Bionic camouflage concealed communication strategy
Science and Technology Daily Tianjin, October 30 (reporter Sun Yusong correspondent Zhao Xijun) mobile communications, real-time intercom, satellite phones... The new generation of mobile communication technology is becoming more and more well known, but we may know very little about how submarines, manned submersibles, etc. in the ocean communicate. In land, sea and air communication, for underwater communication with the ocean as a typical representative, it is a communication field that human beings are still trying to explore, and its difficulty even exceeds that of "nine days and the moon".
Recently, Associate Professor Jiang Jiajia of the State Key Laboratory of Precision Testing Technology and Instruments of Tianjin University proposed a new bionic camouflage concealed hydroacoustic communication method that imitates the barking pattern of sperm whales. This method borrows the "language" of whales to achieve deep-sea covert communication, which has the characteristics of strong camouflage and deception, highly concealed information transmission, and long communication distance, and has broad application prospects in the field of national defense and military. The paper "Bionic Invisibility for Underwater Acoustic Secure Communication" was published in IEEE Communications Magazine, a top journal in the field of international communications. Associate Professor Jiang Jiajia is the first author of the paper, and the corresponding author of the article is Professor Duan Fajie of the School of Fine Instrumentation of Tianjin University.
Submarines, underwater robots, underwater gliders and other underwater military platforms must emit communication waves outward when carrying out underwater information transmission, networking and other military activities, but it is also easy to cause their own exposure and endanger the security of the platform. Underwater covert communications have become the focus of attention of military experts in various countries.
The traditional method of solving underwater covert communication can be mainly classified into two categories, the first type of method is to change the parameters of artificial communication signals, such as frequency hopping, time hopping, etc., to increase the difficulty of the enemy interception of communication signals, so that the probability of interception is reduced, that is, the strategy of low interception probability. However, such methods use artificial communication signals with obvious characteristics, which are easily identified and classified by enemy reconnaissance systems, resulting in limited concealment. The second method is to increase the difficulty of the enemy to detect the communication signal by reducing the transmitted power of the communication signal, that is, the probability of detection is low, but the reduction of power will greatly limit the distance of communication and cannot meet the needs of underwater long-distance covert communication.
In order to solve this problem, the scientific research team proposed for the first time to use the original call of the sperm whale as a communication information carrier, and at the same time to simulate the original call string of the sperm whale to construct a bionic communication signal string, and to achieve the hidden transmission of underwater communication information with the bionic camouflage strategy.
Mimicking the call of a sperm whale and using it for underwater communication, why can it evade enemy reconnaissance detection? Originally, the current mainstream underwater communication and reconnaissance system classified the calls issued by whales and dolphins in the ocean as marine noise and filtered out, and Tianda researchers conducted in-depth research on the calls of sperm whales in the ocean, synthesized a number of core technologies, and proposed a fast and accurate sperm whale call pulse extraction method. Based on the constraints of autocorrelation, cross-correlation and correlation thresholds, a large number of call pulses that meet the requirements of delay difference communication coding are screened from the extracted call pulse library, and a jump group differential delay difference communication codec method is developed according to the law of sperm whale call string.
Bionic camouflage communication frame structure and coding principle
(a)-(d) Bionic camouflage communication frames and their processing processes, (e) bionic camouflage communication frame time-frequency plots, (f) real whale call string time
Since the communication code uses the original whale call pulse, at the same time, the time interval law between the communication codes in the communication string is highly matched with the time interval law between the call pulses in the real call string of the sperm whale, so the bionic communication string that is constructed has a very strong camouflage and deception performance, so as to achieve a high degree of concealed transmission of information.
At the same time, because it is concealed by camouflage rather than by reducing the transmission power of the communication wave, the communication wave is not afraid of being detected and intercepted by the enemy, and the problem of long-distance covert communication can be solved by increasing the transmission power of the communication wave.
The effectiveness and camouflage concealment of this technological achievement have been well verified by the lake test and the neural network signal classifier test respectively.
It is understood that the technology has strong scalability, can be extended to dolphins and other marine mammals, and can be widely used in underwater submarine communications, submarine-based communications, submarine-based communications, UUV-UUV communications, maritime remote control telemetry, underwater measurement, underwater LAN interconnection, offshore platform and underwater equipment remote control, underwater communication - detection - positioning - navigation integrated design and other national defense and military fields, with a wide range of application prospects.
On October 17, the research results were published in the top issue of the international communication field "IEEE Communications Magazine", and the JCR impact factor of the Chinese Academy of Sciences was 10.435, ranking second in the world in the field of communications.
The research was supported by the National Natural Science Youth Fund of China, the "Young Talents Lifting Project" project of the China Association for Science and Technology, and the Tianjin Natural Science Youth Fund.