LTE-Advanced - Evolving LTE towards IMT-Advanced
24 Oct 2008-pp 1-5
TL;DR: High-level overview of some technology components currently considered for the evolution of LTE including complete fulfillment of the IMT-advanced requirements, including extended spectrum flexibility, multi-antenna solutions, coordinated multipoint transmission/reception, and the use of advanced repeaters/relaying are provided.
Abstract: This paper provides a high-level overview of some technology components currently considered for the evolution of LTE including complete fulfillment of the IMT-advanced requirements. These technology components include extended spectrum flexibility, multi-antenna solutions, coordinated multipoint transmission/reception, and the use of advanced repeaters/relaying. A simple performance assessment is also included, indicating potential for significantly increased performance.
Citations
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TL;DR: The existing state-of-the-art in wireless sensor networks for agricultural applications is reviewed thoroughly and various case studies to thoroughly explore the existing solutions proposed in the literature in various categories according to their design and implementation related parameters.
627 citations
Cites background from "LTE-Advanced - Evolving LTE towards..."
...3G (Goodman and Myers, 2005) and 4G (Parkvall et al., 2008) are the third and fourth generations of mobile communication technology....
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...3G (Goodman and Myers, 2005) and 4G (Parkvall et al., 2008)...
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24 Aug 2009
TL;DR: This paper presents a MATLAB-based downlink physical-layer simulator for LTE that can efficiently be executed on multi-core processors to significantly reduce the simulation time.
Abstract: Research and development of signal processing algorithms for UMTS Long Term Evolution (LTE) requires a realistic, flexible, and standard-compliant simulation environment. To facilitate comparisons with work of other research groups such a simulation environment should ideally be publicly available. In this paper, we present a MATLAB-based downlink physical-layer simulator for LTE. We identify different research applications that are covered by our simulator. Depending on the research focus, the simulator offers to carry out single-downlink, single-cell multi-user, and multi-cell multi-user simulations. By utilizing the Parallel Computing Toolbox of MATLAB, the simulator can efficiently be executed on multi-core processors to significantly reduce the simulation time.
515 citations
Cites methods from "LTE-Advanced - Evolving LTE towards..."
...By utilizing the Parallel Computing Toolbox of MATLAB, the simulator can efficiently be executed on multi-core processors to significantly reduce the simulation time....
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Book•
31 Jan 2013TL;DR: The use of multiple antennas at base stations is a key component in the design of cellular communication systems that can meet high-capacity demands in the downlink.
Abstract: The use of multiple antennas at base stations is a key component in the design of cellular communication systems that can meet high-capacity demands in the downlink. Under ideal conditions, the gai ...
456 citations
Cites background from "LTE-Advanced - Evolving LTE towards..."
...terpart of SDMA in multi-cell systems have been given many names, including co-processing [233], cooperative processing [321], network MIMO [279], coordinated multi-point (CoMP) [202], and multi-cell processing [81]....
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TL;DR: A novel resource allocation scheme based on a column generation method for D2D communications in LTE-Advanced networks is introduced to maximize the spectrum utilization by finding the minimum transmission length in terms of time slots while protecting the cellular users from harmful interference and guaranteeing the QoS of D1D links.
Abstract: The Long Term Evolution-Advanced (LTEAdvanced) networks are being developed to provide mobile broadband services for the fourth generation (4G) cellular wireless systems. Deviceto- device (D2D) communications is a promising technique to provide wireless peer-to-peer services and enhance spectrum utilization in the LTE-Advanced networks. In D2D communications, the user equipments (UEs) are allowed to directly communicate between each other by reusing the cellular resources rather than using uplink and downlink resources in the cellular mode when communicating via the base station. However, enabling D2D communications in a cellular network poses two major challenges. First, the interference caused to the cellular users by D2D devices could critically affect the performances of the cellular devices. Second, the minimum quality-of-service (QoS) requirements of D2D communications need to be guaranteed. In this article, we introduce a novel resource allocation scheme (i.e. joint resource block scheduling and power control) for D2D communications in LTE-Advanced networks to maximize the spectrum utilization while addressing the above challenges. First, an overview of LTE-Advanced networks, and architecture and signaling support for provisioning of D2D communications in these networks are described. Furthermore, research issues and the current state-of-the-art of D2D communications are discussed. Then, a resource allocation scheme based on a column generation method is proposed for D2D communications. The objective is to maximize the spectrum utilization by finding the minimum transmission length in terms of time slots for D2D links while protecting the cellular users from harmful interference and guaranteeing the QoS of D2D links. The performance of this scheme is evaluated through simulations.
419 citations
Cites background from "LTE-Advanced - Evolving LTE towards..."
...There are two main requirements for LTE-Advanced systems [2]....
