancement feature of LTE-A is bandwidth extension by the use of multi-carrier technology to support deployment bandwidth of up to 100MHz. To achieve such high data rate in IMT-Advanced mobile systems, carrier aggregation technology by 3GPP has been introduced to support very-high-data rate transmissions over wide frequency bandwidth in the new LTE-Advanced standards. This work includes the details of Downlink LTE Advanced System Model and thereby all the performance analysis of Non Contiguous Carrier Aggregation are done and an overview of LTE-Advanced CA scenarios is discussed. Also component carrier parameters and oversampling factor are found and using these parameters power spectrum is plotted. The main outcome from this work is increase in the throughput of the system by increasing the number of carrier components or by increasing bandwidth. Many proposals on carrier aggregation in LTE-A have been published but still there is a need of research to be carried out in this field as this technology has not fully matured.

1 citations


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

  • ...The extension carrier is addressed by using a separate PDCCH and also uses a separate HARQ process [13]....

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Dissertation
10 Aug 2016
TL;DR: This dissertation aims to provide a history of literature and its reception in the 21st Century through the lens of science, literature, and medicine.
Abstract: .................................................................................................................... IV TABLE OF CONTENTS ................................................................................................. V LIST OF PUBLICATIONS ........................................................................................... IX AWARDS AND MEDALS ............................................................................................... X LIST OF TABLES .......................................................................................................... XI LIST OF FIGURES .......................................................................................................XII LIST OF ABBREVIATIONS ....................................................................................... XV 1.0 INTRODUCTION...................................................................................................1 1.1 Motivation ............................................................................................................ 1 1.2 Research objectives .............................................................................................. 4 1.3 Problem statement ................................................................................................ 5 1.4 Research questions ............................................................................................... 5 1.5 Research contributions ......................................................................................... 6 1.6 Thesis outline ....................................................................................................... 6 2.0 LITERATURE REVIEW ......................................................................................8 2.1 Cognitive radio ..................................................................................................... 8 2.1.

1 citations


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

  • ...16 [3], and Long Term Evaluation [4] and advanced-LTE [5], has caused increasing stress on the limited spectrum availability as a result of the traditional static spectrum assignment policies adopted by the telecom regulatory authorities worldwide....

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Dissertation
16 Apr 2015
TL;DR: This thesis investigates the effect of amplifier non-linearity on the bit-error-rate of a two-way cooperative communication system that employs linear modulation and amplify-and-forward, and proposes two signal forwarding techniques that offer MPSK modulations immunity against non- linear amplifier distortion.
Abstract: Relay/cooperative communication has been an active area of research in the past few years In most of the investigations, the amplifiers used in the system are assumed to be linear In this thesis, we first investigate the effect of amplifier non-linearity has on the bit-error-rate (BER) of a two-way cooperative communication system that employs linear modulation and amplify-and-forward (AF) It was found that irreducible error floor arises, caused by the inter-modulation effect with non-linear amplification and the subsequent imperfect self-interference cancellation As a result of this finding, we propose two signal forwarding techniques that offer MPSK modulations immunity against non-linear amplifier distortion The first technique, termed multiply-and-forward (MF), scales the product of the two received signals at the relay for downlink transmission The second technique, termed phase-forward (PF), has a similar product structure, except that the amplitude information in the product signal is discarded We show that both schemes do not exhibit the irreducible error characteristic found in AF when the amplifier is non-linear The PF scheme, in particular, can attain a BER lower than that of AF even when the amplifier is linear The conclusion is reached that MF and PF are suitable signal forwarding strategies for two-way cooperative communication in the presence of amplifier non-linearity, with PF being the more robust of the two Due to the multiplicative nature of the MF and PF, self-informantion cancellation becomes simple when differential modulation is used in the two-way cooperative relay system With differential modulation, there is no explicit channel state information (CSI) estimation and and this leads to a saving of pilot symbol overhead In the second and third parts of this thesis proposal, we extend the MF and PF protocols to DPSK and CPFSK modulations Specifically, we demonstrate that the proposed forwarding methods has low computational complexity at the relay as well as simple self-information cancellation at the receiver in the last phase of the cooperative communication

1 citations


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

  • ...where w1 and w2 are weighting coefficients [9,10,12]....

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  • ...For instance, the third generation partnership project (3GPP) has included relaying technologies in its long term evolution (LTE) standardization [8, 9]....

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Proceedings ArticleDOI
01 Dec 2014
TL;DR: The running distance of the AGV was improved from 10 meters to the whole length of the testing course, and the least square method on the wall-floor boundaries was applied.
Abstract: In our research, we have studied the autonomous running control system of the automatic guided vehicles (AGV) used in the manufacturing facilities using the tablet PC. The moving direction of automatic vehicle is controlled by the results of image processing methods on captured images of the tablet PC. In the image processing step, after detecting edges we obtain wall-floor boundaries by analyzing those edges. By applying the least square method on the wall-floor boundaries, we calculate the moving direction of the AGV. To improve the accuracy of the moving direction, we divide the edge detection image into grid cells and remove all edges in cells with sparse edges. Furthermore, we divided all boundary points into vertical subdivisions, estimated unusual small boundaries and discarded them. As a result of our research, the running distance of the AGV was improved from 10 meters to the whole length of the testing course. The distance of testing course is 100 meters long.

1 citations


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

  • ...As a result of the development of mobile technology, the speed of mobile communication such as LTE (Long Term Evolution) [2-3] is significantly increasing and the performance of mobile processors is improving very fast [4-5]....

    [...]

References
More filters
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.