Secrecy capacity and secure outage performance for rayleigh fading simo channel

In this paper, we consider the problem of secret communication through Rayleigh fading single-input multiple-output (SIMO) broadcast channel in the presence of an eavesdropper. At first, we define the ergodic secrecy capacity and find the optimal power allocation at the transmitter that achieves the secrecy capacity for the full channel state information (CSI) case, where transmitter has access to both the main channel and eavesdropper´s channel gains, and for the case of only main channel CSI at the transmitter. Then, we define the secrecy capacity in case of open-loop transmission scheme and present the analytical expression for the lower bound of ergodic secrecy capacity. We also find the analytical expression for secure outage probability to study the secure outage performance of the proposed model.