  The spectral efficiency (SE) of Massive MIMO (MaMIMO) systems is affected by
low quality channel estimates. Rate-Splitting (RS) has recently gained some
interest in multiuser multiple antenna systems as an effective means to
mitigate the multi-user interference due to imperfect channel state
information. This paper investigates the benefits of RS in the downlink of a
single-cell MaMIMO system when all the users use the same pilot sequence for
channel estimation. Novel expressions for the SE achieved in the downlink by a
single-layer RS strategy (that relies on a single successive interference
cancellation at each user side) are derived and used to design precoding
schemes and power allocation strategies for common and private messages.
Numerical results are used to show that the proposed RS solution achieves
higher spectral efficiency that conventional MaMIMO with maximum ratio
precoding.
