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Massive MIMO network deployments are expected to be a key feature of the upcoming 5G communication systems. Such networks are able to achieve a high level of channel quality and can simultaneously serve multiple users with the same resources. In this paper, realistic massive MIMO channels are evaluated both in single and multi-cell environments. The favorable propagation property is evaluated in the...
Advanced radio channel modeling continues to be of great interest in order to facilitate innovation and pursue performance prediction of wireless networks; in particular, dual-polarized antenna systems for 4.5 and 5G require models that properly capture the complex phenomenon of depolarization. Accordingly, we present and validate a ray-based model for dual-polarized channel characterization. We present...
Ray-based and hybrid propagation models are today considered as valuable solutions to fulfill 5G wireless channel modeling requirements. They are a complement or alternative to the stochastic approaches when link-level and system-level simulations deal with millimeter-wave (mmWave), ultra-dense deployment and/or large antenna arrays. The present article proposes an extension of an urban ray-based...
Future dense small-cell networks are one of the key 5G candidates to offer outdoor high access data rates, especially in millimeter wave (mmWave) frequency bands. At those frequencies, the free space propagation loss and shadowing (from buildings, vegetation or any kind of obstacles) are far stronger than in the traditional radio cellular spectrum. Therefore, the cell range is expected to be limited...
Future small-cell networks using the millimeter-wave (mmW) band to provide backhauling or user access need for adequate and innovative simulation tools in order to optimize the pre-deployment design and thus reduce installation and post-deployment optimization costs. The proposed paper makes some recommendations on the inputs and simulation blocks required for the mmW small-cell design. A particular...
This paper analyses the outdoor small-cell millimeter-wave (mmW) propagation using ray-based simulation tools. The main characteristics of the wireless channel, i.e. pathloss, delay and angular spreads, are characterized through various small-cell scenarios, and by comparison between several frequency bands. The 2.4 GHz and 5 GHz bands represent the traditional sub-6GHz frequencies in public radio-communication...
This paper presents a detailed analysis of a dense outdoor 4G small-cell backhaul and access networks using advanced simulation and design tools in a realistic urban environment. First, the RAN is simulated and analyzed. The deployment of a dense small-cell layer leads to a 504% capacity increase (to 332 Mbps/km2) compared to the macro-only network but also to a 199% power consumption rise. The impact...
This paper presents the system-level evaluation of a new directive compact antenna devoted to small-cells. The parasitic antenna array gets a maximum directivity of 7.9 dBi with a compact size (inter element distance of 0.1λ), which makes it a very interesting candidate for integration in small-cell equipment. Such super-directivity is reached at the cost of a degraded antenna efficiency/gain. After...
In this paper we assess the benefit of WiFi offloading over dense urban scenarios in terms of both Quality of Service (QoS) and Electromagnetic Field (EMF) exposure. This study relies on results obtained with two complementary simulation platforms: a two-tier dynamic system-level simulator and a 3D coverage-based simulator. Outputs are usual service coverage key performance indicators, handover probability...
This paper presents a study on the performance of a dense urban small-cell densification, where the limitations and design challenges related to the wireless small-cell backhaul are considered. While most evaluations of the small-cell capability to increase the end-user experience do simply assume ideal backhaul, here a wireless and capacity-limited backhaul is introduced. The design methodology,...
This paper presents a new metric to evaluate electromagnetic exposure induced by wireless cellular networks. This metric takes into account the exposure induced by base station antennas as well as exposure induced by wireless devices to evaluate average global exposure of the population in a specific geographical area. The paper first explains the concept and gives the formulation of the Exposure...
In spite of the growing presence of wireless communications, some concerns have recently loomed about the potential risks of the exposure to the electromagnetic fields they induce. In this paper we introduce a methodology that would allow to study the performance of enhanced access selection mechanisms, which include the willingness to reduce such exposure. The proposed framework has been conceived...
In this paper, we propose a simplified approach for the Mixed Integer Non-linear Programming (MINLP) problem in the context of dynamic resource allocation for multiuser downlink Orthogonal Frequency Division Multiplexing (OFDM) systems. Our solution is based on the appropriate selection of the K-best branches of the branch and bound technique. The proposed algorithm significantly decreases the computational...
This paper analyzes LTE-A Heterogeneous Network (HetNet) performance in terms of usual Quality of Service (QoS), energy efficiency and Electromagnetic Field (EMF) exposure. The main objective is to identify network deployment rules that would allow achieving optimal performance from multiple key indicators taking into account a realistic forecast of wireless data traffic demand growth. This study...
The performance of several LTE-A heterogeneous networks are evaluated with the objective to identify network topologies and configurations that achieve a target Quality of Service (QoS) while minimizing Electromagnetic Field (EMF) exposure and energy consumption. Characterization of the EMF exposure relies on metrics taking into account contributions from both uplink and downlink. Results are obtained...
This paper presents the benefits of using a 3D ray-based propagation model to rapidly and accurately simulate MIMO performance in various complex urban environments, focusing on the channel rank prediction. The impact of the predicted channel complexity on the channel rank is first analyzed and illustrated in a single cell scenario. Then the MIMO performance is assessed on a heterogeneous LTE network...
In spite of the existing protection limits and despite the fact that no research results have proven any health effects below these limits, the public fears towards electromagnetic fields, mobile telephony and the radiofrequencies used, remain important. The EMF exposure from wireless communication systems and networks is often cited as a major cause of public concern and is frequently given considerable...
Indoor small-cell (Femto) technology recently gained attention due to its potential benefits for wireless carriers (significant capacity offload and extension of coverage at low cost). These indoor small-cell base stations are seen as enablers of heterogeneous networks in urban areas. However, there are still hard technical challenges to be addressed (e.g. the optimization of the interference management)...
LTE and LTE-Advanced have introduced complex system features to improve system capacity. Although exhaustively simulated, it often happens that the simulated capacity figures differ from the actual performance seen in the field. This paper explores the combination of real measurements from LTE devices and realistic propagation models to generate coverage maps that are truly representative of radio...
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