  Stacked intelligent metasurfaces (SIMs) have recently gained significant
interest since they enable precoding in the wave domain that comes with
increased processing capability and reduced energy consumption. The study of
SIMs and high frequency propagation make the study of the performance in the
near field of crucial importance. Hence, in this work, we focus on SIM-assisted
multiuser multiple-input multiple-output (MIMO) systems operating in the near
field region. To this end, we formulate the weighted sum rate maximisation
problem in terms of the transmit power and the phase shifts of the SIM. By
applying a block coordinate descent (BCD)-relied algorithm, numerical results
show the enhanced performance of the SIM in the near field with respect to the
far field.
