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Publications (3)0 Total impact

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    ABSTRACT: As the enormous development of IT technology, the convergence technology enlarges its research areas. Recently, OFDMA which was widely used in satellite and wireline communications is applied to broadband wireless communication systems. In order to employ the OFDMA to next generation mobile systems, throughput maximization and power efficient control mechanism is needed. This paper proposes the multi- level scheme for the power efficient feedback of channel state information without degrading system performance. Also, we propose a sub-optimal resource allocation scheme based on a greedy algorithm which guarantees fairness with reduced complexity. Proposed scheme is evaluated by system level simulation which uses a spatial channel model and the results show that the proposed scheme follows proportional fair throughput and reduces signaling overheads for feedback. 1
    Convergence Information Technology, International Conference on. 11/2007;
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    ABSTRACT: This paper analyzes the interference aspects of tri-sectored OFDMA systems and evaluates the performance of some subchannel allocation schemes to mitigate inter-sector interference. To maximize spectral efficiency, it is preferred to adopt frequency reuse of 1. But, carrier to interference and noise ratio (CINR) values at the boundary of sectors are extremely deteriorated. Two subchannel allocation methods are compared and evaluated in this environment. One is to maximize disparity, which is to maximize the number of subchannels in good CINR values, and the other is to minimize disparity, which is to maximize the number of subchannels in moderate CINR values. These schemes are compared under proportionally fair scheduling algorithm. Simulation results regarding to throughput show that the schemes outperform random allocation schemes in 802.16 based systems.
    Vehicular Technology Conference, 2007. VTC-2007 Fall. 2007 IEEE 66th; 11/2007
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    ABSTRACT: The traffic state control scheme is a radio resource management (RRM) technique which optimizes the use of radio resources and reduces the mobile's power consumption. In this paper, we propose an efficient traffic state control scheme which is based on the three-state model. It exploits utilization of limited radio resources by dynamically switching mobile states. We evaluate the performance of traffic state control schemes on a packet based wireless OFDMA system. The simulation result shows that proposed scheme provides efficient resource allocation in overloaded system.
    Advanced Communication Technology, 2006. ICACT 2006. The 8th International Conference; 03/2006