Research Of EMC Modeling And Interference Prediction In Cosite Communication System

In cosite communication system, the overlaps of the spectrum among equipments are serious, and lead to many mutual interference. Suitable measures must be taken in order to improve the system's electromagnetic compatibility.EMC prediction is a very important and effective means.In this paper, the link layer of the electromagnetic interference in cosite communication system was analyzed, and its main characteristics were extracted, its model was established. For the characteristics of the equipments' RF ports, the base and harmonic waves' mechanisms of the interference were analyzed and their non-ideal models in time domain were proposed, then a cosite communication system's EMC prediction model that combined the RF ports' and link layer's characteristics was formed. For this model, the SINAD criterion in RF ports and BER criterion in link layer were set up, and the correlation analysis of SINAD and BER was made, based on the analysis, a hierarchical prediction method based on the combination of SINAD and BER was proposed. Using this method, EMC predictions based on fixed frequency and frequency hopping equipments were done, and a method for solving the confidence probability based on the uncertainty of the jammer was proposed. In the end, the prediction software was made.The accuracy of the method was proved by the comparing the simulation results with the test results. It shows that the prediction and the corresponding software have a strong engineering guidance and value in use.