Research On Key Technologies Of Digital Domain Suppression Of Co-site Interference In Equipment-intensive Places

The simultaneous signal transmission and receiving of the same frequency band communication equipment in the limited area,the same frequency interference between the densely distributed equipment seriously reduces the communication quality,and the same frequency co-site interference must be eliminated in order to guarantee normal communication.In view of the above problems,this paper mainly studies the digital domain interference to eliminate technology of co-site interference.Considering the fast time-change characteristics of wireless channels and the implementation complexity constraints of hardware platforms,this paper designs a low-complexity digital domain co-site interference adaptive suppression architecture,which works as follows:First,the application scenario of co-frequency co-site interference is analyzed,and the mathematical model of digital domain co-site interference algorithm is deduced.Considering the relative delay between receiving signal and reference signal,a double sliding time synchronization algorithm is designed and feasibility is verified.At the same time,in order to realize the real-time interference suppression of digital domain,the adaptive filtering algorithm based on the push minimum diplose is used to reconstruct and eliminate the interference signal.The theoretical analysis and simulation results show that the digital domain interference suppression structure based on RF front-end feedback can effectively suppress the quantitative noise of nonlinear and RF channels.Secondly,the influence of engineering non-ideal factors on the suppression performance of co-frequency co-site interference is analyzed and verified.The dry-noise ratio,related length and forgetting factors,expected signal power,fractional delay,synchronous offset and filter order in the time synchronization algorithm are simulated and verified.The simulation results show that when there is an expected signal,the synchronous offset is within 1 symbol and the forgetting factor is not less than 0.9999,the interference suppression can reach 30 d B,and the signal-to-noise ratio is expected to deteriorate no more than 3d B.Third,finish the hardware implementation and performance testing of co-site interference suppression in the digital domain.The structure design and state transition process of each core module are analyzed in detail,as well as the hardware resource consumption after placement and routing.The system platform was built in the laboratory environment,and the co-site interference suppression performance test was completed.The test results show that the actual suppression performance is less than5 d B worse than the theoretical limit,which is caused by the fixed-point data bit width and the influence of non-ideal factors in the test equipment.The research results of the thesis can provide theoretical support for the design of wireless communication data links on platforms such as densely distributed hybrid wireless communication networks at close distances,and aircraft,warships,and military command vehicles that carry dense electromagnetic wave transceivers.