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Mohammadreza Ataei

Instructor : Prof. J.Omidi

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1)Non-Cooperative Games a discipline for modeling situations

2) Auction Design a method to determine the value of a commodity that has

an undetermined or variable price

3) Graph Coloring assigning a color to the vertices of a bidirectional graph

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Nash Equilibrium

Pareto-optimality and Price of Anarchy◦ Pareto Superior

◦ Pareto Optimal: if there exists no other strategy profile that is Pareto-superior

to this strategy profile

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Channel allocation problem

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unlicensed band wireless systems

◦ Severe interference◦ Tragedy of commons

cognitive radios

◦ Primary user identification◦ Potential interference◦ Cognition & decision making

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Non-cooperative Each System : Power Allocation -> Maximize The

Rate

: power spectral density Freq. flat allocation :

-> N.E. (repeated game-> Pareto efficient)

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fixed number of channels Each WiFi operator : channel assignment for its own APs -> maximize the total number of mobile users Graph Coloring Local Bargaining :

◦ 2-buyer-1-seller bargains◦ 1-buyer-multiple-seller bargains

poor performance

-> GLOBAL BARGAINING

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primary users acquire their own radio band each radio band is divided into several channels CGs are free to utilize channels as long as they do

not interfere with the primary users CGs cooperate with each other CGs : channel allocation -> maximum utilization

Secondary users 1 and 3 can emit on channel A graph coloring

◦ With coordination Mobile

◦ ->local bargaining

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primary user lets secondary users access its spectrum subject to a given power constraint◦ ->total interference must be below a threshold

auction-based spectrum sharing CGs : submit bids ->maximize its payoff minus cost non-cooperative game ->

total received power :

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Each CG : access to the available sub-channels -> Reach QoS constraint in terms of throughput

Solving The Game : NP-hard

Reduce to 2 optimization problems ◦ -> always exists a NE for the non-cooperative

For better results : virtual referee -> limit sub-channel access

-> each user must have access to at least one sub-channel

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Shared Spectrum Company SSC. Dynamic Spectrum Sharing. In Presentation to IEEE Communications Society, 2005.

B. Fette. Cognitive Radio Technology. Newnes, 2006.

J. Mitola III. Cognitive Radio Architecture: The Engineering Foundations of Radio XML. Wiley, 2006.

. Nash. Equilibrium Points in N-person Games. Proceedings of the National Academy of Sciences, 36:48–49, 1950.

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Thanks For Your Attention

QUESTIONS?