Research And Demonstration On Key Technologies Of Anti-interference And Anti-interception In Wideband Communication

Existing anti-jamming and anti-interception technologies mainly start from the direction of signal avoidance and suppression,such as frequency hopping spread spectrum,direct sequence spread spectrum,signal masking and their optimization technology.There is a trade-off between spectrum overhead and performance improvement when anti-jamming and anti-interception technologies are applied directly to wideband communication system at the cost of increasing frequency band loss.The paper focuses on the optimization of anti-interference and anti-interception technology in the physical layer of wideband communication system,and introduces frequency hopping and strong signal masking to enhance network reliability and concealment ability.The main research work of the paper is as follows:1.For single-tone and multi-tone jamming,baseband frequency hopping can average interference effects on data subcarriers of Orthogonal Frequency Division Multiplexing systems and provide diversity gain.The paper summarizes the model and anti-interference principle of all-subcarrier baseband frequency hopping system and analyses that it will diffuse interference influence and reduce anti-interference performance for partial band noise jamming.Baseband frequency hopping based on spectrum sensing is proposed in combination with subcarrier deduction.The simulation and test results prove baseband frequency hopping based on spectrum sensing has better anti-jamming ability than all-subcarrier baseband frequency hopping in the same jamming environment.2.The paper presents radio frequency hopping based on spectrum sensing to counter wideband noise jamming and tracking jamming.Both received signal strength indicator and error vector magnitude are quality parameters of frequency points in the spectrum sensing module.The system model design is mainly divided into four steps,including frequency quality detection,perception information interaction,frequency hopping pattern decision and data service transmission.The frequency point usage times in hopping pattern can be changed in real time according to their quality.The test results confirm the effectiveness and practicability of radio frequency hopping based on spectrum sensing.3.Strong signal masking technology is combined with Orthogonal Frequency Division Multiplexing system in the paper.Three kinds of masking system which take random data,preamble sequence and mirror preamble sequence as known signals are proposed and data power parameter design is given.The simulation results show that the bit error rate performance of preamble sequence mirror masking system is better than the other two masking systems when intercepted data similarity is similar.The paper introduces serial interference cancellation and analyzes the demodulation influence of asynchronous signal in receiver.The test results show that power attenuation range of data reception in physical layer,and demonstrate data concealment function of the technology.