LTE Advanced

About: LTE Advanced is a research topic. Over the lifetime, 4055 publications have been published within this topic receiving 74262 citations. The topic is also known as: Long-Term Evolution Advanced & LTE-A.

Coordinated Dynamic Spectrum Management of LTE-U and Wi-Fi Networks

Abstract: This paper investigates the co-existence of Wi-Fi and LTE in emerging unlicensed frequency bands which are intended to accommodate multiple radio access technologies. Wi-Fi and LTE are the two most prominent access technologies being deployed today, motivating further study of the inter-system interference arising in such shared spectrum scenarios as well as possible techniques for enabling improved co-existence. An analytical model for evaluating the baseline performance of co-existing Wi-Fi and LTE is developed and used to obtain baseline performance measures. The results show that both Wi-Fi and LTE networks cause significant interference to each other and that the degradation is dependent on a number of factors such as power levels and physical topology. The model-based results are partially validated via experimental evaluations using USRP based SDR platforms on the ORBIT testbed. Further, inter-network coordination with logically centralized radio resource management across Wi-Fi and LTE systems is proposed as a possible solution for improved co-existence. Numerical results are presented showing significant gains in both Wi-Fi and LTE performance with the proposed inter-network coordination approach.

MU-MIMO in LTE Systems

Abstract: A relatively recent idea of extending the benefits of MIMO systems to multiuser scenarios seems promising in the context of achieving high data rates envisioned for future cellular standards after 3G (3rd Generation). Although substantial research has been done on the theoretical front, recent focus is on making Multiuser Multiple-Input Multiple-Output (MUMIMO) practically realizable. This paper presents an overview of the different MU-MIMO schemes included/being studied in 3GPP standardization from LTE (long-term evolution) to LTE Advanced. MU-MIMO system concepts and implementation aspects have been studied here. Various low-complexity receiver architectures are investigated, and their performance assessed through link-level simulations. Appealing performance offered by low-complexity interference aware (IA) receivers is notably emphasized. Furthermore, system level simulations for LTE Release 8 are provided. Interestingly, it is shown that MU-MIMO only offers marginal performance gains with respect to single-user MIMO. This arises from the limited MU-MIMO features included in Release 8 and calls for improved schemes for the upcoming releases.

Multiple-antenna techniques in LTE-advanced

Abstract: In this article we discuss the different multiple antenna techniques introduced in LTE-Advanced. Rather than describing the technical details of the adopted solutions, we approach the problem starting from the design targets and the antenna deployments prioritized by the operators. Then we present the main enabling solutions introduced for downlink and uplink transmissions, and subsequently assess the performance of these solutions in different scenarios. Finally, we discuss some possible future developments.

Simulating LTE/LTE-Advanced Networks with SimuLTE

Abstract: In this work we present SimuLTE, an OMNeT++-based simulator for LTE and LTE-Advanced networks. Following well-established OMNeT++ programming practices, SimuLTE exhibits a fully modular structure, which makes it easy to be extended, verified, and integrated. Moreover, it inherits all the benefits of such a widely used and versatile simulation framework as OMNeT++, i.e., experiment support and seamless integration with the OMNeT++ network modules, such as INET. This allows SimuLTE users to build up mixed scenarios where LTE is only a part of a wider network. This paper describes the architecture of SimuLTE, with particular emphasis on the modeling choices at the MAC layer, where resource scheduling is located. Furthermore, we describe some of the verification and validation efforts and present an example of the performance analysis that can be carried out with SimuLTE.

LTE-advanced modem design: challenges and perspectives

Abstract: The commercial deployment of LTE Release 8 is gaining significant momentum all over the globe, and LTE is evolving to LTE-Advanced, which offers various new features to meet or exceed IMT-Advanced requirements. Since LTE-Advanced targets ambitious spectral efficiency and peak throughput, it poses tremendous system design challenges to operators and manufacturers, especially for mobile terminals. This article discusses modem design issues related to carrier aggregation, enhanced ICIC for HetNet, detection of eight-layer transmission, reference signals for enhanced multi-antenna support, and HARQ buffer management. We provide an overview of technical challenges and sketch the perspectives for tackling them to exploit the full benefits of the LTE-Advanced system.