Resilience of Forward Error Corrections in Harsh Electromagnetic Environments: Fault Mechanisms and Fault Elimination Techniques

This dissertation addresses the challenge of ensuring resilient communication in modern safety–critical systems that operate in increasingly polluted electromagnetic environments. While forward error corrections can provide protection at the physical layer of communication, there remains a theoretical vulnerability to undetectable corruption, which could potentially pose a serious risk to users, bystanders, and the environment. This vulnerability occurs when a code word is corrupted in a way that turns it into another valid code word. To investigate this issue, this dissertation first investigates whether undetectable corruption can occur in real–world electromagnetic polluted environments. Through laboratory measurements, it is found that good electronic design and the use of forward error corrections can significantly improve electromagnetic resiliency of communication channels. However, the study also shows that even with both, communication channels remain vulnerable to undetectable corruption. Therefore, this dissertation proposes electromagnetic resilient forward error corrections as a software–based solution to reduce these vulnerabilities to an acceptable level.

In the second step of this study, the effectiveness of Reed–Solomon codes against steady–state single–frequency electromagnetic disturbances is evaluated using a basic simulation framework without any modulation to isolate the root cause of undetectable corrupted data. The investigation reveals that repetitive or alternating patterns in the code words are the primary cause of these corruptions. To address this issue, a range of fault elimination techniques are proposed to enhance the electromagnetic resilience of Reed-Solomon codes. These techniques include an already available technique in the market, Over–Voltage Detection, which only allows data within the normal operating voltage range to pass through. Additionally, there are new proposed techniques including Single Symbol Inversion, which inverts a single symbol to break the repetitiveness of code words; Encoder Tuning, which selects a specific root in the generator polynomial to generate codebooks that contain no repetitive or alternating patterns except for the all 0s code word; and its extension, Encoder Tuning Plus, which eliminates the all 0s code word as well. After conducting a comprehensive comparison among these techniques, it is found that Encoder Tuning Plus provides the best balance between availability and safety and is the most optimal solution for enhancing the electromagnetic resilience of Reed–Solomon codes.

To build upon the previous findings, the study integrates a modem module into the simulation framework to analyze the electromagnetic resilience of various modulated forward error corrections, including Reed–Muller codes, Reed–Solomon codes, and Convolutional codes, against harsh electromagnetic disturbances. The study demonstrates that higher orders of Phase–Shift Keying modulation provide greater resilience against single–frequency electromagnetic disturbances, breaking repetitive patterns in code words and decreasing the likelihood of undetectable corruption. However, lower orders of modulation still retain these patterns, necessitating the development of an inversion–based fault elimination technique to detect these patterns. The study reveals that higher randomness and Hamming distance in the generated code words offer greater resilience against this type of disturbance. Furthermore, the results demonstrate that modulated Reed–Solomon codes, along with the proposed fault elimination technique, offer the best balance between safety and availability in practical applications. Finally, the study concludes by proposing a valorization plan to introduce the proposed electromagnetic resilient forward error corrections to the market. This plan encompasses strategic approaches such as establishing partnerships, pursuing licensing opportunities, and offering consulting services to effectively exploit market opportunities.