Spectrum Sensing Attack And Countermeasure In Cognitive Radio

The proliferation of wireless applications and services has made the wireless spectrum of limited natural resources increasingly scarce.The low utilization of the existing spectrum has prompted the birth of cognitive radio,and the spectrum sharing mechanism in cognitive radios has made it as the most effective technology for mitigating spectrum shortages.Spectrum sensing is a core technology for realizing cognitive radio technology.In order to ensure that it does not cause interference to authorized users,spectrum sensing must have weak signal detection capabilities,which makes spectrum sensing vulnerable,and resulting in spectrum security risks.Through spectrum sensing,cognitive users can use free band to transmit data.The attacker can implement sensing spoofing in the sensing slot to increase the probability of false alarms for cognitive users.In the data slot,the attacker can perform communication interference to increase the bit error rate of cognitive user data transmission,and then reducing the cognitive radio network throughput.Changes in the behavior of the attacker can also lead to changes in cognitive users’ behavioral strategies.In this paper,we study the following three aspects of cognitive technology spectrum sensing confrontation technology:A new optimization algorithm is proposed for the attackers who have the ability to estimate the spectrum use status in cognitive radio networks.The false alarm probability of the sensing slot and the bit error rate of the data transmission phase are jointly optimized to find the best power distribution factor in the two phases and each band for the attacker.Computer simulations show that the proposed algorithm has good attack performance.First,in view of the uncertainty of spectrum sensing results between the secondary users and the attackers,a joint optimization method is proposed on the basis of the error probability of the sensing slot and the bit error rate of the data transmission slot,and the optimal interference power allocation strategy in the time and frequency domain is given.Computer simulation shows that compared with the existing methods,it has better attack performance.Then,considering that both attackers and secondary users are sensible and have the ability to dynamically update confrontation strategies,we propose to use game theory to simulate this dynamic process.By introducing the power consumption factor,based on the assumption that the attacker knows the secondary user’s sensing result,the Nash equilibrium point of the best action strategy of both parties is obtained.However,the more practical situation is that the attacker does not know the secondary user’s perception result,and the dynamic confrontation between the attacker and the secondary user can be modeled as an incomplete information game problem.Due to the complexity of multi-band incomplete information game computation,this paper presents a new method to transform the multi band power allocation into the conventional optimization problem by analyzing the Nash equilibrium results of the incomplete information game between the two parties.Computer simulations verify the feasibility and effectiveness of the method.