249 research outputs found
Price-Based Resource Allocation for Spectrum-Sharing Femtocell Networks: A Stackelberg Game Approach
This paper investigates the price-based resource allocation strategies for
the uplink transmission of a spectrum-sharing femtocell network, in which a
central macrocell is underlaid with distributed femtocells, all operating over
the same frequency band as the macrocell. Assuming that the macrocell base
station (MBS) protects itself by pricing the interference from the femtocell
users, a Stackelberg game is formulated to study the joint utility maximization
of the macrocell and the femtocells subject to a maximum tolerable interference
power constraint at the MBS. Especially, two practical femtocell channel
models: sparsely deployed scenario for rural areas and densely deployed
scenario for urban areas, are investigated. For each scenario, two pricing
schemes: uniform pricing and non-uniform pricing, are proposed. Then, the
Stackelberg equilibriums for these proposed games are studied, and an effective
distributed interference price bargaining algorithm with guaranteed convergence
is proposed for the uniform-pricing case. Finally, numerical examples are
presented to verify the proposed studies. It is shown that the proposed
algorithms are effective in resource allocation and macrocell protection
requiring minimal network overhead for spectrum-sharing-based two-tier
femtocell networks.Comment: 27 pages, 7 figures, Submitted to JSA
Power Control in Two-Tier Femtocell Networks
In a two tier cellular network -- comprised of a central macrocell underlaid
with shorter range femtocell hotspots -- cross-tier interference limits overall
capacity with universal frequency reuse. To quantify near-far effects with
universal frequency reuse, this paper derives a fundamental relation providing
the largest feasible cellular Signal-to-Interference-Plus-Noise Ratio (SINR),
given any set of feasible femtocell SINRs. We provide a link budget analysis
which enables simple and accurate performance insights in a two-tier network. A
distributed utility-based SINR adaptation at femtocells is proposed in order to
alleviate cross-tier interference at the macrocell from cochannel femtocells.
The Foschini-Miljanic (FM) algorithm is a special case of the adaptation. Each
femtocell maximizes their individual utility consisting of a SINR based reward
less an incurred cost (interference to the macrocell). Numerical results show
greater than 30% improvement in mean femtocell SINRs relative to FM. In the
event that cross-tier interference prevents a cellular user from obtaining its
SINR target, an algorithm is proposed that reduces transmission powers of the
strongest femtocell interferers. The algorithm ensures that a cellular user
achieves its SINR target even with 100 femtocells/cell-site, and requires a
worst case SINR reduction of only 16% at femtocells. These results motivate
design of power control schemes requiring minimal network overhead in two-tier
networks with shared spectrum.Comment: 29 pages, 10 figures, Revised and resubmitted to the IEEE
Transactions on Wireless Communication
D5.2 - Evaluation of Selected Measurement-based Techniques
Deliverable D5.2 del projecte FARAMIRPreprin
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