  We consider globally optimal precoder design for rate splitting multiple
access in Gaussian multiple-input single-output downlink channels with respect
to weighted sum rate and energy efficiency maximization. The proposed algorithm
solves an instance of the joint multicast and unicast beamforming problem and
includes multicast- and unicast-only beamforming as special cases. Numerical
results show that it outperforms state-of-the-art algorithms in terms of
numerical stability and converges almost twice as fast.
