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.

On Relay Selection Schemes for Relay-Assisted D2D Communications in LTE-A Systems

Abstract: Device-to-device (D2D) communication is a promising technique for traffic offloading in next-generation cellular systems. However, the use of only direct D2D communications limits the advantages of D2D communications due to relatively long separation distances or poor link quality between source and destination user equipments (UEs). Relay-assisted D2D communication was proposed as a supplement to direct D2D communications for enhancing traffic offloading capacity in long-term evolution–advanced (LTE-A) systems. This work aims to design a relay UE selection strategy for D2D communications, which improves D2D communication performance significantly. We propose a cross-layer relay selection scheme that considers several criteria jointly, including end-to-end data rate, relay-capable UE (RUE) remaining battery time, and end-to-end transmission delay on relay-assisted D2D path. We show how to leverage these criteria at an eNB performing relay selection in D2D communications. In particular, an end-to-end delay estimation model is established based on queuing theory. Simulation results validate the performance of the proposed scheme in terms of total amount of data transmitted under RUE remaining battery and end-to-end transmission delay.

Cognitive Interference Management for LTE-A Femtocells with Distributed Carrier Selection

Abstract: The concept of small cells such as femtocells has been regarded as a promising solution to overcome the indoor coverage problem and deal with the growth of traffic within macrocells. However, the unpredictable deployment pattern of such cells makes centralized network planning impractical and requires more efficient interference management and distributed spectrum planning schemes to realize the benefit of femtocells. In this paper, we propose a cognitive-based interference management solution for LTE-Advanced (LTE-A) femtocells by sharing measured pathloss information among neighbors and selecting component carriers according to the estimated mutual interference. System-level simulation results demonstrate that the proposed scheme can effectively avoid spectrum collision and significantly improve overall network capacity.

5G New Radio for Terrestrial Broadcast: A Forward-Looking Approach for NR-MBMS

Abstract: 3GPP LTE eMBMS release (Rel-) 14, also referred to as further evolved multimedia broadcast multicast service (FeMBMS) or enhanced TV (EnTV), is the first mobile broadband technology standard to incorporate a transmission mode designed to deliver terrestrial broadcast services from conventional high power high tower (HPHT) broadcast infrastructure. With respect to the physical layer, the main improvements in FeMBMS are the support of larger inter-site distance for single frequency networks (SFNs) and the ability to allocate 100% of a carrier’s resources to the broadcast payload, with self-contained signaling in the downlink. From the system architecture perspective, a receive-only mode enables free-to-air (FTA) reception with no need for an uplink or SIM card, thus receiving content without user equipment registration with a network. These functionalities are only available in the LTE advanced pro specifications as 5G new radio (NR), standardized in 3GPP from Rel-15, has so far focused entirely on unicast. This paper outlines a physical layer design for NR-MBMS, a system derived, with minor modifications, from the 5G-NR specifications, and suitable for the transmission of linear TV and radio services in either single-cell or SFN operation. This paper evaluates the NR-MBMS proposition and compares it to LTE-based FeMBMS in terms of flexibility, performance, capacity, and coverage.

Fountain Coded Cooperative Communications for LTE-A Connected Heterogeneous M2M Network

Abstract: Machine-to-machine communication over long-term evolution advanced (LTE-A) network has emerged as a new communication paradigm to support a variety of applications of Internet of Things. One of the most effective techniques to accommodate a large volume of machine type communication (MTC) devices in LTE-A is clustering where devices (nodes) are grouped into number of clusters and forward their traffics to the base station (e.g., LTE eNodeB) through some special nodes called cluster heads (CHs). In many applications, the CHs change location with time that causes variation in distances between neighboring CHs. When these distances increase, the performance of data transmission may degrade. To address this issue, we propose to employ intermediate non-CH nodes as relays between neighboring CHs. Our solution covers many aspects from relay selection to cooperative formation to meet the user’s QoS requirements. As the number of total relay plays a significant role in cooperative communications, we first design a rateless-coded-incremental-relay selection algorithm based on greedy techniques to guarantee the required data rate with a minimum cost. After that, we develop both source-feedback and non-source-feedback-based fountain coded cooperative communication protocols to facilitate the data transmission between two neighbor CHs. Numerical results are presented to demonstrate the performance of these protocols with different relay selection methods under Rayleigh fading channel. It shows that the proposed source-feedback-based protocol outperforms its non-source-feedbackprotocol counterpart in terms of a variety of metrics.

Performance evaluation of inter-cell interference coordination and cell range expansion in heterogeneous networks for LTE-Advanced downlink

Abstract: In Long-Term Evolution (LTE)-Advanced, heterogeneous networks where femtocells and picocells are overlaid onto macrocells are extensively discussed in addition to traditional well-planned macrocell deployment to improve further the system throughput. In heterogeneous network deployment, combined usage of inter-cell interference coordination (ICIC) and cell range expansion (CRE) is very effective in improving the system and cell-edge throughput. In this combined usage, the fraction of the sets of user equipment (UEs) connected to the picocells, which are controlled through CRE, and that connected to macrocells affect the gain from the ICIC. Therefore, this paper evaluates the performance of ICIC and CRE in picocell deployments in the LTE-Advanced downlink. Simulation results (4 picocells and 30 UEs are located within 1 macrocell) assuming a full buffer model show that when the CRE offset value is set between 8 to 20 dB, almost the same user throughput performance is obtained by allocating the appropriate resources to protect UEs that connect to the picocells.