Research And Implementation Of Key Technologies For Transceiving And Receiving Of Non-stationary Wireless Communication Waveform In Complex Electromagnetic Environment

Since the emergence of modern communication technology,wireless communication has gradually penetrated into every aspect of the human world.However,due to the openness of the wireless channel and the complexity of the propagation environment,the wireless communication signals transmitted in it are not only easily interfered by the channel environment,but also easily intercepted and intercepted by a third party.Therefore,it is necessary to ensure the transmission quality and transmission security of wireless communication.Particularly important.Spread spectrum communication is widely used because of its anti-interference and anti-interception capabilities,but with the development of various interception and attack technologies,traditional spread-spectrum communication technology can no longer meet the transmission requirements of low interception and anti-interference.Non-stationary waveform design is based on the waveform design of the transmission signal to construct a transmission signal waveform with non-stationary statistical characteristics,thereby further reducing the probability of the signal being intercepted and improving the anti-interception performance of the signal.This thesis researches the key technologies of transmitting and receiving non-stationary wireless communication waveforms in a complex electromagnetic environment.The main contents include:First,the relevant technical principles and complex electromagnetic environment model of non-stationary waveform wireless communication system are introduced.Firstly,the traditional spread spectrum communication technology is introduced in detail,and the common spread spectrum sequence and common spread spectrum communication technology are analyzed;on this basis,the principle and construction method of the nonstationary wireless communication waveform are given,and A brief comparison is made between non-stationary waveforms and traditional spread-spectrum communication waveforms;finally,complex electromagnetic environment models including channel models and interference models are introduced and analyzed.Second,the specific design scheme and transceiver scheme of the non-stationary waveform are given.Firstly,for the low interception performance requirements,the transmission waveform design is analyzed,and a non-stationary waveform design scheme is given.Then,according to the project application scenario and system performance requirements,the communication link parameter design scheme and waveform transmission scheme are given.After that,the key technologies of modem and demodulation related to non-stationary waveform,residual frequency offset estimation and compensation,and interference detection and suppression are studied and analyzed,and use simulation to analyze these schemes and technologies,verify the feasibility of the scheme,and analyze the specific performance of these technical schemes.Thirdly,the hardware implementation and testing of the non-stationary waveform transceiver link are carried out.Firstly,the FPGA implementation of the transmitter and receiver was carried out,and the preliminary logical function verification of the link was carried out using Modelsim;on this basis,the transceiver prototype of the system was built with the help of the NI platform,and the test and application environment were built,and the system was actually tested.Bit error test and Anti interception test,the results verify that the performance of the non-stationary waveform wireless communication system meets the design expectations.