In orthogonal frequency division multiple access(OFDMA) based femtocell networks,the co-tier interference among femto base stations(FBS) becomes important in multiuser and densely deployed environment.In order to miti...In orthogonal frequency division multiple access(OFDMA) based femtocell networks,the co-tier interference among femto base stations(FBS) becomes important in multiuser and densely deployed environment.In order to mitigate the co-tier interference and enhance the system total throughput,this paper proposed a best effort spectrum allocation scheme based on the extension of graph theory.In the scheme,a controller was proposed to collect the channel state information(CSI)of all femtocell user equipments(FUEs) in a certain range.Then,the controller evaluated the signal-to-interference Ratio(SIR) of each FUE and determined the set of its interference neighbors.By calculating the received power matrix(RPM) among FUEs and building interference graph matrix(IGM),different spectrum resource blocks(RBs) were assigned to the users with interference relation,while users without interference relation shared the same RBs,which could increase the spectrum efficiency.Simulation results show that the proposed algorithm can significantly improve the RB usage efficiency compared with the basic graph coloring theory,and more than 80% improvement can be acquired in dense deployment scenario.Besides,the throughput of both cell edge macro user equipments(MUEs) and cell edge FUEs is guaranteed on the premise of low interference.展开更多
In Vietnam, in the current period, public investment plays an important role in the improvement of technical infrastructure systems, economic and social development of motivation to promote national development. Howev...In Vietnam, in the current period, public investment plays an important role in the improvement of technical infrastructure systems, economic and social development of motivation to promote national development. However, the question is how to ensure that these sources of funds are used most effectively in terms of limited resources. In this article, the author would like to emphasize the critical role of the state auditor which is not only in the transparency of information, in enhancing the trust of the citizens, but also in providing important and reliable information to the public sector agencies, units, investors, and people in the society. From that, it could help to serve the management and administration of revenues and expenditures of the state budget as well as reasonably and efficiently using financial resources and assets. In case of perfectly conducting those tasks, they will contribute the power to the economy, fight corruption as loss or waste, and detect and prevent violations of law; improve the efficient use of the budget, the money, and property of the state; and serve effectively for the operation of the National Assembly and People＇s Councils at all levels of the implementation and monitoring function to decide important issues of national and local governments. With the above information, these matters in Vietnam will be solved through this paper that consists of five parts： （1） the basics about the current public investment in Vietnam; （2） the role of state auditing in improving performance management and monitoring of investment; （3） the limitations of state auditing in public investment; （4） many solutions to promote the role of state auditing in improving the effective investment activities; and （5） conclusion.展开更多
基金supported by the National Key Technology R&D Program of China(2012ZX03001031-004)the Fundamental Research Funds for the Central Universities (BUPT 2013RC0111)
文摘In orthogonal frequency division multiple access(OFDMA) based femtocell networks,the co-tier interference among femto base stations(FBS) becomes important in multiuser and densely deployed environment.In order to mitigate the co-tier interference and enhance the system total throughput,this paper proposed a best effort spectrum allocation scheme based on the extension of graph theory.In the scheme,a controller was proposed to collect the channel state information(CSI)of all femtocell user equipments(FUEs) in a certain range.Then,the controller evaluated the signal-to-interference Ratio(SIR) of each FUE and determined the set of its interference neighbors.By calculating the received power matrix(RPM) among FUEs and building interference graph matrix(IGM),different spectrum resource blocks(RBs) were assigned to the users with interference relation,while users without interference relation shared the same RBs,which could increase the spectrum efficiency.Simulation results show that the proposed algorithm can significantly improve the RB usage efficiency compared with the basic graph coloring theory,and more than 80% improvement can be acquired in dense deployment scenario.Besides,the throughput of both cell edge macro user equipments(MUEs) and cell edge FUEs is guaranteed on the premise of low interference.
文摘In Vietnam, in the current period, public investment plays an important role in the improvement of technical infrastructure systems, economic and social development of motivation to promote national development. However, the question is how to ensure that these sources of funds are used most effectively in terms of limited resources. In this article, the author would like to emphasize the critical role of the state auditor which is not only in the transparency of information, in enhancing the trust of the citizens, but also in providing important and reliable information to the public sector agencies, units, investors, and people in the society. From that, it could help to serve the management and administration of revenues and expenditures of the state budget as well as reasonably and efficiently using financial resources and assets. In case of perfectly conducting those tasks, they will contribute the power to the economy, fight corruption as loss or waste, and detect and prevent violations of law; improve the efficient use of the budget, the money, and property of the state; and serve effectively for the operation of the National Assembly and People＇s Councils at all levels of the implementation and monitoring function to decide important issues of national and local governments. With the above information, these matters in Vietnam will be solved through this paper that consists of five parts： （1） the basics about the current public investment in Vietnam; （2） the role of state auditing in improving performance management and monitoring of investment; （3） the limitations of state auditing in public investment; （4） many solutions to promote the role of state auditing in improving the effective investment activities; and （5） conclusion.
