8,807 research outputs found
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
Joint Access Point Selection and Power Allocation for Uplink Wireless Networks
We consider the distributed uplink resource allocation problem in a
multi-carrier wireless network with multiple access points (APs). Each mobile
user can optimize its own transmission rate by selecting a suitable AP and by
controlling its transmit power. Our objective is to devise suitable algorithms
by which mobile users can jointly perform these tasks in a distributed manner.
Our approach relies on a game theoretic formulation of the joint power control
and AP selection problem. In the proposed game, each user is a player with an
associated strategy containing a discrete variable (the AP selection decision)
and a continuous vector (the power allocation among multiple channels). We
provide characterizations of the Nash Equilibrium of the proposed game, and
present a set of novel algorithms that allow the users to efficiently optimize
their rates. Finally, we study the properties of the proposed algorithms as
well as their performance via extensive simulations.Comment: Revised and Resubmitted to IEEE Transactions on Signal Processin
A Comprehensive Survey of Potential Game Approaches to Wireless Networks
Potential games form a class of non-cooperative games where unilateral
improvement dynamics are guaranteed to converge in many practical cases. The
potential game approach has been applied to a wide range of wireless network
problems, particularly to a variety of channel assignment problems. In this
paper, the properties of potential games are introduced, and games in wireless
networks that have been proven to be potential games are comprehensively
discussed.Comment: 44 pages, 6 figures, to appear in IEICE Transactions on
Communications, vol. E98-B, no. 9, Sept. 201
Distributed Uplink Resource Allocation in Cognitive Radio Networks -- Part I: Equilibria and Algorithms for Power Allocation
Spectrum management has been identified as a crucial step towards enabling
the technology of a cognitive radio network (CRN). Most of the current works
dealing with spectrum management in the CRN focus on a single task of the
problem, e.g., spectrum sensing, spectrum decision, spectrum sharing or
spectrum mobility. In this two-part paper, we argue that for certain network
configurations, jointly performing several tasks of the spectrum management
improves the spectrum efficiency. Specifically, our aim is to study the uplink
resource management problem in a CRN where there exist multiple cognitive users
(CUs) and access points (APs). The CUs, in order to maximize their uplink
transmission rates, have to associate to a suitable AP (spectrum decision), and
to share the channels used by this AP with other CUs (spectrum sharing). These
tasks are clearly interdependent, and the problem of how they should be carried
out efficiently and in a distributed manner is still open in the literature.Comment: Submitted to IEEE Transactions on Signal Processin
Carrier Sense Multiple Access Tuning Parameters using Game Theory
Ad Hoc and Mesh networks are good samples of multi agent systems, where their
nodes access the channel through carrier sense multiple access method, while a
node channel access influence the access of neighbor nodes to the channel.
Hence, game theory is a strong tool for studying this kind of networks. Carrier
sense multiple access parameters such as minimum and maximum size of contention
window and persistence factor can be modified based on game theoretic methods.
In this study different games for tuning the parameters is investigated and
different challenges are examined.Comment: 9 page
Distributed Uplink Resource Allocation in Cognitive Radio Networks -- Part II: Equilibria and Algorithms for Joint Access Point Selection and Power Allocation
In the first part of this paper, we have studied solely the spectrum sharing
aspect of the above problem, and proposed algorithms for the CUs in the single
AP network to efficiently share the spectrum. In this second part of the paper,
we build upon our previous understanding of the single AP network, and
formulate the joint spectrum decision and spectrum sharing problem in a
multiple AP network into a non-cooperative game, in which the feasible strategy
of a player contains a discrete variable (the AP/spectrum decision) and a
continuous vector (the power allocation among multiple channels). The structure
of the game is hence very different from most non-cooperative spectrum
management game proposed in the literature. We provide characterization of the
Nash Equilibrium (NE) of this game, and present a set of novel algorithms that
allow the CUs to distributively and efficiently select the suitable AP and
share the channels with other CUs. Finally, we study the properties of the
proposed algorithms as well as their performance via extensive simulations.Comment: Submitted to IEEE Transactions on Signal Processin
Distributed Learning for Channel Allocation Over a Shared Spectrum
Channel allocation is the task of assigning channels to users such that some
objective (e.g., sum-rate) is maximized. In centralized networks such as
cellular networks, this task is carried by the base station which gathers the
channel state information (CSI) from the users and computes the optimal
solution. In distributed networks such as ad-hoc and device-to-device (D2D)
networks, no base station exists and conveying global CSI between users is
costly or simply impractical. When the CSI is time varying and unknown to the
users, the users face the challenge of both learning the channel statistics
online and converge to a good channel allocation. This introduces a multi-armed
bandit (MAB) scenario with multiple decision makers. If two users or more
choose the same channel, a collision occurs and they all receive zero reward.
