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.

Physical uplink control management in lte/lte-a systems with unlicensed spectrum

Abstract: Uplink control channel management is disclosed for LTE/LTE-A communication systems with unlicensed spectrum in which two or more physical resource blocks (PRBs) are allocated for uplink control channel transmission. The uplink control information (UCI) payload may be determined based on clear channel assessment (CCA) information associated with carriers scheduled for transmission of the UCI data. With the UCI payload determined, two or more uplink control channel messages may be generated according to at least one control channel format, wherein uplink control channel messages include the UCI payload. These generated uplink control channel messages may then be transmitted over the allocated PRBs.

Uplink Scheduling and Power Allocation for M2M Communications in SC-FDMA-Based LTE-A Networks With QoS Guarantees

Abstract: Providing diverse and strict quality-of-service (QoS) guarantees is one of the most important requirements in machine-to-machine (M2M) communications, which is particularly need for appropriate resource allocation for a large number of M2M devices. To efficiently allocate resource blocks (RBs) for M2M devices while satisfying QoS requirements, we propose group-based M2M communications, in which M2M devices are clustered based on their wireless transmission protocols, their QoS characteristics, and their requirements. To perform joint RB and power allocation in SC-FDMA-based LTE-A networks, we formulate a sum-throughput maximization problem, while respecting all the constraints associated with SC-FDMA scheme, as well as QoS requirements in M2M devices. The constraints in uplink SC-FDMA air interface in LTE-A networks complicate the resource allocation problem. We solve the resource allocation problem by first transforming it into a binary integer programming problem and then formulate a dual problem using the Lagrange duality theory. Numerical results show that the proposed algorithm outperforms traditional Greedy algorithm in terms of throughput maximization while satisfying QoS requirements, and its performance is close to the optimal design.

Capacity evaluation of Aerial LTE base-stations for public safety communications

Abstract: Aerial-Terrestrial communication networks able to provide rapidly-deployable and resilient communications capable of offering broadband connectivity are emerging as a suitable solution for public safety scenarios. During natural disasters or unexpected events, terrestrial infrastructure can be seriously damaged or disrupted due to physical destruction of network components, disruption in subsystem interconnections and/or network congestion. In this context, Aerial-Terrestrial communication networks are intended to provide temporal large coverage with the provision of broadband services at the disaster area. This paper studies the performance of Aerial UMTS Long Term Evolution (LTE) base stations in terms of coverage and capacity. Network model relies on appropriate channel model, LTE 3GPP specifications and well known schedulers are used. The results show the effect of the temperature, bandwidth, and scheduling discipline on the system capacity while at the same time coverage is investigated in different public safety scenarios.

Backhaul-Aware User Association in FiWi Enhanced LTE-A Heterogeneous Networks

Abstract: In this paper, we shed some light on the latency and reliability issues of mobile backhaul networks, which have been largely ignored in the past, and examine their impact on LTE-A heterogeneous networks (HetNets). Specifically, we propose a backhaul-aware user association algorithm for fiber-wireless (FiWi) enhanced LTE-A HetNets. The performance limiting factors of state-of-the-art fiber backhaul infrastructures are highlighted and a variety of solutions are described. To mitigate the vulnerability of the backhaul against fiber cuts, we introduce different advanced protection techniques. Accounting for the given conditions of the backhaul in terms of delay and reliability, we present a distributed load-balancing algorithm for user association in FiWi-LTE HetNets. The proposed algorithm is analyzed and evaluated numerically by comparing its performance with state-of-the-art alternative approaches in terms of average delay, blocking probability, average achievable throughput, and service interruption percentage. The obtained results demonstrate that our algorithm outperform its counterparts in terms of delay and service interruption percentage, while its average achievable throughput is the same as that of a backhaul-unaware alternative solution. In addition, the blocking probability of the proposed backhaul-aware load-balancing method is shown to be higher than that of backhaul-unaware ones.

Analysis of adjustable and fixed DRX mechanism for power saving in LTE/LTE-Advanced

Abstract: The 4G standard Long Term Evolution (LTE) has been developed for high-bandwidth mobile access for today's data-heavy applications, consequently, a better experience for the end user. To extend the user equipment battery lifetime, plus further support various services and large amount of data transmissions, the 3GPP standards for LTE/LTE-Advanced has adopted discontinuous reception (DRX). However, there is a need to optimize the DRX parameters, so as to maximize power saving without incurring network re-entry and packet delays. In this paper, we provide an overview of the fixed frame DRX cycle and compare it against an adjustable DRX cycle of the LTE/LTE-Advanced power saving mechanism, by modelling the system with bursty packet data traffic using a semi-Markov process. Based on the analytical model, we will show the trade-off relationship between the power saving and wake-up delay performance.