Joint packet generation and covert communication in delay-intolerant status update systems
IEEE Transactions on Vehicular Technology
School of Science
National Natural Science Foundation of China (grants 62071486 and 62171464), Natural Science Foundation on Frontier Leading Technology Basic Research Project of Jiangsu (grant BK20212001), Key R&D Program of Jiangsu Province Key project and topics (grant BE2021095), UNSW Digital Grid Futures Institute, UNSW, Sydney, Australian Research Council’s Discovery Project (grant DP210102169).
In this letter, we jointly investigate packet generation and covert communication in delay-intolerant status update systems. For the first time, we establish a bridge between the prior transmission probability and the finite block-length in covert communication by modeling the stochastic status packet generation as a Poisson process. Considering a general prior transmission probability model, we derive closed-form expressions for the covertness constraint, the average packet error probability, and the effective covert throughput (ECT) to reveal the non-trivial tradeoff between the communication covertness and reliability. An optimization problem to maximize ECT is also formulated, and then the optimal transmit power and block-length are obtained, respectively. In contrast to exiting results, our examination shows that the longest block-length and the widely adopted equal prior probabilities are generally suboptimal when jointly considering the packet generation and covert communication.