We determined the linear complexity of a family of p2-periodic binary threshold sequences and a family of p2-periodic binary sequences constructed using the Legendre symbol,both of which are derived from Fermat quotie...We determined the linear complexity of a family of p2-periodic binary threshold sequences and a family of p2-periodic binary sequences constructed using the Legendre symbol,both of which are derived from Fermat quotients modulo an odd prime p.If 2 is a primitive element modulo p2,the linear complexity equals to p2-p or p2-1,which is very close to the period and it is large enough for cryptographic purpose.展开更多
In Cognitive Radio(CR)networks,there is a common assumption that secondary devices always obey commands and are under full control.However,this assumption may become unrealistic for future CR networks with more intell...In Cognitive Radio(CR)networks,there is a common assumption that secondary devices always obey commands and are under full control.However,this assumption may become unrealistic for future CR networks with more intelligent,sophisticated and autonomous devices.Imperfect spectrum sensing and illegal behaviour of secondary users can result in harmful interference to primary users.In this paper,we propose a novel concept of Proactive-Optimization CR(POCR)networks,in which highly intelligent secondary users always try to proactively consider potentially harmful interference when making their behaviour decision.Furthermore,we propose an optimal transmission behaviour decision scheme for secondary users in POCR networks considering the possible harmful interference and penalties from primary users.Specifically,we formulate the system as a Partially-Observable Markov Decision Process(POMDP)problem.With this formulation,a low-complexity dynamic programming framework is presented to obtain the optimal behaviour policy.Extensive simulation results are presented to illustrate the significant performance improvement of the proposed scheme compared with the existing one that ignores the proactive-optimization of secondary users.展开更多
基金the National Natural Science Foundation of China，the Open Funds of State Key Laboratory of Information Security (Chinese Academy of Sciences)，the Program for New Century Excellent Talents in Fujian Province University
文摘We determined the linear complexity of a family of p2-periodic binary threshold sequences and a family of p2-periodic binary sequences constructed using the Legendre symbol,both of which are derived from Fermat quotients modulo an odd prime p.If 2 is a primitive element modulo p2,the linear complexity equals to p2-p or p2-1,which is very close to the period and it is large enough for cryptographic purpose.
基金supported in part by the National Natural Science Foundation of China under Grants No. 61101113,No. 61072088,No.61201198the Beijing Natural Science Foundation under Grants No. 4132007,No. 4132015,No. 4132019the Research Fund for the Doctoral Program of Higher Education of China under Grant No. 20111103120017
文摘In Cognitive Radio(CR)networks,there is a common assumption that secondary devices always obey commands and are under full control.However,this assumption may become unrealistic for future CR networks with more intelligent,sophisticated and autonomous devices.Imperfect spectrum sensing and illegal behaviour of secondary users can result in harmful interference to primary users.In this paper,we propose a novel concept of Proactive-Optimization CR(POCR)networks,in which highly intelligent secondary users always try to proactively consider potentially harmful interference when making their behaviour decision.Furthermore,we propose an optimal transmission behaviour decision scheme for secondary users in POCR networks considering the possible harmful interference and penalties from primary users.Specifically,we formulate the system as a Partially-Observable Markov Decision Process(POMDP)problem.With this formulation,a low-complexity dynamic programming framework is presented to obtain the optimal behaviour policy.Extensive simulation results are presented to illustrate the significant performance improvement of the proposed scheme compared with the existing one that ignores the proactive-optimization of secondary users.
