782 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
Spectrum Coordination in Energy Efficient Cognitive Radio Networks
Device coordination in open spectrum systems is a challenging problem,
particularly since users experience varying spectrum availability over time and
location. In this paper, we propose a game theoretical approach that allows
cognitive radio pairs, namely the primary user (PU) and the secondary user
(SU), to update their transmission powers and frequencies simultaneously.
Specifically, we address a Stackelberg game model in which individual users
attempt to hierarchically access to the wireless spectrum while maximizing
their energy efficiency. A thorough analysis of the existence, uniqueness and
characterization of the Stackelberg equilibrium is conducted. In particular, we
show that a spectrum coordination naturally occurs when both actors in the
system decide sequentially about their powers and their transmitting carriers.
As a result, spectrum sensing in such a situation turns out to be a simple
detection of the presence/absence of a transmission on each sub-band. We also
show that when users experience very different channel gains on their two
carriers, they may choose to transmit on the same carrier at the Stackelberg
equilibrium as this contributes enough energy efficiency to outweigh the
interference degradation caused by the mutual transmission. Then, we provide an
algorithmic analysis on how the PU and the SU can reach such a spectrum
coordination using an appropriate learning process. We validate our results
through extensive simulations and compare the proposed algorithm to some
typical scenarios including the non-cooperative case and the
throughput-based-utility systems. Typically, it is shown that the proposed
Stackelberg decision approach optimizes the energy efficiency while still
maximizing the throughput at the equilibrium.Comment: 12 pages, 10 figures, to appear in IEEE Transactions on Vehicular
Technolog
On the Two-user Multi-carrier Joint Channel Selection and Power Control Game
In this paper, we propose a hierarchical game approach to model the energy
efficiency maximization problem where transmitters individually choose their
channel assignment and power control. We conduct a thorough analysis of the
existence, uniqueness and characterization of the Stackelberg equilibrium.
Interestingly, we formally show that a spectrum orthogonalization naturally
occurs when users decide sequentially about their transmitting carriers and
powers, delivering a binary channel assignment. Both analytical and simulation
results are provided for assessing and improving the performances in terms of
energy efficiency and spectrum utilization between the simultaneous-move game
(with synchronous decision makers), the social welfare (in a centralized
manner) and the proposed Stackelberg (hierarchical) game. For the first time,
we provide tight closed-form bounds on the spectral efficiency of such a model,
including correlation across carriers and users. We show that the spectrum
orthogonalization capability induced by the proposed hierarchical game model
enables the wireless network to achieve the spectral efficiency improvement
while still enjoying a high energy efficiency.Comment: 31 pages, 13 figures, accepted in IEEE Transactions on Communication
A Pricing-Based Cooperative Spectrum Sharing Stackelberg Game
We consider the problem of cooperative spectrum sharing among a primary user
(PU) and multiple secondary users (SUs) under quality of service (QoS)
constraints. The SUs network is controlled by the PU through a relay which gets
a revenue for amplifying and forwarding the SUs signals to their respective
destinations. The relay charges each SU a different price depending on its
received signal-to-interference and-noise ratio (SINR). The relay can control
the SUs network and maximize any desired PU utility function. The PU utility
function represents its rate, which is affected by the SUs access, and its
gained revenue to allow the access of the SUs. The SU network can be formulated
as a game in which each SU wants to maximize its utility function; the problem
is formulated as a Stackelberg game. Finally, the problem of maximizing the
primary utility function is solved through three different approaches, namely,
the optimal, the heuristic and the suboptimal algorithms.Comment: 7 pages. IEEE, WiOpt 201
Spectrum Sharing in RF-Powered Cognitive Radio Networks using Game Theory
We investigate the spectrum sharing problem of a radio frequency (RF)-powered
cognitive radio network, where a multi-antenna secondary user (SU) harvests
energy from RF signals radiated by a primary user (PU) to boost its available
energy before information transmission. In this paper, we consider that both
the PU and SU are rational and self-interested. Based on whether the SU helps
forward the PU's information, we develop two different operation modes for the
considered network, termed as non-cooperative and cooperative modes. In the
non-cooperative mode, the SU harvests energy from the PU and then use its
available energy to transmit its own information without generating any
interference to the primary link. In the cooperative mode, the PU employs the
SU to relay its information by providing monetary incentives and the SU splits
its energy for forwarding the PU's information as well as transmitting its own
information. Optimization problems are respectively formulated for both
operation modes, which constitute a Stackelberg game with the PU as a leader
and the SU as a follower. We analyze the Stackelberg game by deriving solutions
to the optimization problems and the Stackelberg Equilibrium (SE) is
subsequently obtained. Simulation results show that the performance of the
Stackelberg game can approach that of the centralized optimization scheme when
the distance between the SU and its receiver is large enough.Comment: Presented at PIMRC'1
Stackelberg Game for Distributed Time Scheduling in RF-Powered Backscatter Cognitive Radio Networks
In this paper, we study the transmission strategy adaptation problem in an
RF-powered cognitive radio network, in which hybrid secondary users are able to
switch between the harvest-then-transmit mode and the ambient backscatter mode
for their communication with the secondary gateway. In the network, a monetary
incentive is introduced for managing the interference caused by the secondary
transmission with imperfect channel sensing. The sensing-pricing-transmitting
process of the secondary gateway and the transmitters is modeled as a
single-leader-multi-follower Stackelberg game. Furthermore, the follower
sub-game among the secondary transmitters is modeled as a generalized Nash
equilibrium problem with shared constraints. Based on our theoretical
discoveries regarding the properties of equilibria in the follower sub-game and
the Stackelberg game, we propose a distributed, iterative strategy searching
scheme that guarantees the convergence to the Stackelberg equilibrium. The
numerical simulations show that the proposed hybrid transmission scheme always
outperforms the schemes with fixed transmission modes. Furthermore, the
simulations reveal that the adopted hybrid scheme is able to achieve a higher
throughput than the sum of the throughput obtained from the schemes with fixed
transmission modes
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