A Correction of EMI Prediction Method Based on Interference Margin in DSSS Scenarios

It is necessary to provide methods for performing electromagnetic interference(EMI) predictions when several types of devices operate at the same time. Generally, interference margin quantitatively specifies the interference strength between jammer and victim devices. Designated as fast prediction method, there are some empirical equations in the margin calculation. In some situations of direct spread spectrum system(DSSS), the value of interference margin is inaccurate because of its additional processing gain, taking into account the anti-jamming technique. It may lead to inefficient and inaccurate EMI prediction or even the large difference of interference margin. The focus of this paper is to propose a correction of the conventional prediction method by presenting direct spread transmitting spectrum's effect on the calculation of interference margin and the prediction method, aiming to solve engineering problems. The result shows that the accuracy of EMI margin is improved using correction method in some direct spread spectrum scenarios.