The interference alignment （IA） algorithm based on FDPM subspace tracking （FDPM-ST IA） is proposed for MIMO cognitive network （CRN） with multiple primary users in this paper. The feasibility conditions of FDPM-S...The interference alignment （IA） algorithm based on FDPM subspace tracking （FDPM-ST IA） is proposed for MIMO cognitive network （CRN） with multiple primary users in this paper. The feasibility conditions of FDPM-ST IA is also got. Futherly, IA scheme of secondary network and IA scheme of primary network are given respectively without assuming a priori knowledge of interference covariance matrices. Moreover, the paper analyses the computational complexity of FDPM-ST IA. Simulation results and theoretical calculations show that the proposed algorithm can achieve higher sum rate with lower computational complexity.展开更多
This paper discusses one of the contemporary challenging issues--it is the challenge of e-commerce to the sovereignty of the state, where governments are unable to implement their own laws on disputed cases resulting ...This paper discusses one of the contemporary challenging issues--it is the challenge of e-commerce to the sovereignty of the state, where governments are unable to implement their own laws on disputed cases resulting from trans-border e-commerce interactions. The objective of the current research is to draw attention to the impact of international characteristics of e-commerce on the sovereignty of state, and to identify the factors affecting this sovereignty. The issue of the dynamieity of time and place will be taken into consideration, where activities carded out over the internet are characterized by their cross-border dimension. Based on real e-commerce case studies disputed on international level, this paper will draw on the legal perspective of cyberspace, identifying the relationship between cyberspace and state sovereignty, and outlining the mechanisms by which cyberspace could cross borders and the territory of the state despite all the precautions taken by the state to protect its sovereignty.展开更多
We give a strategy for nonlocal unambiguous discrimination (UD) among N linearly independent nonorthogonal qudit states lying in a higher-dimensional Hilbert space. The procedure we use is a nonlocal positive operator...We give a strategy for nonlocal unambiguous discrimination (UD) among N linearly independent nonorthogonal qudit states lying in a higher-dimensional Hilbert space. The procedure we use is a nonlocal positive operator valued measurement (POVM) in a direct sum space. This scheme is designed for obtaining the conclusive nonlocal measurement results with a finite probability of success. We construct a quantum network for realizing the nonlocal UD with a set of two-level remote rotations, and thus provide a feasible physical means to realize the nonlocal UD.展开更多
基金the National Nature Science Foundation of China under Grant No.61271259 and 61301123,the Chongqing Nature Science Foundation under Grant No.CTSC2011jjA40006,and the Research Project of Chongqing Education Commission under Grant No.KJ120501 and KJ120502
文摘The interference alignment （IA） algorithm based on FDPM subspace tracking （FDPM-ST IA） is proposed for MIMO cognitive network （CRN） with multiple primary users in this paper. The feasibility conditions of FDPM-ST IA is also got. Futherly, IA scheme of secondary network and IA scheme of primary network are given respectively without assuming a priori knowledge of interference covariance matrices. Moreover, the paper analyses the computational complexity of FDPM-ST IA. Simulation results and theoretical calculations show that the proposed algorithm can achieve higher sum rate with lower computational complexity.
文摘This paper discusses one of the contemporary challenging issues--it is the challenge of e-commerce to the sovereignty of the state, where governments are unable to implement their own laws on disputed cases resulting from trans-border e-commerce interactions. The objective of the current research is to draw attention to the impact of international characteristics of e-commerce on the sovereignty of state, and to identify the factors affecting this sovereignty. The issue of the dynamieity of time and place will be taken into consideration, where activities carded out over the internet are characterized by their cross-border dimension. Based on real e-commerce case studies disputed on international level, this paper will draw on the legal perspective of cyberspace, identifying the relationship between cyberspace and state sovereignty, and outlining the mechanisms by which cyberspace could cross borders and the territory of the state despite all the precautions taken by the state to protect its sovereignty.
基金supported by the Natural Science Foundation of Guangdong Province, China (Grant No. 06029431)
文摘We give a strategy for nonlocal unambiguous discrimination (UD) among N linearly independent nonorthogonal qudit states lying in a higher-dimensional Hilbert space. The procedure we use is a nonlocal positive operator valued measurement (POVM) in a direct sum space. This scheme is designed for obtaining the conclusive nonlocal measurement results with a finite probability of success. We construct a quantum network for realizing the nonlocal UD with a set of two-level remote rotations, and thus provide a feasible physical means to realize the nonlocal UD.
