Goal-Oriented Relay-Assisted Communication for Real-Time State Tracking

This paper investigates the state synchronization probability (SSP) of a goal-oriented relay-assisted real-time state tracking system, where a source node monitors a discrete-time Markov chain and transmits state updates either directly to a destination or via a relay. The goal-oriented approach emphasizes timely and accurate delivery of semantically significant updates to support real-time decision-making. While relay-assisted communication improves coverage and reliability, its impact on SSP within a goal-oriented framework remains unexplored. To the best of our knowledge, this is the first study to evaluate SSP in such a system. In relay-assisted state tracking, possible simultaneous transmissions from the source and relay result in superimposed signals at the destination, necessitating Successive Interference Cancellation (SIC) for decoding. Notably, decoding the source's packet depends on prior successful decoding of the relay's packet, even though the source carries the most recent state information. This dependency highlights SIC's critical role and motivates further exploration of its impact on SSP. To analyze SSP, we model the SIC-enabled relay-assisted system using a Markov chain and derive its theoretical expression. Results show that incorporating SIC significantly enhances SSP. Without SIC, interference from simultaneous transmissions can degrade performance, making relay-assisted schemes less effective than direct transmission. These findings highlight SIC's pivotal role in enabling efficient relay-assisted state tracking systems.