LTE-advanced: next-generation wireless broadband technology [Invited Paper]
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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28 Sep 2020
TL;DR: Simulations results show that the mobility control for M2M in Long Term Evolution (LTE) systems with cooperative relaying for CCI avoidance and (EE) improvement outperforms the non cooperative scheme.
Abstract: Energy efficiency (EE) is an important objective for machine-to-machine (M2M) communication systems in wireless network, due to the limited capacity of batteries in user equipments (UEs). In addition, M2M devices at the cell edge inevitably suffer from the co-channel interference (CCI). This paper addresses the mobility control (MC) for M2M in Long Term Evolution (LTE) systems with cooperative relaying for CCI avoidance and (EE) improvement. Considering the signalto-interference ratio (SINR) gain and lifetime, the proposed scheme allows M2M devices in the cell edge to achieve high EE. Simulations results show that the MC scheme under cooperative relaying outperforms the non cooperative scheme.
2 citations
Cites methods from "LTE-advanced: next-generation wirel..."
...In cellular network, the cooperative relaying technique is used to improve service coverage, spectral efficiency, and cell-edge user throughput [4]....
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TL;DR: The authors derive exact expressions for the mean power of the desired signal received by an arbitrary user and of the interference caused by the mismatched precoder and show that for attaining a given signal-to-interference power ratio (SIR) these systems are limited by a maximum feedback delay of updated channel state information.
Abstract: Coordination of base stations is a promising technique for reducing inter-cell interference in next-generation cellular systems. For the downlink of such systems, the authors study the degradation of zero-forcing precoded transmissions caused by imperfect channel estimation and channel variation over time. They derive exact expressions for the mean power of the desired signal received by an arbitrary user and of the interference caused by the mismatched precoder. By using these expressions, they show that for attaining a given signal-to-interference power ratio (SIR) these systems are limited by a maximum feedback delay of updated channel state information. Finally, they present a procedure to calculate the maximum tolerable feedback delay and to determine the separation between the non-precoded pilot symbols for guaranteeing a desired SIR.
2 citations
01 Sep 2016
TL;DR: Measurement results from a full-scale real life deployment with a Long Term Evolution (LTE) IBS solution are presented and it is found that cell splitting is an excellent way to enable increased indoor capacity.
Abstract: In Building Solutions (IBS) are a well-established approach to providing indoor cellular coverage. The increasing wireless mobile broadband traffic and the fact that most broadband data is consumed indoors increases the interest to understand the IBS capacity potential. For a given available spectrum, a straightforward capacity solution is cell-splitting. In this paper, measurement results from a full-scale real life deployment with a Long Term Evolution (LTE) IBS solution are presented. Two cell-splitting scenarios in a three floor, 7500 m2 office building have been tested, both by collecting traffic and radio statistics from actual users, as well as performing controlled walk-tests in the building. It is found that cell splitting is an excellent way to enable increased indoor capacity. The isolation between floors as well as within a floor is higher than in a typical macro scenario. High throughput and fraction of spatial multiplexing is maintained even with artificially generated 100% activity. The capacity is assessed to around 2 kbps/m2/MHz with a 6 cell solution.
2 citations
TL;DR: In this article, a survey on subjecting Electronic Product Code and non-ID objects to IP identification for IoT devices, including their advantages and disadvantages, is presented in tabular format.
Abstract: Over the last decade, both research on the Internet of Things (IoT) and real-world IoT applications have grown exponentially. The IoT provides us with smarter cities, intelligent homes, and generally more comfortable lives. However, the introduction of these devices has led to several new challenges that must be addressed. One of the critical challenges facing interacting with IoT devices is to address billions of devices (things) around the world, including computers, tablets, smartphones, wearable devices, sensors, and embedded computers, and so on. This article provides a survey on subjecting Electronic Product Code and non-ID objects to IP identification for IoT devices, including their advantages and disadvantages thereof. Different metrics are here proposed and used for evaluating these methods. In particular, the main methods are evaluated in terms of their: (i) computational overhead, (ii) scalability, (iii) adaptability, (iv) implementation cost, and (v) whether applicable to already ID-based objects and presented in tabular format. Finally, the article proves that this field of research will still be ongoing, but any new technique must favorably offer the mentioned five evaluative parameters.
2 citations
TL;DR: Two reduced-complexity algorithms for each of the QoS problem and the MMF problem are investigated together for transmit beamforming in broadband multigroup multicast channels with frequency-selective fading characters by introducing the time-frequency correlations.
Abstract: Spectral efficient transmission techniques are necessary and promising for future broadband wireless communications, where the quality of service (QoS) and/or max-min fair (MMF) of intended users are often considered simultaneously. In this paper, both the QoS problem and the MMF problem are investigated together for transmit beamforming in broadband multigroup multicast channels with frequency-selective fading characters. We first present a basic algorithm by directly using the results in frequency-flat multigroup multicast systems (Karipidis et al., 2008), namely, the approximation algorithms in this paper, for both problems, respectively. Due to high computational consumption nature of the approximation algorithms, two reduced-complexity algorithms for each of the two problems are proposed separately by introducing the time-frequency correlations. In addition, parameters in the new time-frequency formulations, such as the number of optimization matrix variables and the taps of the
beamformer with finite impulse response (FIR) structure, can be used to make a reasonable tradeoff between computational
burden and system performance. Insights into the relationship between the two problems and some analytical results of the
computational complexity of the proposed algorithms are also studied carefully. Numerical simulations indicate the efficiency
of the proposed algorithms.
2 citations
References
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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
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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