  In this paper, we analyze the performance of regularized channel inversion
(RCI) precoding in multiple-input single-output (MISO) broadcast channels with
confidential messages under transmit-side channel correlation. We derive a
deterministic equivalent for the achievable per-user secrecy rate which is
almost surely exact as the number of transmit antennas and the number of users
grow to infinity in a fixed ratio, and we determine the optimal regularization
parameter that maximizes the secrecy rate. Furthermore, we obtain deterministic
equivalents for the secrecy rates achievable by: (i) zero forcing precoding and
(ii) single user beamforming. The accuracy of our analysis is validated by
simulations of finite-size systems.
