Decision Algorithm Based on the Modified Bellman Equation to Deal With EMI-Induced Errors in Hamming-Based Communications

Abstract

This article presents a decision-making algorithm based on a modified version of the Bellman equation to deal with electromagnetic interference errors in a communication channel inside a harsh electromagnetic reverberant environment. The Bellman equation is a fundamental concept in decision-making problems such as Markov decision processes. Such processes model decision making in situations where the outcomes are partly random and partly controlled by an agent (decision maker). Recent studies have implemented Markov decision processes as a tool for risk assessment in areas such as robotics or aviation. However, so far, no research has been reported that uses the Bellman equation or Markov decision processes to deal with risks related to electromagnetic disturbances. In our study, a wired communication channel that uses non-return-to-zero-level data encoding and Hamming code for error detection and correction is disturbed. First, the packet error rate (PER) is calculated and compared with and without the proposed algorithm for different electromagnetic disturbance frequencies and bit rates. The gain is compared at different PERs when the algorithm's parameters (called rewards) are optimized and when these are set as random. Finally, the influence of the rewards and the maximum number of resends on the algorithm's performance is also studied.