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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01 Jan 2014
TL;DR: The aircraft of the future will have an increased need for airborne communications among aircraft and between aircraft andBetween aircraft and the ground, and in contrast an airborne high speed data communications solution will need to be a wireless one.
Abstract: The aircraft of the future will have an increased need for airborne communications among aircraft and between aircraft and the ground. Communications will include traffic such as on board passenger generated internet traffic, aircraft telemetry and information on air traffic control and weather. The likely data requirements are such that the data generated by passengers will be far greater than the aircraft generated data traffic. Passengers will expect data service on the aircraft similar to what they typically experience on the ground. Multimedia activities such video streaming are very bandwidth intensive and the provision of these services presents a serious technical challenge. On the ground, fibre optic cables are the method of choice for the provision of high speed data service and in contrast an airborne high speed data communications solution will need to be a wireless one. Future Trends in Spectrum Management and Technology Choices for Broadband Aeronautical Communications
1 citations
TL;DR: A novel theoretical framework for MIMO channel modeling and characterization in order to facilitate the MIMo system design and performance evaluation is proposed and the angle of arrival estimation based on the proposed practical framework using field test measurement data is presented.
Abstract: The utilization of multiple antennas and space–time codes in multiple-input and multiple-output (MIMO) communication systems significantly improves the transmission channel capacity without using additional bandwidth and power. The improvement is achieved by decomposing the spatial structure of transmission channels and performing appropriate temporal and spatial multiplexing. In this paper, we propose a novel theoretical framework for MIMO channel modeling and characterization in order to facilitate the MIMO system design and performance evaluation. The channels are represented in space, time, wave vector, and frequency domains while the space–time and wave vector–frequency interdependences are considered. A realization of the theoretical framework, in a form of a practical framework, is also proposed to address the channel modeling and characterization at both transmitter and receiver sides. The utilization of the practical framework in MIMO communication system design is discussed to illustrate its applications in realistic scenarios. The angle of arrival estimation based on the proposed practical framework using field test measurement data is also presented as illustrative examples.
1 citations
Cites methods from "LTE-advanced: next-generation wirel..."
...These communications technologies, including LTE-Advanced [1] and mobile WiMAX [2], are expected to provide the peak downlink and uplink transmission rates of 1 Gbps and...
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...These communications technologies, including LTE-Advanced [1] and mobile WiMAX [2], are expected to provide the peak downlink and uplink transmission rates of 1 Gbps and 500 Mbps, respectively, and to maintain connections in high mobility scenarios, e.g., at 100 km/h on highways and at 350 km/h on bullet trains....
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TL;DR: Simulation results validate the advantages of the proposed algorithm, especially under low signal-to-noise ratio conditions, and it is shown that the range reconstruction accuracy can be further improved.
Abstract: Recent literature shows that with sufficient cyclic prefix, orthogonal frequency-division multiplexing signals can convert a synthetic aperture radar (SAR) image with interrange cell interference (IRCI) to an IRCI-free SAR image. In this letter, the imaging algorithm is carefully investigated and it is shown that the range reconstruction accuracy can be further improved. By reformulating the system model in a linear model form, the minimum variance unbiased estimator of the range profile is derived, which can attain the Cramer–Rao lower bound, making our algorithm more effective than current algorithms under noisy conditions. Simulation results validate the advantages of the proposed algorithm, especially under low signal-to-noise ratio conditions.
1 citations
Additional excerpts
...ORTHOGONAL frequency-division multiplexing (OFDM) has been widely used in wireless communication applications and achieved a great success in the past 20 years [1]–[3]....
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02 Jun 2013
TL;DR: This work analyzes the performance of a dual-hop relay system with correlated antennas at the source and the destination and extends the analysis to obtain expressions for the outage probability and SER for multiple-relay systems.
Abstract: We analyze the performance of a dual-hop relay system with correlated antennas at the source and the destination. Orthogonal space time block coding (OSTBC) is employed at the source. Single-antenna relays with and without direct transmission between the source and the destination are stud- ied. Assuming non-identically distributed Nakagami-m fading channels, closed- form expressions of outage probability, average symbol error rate (SER), and moment generating function (MGF) of the instantaneous end-to-end signal-to-noise ratio (SNR) are derived for the single- relay case. Asymptotic analysis is also performed to obtain the diversity order for the single-relay system. Furthermore, the analysis is extended to obtain expressions for the outage probability and SER for multiple-relay systems. Analytical results are validated with Monte-Carlo simulations using Mathematica and MATLAB programs.
1 citations
Cites methods from "LTE-advanced: next-generation wirel..."
...Thus, the use of collocated MIMO antennas in amplifyand-forward (AF) relay networks has been proposed in LTEAdvanced [1] which is a standardization of 4G technologies....
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Dissertation•
12 Dec 2016
TL;DR: During this thesis, the different solutions to the deployment of fronthaul are studied and also the effects and the impacts of jitter on the fr onthaul interface are studied.
Abstract: In Europe, the competition between the mobile operators is so strong that the profitability of the mobile network has decreased The cost to implement, to operate and to upgrade the mobile network is increasing while the revenues generated by the latter are not sufficient Therefore, the operators should find the way to reduce the CAPEX and the OPEX To keep competitive, the operators have begun to think about a novel RAN architecture This new architecture is called Centralized or Cloud Radio Access Network The traditional antenna site consists of the Radio Remote Head (RRH) which performs the radio processing, and the Base Band Unit (BBU) which carries out the digital processing The principle of C-RAN consists to move the BBU from antenna site towards the local secured belonging to an operator called Central Office (CO) The move of BBU from antenna site to CO leads to the appearance of a new network segment called fronthaul During this thesis, the different solutions to the deployment of fronthaul are studied and also the effects and the impacts of jitter on the fronthaul interface
1 citations
Cites background from "LTE-advanced: next-generation wirel..."
...D'après [32] , en termes de latence, la LTE et la LTE-A peuvent être utilisées jusqu'à 30 km de transmission pour 5 km de cavité....
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...The main enhancement of LTE is the Long Term Evolution Advanced (LTE-A) [17] [18]....
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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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