  In this paper, we consider transmitter optimization in multiple-input
single-output (MISO) broadcast channel with common and secret messages. The
secret message is intended for $K$ users and it is transmitted with perfect
secrecy with respect to $J$ eavesdroppers which are also assumed to be
legitimate users in the network. The common message is transmitted at a fixed
rate $R_{0}$ and it is intended for all $K$ users and $J$ eavesdroppers. The
source operates under a total power constraint. It also injects artificial
noise to improve the secrecy rate. We obtain the optimum covariance matrices
associated with the common message, secret message, and artificial noise, which
maximize the achievable secrecy rate and simultaneously meet the fixed rate
$R_{0}$ for the common message.
