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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TL;DR: Based on the analysis in the high signal-to-noise ratio regime, closed-form power allocation policies are developed to improve the outage probability performance of the device- to-device communication assisted by a relay node utilising a one-way amplify-and-forward relaying strategy.
Abstract: This study investigates the outage probability of device-to-device communication assisted by a relay node utilising a one-way amplify-and-forward relaying strategy. The authors assume that all the terminals are equipped with a single antenna and all the users know perfect channel state information. They first derive the exact closed-form expression for characterising the outage probability performance of the system. They subsequently discuss several special scenarios and obtain the asymptotic results for each of the considered scenarios. The results can be easily computed with only the channel statistics. Based on the analysis in the high signal-to-noise ratio regime, closed-form power allocation policies are developed to improve the outage probability performance. The author's analytical results are validated via Monte Carlo computer simulations.
22 citations
Patent•
19 Aug 2011TL;DR: In this paper, a response signal can be efficiently transmitted when the terminal receives downstream allocation control information via an R-PDCCH, provided that a terminal, a base station and a signal transmission control method are available.
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 (204) 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 (208) 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.
22 citations
TL;DR: In this paper, a broadband Class-J power amplifiers (PAs) with compact fundamental impedances on the package plane is presented, and a simple transistor model with knee voltage region is built to predict efficiency performance and clipping waveforms caused by clipping effects.
Abstract: A novel methodology for designing broadband Class-J power amplifiers (PAs) with compact fundamental impedances on the package plane is presented. A simple transistor model with knee voltage region is built to predict efficiency performance and clipping waveforms caused by the clipping effects. To realise the proposed impedance solutions, a broadband matching network is presented based on the shot-stepped Chebyshev impedance transformer. A broadband Gallium Nitride (GaN) PA is designed using this method and achieve a very wide operation band from 0.8 to 3.6 GHz. More than 10 dB gain, 55.8-74.1% drain efficiency and around -30 dBc adjacent channel power ratio are measured without linearisation throughout the entire band. At 33 dBm average output power level, an average power-added efficiency of 27% and adjacent power leakage ratio of -46.3 dBc is obtained with 9 dB peak-to-average power ratio 20 MHz long-term evolution test signals at 2.4 GHz.
22 citations
TL;DR: A cyclic approach is proposed, named as energy-cognitive cycle, which extends the classic cognitive cycle and enables dynamic selection of different available strategies for reducing the energy consumption in the network while satisfying the quality of service constraints.
21 citations
TL;DR: A dynamic group based efficient and secure (DGBES-AKA) protocol for MTC in LTE/LTE-A network is proposed that consists the group key update scheme with key forward and backward secrecy and the formal verification using ProVerif and security analysis of the proposed protocol represent the security against malicious attacks.
Abstract: The machine to machine communication (MTC) has grown into one of the fastest expansion in the area of Information and Communication Technology and is one of the important aspect of the Internet of Things. It allows millions of devices to connect with each other over the internet. MTC has a huge market and massive strength to obtain numerous application scenarios. The applications of MTC are reliable and effective only after a successful authentication of MTC devices. Hence, there are several group based authentication and key agreement (AKA) protocols were proposed by researchers. Whenever a number of MTC devices simultaneously generate the access request to the LTE/LTE-A network, each MTC device needs a separate authentication process to access the core network that leads to genuine signaling congestion problem. In addition, the existing group based AKA protocols did not equip with the group management scheme efficiently and also vulnerable to various known attacks. To avoid the aforesaid problems and mitigate the authentication complexity of the earlier schemes, we propose a dynamic group based efficient and secure (DGBES-AKA) protocol for MTC in LTE/LTE-A network. The proposed protocol consists the group key update scheme with key forward and backward secrecy. The formal verification using ProVerif and security analysis of the proposed protocol represent the security against malicious attacks. Finally, we show the qualitative and quantitative analysis of the DGBES-AKA protocol with the existing protocols. The analysis shows that the proposed protocol has improved results in terms of communication and computation overhead.
21 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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