Research And Implementation Of Key Technologies Of Low-Intercept Multi-Code Channel Wireless Communication

With the rapid development of modern communication technology,more private and sensitive information of individuals or enterprises will be transmitted through wireless networks.In the face of new cracking technologies and new wireless physical layer attacks,traditional information encryption and spread spectrum communication are no longer sufficient.With safe and efficient communication requirements,wireless communication faces serious security problems.Low Probability of Interception(LPI)communication is a technology to improve the security of wireless communication physical layer transmission.According to the characteristics of the wireless channel,the physical layer technology is used to hide the parameter characteristics of the transmitted waveform,so that non-cooperative parties cannot perform Effective signal interception and characteristic analysis,so as to achieve the purpose of safe communication.This paper studies the two key technologies of lowintercept signal waveform design and multi-code channel transmission in low-intercept probability communication,namely,improving the system’s transmission resistance to interception and frequency band utilization.Under the premise of ensuring the safety of wireless communication,improving the system’s performance Transmission rate.The main research contents include:First,explain the relevant technical principles of the low-intercept multi-code channel communication system.Including the basic principles of low interception system model and interception analysis method,spread spectrum technology and multi-code channel technology.It mainly explains the performance indicators of the spread spectrum system,the transmission and reception schemes of common spread spectrum systems and the characteristics of commonly used spread spectrum sequences.Second,the interception analysis method is used to verify that the joint randomization scheme can effectively improve the anti-interception ability of the signal,and combined with the actual application background,a specific transmission scheme for the low-interception multi-code channel communication system is given,including the transmission frame structure and the receiving and sending processing flow.The focus is on the design scheme of joint randomization of signal parameters,inter-code interference cancellation and variable bandwidth filter scheme,and the feasibility of the inter-code interference cancellation and variable bandwidth filter scheme is verified by MATLAB simulation.Third,the FPGA implementation of the system transmission scheme is completed on the hardware platform,and the design ideas and implementation processes of modules such as multi-code channel spread spectrum superposition,inter-code interference cancellation,cross-clock domain processing,and variable rate up-sampling are explained in detail.Finally,in the closed-loop test on the board,it was verified that the logic function of the entire system was implemented correctly,and the actual test error rate was consistent with the simulation result,which met the requirements of low intercept and high rate transmission.