757 research outputs found
Downlink Small-cell Base Station Cooperation Strategy in Fractal Small-cell Networks
Coordinated multipoint (CoMP) communications are considered for the
fifth-generation (5G) small-cell networks as a tool to improve the high data
rates and the cell-edge throughput. The average achievable rates of the
small-cell base stations (SBS) cooperation strategies with distance and
received signal power constraints are respectively derived for the fractal
small-cell networks based on the anisotropic path loss model. Simulation
results are presented to show that the average achievable rate with the
received signal power constraint is larger than the rate with a distance
constraint considering the same number of cooperative SBSs. The average
achievable rate with distance constraint decreases with the increase of the
intensity of SBSs when the anisotropic path loss model is considered. What's
more, the network energy efficiency of fractal smallcell networks adopting the
SBS cooperation strategy with the received signal power constraint is analyzed.
The network energy efficiency decreases with the increase of the intensity of
SBSs which indicates a challenge on the deployment design for fractal
small-cell networks.Comment: 5 figures. Accepted by Globecom 201
Non-Terrestrial Networks in the 6G Era: Challenges and Opportunities
Many organizations recognize non-terrestrial networks (NTNs) as a key
component to provide cost-effective and high-capacity connectivity in future
6th generation (6G) wireless networks. Despite this premise, there are still
many questions to be answered for proper network design, including those
associated to latency and coverage constraints. In this paper, after reviewing
research activities on NTNs, we present the characteristics and enabling
technologies of NTNs in the 6G landscape and shed light on the challenges in
the field that are still open for future research. As a case study, we evaluate
the performance of an NTN scenario in which satellites use millimeter wave
(mmWave) frequencies to provide access connectivity to on-the-ground mobile
terminals as a function of different networking configurations.Comment: 8 pages, 4 figures, 2 tables, submitted for publication to the IEE
Propagation measurements and estimation of channel propagation models in urban environment
Wireless communication is a telecommunication technology, which enables wireless transmission between the portable devices to provide wireless access in all types of environments. In this research, the measurements and various empirical models are analysed and compared in order to find out a suitable propagation model to provide guidelines for cell planning of wireless communication systems. The measured data was taken in urban region with low vegetation and some trees at 900 MHz frequency band. Path loss models are useful planning tools, which permit the designers of cellular communication to obtain optimal levels for the base station deployment and meeting the expected service level requirements. Outcomes show that these empirical models tend to overestimate the propagation loss. As one of the key outputs, it was observed that the calculations of Weissberger model fit with the measured data in urban environment
Wireless Performance Evaluation of Building Layouts: Closed-Form Computation of Figures of Merit
This paper presents a part of our ground-breaking work on evaluation of
buildings in terms of wireless friendliness in the building-design stage. The
main goal is to devise construction practices that provide for a good
performance of wireless networks deployed in buildings. In this paper, the
interference gain (IG) and power gain (PG) are defined as two figures of merit
(FoM) of the wireless performance of buildings. The FoMs bridge the gap between
building design and wireless communications industries. An approach to derive
exact closed-form equations for these FoMs is proposed for the first time. The
derived analytic expressions facilitate straightforward and more
computationally efficient numerical evaluation of the proposed FoMs as compared
to Monte Carlo simulations for well-known indoor propagation models. It is
shown that the derived closed-form expression can be readily employed to
evaluate the impact of building properties, such as the sizes and the aspect
ratios (ARs) of rooms, on the wireless performance. The proposed approach sheds
light to architects on evaluation and design of wireless-friendly building
layouts
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