Movable antenna (MA) is an emerging technology that utilizes localized antenna movement to pursue better channel conditions for enhancing communication performance. In this paper, we study the MA-enhanced multicast transmission from a base station equipped with multiple MAs to multiple groups of single-MA users. Our goal is to maximize the minimum weighted signal-to-interference-plus-noise ratio (SINR) among all the users by jointly optimizing the position of each transmit/receive MA and the transmit beamforming. To tackle this challenging problem, we first consider the single-group scenario and propose an efficient algorithm based on the techniques of alternating optimization and successive convex approximation. Particularly, when optimizing transmit or receive MA positions, we construct a concave lower bound for the signal-to-noise ratio (SNR) of each user by applying only the second-order Taylor expansion, which is more effective than existing works utilizing two-step approximations. The proposed design is then extended to the general multi-group scenario. Simulation results demonstrate that significant performance gains in terms of achievable max-min SNR/SINR can be obtained by our proposed algorithm over benchmark schemes. Additionally, the proposed algorithm can notably reduce the required amount of transmit power or antennas for achieving a target level of max-min SNR/SINR performance compared to benchmark schemes.

翻译：可移动天线（MA）是一种新兴技术，通过局部天线移动追求更优信道条件以提升通信性能。本文研究了从配备多个MA的基站向多个单MA用户组进行的MA增强型多播传输。我们的目标是通过联合优化每个发射/接收MA的位置和发射波束赋形，最大化所有用户中最小加权信干噪比（SINR）。为应对这一挑战性问题，我们首先考虑单组场景，并基于交替优化和逐次凸逼近技术提出了一种高效算法。特别地，在优化发射或接收MA位置时，我们仅利用二阶泰勒展开为每个用户的信噪比（SNR）构造凹下界，这比采用两步近似的现有工作更为有效。所提设计随后扩展至通用多组场景。仿真结果表明，与基准方案相比，我们提出的算法在可实现的最大最小SNR/SINR方面获得了显著的性能增益。此外，与基准方案相比，所提算法可显著减少为实现目标最大最小SNR/SINR性能所需的发射功率或天线数量。