Abstract: The capacity of conventional cellular networks has
reached its upper bound and it can be well handled by introducing
femtocells with low-cost and easy-to-deploy. Spectrum interference
issue becomes more critical in peace with the value-added multimedia
services growing up increasingly in two-tier cellular networks.
Spectrum allocation is one of effective methods in interference
mitigation technology. This paper proposes a game-theory-based on
OFDMA downlink spectrum allocation aiming at reducing co-channel
interference in two-tier femtocell networks. The framework is
formulated as a non-cooperative game, wherein the femto base
stations are players and frequency channels available are strategies.
The scheme takes full account of competitive behavior and
fairness among stations. In addition, the utility function reflects
the interference from the standpoint of channels essentially. This
work focuses on co-channel interference and puts forward a negative
logarithm interference function on distance weight ratio aiming
at suppressing co-channel interference in the same layer network.
This scenario is more suitable for actual network deployment and
the system possesses high robustness. According to the proposed
mechanism, interference exists only when players employ the same
channel for data communication. This paper focuses on implementing
spectrum allocation in a distributed fashion. Numerical results show
that signal to interference and noise ratio can be obviously improved
through the spectrum allocation scheme and the users quality of
service in downlink can be satisfied. Besides, the average spectrum
efficiency in cellular network can be significantly promoted as
simulations results shown.
Abstract: Femtocells are regarded as a milestone for next
generation cellular networks. As femtocells are deployed in an
unplanned manner, there is a chance of assigning same resource to
neighboring femtocells. This scenario may induce co-channel
interference and may seriously affect the service quality of
neighboring femtocells. In addition, the dominant transmit power of a
femtocell will induce co-tier interference to neighboring femtocells.
Thus to jointly handle co-tier and co-channel interference, we
propose an interference-free power and resource block allocation
(IFPRBA) algorithm for closely located, closed access femtocells.
Based on neighboring list, inter-femto-base station distance and
uplink noise power, the IFPRBA algorithm assigns non-interfering
power and resource to femtocells. The IFPRBA algorithm also
guarantees the quality of service to femtouser based on the
knowledge of resource requirement, connection type, and the
tolerable delay budget. Simulation result shows that the interference
power experienced in IFPRBA algorithm is below the tolerable
interference power and hence the overall service success ratio, PRB
efficiency and network throughput are maximum when compared to
conventional resource allocation framework for femtocell (RAFF)
algorithm.