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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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21 May 2013
TL;DR: An overview of carrier aggregation algorithms is presented and using Matlab simulations study feasibility of using Discontiguous Orthogonal Frequency Division Multiplexing (DOFDM) for carrier aggregation concluded that DOFDM enables carrier aggregation without sacrificing bit error rates for users.
Abstract: In Long-Term Evolution (LTE), maximum bandwidth allocation of channels in downlink and uplink is 20 MHz. To meet an increasing demand of data rate for users in next generation wireless communication systems such as LTE-Advanced, bandwidth up to 100MHz or above is required. A key technology to achieve higher bandwidths up to 100MHz is carrier aggregation. To provide maximum bandwidth to the users and optimum use of radio resources for the operators , the carriers of same or different bandwidths can be aggregated using carrier aggregation. This paper presents an overview of carrier aggregation algorithms and using Matlab simulations study feasibility of using Discontiguous Orthogonal Frequency Division Multiplexing (DOFDM) for carrier aggregation. It is concluded that DOFDM enables carrier aggregation without sacrificing bit error rates for users.
Proceedings ArticleDOI
15 Dec 2014
TL;DR: An efficient spectrum sharing for a dense small cell network, where a user is usually communicable with multiple cells is proposed, which optimally determines the time portion of each spectrum usage manner, while satisfying the intended spectrum sharing goal.
Abstract: Network densification with small cells deployment is regarded as one of the promising approaches to meet a huge demand of rapidly increasing wireless capacity. Such an approach can lead a dramatic increase of wireless capacity, but the interference issue still exists, which could be even more severe when the cells are too closely placed. This paper proposes an efficient spectrum sharing for a dense small cell network, where a user is usually communicable with multiple cells. Assuming either a simultaneous or a dedicated manner of the spectrum usage, an optimal spectrum sharing problem in order that the total system throughput is e maximized while user specific required data rate can be guaranteed. The proposed solution optimally determines the time portion of each spectrum usage manner, while satisfying the intended spectrum sharing goal.
Proceedings ArticleDOI
Yejian Chen1
01 Dec 2013
TL;DR: This paper presents a joint transmission and Interference Cancellation (IC) algorithm as a partially centralized Coordinated Multi-Point (CoMP) scheme, and a dedicated frequency planning scheme is taken into account to support and increase the reasonability of the considered CoMP scheme.
Abstract: In this paper, we present a joint transmission and Interference Cancellation (IC) algorithm as a partially centralized Coordinated Multi-Point (CoMP) scheme. Being the evolution of our previous investigation, the User Equipment (UE) is equipped with multiple antenna arrays, and channel decoder can be optionally involved in the IC stage to improve the performance. The performance of the solution can be evaluated not only in the single-link simulation, but also in a multi-link simulation with certain system simplification, both of which have the same signal processing flow, and are bit-true simulators. This is driven by one of the major objectives to have a relatively clear view of the performance deviation between link level and system level, and the influence of Multiple-Input Multiple-Output (MIMO) technique. Especially, a dedicated frequency planning scheme is taken into account to for the proposed algorithm to support and increase the reasonability of the considered CoMP scheme.

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

  • ...It is pointed out in [3][6] that Coordinated Multi-Point transmission and reception (CoMP) schemes should be regarded as a key technique to achieve further system gain for 4G and B4G system, considering MIMO Joint Processing/Transmission (JP/JT), which apparently establishes another trade-off between the gain via CoMP and the loss due to coordination signaling via backhaul....

