24,771 research outputs found
User Transmit Power Minimization through Uplink Resource Allocation and User Association in HetNets
The popularity of cellular internet of things (IoT) is increasing day by day
and billions of IoT devices will be connected to the internet. Many of these
devices have limited battery life with constraints on transmit power. High user
power consumption in cellular networks restricts the deployment of many IoT
devices in 5G. To enable the inclusion of these devices, 5G should be
supplemented with strategies and schemes to reduce user power consumption.
Therefore, we present a novel joint uplink user association and resource
allocation scheme for minimizing user transmit power while meeting the quality
of service. We analyze our scheme for two-tier heterogeneous network (HetNet)
and show an average transmit power of -2.8 dBm and 8.2 dBm for our algorithms
compared to 20 dBm in state-of-the-art Max reference signal received power
(RSRP) and channel individual offset (CIO) based association schemes
An Exclusion zone for Massive MIMO With Underlay D2D Communication
Fifth generation networks will incorporate a variety of new features in
wireless networks such as data offloading, D2D communication, and Massive MIMO.
Massive MIMO is specially appealing since it achieves huge gains while enabling
simple processing like MRC receivers. It suffers, though, from a major
shortcoming refereed to as pilot contamination. In this paper we propose a
frame-work in which, a D2D underlaid Massive MIMO system is implemented and we
will prove that this scheme can reduce the pilot contamination problem while
enabling an optimization of the system spectral efficiency. The D2D
communication will help maintain the network coverage while allowing a better
channel estimation to be performed
A Stochastic Geometry Framework for LOS/NLOS Propagation in Dense Small Cell Networks
The need to carry out analytical studies of wireless systems often motivates
the usage of simplified models which, despite their tractability, can easily
lead to an overestimation of the achievable performance. In the case of dense
small cells networks, the standard single slope path-loss model has been shown
to provide interesting, but supposedly too optimistic, properties such as the
invariance of the outage/coverage probability and of the spectral efficiency to
the base station density. This paper seeks to explore the performance of dense
small cells networks when a more accurate path-loss model is taken into
account. We first propose a stochastic geometry based framework for small cell
networks where the signal propagation accounts for both the Line-of-Sight (LOS)
and Non-Line-Of-Sight (NLOS) components, such as the model provided by the 3GPP
for evaluation of pico-cells in Heterogeneous Networks. We then study the
performance of these networks and we show the dependency of some metrics such
as the outage/coverage probability, the spectral efficiency and Area Spectral
Efficiency (ASE) on the base station density and on the LOS likelihood of the
propagation environment. Specifically, we show that, with LOS/NLOS propagation,
dense networks still achieve large ASE gain but, at the same time, suffer from
high outage probability.Comment: Typo corrected in eq. (3); Typo corrected in legend of Fig. 1-2;
Typos corrected and definitions of some variables added in Section III.E;
Final result unchanged; Paper accepted to IEEE ICC 201
Evaluation of the potential for energy saving in macrocell and femtocell networks using a heuristic introducing sleep modes in base stations
In mobile technologies two trends are competing. On the one hand, the mobile access network requires optimisation in energy consumption. On the other hand, data volumes and required bit rates are rapidly increasing. The latter trend requires the deployment of more dense mobile access networks as the higher bit rates are available at shorter distance from the base station. In order to improve the energy efficiency, the introduction of sleep modes is required. We derive a heuristic which allows establishing a baseline of active base station fractions in order to be able to evaluate mobile access network designs. We demonstrate that sleep modes can lead to significant improvements in energy efficiency and act as an enabler for femtocell deployments
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