  This letter investigates the secure delivery performance of the
rate-splitting multiple access scheme in land mobile satellite (LMS) systems,
considering that the private messages intended by a terminal can be
eavesdropped by any others from the broadcast signals. Specifically, the
considered system has an N-antenna satellite and numerous single-antenna land
users. Maximum ratio transmission (MRT) and matched-filtering (MF) precoding
techniques are adopted at the satellite separately for the common messages
(CMs) and for the private messages (PMs), which are both implemented based on
the estimated LMS channels suffering from the Shadowed-Rician fading. Then,
closed-form expressions are derived for the ergodic rates for decoding the CM,
and for decoding the PM at the intended user respectively, and more
importantly, we also derive the ergodic secrecy rate against eavesdropping.
Finally, numerical results are provided to validate the correctness of the
proposed analysis models, as well as to show some interesting comparisons.
