Channel Truncation Inspired Short-Packet Covert Communication with Poisson Packet Generation

In this paper, we consider short-packet covert communications with Poisson packet generation. To guarantee an optimal prior transmission probability while improving the communication reliability, we propose a novel covert communication scheme based on the channel truncation transmission. For the proposed scheme, we derive close-form expressions for the lower bound on covertness constraint, the average packet error probability, and the effective covert throughput (ECT). Then, the transmit power and the channel truncation threshold are jointly optimized to maximize ECT, while the close-form expression for the optimal channel truncation threshold with a given transmit power is obtained. Our examination shows the superiority of the proposed transmission scheme relative to a benchmark scheme without channel truncation in terms of achieving a higher ECT.