In this paper,the transmission performances are studied in cognitive radio networks with primary user emulator and relay existence.In the proposed network,the users include primary users,secondary users and primary us...In this paper,the transmission performances are studied in cognitive radio networks with primary user emulator and relay existence.In the proposed network,the users include primary users,secondary users and primary user emulators.The decreasing access priority of the users are primary users,primary user emulators and secondary users.Different user access to the network results in different transmission effects.We impose interference power constraints on the secondary users to protect the primary users from being interfered.We also adopt the transmission mechanism that transits among more than one secondary transmitters,secondary receivers and relays.The transition models of the transmission states are proposed to describe the transmission mechanism.To investigate the transmission performances,the theory of effective capacity is adopted.The transmission performances in terms of effective capacity are expressed and demonstrated under different transmission policies.The overall effective capacity,as the overall data traffic in the cognitive radio network,is calculated.Besides,the overall effective capacity is demonstrated under different transmission strategies.The results show the greedy transmission strategy outperforms the rest of the transmission 8 policies in the overall effective capacity.For a larger number of the users,the effective capacity converges to a certain value.展开更多
根据模仿主用户攻击(primary user emulation,PUE)信号较难同时模仿主用户(primary user,PU)信号的时、空域平稳特征,提出基于循环时空滤波的PU检测方法。该方法首先利用PU信号的循环时空平稳特征设计滤波器,并对滤波输出信号进行本地判...根据模仿主用户攻击(primary user emulation,PUE)信号较难同时模仿主用户(primary user,PU)信号的时、空域平稳特征,提出基于循环时空滤波的PU检测方法。该方法首先利用PU信号的循环时空平稳特征设计滤波器,并对滤波输出信号进行本地判决,再将本地检测二进制结果发送至融合中心(fusion center,FC)进行全局检测,其中FC根据各认知用户(secondary user,SU)检测循环频率的不同将收到的本地检测结果分组,并采用组内-组间二次融合方式获取全局检测结果,这种协作分集检测的方式可以有效降低误检率和计算复杂度。仿真结果表明,该方法可实现在低信干噪比环境下对PU信号的检测。展开更多
Cognitive radio is an effective technology to alleviate the spectrum resource scarcity problem by opportunistically allocating the spare spectrum to unauthorized users. However, a serious denial-of-service(DoS) attack...Cognitive radio is an effective technology to alleviate the spectrum resource scarcity problem by opportunistically allocating the spare spectrum to unauthorized users. However, a serious denial-of-service(DoS) attack,named the ‘primary user emulation attack(PUEA)', exists in the network to deteriorate the system performance. In this paper, we propose a PUEA detection method that exploits the radio channel information to detect the PUEA in the cognitive radio network. In the proposed method, the uniqueness of the channel impulse response(CIR) between the secondary user(SU) and the signal source is used to determine whether the received signal is transmitted by the primary user(PU) or the primary user emulator(PUE). The closed-form expressions for the false-alarm probability and the detection probability of the proposed PUEA detection method are derived. In addition, a modified subspace-based blind channel estimation method is presented to estimate the CIR, in order for the proposed PUEA detection method to work in the scenario where the SU has no prior knowledge about the structure and content of the PU signal. Numerical results show that the proposed PUEA detection method performs well although the difference in channel characteristics between the PU and PUE is small.展开更多
基金supported by National Natural Science Foundation of China(No.61379016)
文摘In this paper,the transmission performances are studied in cognitive radio networks with primary user emulator and relay existence.In the proposed network,the users include primary users,secondary users and primary user emulators.The decreasing access priority of the users are primary users,primary user emulators and secondary users.Different user access to the network results in different transmission effects.We impose interference power constraints on the secondary users to protect the primary users from being interfered.We also adopt the transmission mechanism that transits among more than one secondary transmitters,secondary receivers and relays.The transition models of the transmission states are proposed to describe the transmission mechanism.To investigate the transmission performances,the theory of effective capacity is adopted.The transmission performances in terms of effective capacity are expressed and demonstrated under different transmission policies.The overall effective capacity,as the overall data traffic in the cognitive radio network,is calculated.Besides,the overall effective capacity is demonstrated under different transmission strategies.The results show the greedy transmission strategy outperforms the rest of the transmission 8 policies in the overall effective capacity.For a larger number of the users,the effective capacity converges to a certain value.
基金supported by the National Natural Science Foundation of China(Nos.61471318 and 61671410)the Zhejiang Provincial Natural Science Foundation of China(No.LY14F010014)the State Key Laboratory of Complex Electromagnetic Environment Effects on Electronics and Information System,China(No.CEMEE2015Z0202A)
文摘Cognitive radio is an effective technology to alleviate the spectrum resource scarcity problem by opportunistically allocating the spare spectrum to unauthorized users. However, a serious denial-of-service(DoS) attack,named the ‘primary user emulation attack(PUEA)', exists in the network to deteriorate the system performance. In this paper, we propose a PUEA detection method that exploits the radio channel information to detect the PUEA in the cognitive radio network. In the proposed method, the uniqueness of the channel impulse response(CIR) between the secondary user(SU) and the signal source is used to determine whether the received signal is transmitted by the primary user(PU) or the primary user emulator(PUE). The closed-form expressions for the false-alarm probability and the detection probability of the proposed PUEA detection method are derived. In addition, a modified subspace-based blind channel estimation method is presented to estimate the CIR, in order for the proposed PUEA detection method to work in the scenario where the SU has no prior knowledge about the structure and content of the PU signal. Numerical results show that the proposed PUEA detection method performs well although the difference in channel characteristics between the PU and PUE is small.
