Optimality of Proper Gaussian Signaling for SIMO Wiretap Channels

In this paper, we study the optimality of proper signals for wiretap channels (WTC). We characterize the secrecy capacity of WTC in both separate and augmented forms, and show that proper Gaussian signals can achieve the secrecy capacity for both single-input multiple-output (SIMO) and single-input single-output (SISO) WTC. We also use an accelerated difference of convex functions algorithm (ADCA) to verify our results.