Effectiveness of Frequency Diversity to Create EM-Diversity in Triple-Modular Redundant Data Transmission Systems

This article investigates the effectiveness of frequency diversity, the usage of three different frequencies inside a triple modular redundant data transmission system, to cope with harsh electro-magnetic disturbances. Such a triple modular redundant system uses three different data channels to transmit data after which majority voting is applied to conclude one final output. Using a Monte-Carlo based simulation framework calculates the influence of harsh electromagnetic disturbances on the communication channel. The bit error rate and the amount of undetectable dangerous failures are calculated, and serve as a quality measure for our study. In addition, this article describes a semianalytical model that implements the critical factors that are necessary to get comparable results to the Monte-Carlo simulation framework, with less computational effort. To find the bit frequencies that optimize the bit error rate (BER), and minimize the amount of dangerous failures, a sweep is performed over two out of three data frequencies while fixing the third data frequency, and the electromagnetic interference (EMI) frequency. Notable relationships are recognized in the visual results and further studied. This results in six equations visualizing the relationships between the data and EMI frequencies. Finally, three equations predict the prospective BER, and undetectable failures, which is confirmed using the Monte-Carlo simulation framework.