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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Patent•
06 Jun 2017
TL;DR: In this paper, a control unit selects, from resources associated with CCE and from particular resources reported by a base station, an upstream control channel resource to be used in transmission of response signal, and controls the transmission of the response signal.
Abstract: Provided are a terminal, a base station and a signal transmission control method whereby a response signal can be efficiently transmitted when the terminal receives downstream allocation control information via an R-PDCCH. An extraction unit receives downstream control information via one of a first downstream control channel, which is transmitted by use of one or more control channel elements (CCE) associated with an upstream control channel resource, and a second downstream control channel different from the first downstream control channel, and also receives data via a data channel. A control unit selects, from resources associated with CCE and from particular resources reported by a base station, an upstream control channel resource to be used in transmission of the response signal, and controls the transmission of the response signal.
1 citations
01 Jan 2017
TL;DR: Traffic offloading through small cells provides an effective and cost-efficient way to accommodate mobile users’ traffic and may be undesirable from operators’ perspective.
Abstract: Media-hungry mobile devices and mobile traffic have been experiencing an exponential growth in the past decade. As reported in Cisco Visual Networking Index (VNI) [1], the global mobile traffic grew from 2.1 exabytes/month at the end of 2014 to 3.7 exabytes/month at the end of 2015, corresponding to 74% growth in 2015, and the growth rate is expected to continue at a compound annual growth rate at 53% until 2020. The huge traffic demand has overloaded cellular radio access networks (RANs), which in comparison experience a much slower capacity increase. It becomes a critical challenge for the cellular operators to accommodate the heavy traffic demand in a timely and cost-efficient manner. Directly upgrading RANs may be undesirable from operators’ perspective for the following two concerns: (i) upgrading RANs requires a huge capital investment, which may not be easily recovered even by accommodating the traffic demand, and (ii) acquiring more licensed spectrum bands for the upgraded RANs is difficult and expensive due to the regulation policy. Fortunately, nowadays cellular networks are structured in a multitier architecture, namely, a large number of heterogeneous small cells (such as picocells, femtocells, and WiFi systems) have densely underlaid conventional macrocells [2]. Hence, traffic offloading through small cells provides an effective and cost-efficient way to accommodate mobile users’ traffic.
1 citations
06 Jul 2015
TL;DR: This paper proposes applying network coding between two user equipment in the same cell in the uplink direction and investigates Single Input Single Output (SISO) and Multiple Input Multiple Output (MIMO) models for this scenario.
Abstract: Analog network coding has been successfully employed in conventional two way relaying systems. However, analog two way relaying is successful when the two sender and destination nodes are symmetric. In practical cellular-based mobile communication systems of the likes of Long Term Evolution (LTE), the system is composed of several powerful base-stations and low power users' equipment. Applying classical two way relaying will cause unbearable interference. In this paper we propose applying network coding between two user equipment in the same cell in the uplink direction. We investigate Single Input Single Output (SISO) and Multiple Input Multiple Output (MIMO) models for this scenario. We also study the effect of interference of other nodes in surrounding cells.
1 citations
Cites background from "LTE-advanced: next-generation wirel..."
...LTE-A targets relaying as one of its strategic improvements [6-9]....
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01 Dec 2015
TL;DR: In this paper, resource allocations and procedures of downlink control channels of MHN system are introduced and implementtations of the down link control channels are described.
Abstract: Currently, the need of high speed data rate services at mobile group vehicles moving at high speed has been increased. In ETRI (Electronics and Telecommunications Research Institute), we have been designing and developing a new wireless mobile backhaul system, Mobile Hotspot Network (MHN) system, which can support over 1Gbps data rate services for mobile group vehicles moving at high speed over 400km/h at KTX (Korea Train Express) train. In this paper, resource allocations and procedures of downlink control channels of MHN system are introduced. Performances of the downlink control channels are verified by computer simulation. Furthermore, implementtations of the downlink control channels are described. We have developed the MHN test-bed system and had a target to demonstrate the real time performance of the MHN system in the outdoor environment at the end of 2015. Outdoor demonstration will be done in subway at line 8 subway in Seoul, Korea.
1 citations
Additional excerpts
...Performances of the downlink control channels are verified by computer simulation....
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TL;DR: The potential cross-layer facilitation of the CR-enable HetNet is presented, which enables small cells to sense and to adapt to their surrounding environments and allows stations in each small cell to opportunistically operate in the spectrum hole, constrained by minimal inducing interference.
Abstract: The heterogeneous network (HetNet), which deploys small cells such as picocells, femotcells, and relay nodes within macrocell, is regarded as a cost-efficient and energy-efficient approach to resolve increasing demand for data bandwidth and thus has received a lot of attention from research and industry. Since small cells share the same licensed spectrum with macrocells, concurrent transmission induces severe interference, which causes performance degradation, particularly when coordination among small cell base stations (BSs) is infeasible. Given the dense, massive, and unplanned deployment of small cells, mitigating interference in a distributed manner is a challenge and has been explored in recent papers. An efficient and innovative approach is to apply cognitive radio (CR) into HetNet, which enables small cells to sense and to adapt to their surrounding environments. Consequently, stations in each small cell are able to acquire additional information from surrounding environments and opportunistically operate in the spectrum hole, constrained by minimal inducing interference. This paper summarizes and highlights the CR-based interference mitigation approaches in orthogonal frequency division multiple access (OFDMA)-based HetNet networks. With special discussing the role of sensed information at small cells for the interference mitigation, this paper presents the potential cross-layer facilitation of the CR-enable HetNet. key words: heterogeneous networks (HetNet), small cell, interference management, interference mitigation, cognitive radio
1 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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