Research And Implementation Of Key Technologies Of Low Probability Interception Communication System Based On NI PXIe-1092

The advent of 5g era accelerates the growth of information transmission.A large amount of information will be transmitted in wireless channel with electromagnetic wave as the carrier.Both military communication and civil communication put forward higher needs for the security of information transmission process.In the face of various new interception and decoding means,the traditional communication encryption method has been unable to deal with,and the security of communication has been greatly challenged.The traditional anti interception technology mainly adopts spread spectrum communication.Its low power spectral density can hide the transmitted signal in noise,so it is difficult to be detected by non partners.However,its waveform parameters often remain unchanged for a long time and have the characteristics of cyclostationary.Non partners can obtain the key characteristic parameters of the signal by detecting the signal for a long time and obtaining high-order cumulants such as cyclic spectrum and cumulative power spectrum,so as to decode the effective information.At the same time,the traditional spread spectrum communication sacrifices a lot of frequency band utilization,which is difficult to deal with some high-speed transmission scenarios.Based on the spread spectrum communication theory,low interception communication mainly designs the waveform parameters of the transmitted signal,which makes it more difficult for non partners to detect useful signals,so as to enhance the anti interception performance of transmission.In thesis,the low interception signal waveform is constructed based on the non-stationary signal principle,and the multi code channel technology is used to improve the frequency band utilization of the spread spectrum system.A complete physical layer baseband link for point-to-point transmission is built,which meets the requirements of low interception and high reliability communication with a certain transmission rate.At the same time,thesis gives the complete structure design and transceiver transmission scheme of the system.In the specific transceiver link design,the performance of several key technologies such as up sampling rate frequency conversion,anti multipath receiver,phase offset estimation and compensation are analyzed,and the corresponding implementation scheme is given.By comparing the simulation with the traditional multi-channel spread spectrum signal,the low interception signal constructed in thesis has obvious performance improvement in anti detection,chip anti interception and carrier frequency anti interception.Finally,under different frequency offset,time offset and typical multipath channel conditions,the bit error rate performance of the link built in thesis is simulated and the results are analyzed.Finally,thesis builds the system principle prototype through Ni pxie-1092 platform.The system is divided into four parts: transmitter module,receiver module,data transmission module and rate matching module.The test scenario is built and the system is tested.The performance test results basically comply with the theoretical simulation.The RF test realizes the high-speed and reliable communication of the service.