Research And Design Of Anti-jamming Technology Based On Multi-pulse Joint Transmission

The wireless self-organizing network is a special wireless communication network system,which is widely used because of its topology-free flexibility brought by centerless,self-organizing and multi-hop transmission,especially in the harsh and complicated electromagnetic environment.The basis of the wireless self-organizing network is reliable communication transmission at the physical layer,but the complex and harsh electromagnetic environment will cause serious electromagnetic interference,increased data packet collision,and large attenuation of electromagnetic waves.Anti-jamming technology to effectively improve data transmission quality.The use of channel coding,soft spreading,GMSK modulation,interleaving and other technologies to design the physical layer low bit rate transmission waveform can bring anti-interference performance and enable the signal to be reliably transmitted in a low signal-to-noise ratio environment.In response to sudden interference and signal aliasing,the use of multi-pulse joint transmission introduces combined reception and shear splicing technology at the receiving end to enable the signal to be successfully decoded.In view of the possibility of channel collision and other problems in multi-user transmission,the hybrid technology of time-hopping and frequency-hopping is introduced to reduce the probability of collision,thereby effectively separating the data of each user and improving the communication quality between the nodes of the self-organizing network system.Therefore,it is of great practical significance to study the anti-interference transmission technology related to the physical layer of the self-organizing network.First of all,from the perspective of the system,this thesis refers to the relevant literature to complete the physical layer waveform processing scheme design of the self-organizing network system,using key technologies including RS coding,CCSK spreading,symbol interleaving,GMSK modulation,etc.,using MATLAB software as the platform The simulation of the physical layer transmission waveform was carried out,and the performance of the single pulse transmission signal through different channels and interference conditions was simulated and analyzed.The simulation shows that under the Gaussian channel,the single-pulse signal's bit error performance is excellent,and each anti-jamming technology can effectively improve the system's anti-jamming performance,but under the situation of Rayleigh multipath channel transmission,the bit error performance drops significantly.And completed the functional simulation of the project on the basis of MATLAB simulation.Then,in the case of single-pulse transmission,the performance of the signal is degraded in the multipath channel,and the actual transmission may be affected by burst interference.A multi-pulse joint transmission scheme is proposed.Diversity combining and shear splicing techniques are added at the receiving end,In order to obtain the receiving gain,effectively combat interference.Simulation results show that the use of diversity combining technology can bring 4~8d B of receiving gain,and the shear stitching technology can successfully decode under the condition that the aliasing ratio is not large,and then compare the performance of the two schemes.The comparison results show that the diversity Compared with shear splicing,the merging technology has better performance.Finally,from the practical application point of view,the multi-user multi-pulse signal transmission situation is analyzed for the channel collision problem that cannot be avoided during the application of the self-organizing network.In order to reduce the probability of the data sent by users colliding with each other in the channel,reduce the mutual interference between users as much as possible,and make the proportion of aliasing interference within the controllable range of multi-pulse joint reception,introducing a Time-Hopping and Frequency-Hopping hybrid technology to separate user data.The corresponding Time-Hopping and Frequency-Hopping patterns are designed so that the information reaching the receiving end can be decoded normally using the above-mentioned joint transmission and reception scheme.The simulation shows that the use of Frequency-Hopping and Time-Hopping hybrid technology can bring the improvement of error-reducing performance based on the original research and bring about 2~3d B receiving gain.