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TL;DR: This article surveys the literature over the period of the last decade on the emerging field of self organisation as applied to wireless cellular communication networks, identifying a clear taxonomy and guidelines for design of self organising mechanisms.
Abstract: This article surveys the literature over the period of the last decade on the emerging field of self organisation as applied to wireless cellular communication networks. Self organisation has been extensively studied and applied in adhoc networks, wireless sensor networks and autonomic computer networks; however in the context of wireless cellular networks, this is the first attempt to put in perspective the various efforts in form of a tutorial/survey. We provide a comprehensive survey of the existing literature, projects and standards in self organising cellular networks. Additionally, we also aim to present a clear understanding of this active research area, identifying a clear taxonomy and guidelines for design of self organising mechanisms. We compare strength and weakness of existing solutions and highlight the key research areas for further development. This paper serves as a guide and a starting point for anyone willing to delve into research on self organisation in wireless cellular communication networks.
415 citations
Cites background from "LTE-Advanced - Evolving LTE towards..."
...Relaying has been identified by 3GPP as a means of providing cost effective throughput enhancement and coverage optimisation [115]....
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References
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TL;DR: Under certain mild conditions, this scheme is found to be throughput-wise asymptotically optimal for both high and low signal-to-noise ratio (SNR), and some numerical results are provided for the ergodic throughput of the simplified zero-forcing scheme in independent Rayleigh fading.
Abstract: A Gaussian broadcast channel (GBC) with r single-antenna receivers and t antennas at the transmitter is considered. Both transmitter and receivers have perfect knowledge of the channel. Despite its apparent simplicity, this model is, in general, a nondegraded broadcast channel (BC), for which the capacity region is not fully known. For the two-user case, we find a special case of Marton's (1979) region that achieves optimal sum-rate (throughput). In brief, the transmitter decomposes the channel into two interference channels, where interference is caused by the other user signal. Users are successively encoded, such that encoding of the second user is based on the noncausal knowledge of the interference caused by the first user. The crosstalk parameters are optimized such that the overall throughput is maximum and, surprisingly, this is shown to be optimal over all possible strategies (not only with respect to Marton's achievable region). For the case of r>2 users, we find a somewhat simpler choice of Marton's region based on ordering and successively encoding the users. For each user i in the given ordering, the interference caused by users j>i is eliminated by zero forcing at the transmitter, while interference caused by users j
2,616 citations
"LTE-Advanced - Evolving LTE towards..." refers background or methods in this paper
...For downlink transmissions, a combination of linear zero-forcing beam forming and nonlinear dirty-paper coding [8] is used....
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...One possibility is to do spatial prefiltering of the signal transmitted to a particular terminal to reduce inter-user interference, possibly also complemented by dirty paper coding [8]....
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01 Jan 2004
2,180 citations
11 Sep 2005
TL;DR: The results demonstrate that a mutual-information based metric which accounts for the modulation alphabet is preferable in the considered cases and, furthermore, applicable to the large class of MIMO-OFDM transmission techniques with linear pre- and post-processing.
Abstract: This paper gives an overview of some so-called link performance models used in system level simulations to determine the link packet error rate (PER) at reduced complexity. A subset of link performance models is evaluated in terms of PER prediction accuracy focusing on a single receive and transmit antenna OFDM link with different coding options and channel characteristics. The results demonstrate that a mutual-information based metric which accounts for the modulation alphabet is preferable in the considered cases and, furthermore, applicable to the large class of MIMO-OFDM transmission techniques with linear pre- and post-processing
522 citations
TL;DR: An overview of the 3GPP radio-access technologies for mobile broadband — HSPA and its evolution, and LTE — and the current stage on evolving LTE towards LTE-Advanced and full IMT-Advanced compliance is discussed.
Abstract: This paper provides an overview of the 3GPP radio-access technologies for mobile broadband — HSPA and its evolution, and LTE. The paper also discusses the current stage of the 3GPP activities on evolving LTE towards LTE-Advanced and full IMT-Advanced compliance.
22 citations
03 Apr 2006
TL;DR: A crosslayer approach that explores Tomlinson-Harashima precoding (THP) at the physical layer to reduce the multiuser scheduling burden at the MAC layer, and improves the sum rate of the downlinkMultiuser MIMO system.
Abstract: In this paper, we propose a crosslayer approach that explores Tomlinson-Harashima precoding (THP) at the physical layer to reduce the multiuser scheduling burden at the MAC layer, and improves the sum rate of the downlink multiuser MIMO system. Our proposed scheme is further evaluated with imperfect feedback, obtained by the long range prediction (LRP) technique. Compared to some existing scheduling schemes, the proposed scheme approaches the performance upper bound in certain scenarios, while incurring much less computation complexity. Significant gains are still maintained with imperfect channel state information (CSI), fed back at a rate much lower than the data rate
12 citations