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 Dec 2017
TL;DR: This paper investigates the omni-directional precoding (OP) transmission in uniform planar array (UPA) equipped massive antenna communication systems and proposes m sequences based OP matrices that guarantee the transmitted signal on each antenna has constant envelope thus achieving the full power-efficiency.
Abstract: Common signals in cellular communications, e.g., synchronous signals or broadcast signal, should be transmitted omni-directionally for reliable cell-wide coverage. However, when the multiple antennas are employed, the transmit signals are not inherently omni-directional unless precoding is properly designed. In this paper, we investigate the omni-directional precoding (OP) transmission in uniform planar array (UPA) equipped massive antenna communication systems. Based on the signal model of the line of sight (LOS) transmission for UPA, we derive the mathematical condition of OP matrix. For discrete angles, the Zadoff-Chu sequence that has been used in the design of OP matrix for the uniform linear array (ULA), can be extended to the UPA case by using Kronecker product. As such design does not result exact constant sum-power at any angles if there are a finite number of antennas, we then propose m sequences based OP matrices. The proposed precoding matrices guarantee the transmitted signal on each antenna has constant envelope thus achieving the full power-efficiency. Simulation results are presented in the term of cell-wide coverage. It shows that the proposed m sequence based precoding matrix has better omni-direction performance than existing ZC sequence based precoding that has been proposed for ULA.
4 citations
Cites background from "LTE-advanced: next-generation wirel..."
...For instance, several MIMO communication architecture is described in [1], [2], [3]....
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04 Jul 2011
TL;DR: Simulations show that the proposed preconditioning approaches can substantially increase the computational efficiency of the MGF-matching method while ensuring the convergence of the method.
Abstract: Various low-power node technologies such as relays and femtocells are considered an integral part of the heterogeneous fourth generation radio access networks. However, due to different transmit power levels, antenna configurations, and network planning strategies of such nodes, the interference characteristics in heterogeneous deployments can be significantly different than the conventional macrocell-only deployments. The variations in experienced co-channel interference levels could affect the convergence of numerical interference modeling methodologies and significantly decrease their convergence rates. In this paper, different preconditioning approaches are proposed and their impact on the convergence of numerical co-channel interference approximations is analyzed. The evaluations are performed utilizing a flexible MGF-matching method which approximates the lognormal sum distribution by a lognormal random variable, a well-known approach to model the co-channel interference in mobile cellular networks. Simulations show that the proposed preconditioning approaches can substantially increase the computational efficiency of the MGF-matching method while ensuring the convergence of the method.
4 citations
04 Dec 2014
TL;DR: The performance of MHN DL control channels, especially on the fixed performance to develop RTL design in test-bed system, meet the required SNR, and is verified by computer simulation.
Abstract: Recently, according to the survey, one of the most frequent place to use mobile internet is the moving vehicle, such as bus, subway and train. Therefore, the high speed data rate services for mobile group vehicles moving at high speed are severely required. We design and develop a new system, which can support upto 2.5Gbps data rate services for mobile group vehicles moving at high speed over 400km/h, e.g., KTX (Korea Train Express), TGV (Train a Grande Vitesse) and ICE (InterCity Express), etc. in ETRI (Electronics and Telecommunications Research Institute). In this paper, we propose and design a new structure of the physical layer downlink control channels, and furthermore, we verified the performance of the downlink control channels by computer simulation. Especially, we compared the performance between floating point simulation and fixed point simulation. We verified the performance gap is under 0.5dB. Currently, we develop the test-bed of MHN system and have a target to demonstrate the real time performance of the MHN system on the outdoor environment in 2014. Outdoor demonstration will be done in subway in 1st step. In this paper, we are focusing on the performance of MHN DL control channels, especially on the fixed performance to develop RTL design in test-bed system. We also show the performance of these channels meet the required SNR.
4 citations
01 Sep 2013
TL;DR: A simulation study on the spectral efficiency gains that are achievable with CoMP transmission in an exemplary dense informal settlement area demonstrates that use of CoMP provides capacity enhancements without need for costly deployment of additional macro sites, thus contributing to affordability of broadband access through reduced cost-per-bit.
Abstract: The emerging Long Term Evolution-Advanced (LTE-A) standard promises improvements in throughput, latency, spectrum-flexibility and reduction in costs-per-bit, through use of techniques, such as, coordinated multipoint (CoMP) transmission and reception. LTE-A enhancements provide an attractive long-term solution for operators to implement cost-effective capacity-upgrades and guarantee affordable broadband access in the emerging markets (e.g., Africa). The fast expanding densely-populated informal settlements are among the key areas that could benefit from this new technology. This paper presents a simulation study on the spectral efficiency gains that are achievable with CoMP transmission in an exemplary dense informal settlement area. The results demonstrate that use of CoMP provides capacity enhancements without need for costly deployment of additional macro sites, thus contributing to affordability of broadband access through reduced cost-per-bit. Moreover, we note possible improvements in energy efficiency, by lowering transmit powers without significant impact on CoMP spectral efficiency gains.
4 citations
Cites background from "LTE-advanced: next-generation wirel..."
...The LTE-A enhancements include [5]: carrier aggregation; relaying; advanced multiple-input multiple-output (MIMO) techniques; and coordinated multipoint (CoMP) transmission and reception, in the downlink and uplink, respectively....
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...While commercial deployment of LTE networks gains pace globally, specifications of LTE enhancements have been carried out for evolution towards LTE-Advanced (3GPP Release 10 and beyond) [5]....
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17 Dec 2015
TL;DR: OWTDM method allows increasing the throughput utilization for both transport and access optical networks, by division the data between wavelength-time symbols.
Abstract: This paper presents a new paradigm of optical data transmission based on resource grid forming. Unlike ordinary data transmission over Gigabit Ethernet network, we suggested optical wavelength-time division multiple access networks. The main difference of this method, is division the data between wavelength-time symbols. Thus, each user allocated on necessary set of wavelengths during fixed time interval. This feature allows eliminating the synchronization problem. Moreover, OWTDM method allows increasing the throughput utilization for both transport and access optical networks.
4 citations
Cites background from "LTE-advanced: next-generation wirel..."
...Moreover, the new high throughput 5G networks based on cognitive radio technology exceed the 10 Gb/s per cell threshold [2-6]....
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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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