Variable-rate Frequency Hopping Secure Communication Technology Based On Hyper Digital Chaos

With the continuous development of information technology in military communications,communication countermeasure becomes more and more intense.In order to ensure that communications are not interfered,intercepted and attacked by the enemy,it is necessary to constantly strengthen the security performance of communication systems such as anti-interception and anti-jamming.Frequency hopping communication technology is an effective anti-jamming and secure communication technology in military communication.It can achieve spectrum expansion by carrier frequency hopping to avoid enemy's attack.Facing more and more diverse communication attack jamming strategies and more advanced jamming technology,the security and reliability of frequency hopping communication are facing unprecedented challenges.In order to further enhance the security of frequency hopping communication system,this paper combines digital chaos technology with frequency hopping communication system,proposes a variable-rate frequency hopping secure communication technology scheme based on hyper digital chaos,and proves the superiority of its security performance by theoretical analysis and digital simulation of key indicators such as transmission performance and security performance.The specific technical research includes the following three parts:1.A safe transmission theory model of variable-rate frequency hopping secure communication technology based on hyper digital chaos is established.Multiple chaotic sequences are generated by hyper digital chaos,which are used to control some key parameters of the system,such as carrier frequency value position and frequency hopping rate,and to encrypt and transfer original communication information data.As the key of the secure frequency hopping transmission system,the chaotic initial values are shared by both the sender and the receiver.Only when the legitimate receiver can obtain the chaotic key through frequency hopping synchronization,the correct chaotic sequences can be obtained and the frequency hopping signal can be recovered.Because of the high sensitivity of digital chaos to initial value changes,the proposed frequency hopping communication system based on hyper chaos provides a huge key space of ~1058.Therefore,the enemy cannot obtain the correct key by exhaustive method,and cannot decrypt it.This technology scheme enhances the anti-interception performance of the frequency hopping secure communication system.2.The anti-jamming performance of variable-rate frequency hopping secure communication system based on hyper digital chaos is analyzed comprehensively.Because frequency hopping system will face a variety of jamming threats,in order to enhance the anti-jamming performance of the communication system,we adopt a reconfigurable method to dynamically and rapidly change the frequency hopping rate of the system,to keep the dwell time of carrier frequency in constant dynamic updating with variable speed,which effectively reduces the detection of frequency hopping signal and the acquisition of characteristic information by attackers when communication jamming occurs,and causes the enemy to be unable to track the carrier frequency jump effectively.The change of hopping rate is designed to be controlled by hyper digital chaos.The results of research and analysis in this paper show that variable-rate frequency hopping secure communication technology system based on hyper digital chaos can effectively resist various jamming modes,even for the advanced jamming attack represented by tracking jamming,it also has better anti-jamming performance.3.Frequency division multiplexing(FDM)technology is proposed to effectively enhance the security of variable-rate frequency hopping secure communication system based on hyper digital chaos.In some special cases,the enemy can receive the whole frequency hopping signal directly through the broadband receiver,thus greatly reducing the security performance of communication system by replacement of carrier frequency.In view of this situation,this paper proposes a technical scheme of using frequency division multiplexing technology to enhance the security performance of variable-rate frequency hopping secure communication system.The specific technology is to divide the information data into several(N)segments,disrupt its time sequence by constructing permutation sequence with digital chaos,and then transmit it in a shared channel by using N carrier simultaneous transmission(frequency division multiplexing)technology.After adopting this scheme,even if the enemy can receive the whole frequency hopping signal,it cannot get the correct permutation sequence to stitch into the original data by correctly combining multiple fragments,and the key space provided by the free combination method is N!.Therefore,the application of frequency division multiplexing technology effectively improves the security of the secure communication system.