  This letter investigates the weighted sum rate maximization problem in
movable antenna (MA)-enhanced systems. To reduce the computational complexity,
we transform it into a more tractable weighted minimum mean square error
(WMMSE) problem well-suited for MA. We then adopt the WMMSE algorithm and
majorization-minimization algorithm to optimize the beamforming and antenna
positions, respectively. Moreover, we propose a planar movement mode, which
constrains each MA to a specified area, we obtain a low-complexity closed-form
solution. Numerical results demonstrate that the MA-enhanced system outperforms
the conventional system. Besides, the computation time for the planar movement
mode is reduced by approximately 30\% at a little performance expense.
