Centralized and Distributed Solutions for Fast Muting Adaptation in LTE-Advanced HetNets

Enhanced Intercell Interference Coordination
(eICIC) is known to provide promising performance benefits
for LTE-Advanced Heterogeneous Networks. The use of
eICIC facilitates more flexible inter-layer load balancing by
means of small cell Range Extension (RE) and Almost Blank
Subframes (ABS). Even though the eICIC configuration (RE and
ABS) ideally should be instantaneously adapted to follow the
fluctuations of the traffic and the channel conditions over time,
previous studies have focused on slow intercell coordination.
In this paper, we investigate fast dynamic eICIC solutions for
centralized and distributed Radio Resource Management (RRM)
architectures. The centralized RRM architecture assumes macro
and Remote Radio Heads (RRHs) inter-connected via high-speed
fronthaul connections, while the distributed architecture is
based on traditional macro and pico cells deployments with
X2 backhaul interface. Two different fast muting adaptation
algorithms are derived, and it is shown how those can be
appplied to both the centralized and the distributed architecture.
Performance results with bursty traffic show that the fast
dynamic adaptation provides significant gains, both in 5%-ile
and 50%-ile user throughput, as well as improvements in
user fairness. The best performance is naturally obtained for
the centralized architecture, although the performance of the
distributed architecture is comparable for the cases where
enhanced X2 intercell information exchange is exploited.