  A novel multicast communication system with movable antennas (MAs) is
proposed, where the antenna position optimization is exploited to enhance the
transmission rate. Specifically, an MA-assisted two-user multicast
multiple-input single-input system is considered. The joint optimization of the
transmit beamforming vector and transmit MA positions is studied by modeling
the motion of the MA elements as discrete movements. A low-complexity greedy
search-based algorithm is proposed to tackle this non-convex inter-programming
problem. A branch-and-bound (BAB)-based method is proposed to achieve the
optimal multicast rate with a reduced time complexity than the brute-force
search by assuming the two users suffer similar line-of-sight path losses.
Numerical results reveal that the proposed MA systems significantly improve the
multicast rate compared to conventional fixed-position antennas (FPAs)-based
systems.
