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Publications (5)0.54 Total impact

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    ABSTRACT: In this paper we investigate a cooperative jamming (CJ) strategy based Stackelberg security game to improve physical layer security over multiuser OFDMA networks. Each source node tries to deliver messages to its intended destination node securely in the presence of a passive eavesdropper. Fortunately, these node pairs can resort to a friendly jammer to enhance their communication. But the jamming service is not free and the friendly jammer charges each pair for some cost. Obviously there is a tradeoff between the friendly jammer and the source-destination pairs. Consequently, a two-level Stackelberg game model is proposed, where the friendly jammer plays the seller and the source-destination pairs are the buyers. We analyze the Stackelberg Equilibrium from two sides respectively and prove the existence and uniqueness of the Stackelberg Equilibrium. Correspondingly, we also develop a distributed iterative power allocation algorithm to reach the Stackelberg Equilibrium point. Numerical Results demonstrate that the system sum secrecy rate is really improved and the physical layer security performance is effectively meliorated.
    Wireless Communications and Networking Conference (WCNC), 2013 IEEE; 01/2013
  • An Wang, Yueming Cai, Zhao Hou
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    ABSTRACT: In a full frequency reused OFDMA system, inter-cell interference severely restricts the system's performance. Resource allocation, as an effective interference mitigation technique, is a key technique in the OFDMA system. In this paper, we investigate a novel resource allocation algorithm based on game theory. Firstly, available subcarriers are allocated according to the normalized channel gain. When it comes to power allocation, a novel non-cooperative game model based on arc tangent function is established. To ensure fairness, we introduce a pricing function to the utility function. Simulation results show that our proposed algorithm can acquire higher rate than previous algorithms at a reasonable power cost. Moreover, our proposed algorithm can converge within 5 iterations with low complexity.
    01/2011;
  • Zhao Hou, Dan Wu, Yueming Cai
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    ABSTRACT: In this paper, we develop a distributed power control scheme for relay channels with confidential message in an uplink OFDMA-relay cellular by Amplify-and-Forward mode. We introduce a two-stage game in a progressive optimization. In this scenario, the relay is considered not only as a sender that assists the information transmission, but also as an eavesdropper who can wiretap information. In the two steps, we design two different form of utility function for ensuring the reliability in the relay channel and enhancing the security capacity of each user. In addition, the existence of Nash Equilibrium in the two steps of the game model is confirmed. Simulation results demonstrate that the proposed scheme can effectively ensure the security capacity requirement for each user as well as achieve the fairness of power allocation in users, in addition of energy conservation.
    01/2011;
  • Zhao Hou, Dan Wu, Yueming Cai
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    ABSTRACT: Subcarrier and power allocation plays an important part in optimizing the performance of OFDMA systems. However, inter-cellular interference is often neglected in resource allocation. In this paper, with the inter-cell interference taken into account, we propose a subcarrier and power allocation framework based on Game Theory in uplink OFDMA multi-cellular systems. In this algorithm, the subcarrier allocation is based on the normalized channel gain, and the power allocation is achieved by the pricing function. The existence of Nash Equilibrium is proved, and the effect of the algorithm in this paper is discussed about its iterative property and cost factors. Simulation results demonstrate that the inter-cell interference can virtually affect the system performance, and the proposed algorithm could achieve better fairness in users.
    Communication Technology (ICCT), 2010 12th IEEE International Conference on; 12/2010
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    Zhao Hou, Yueming Cai, Dan Wu
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    ABSTRACT: In this article, we propose a semi-distributed resource allocation framework for the resource optimization in multi-cell uplink cooperative orthogonal frequency division multiplexing systems. Specifically, we model the resource allocation framework as an optimal problem. This optimization problem is divided into two steps. First, using integer programming, we achieve the joint relay selection and subcarrier allocation based on maximizing system sum rate in a centralized way. Second, the distributed power allocation is achieved based on game theory, for cooperative and non-cooperative users, respectively. For cooperative mobile stations, an improved utility is proposed to regulate power allocation in the two time slots. Besides the existence of Nash equilibrium (NE), a new approach for the strict mathematical proof of the uniqueness of NE is proposed. Simulation results demonstrate that the proposed algorithm successfully combines the merits of centralized and distributed framework. It can effectively make use of relays to enhance the sum rate of users as well as achieve the fairness among users.
    EURASIP Journal on Wireless Communications and Networking 2011(1). · 0.54 Impact Factor