6 research outputs found
Improving Macrocell - Small Cell Coexistence through Adaptive Interference Draining
The deployment of underlay small base stations (SBSs) is expected to
significantly boost the spectrum efficiency and the coverage of next-generation
cellular networks. However, the coexistence of SBSs underlaid to an existing
macro-cellular network faces important challenges, notably in terms of spectrum
sharing and interference management. In this paper, we propose a novel
game-theoretic model that enables the SBSs to optimize their transmission rates
by making decisions on the resource occupation jointly in the frequency and
spatial domains. This procedure, known as interference draining, is performed
among cooperative SBSs and allows to drastically reduce the interference
experienced by both macro- and small cell users. At the macrocell side, we
consider a modified water-filling policy for the power allocation that allows
each macrocell user (MUE) to focus the transmissions on the degrees of freedom
over which the MUE experiences the best channel and interference conditions.
This approach not only represents an effective way to decrease the received
interference at the MUEs but also grants the SBSs tier additional transmission
opportunities and allows for a more agile interference management. Simulation
results show that the proposed approach yields significant gains at both
macrocell and small cell tiers, in terms of average achievable rate per user,
reaching up to 37%, relative to the non-cooperative case, for a network with
150 MUEs and 200 SBSs
Series Expansion for Interference in Wireless Networks
The spatial correlations in transmitter node locations introduced by common
multiple access protocols makes the analysis of interference, outage, and other
related metrics in a wireless network extremely difficult. Most works therefore
assume that nodes are distributed either as a Poisson point process (PPP) or a
grid, and utilize the independence properties of the PPP (or the regular
structure of the grid) to analyze interference, outage and other metrics.
But,the independence of node locations makes the PPP a dubious model for
nontrivial MACs which intentionally introduce correlations, e.g. spatial
separation, while the grid is too idealized to model real networks. In this
paper, we introduce a new technique based on the factorial moment expansion of
functionals of point processes to analyze functions of interference, in
particular outage probability. We provide a Taylor-series type expansion of
functions of interference, wherein increasing the number of terms in the series
provides a better approximation at the cost of increased complexity of
computation. Various examples illustrate how this new approach can be used to
find outage probability in both Poisson and non-Poisson wireless networks.Comment: Submitted to IEEE Transactions on Information Theor
Generalized Interference Alignment—Part II: Application to Wireless Secrecy
In contrast to its wired counterpart, wireless communication is highly susceptible to eavesdropping due to the broadcast nature of the wireless propagation medium. Recent works have proposed the use of interference to reduce eavesdropping capabilities in wireless wiretap networks. However, the concurrent effect of interference on both eavesdropping receivers (ERs) and legitimate receivers has not been thoroughly investigated, and careful engineering of the network interference is required to harness the full potential of interference for wireless secrecy. This two-part article addresses this issue by proposing a generalized interference alignment (GIA) technique, which jointly designs the transceivers at the legitimate partners to impede the ERs without interfering with LRs. In Part I, we have established a theoretical framework for the GIA technique. In Part II, we will first propose an efficient GIA algorithm that is applicable to large-scale networks and then evaluate the performance of this algorithm in stochastic wireless wiretap network via both analysis and simulation. These results reveal insights into when and how GIA contributes to wireless secrecy