Symbol Diversity as a Means to Make PAM-4 Modulation More Resilient in Harsh Electromagnetic Environments

In this article, symbol diversity is presented for the pulse amplitude modulation PAM-4 encoding scheme. This technique is implemented in order to incorporate electromagnetic resilience in a triple modular redundant communication channel that is subjected to electromagnetic disturbances in reverberant environments. An in-depth numerical study is carried out in light of new electromagnetic disturbance condition monitoring definitions that provide a better insight into the actual state of the system. An explanation of the different fault mechanisms based on the new definitions is provided for the proposed PAM-4 symbol diversity setup and is compared with an undiverse PAM-4 system with a two-out-of-three majority voter. The results show that the proposed symbol diversity technique is quite an effective measure for incorporating fault tolerance in the system design.