The secrecy capacity of a class of parallel Gaussian compound wiretap channels

The compound wiretap channel provides a general framework for studying secrecy communication under channel uncertainty. Characterizing the secrecy capacity of nondegraded compound wiretap channels is a challenging problem in information theory. This paper considers the class of parallel Gaussian compound wiretap channels with only one possible channel realization for the legitimate receiver and characterizes the secrecy capacity. (Such parallel Gaussian compound wiretap channels are generally nondegraded.) Moreover, it is shown that the proposed coding scheme strictly outperforms the best known single-letter scheme with Gaussian codebooks.