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Dissertation
29 Nov 2018
TL;DR: In this paper, a measurement and modelling procedure to investigate radio frequency (RF) propagation inside an aircraft is proposed, which takes into account the deployment of a multi-cell onboard system, and the proposed procedure is verified through another set of measurements where reference signal received power (RSRP) levels inside the aircraft are measured.
Abstract: One of the key requirements of fifth generation (5G) systems is having a connection to mobile networks without interruption at anytime and anywhere, which is also known as seamless connectivity. Nowadays, fourth generation (4G) systems, Long Term Evolution (LTE) and Long Term Evolution Advanced (LTE-A), are mature enough to provide connectivity to most terrestrial mobile users. However, for airborne mobile users, there is no connection that exists without interruption. According to the regulations, mobile connectivity for aircraft passengers can only be established when the altitude of the aircraft is above 3000 m. Along with demands to have mobile connectivity during a flight and the seamless connectivity requirement of 5G systems, there is a notable interest in providing in-flight wireless services during all phases of a flight. In this thesis, many issues related to the deployment and operation of the onboard systems have been investigated. A measurement and modelling procedure to investigate radio frequency (RF) propagation inside an aircraft is proposed in this thesis. Unlike in existing studies for in-cabin channel characterization, the proposed procedure takes into account the deployment of a multi-cell onboard system. The proposed model is verified through another set of measurements where reference signal received power (RSRP) levels inside the aircraft are measured. The results show that the proposed model closely matches the in-cabin RSRP measurements. Moreover, in order to enforce the distance between a user and an interfering resource, cell sectorization is employed in the multi-cell onboard system deployment. The proposed propagation model is used to find an optimum antenna orientation that minimizes the interference level among the neighbouring evolved nodeBs (eNBs). Once the optimum antenna deployment is obtained, comprehensive downlink performance evaluations of the multi-cell, multi-user onboard LTE-A system is carried out. Techniques that are proposed for LTE-A systems, namely enhanced inter-cell interference coordination (eICIC) and carrier aggregation (CA), are employed in the system analysis. Different numbers of eNBs, antenna mounting positions and scheduling policies are examined. A scheduling algorithm that provides a good tradeoff between fairness and system throughput is proposed. The results show that the downlink performance of the proposed onboard LTE-A system achieves not only 75% of the theoretical limits of the overall system throughput but also fair user data rate performance, irrespective of a passenger’s seat location. In order to provide the seamless connectivity requirement of 5G systems, compatibility between the proposed onboard system deployment and the already deployed terrestrial networks is investigated. Simulation based analyses are carried out to investigate power leakage from the onboard systems while the aircraft is in the parked position on the apron. According to the regulations, the onboard system should not increase the noise level of the already deployed terrestrial system by 1 dB. Results show that the proposed onboard communication system can be operated while the aircraft is in the parked position on the apron without exceeding the 1 dB increase in the noise level of the already deployed terrestrial 4G network. Furthermore, handover parameters are obtained for different transmission power levels of both the terrestrial and onboard systems to make the transition from one system to another without interruption while a passenger boards or leaves the aircraft. Simulation and measurement based analyses show that when the RSRP level of the terrestrial system is below −65 dBm around the aircraft, a boarding passenger can be smoothly handed over to the onboard system and vice versa. Moreover, in order to trigger the handover process without interfering with the data transmission, a broadcast control channel (BCCH) power boosting feature is proposed for the in-cabin eNBs. Results show that employing the BCCH power boosting feature helps to trigger the handover process as soon as the passengers step on board the aircraft.
01 Sep 2016
TL;DR: The Southern Africa Telecommunication Networks and Applications Conference (SATNAC): Broadband Evolution - Unlocking "The Internet of Things" 2016, George, Western Cape, South Africa, 4-7 September 2016 as mentioned in this paper
Abstract: Southern Africa Telecommunication Networks and Applications Conference (SATNAC): Broadband Evolution - Unlocking “The Internet of Things” 2016, George, Western Cape, South Africa, 4-7 September 2016

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

  • ...Bandwidth extension in LTE-A is supported via carrier aggregation, where it allows a maximum bandwidth deployment of 100 MHz, this bandwidth deployment enables a peak target data rates of 1 Gbps in the downlink (DL) and 500 Mbps in the uplink (UL) [5]....

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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 Home Internet and FIOS?

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.