Continuous Message Transmission for Covert Communication

In this letter, we investigate continuous message transmission schemes for covert communication under the long-term detection of an adversary. The amount of information is employed to evaluate the performance of communication and analyzed in two cases. For the first case where the number of messages is predetermined, we derive that equal-power allocation is the optimal scheme to maximize the amount of information. For the second case where the number of messages is not predetermined, we propose a power-series based power allocation scheme to satisfy the covert constraint. Moreover, the amount of information in the second case is analyzed and shown to be arbitrarily close to that in the first case.