7,430 research outputs found
Spatial spectrum and energy efficiency of random cellular networks
It is a great challenge to evaluate the network performance of cellular
mobile communication systems. In this paper, we propose new spatial spectrum
and energy efficiency models for Poisson-Voronoi tessellation (PVT) random
cellular networks. To evaluate the user access the network, a Markov chain
based wireless channel access model is first proposed for PVT random cellular
networks. On that basis, the outage probability and blocking probability of PVT
random cellular networks are derived, which can be computed numerically.
Furthermore, taking into account the call arrival rate, the path loss exponent
and the base station (BS) density in random cellular networks, spatial spectrum
and energy efficiency models are proposed and analyzed for PVT random cellular
networks. Numerical simulations are conducted to evaluate the network spectrum
and energy efficiency in PVT random cellular networks.Comment: appears in IEEE Transactions on Communications, April, 201
On Modeling Heterogeneous Wireless Networks Using Non-Poisson Point Processes
Future wireless networks are required to support 1000 times higher data rate,
than the current LTE standard. In order to meet the ever increasing demand, it
is inevitable that, future wireless networks will have to develop seamless
interconnection between multiple technologies. A manifestation of this idea is
the collaboration among different types of network tiers such as macro and
small cells, leading to the so-called heterogeneous networks (HetNets).
Researchers have used stochastic geometry to analyze such networks and
understand their real potential. Unsurprisingly, it has been revealed that
interference has a detrimental effect on performance, especially if not modeled
properly. Interference can be correlated in space and/or time, which has been
overlooked in the past. For instance, it is normally assumed that the nodes are
located completely independent of each other and follow a homogeneous Poisson
point process (PPP), which is not necessarily true in real networks since the
node locations are spatially dependent. In addition, the interference
correlation created by correlated stochastic processes has mostly been ignored.
To this end, we take a different approach in modeling the interference where we
use non-PPP, as well as we study the impact of spatial and temporal correlation
on the performance of HetNets. To illustrate the impact of correlation on
performance, we consider three case studies from real-life scenarios.
Specifically, we use massive multiple-input multiple-output (MIMO) to
understand the impact of spatial correlation; we use the random medium access
protocol to examine the temporal correlation; and we use cooperative relay
networks to illustrate the spatial-temporal correlation. We present several
numerical examples through which we demonstrate the impact of various
correlation types on the performance of HetNets.Comment: Submitted to IEEE Communications Magazin
Modeling Interference Between OFDM/OQAM and CP-OFDM: Limitations of the PSD-Based Model
To answer the challenges put out by the next generation of wireless networks
(5G), important research efforts have been undertaken during the last few years
to find new waveforms that are better spectrally localized and less sensitive
to asynchronism effects than the widely deployed Cyclic Prefix Orthogonal
Frequency Division Multiplexing (CP-OFDM). One of the most studied schemes is
OFDM-Offset Quadrature Amplitude Modulation (OFDM/OQAM) based on the PHYDYAS
filter pulse. In the recent literature, spectrum coexistence between OFDM/OQAM
and CP-OFDM is commonly studied based on the Power Spectral Density (PSD)
model. In this paper, we show that this approach is flawed and we show that the
actual interference injected by OFDM/OQAM systems onto CP-OFDM is much higher
than what is classically expected with the PSD based model in the literature.
We show that though using OFDM/OQAM in secondary systems is still advantageous,
it brings limited gain in the context of coexistence with incumbent CP-OFDM
systems.Comment: 7 pages, 9 figures, ICT 201
- …