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.

Dual connectivity for LTE-advanced heterogeneous networks

Abstract: Dual connectivity (DC) allows user equipments (UEs) to receive data simultaneously from different eNodeBs (eNBs) in order to boost the performance in a heterogeneous network with dedicated carrier deployment. Yet, how to efficiently operate with DC opens a number of research questions. In this paper we focus on the case where a macro and a small cell eNBs are inter-connected with traditional backhaul links characterized by certain latency, assuming independent radio resource management (RRM) functionalities residing in each eNB. In order to fully harvest the gain provided by DC, an efficient flow control of data between the involved macro and small cell eNBs is proposed. Moreover, guidelines for the main performance determining RRM algorithms such as UE cell association and packet scheduling are also presented. It is demonstrated how proper configuration of the proposed flow control algorithm offers efficient trade-offs between reducing the probability that one of the eNBs involved in the DC runs out of data and limiting the buffering time. Simulation results show that the performance of DC over traditional backhaul connections is close to that achievable with inter-site carrier aggregation (CA) and virtually zero-latency fronthaul connections, and in any case it is significantly higher compared to the case without DC.

Interference avoidance for in-device coexistence in 3GPP LTE-advanced: challenges and solutions

Abstract: With the ever growing usage of various wireless technologies and services, more and more handheld devices are equipped with multiple radio transceivers (e.g., LTE, WiFi, Bluetooth, and GNSS). As a result, in-device coexistence interference has become a serious problem due to the extreme proximity of multiple radio transceivers within the same device. It has been shown by the studies of 3GPP that for some specific frequency bands, concurrent operations of LTE and ISM/GNSS radios working in adjacent or sub-harmonic frequencies will result in significant in-device coexistence interference that cannot be completely eliminated by filter technology. This motivates 3GPP to introduce signaling mechanisms and procedures, which enable the devices to effectively solve the indevice coexistence problems with help from the LTE network. This article first discusses the scenarios in which coexistence interference may happen, and then provides an overview of main solutions and related procedures specified in 3GPP Release-11 standards for LTE. In addition, some aspects of device-internal coordination and implementation to facilitate the coexistence scenarios are also discussed.

Method and system for configuration of measurement reference signals in LTE-A system

Abstract: The invention discloses a method and a system for configuration of measurement reference signals in an LTE-A system, thereby leading a base station to be convenient to trigger a UE to send SRS signals at any time and measuring a channel at any time. The configuration method comprises the following steps: leading the base station to trigger one or more user equipment (UE) to send non-periodic measurement reference signals (SRS) on one or more uplink sub-frames through downlink control signaling. The adoption of the non-periodic SRS configuration method and the system can determine resources used by the non-periodic SRS, improve the UE channel measurement efficiency and better meet the requirements on the channel measurement of the LTE-A system. In addition, the impacts and the conflicts of periodic and non-periodic SRS in the LTE-A system can be effectively avoided by reserving the non-periodic SRS resources.

Exploiting LTE-Advanced HetNets and FeICIC for UAV-Assisted Public Safety Communications

Abstract: Ensuring ubiquitous mission-critical public safety communications (PSC) to all the first responders in the public safety network is crucial at an emergency site. Recently, the use of unmanned aerial vehicles (UAVs) has received extensive interest for PSC to fill the coverage holes and establish reliable connectivity. The UAVs can be deployed as unmanned aerial base stations (UABSs) as part of a heterogeneous network (HetNet) PSC infrastructure. In this paper, we design a PSC LTE-Advanced HetNet for different path loss models and deployment mechanism for UABSs. We enhance the system-wide spectral efficiency (SE) of this PSC HetNet by apply cell range expansion (CRE) to UABSs and mitigating the inter-cell interference arising in the HetNet by applying 3GPP Release-10 enhanced inter-cell interference coordination (eICIC) and 3GPP Release-11 further-enhanced inter-cell interference coordination (FeICIC). Through Monte Carlo simulations, we compare the system-wide fifth percentile SE when UABSs are deployed on a hexagonal grid and when their locations are optimized using a genetic algorithm, while also jointly optimizing the CRE and the inter-cell interference coordination parameters. Our results show that at optimized UABS locations, reduced power subframes defined in 3GPP Release-11 can provide considerably better fifth percentile SE than the 3GPP Release-10 with almost blank subframes (eICIC).

Implementation and Validation of an LTE D2D Model for ns-3

Abstract: The ability to perform device-to-device (D2D) communication in Long Term Evolution (LTE)-based cellular networks became possible with the introduction of Proximity Services (ProSe) functionalities in the 3rd Generation Partnership Program (3GPP) specifications. In this paper, we provide a description of the ProSe implementation that extends the LTE model already available in ns-3. Our model contains key features defined in LTE Release 12 and further enhanced in LTE Release 13 related to synchronization, discovery, and communication. We also provide validation of each feature by comparing simulation results with analytical models developed as part of our work on D2D communication.