Design and Optimization on Covert Communication-Oriented Short Packet D2D

In this work, we investigate the relationship between the packet length and the prior probability by modeling the random generation process of short packets as a Poisson process in a D2D semantic communication scenario with monitors. Firstly, we derive closed expressions for the covert constraint, average bit error rate (ABER) and effective covert throughput (ECT) of the system. They reveal the trade-off relationships of packet length, power of cellular user and D2D pair transmission power on system covertness and effectiveness. Then, we consider optimizing the packet length, power of cellular network users and the transmission power of the D2D pair to maximize the effective covert throughput of the whole system. Finally, we find that the maximum packet length and the prior probability of 0.5 are not always optimal through numerical simulations.