We propose a distributed channel allocation algorithm that each user runs and
converges to the optimal allocation while achieving an order optimal regret of
O\left(\log T\right). The algorithm is based on a carrier sensing multiple
access (CSMA) implementation of the distributed auction algorithm. It does not
require any exchange of information between users. Users need only to observe a
single channel at a time and sense if there is a transmission on that channel,
without decoding the transmissions or identifying the transmitting users. We
demonstrate the performance of our algorithm using simulated LTE and 5G
channels
Intelligent Wireless Communications Enabled by Cognitive Radio and Machine Learning
The ability to intelligently utilize resources to meet the need of growing
diversity in services and user behavior marks the future of wireless
communication systems. Intelligent wireless communications aims at enabling the
system to perceive and assess the available resources, to autonomously learn to
adapt to the perceived wireless environment, and to reconfigure its operating
mode to maximize the utility of the available resources. The perception
capability and reconfigurability are the essential features of cognitive radio
while modern machine learning techniques project great potential in system
adaptation. In this paper, we discuss the development of the cognitive radio
technology and machine learning techniques and emphasize their roles in
improving spectrum and energy utility of wireless communication systems. We
describe the state-of-the-art of relevant techniques, covering spectrum sensing
and access approaches and powerful machine learning algorithms that enable
spectrum- and energy-efficient communications in dynamic wireless environments.
We also present practical applications of these techniques and identify further
research challenges in cognitive radio and machine learning as applied to the
existing and future wireless communication systems
General Auction-Theoretic Strategies for Distributed Partner Selection in Cooperative Wireless Networks
It is unrealistic to assume that all nodes in an ad hoc wireless network
would be willing to participate in cooperative communication, especially if
their desired Quality-of- Service (QoS) is achievable via direct transmission.
An incentivebased auction mechanism is presented to induce cooperative behavior
in wireless networks with emphasis on users with asymmetrical channel fading
conditions. A single-object secondprice auction is studied for cooperative
partner selection in singlecarrier networks. In addition, a multiple-object
bundled auction is analyzed for the selection of multiple simultaneous partners
in a cooperative orthogonal frequency-division multiplexing (OFDM) setting. For
both cases, we characterize equilibrium outage probability performance, seller
revenue, and feedback bounds. The auction-based partner selection allows
winning bidders to achieve their desired QoS while compensating the seller who
assists them. At the local level sellers aim for revenue maximization, while
connections are drawn to min-max fairness at the network level. The proposed
strategies for partner selection in self-configuring cooperative wireless
networks are shown to be robust under conditions of uncertainty in the number
of users requesting cooperation, as well as minimal topology and channel link
information available to individual users.Comment: 13 pages, to appear, IEEE Transactions on Communication
Resource Allocation for Device-to-Device Communications in Multi-Cell Multi-Band Heterogeneous Cellular Networks
Heterogeneous cellular networks (HCNs) with millimeter wave (mm-wave)
communications are considered as a promising technology for the fifth
generation mobile networks. Mm-wave has the potential to provide multiple
gigabit data rate due to the broad spectrum. Unfortunately, additional free
space path loss is also caused by the high carrier frequency. On the other
hand, mm-wave signals are sensitive to obstacles and more vulnerable to
blocking effects. To address this issue, highly directional narrow beams are
utilized in mm-wave networks. Additionally, device-to-device (D2D) users make
full use of their proximity and share uplink spectrum resources in HCNs to
increase the spectrum efficiency and network capacity. Towards the caused
complex interferences, the combination of D2D-enabled HCNs with small cells
densely deployed and mm-wave communications poses a big challenge to the
resource allocation problems. In this paper, we formulate the optimization
problem of D2D communication spectrum resource allocation among multiple
micro-wave bands and multiple mm-wave bands in HCNs. Then, considering the
totally different propagation conditions on the two bands, a heuristic
algorithm is proposed to maximize the system transmission rate and approximate
the solutions with sufficient accuracies. Compared with other practical
schemes, we carry out extensive simulations with different system parameters,
and demonstrate the superior performance of the proposed scheme. In addition,
the optimality and complexity are simulated to further verify effectiveness and
efficiency.Comment: 13 pages, 11 figures, IEEE Transactions on Vehicular Technolog
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