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：移动天线（MA）是一种新兴技术，通过局部天线移动来追求更优信道条件，以提升通信性能。本文研究从配备多个移动天线的基站到多组单移动天线用户的增强型组播传输。我们的目标是通过联合优化每个发射/接收移动天线的位置和发射波束成形，最大化所有用户中的最小加权信干噪比（SINR）。为解决这一难题，我们首先考虑单组场景，并基于交替优化和逐次凸近似技术提出一种高效算法。特别地，在优化发射或接收移动天线位置时，我们仅通过二阶泰勒展开为每个用户的信噪比（SNR）构造凹下界，该方法比现有利用两步近似的方案更为有效。随后将所提设计推广至通用多组场景。仿真结果表明，与基准方案相比，所提算法在可达最大最小信噪比/信干噪比方面可获得显著性能增益。此外，与基准方案相比，所提算法可显著降低实现目标最大最小信噪比/信干噪比性能所需的发射功率或天线数量。