2 research outputs found
Spatio-temporal Interference Correlation and Joint Coverage in Cellular Networks
This paper provides an analytical framework with foundations in stochastic
geometry to characterize the spatio-temporal interference correlation as well
as the joint coverage probability at two spatial locations in a cellular
network. In particular, modeling the locations of cellular base stations (BSs)
as a Poisson Point Process (PPP), we study interference correlation at two
spatial locations and separated by a distance , when the
user follows \emph{closest BS association policy} at both spatial locations and
moves from to . With this user displacement, two scenarios can
occur: i) the user is handed off to a new serving BS at , or ii) no
handoff occurs and the user is served by the same BS at both locations. After
providing intermediate results such as probability of handoff and distance
distributions of the serving BS at the two user locations, we use them to
derive exact expressions for spatio-temporal interference correlation
coefficient and joint coverage probability for any distance separation . We
also study two different handoff strategies: i) \emph{handoff skipping}, and
ii) \emph{conventional handoffs}, and derive the expressions of joint coverage
probability for both strategies. The exact analysis is not straightforward and
involves a careful treatment of the neighborhood of the two spatial locations
and the resulting handoff scenarios. To provide analytical insights, we also
provide easy-to-use expressions for two special cases: i) static user ()
and ii) highly mobile user (. As expected, our analysis
shows that the interference correlation and joint coverage probability decrease
with increasing , with corresponding to a completely
uncorrelated scenario
Spatio-Temporal Correlation of Interference in MANET Under Spatially Correlated Shadowing Environment
Correlation of interference affects spatio-temporal aspects of various
wireless mobile systems, such as retransmission, multiple antennas and
cooperative relaying. In this paper, we study the spatial and temporal
correlation of interference in mobile ad-hoc networks under a correlated
shadowing environment. By modeling the node locations as a Poisson point
process with an i.i.d. mobility model and considering Gudmundson (1991)' s
spatially correlated shadowing model, we theoretically analyze the relationship
between the correlation distance of log-normal shadowing and the spatial and
temporal correlation coefficients of interference. Since the exact expressions
of the correlation coefficients are intractable, we obtain their simple
asymptotic expressions as the variance of log-normal shadowing increases. We
found in our numerical examples that the asymptotic expansions can be used as
tight approximate formulas and useful for modeling general wireless systems
under spatially correlated shadowing.Comment: to appear in IEEE Transactions on Mobile Computin