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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09 Jun 2013
TL;DR: A robust, suboptimum, low complexity frequency domain iterative block decision feedback equalization (FD-IBDFE) for SC-FDMA system based on the minimum mean square error (MMSE) criterion.
Abstract: Recently, single-carrier frequency-division multiple access (SC-FDMA) has been adopted as the uplink transmission scheme in Third-Generation Partnership Project Long-Term Evolution (3GPP-LTE). In this paper, we propose a robust, suboptimum, low complexity frequency domain iterative block decision feedback equalization (FD-IBDFE) for SC-FDMA system. Based on the minimum mean square error (MMSE) criterion, we optimize the coefficients of the feedforward and feedback filters. Simulation results show that, at the first iteration, the proposed FD-IBDFE achieves above 3.0 dB performance improvement over MMSE FD linear equalization for QPSK, 8PSK and 16QAM modulations. Furthermore, it also shows that, with soft-decision feedback, our algorithm converges faster and gets better performance than that of high complexity time domain Exact-MMSE-LE turbo equalization.
2 citations
Cites methods from "LTE-advanced: next-generation wirel..."
...Single-carrier frequency-division multiple access (SCFDMA) is a combination of FDMA and single-carrier frequency domain equalization (SC-FDE), and has been adopted as the uplink transmission scheme in Third-Generation Partnership Project Long-Term Evolution (3GPP-LTE) [1], [2]....
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01 Sep 2014
TL;DR: In this article, the authors provide specifications of the parameters defining the design of medium access control protocols for orthogonal frequency division multiple access (OFDMA) passive optical networks (PONs).
Abstract: This paper provides specifications of the parameters defining the design of medium access control (MAC) protocols for orthogonal frequency division multiple access (OFDMA) passive optical networks (PONs). Network architecture has been designed for MAC evaluation based on the wired-wireless converged topology, extendable in reach, subcarriers and optical network units (ONUs), the upstream and downstream bitrates and modulation formats and the explored bandwidth allocation schemes. Dynamic bandwidth allocation (DBA) in synergy with queue scheduling in ONUs, can handle rapidly fluctuating traffic while decreasing packet delay. The former is achieved using the granularity of OFDMA and time division multiple access (TDMA) sustained by capacity control. The foreseen functionalities have been attained by the extension of the upcoming 10-Gigabit-capable passive optical network (XG-PON) frame structures. The MAC requirements enabling wireless backhauling are uniquely explored with respect to centralization at the Optical Line Terminal (OLT).
2 citations
Cites background from "LTE-advanced: next-generation wirel..."
...In addition, BS bandwidths could reach up to 400 Mbits/s with current deployment scenarios and up to 3 Gbits/s per site with their future extensions [5]....
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Dissertation•
17 Aug 2012
TL;DR: In this article, the authors focus on the use of MIMO detectors in sistemas de Multiplas Entradas and Multipla Saidas (MIMO) for the purpose of improving the transmissão performance.
Abstract: O uso de sistemas de Multiplas Entradas e Multiplas Saidas (Multiple Input Multiple Output - MIMO) tem permitido a recente evolucao dos novos padroes de comunicacao movel. A tecnica MIMO da Multiplexacao Espacial, em particular, prove um aumento linear na capacidade de transmissao com o minimo entre numero de antenas transmissoras e antenas receptoras. Para se obter um desempenho proximo a capacidade em sistemas com Multiplexacao Espacial faz-se necessario o
uso de um detector MIMO com decisao suave do tipo Maximum A Posteriori Probability. Entretanto, tal detector e muito complexo para solucoes praticas. Assim, o objetivo dos algoritmos de deteccao MIMO voltados para implementacao e obter uma boa aproximacao do detector ideal mantendo um nivel de complexidade aceitavel. Alem disso, o algoritmo precisa ser mapeado para uma arquitetura VLSI de
area pequena e que atenda a taxa de transmissao exigida pelos padroes de comunicacoes moveis. Sendo a multiplexacao espacial uma tecnica recente, defende-se que ainda ha muito espaco para evolucao dos algoritmos e arquiteturas relacionadas. Por isso, esta tese se focou no estudo de algoritmos sub-otimos e arquiteturas VLSI para
detectores MIMO de banda larga com decisao suave. Como resultado, algoritmos ineditos foram desenvolvidos partindo de propostas de otimizacoes para algoritmos ja estabelecidos. Baseado nesses resultados, novas arquiteturas de detectores MIMO com modulacao configuravel e competitivos parâmetros de area, desempenho e taxa
de processamento sao aqui propostas. Os algoritmos desenvolvidos foram extensivamente simulados e as arquiteturas sintetizadas para que os resultados pudessem servir como referencia para outros trabalhos na area.
2 citations
Cites background from "LTE-advanced: next-generation wirel..."
...Os sistemas de banda larga visionados para os próximos anos exigem detectores MIMO configuráveis para diversos esquemas de configuração de antena e modulação (QPSK, 16QAM, 64QAM), e taxas de transmissão superiores a 1 Gbps [19]....
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...Os sistemas de banda larga visionados para os próximos anos exigem detectores MIMO configuráveis para diversos esquemas de configuração de antena e modulação (QPSK, 16QAM, 64QAM), e taxas de transmissão superiores a 1 Gbps [19]....
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08 Jun 2015
TL;DR: A new advanced medium access control protocol is described to support 100 km reach access networks, exhibiting the required quality-of-service for next generation passive optical networks based on orthogonal frequency division multiple access.
Abstract: A new advanced medium access control protocol is described to support 100 km reach access networks, exhibiting the required quality-of-service for next generation passive optical networks based on orthogonal frequency division multiple access. The protocol enables the optical network units (ONUs) to utilize the idle period in each packet transmission time based on their originally granted bandwidth, using the same subcarriers but different time slots to increase the effective transmission bandwidth. The network throughput, end-to-end packet delay and packet loss rate are evaluated by means of both service level agreement and class-of-service differentiation. As a result the packet delay at 80% ONU offered load is less than 3 ms even for the lowest service level ONUs. In addition, the throughput efficiency is 94% of the total network capacity of 40 Gbps, for 100 km long-reach links.
2 citations
Cites background from "LTE-advanced: next-generation wirel..."
...Corporations and Telco services also require increased performance while in the short term base station (BS) bandwidths could reach 400 Mbps, increasing to 3 Gbps in the future [6]....
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TL;DR: Simulation results show that the proposed mobile network priority-based queueing (MPQ) scheme is able to support differentiated packet forwarding behavior for mobile traffic with both DQB and OQB allocations in a mobile core network.
Abstract: As current mobile core network systems are expected to evolve into all-IP networks, packet switching will be a prerequisite for all mobile applications. Next-generation mobile networks, as envisioned by ITU-T, are packet-based networks capable of providing consistent and ubiquitous service to end users, independent of the network, access technology, and device used. This study discusses the differentiated packet forwarding performance of four major types of mobile network traffic under the proposed mobile network priority-based queueing (MPQ) scheme with two queueing buffer allocations, namely dynamic queueing buffer (DQB) allocation and overflow queueing buffer (OQB) allocation. As different queueing buffer allocations are adopted to store arriving packets in DQB and OQB, the MPQ scheme shows different packet forwarding performance under these two methods. In this study, we use ns2 (Network Simulator version 2) as the simulation platform to simulate several scenarios. The simulation results show that the MPQ scheme is able to support differentiated packet forwarding behavior for mobile traffic with both DQB and OQB allocations in a mobile core network. Some issues were identified in the MPQ scheme with both DQB and OQB allocation, which will need to be addressed.
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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