Movable antenna (MA) is an emerging technology that utilizes localized antenna movement to achieve 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 using only the second-order Taylor expansion, which simplifies the problem-solving process compared to the existing two-step approximation method. The proposed design is then extended to the general multi-group scenario. Simulation results show that the proposed algorithm converges faster than the existing two-step approximation method, achieving a 3.4% enhancement in max-min SNR. Moreover, it can improve the max-min SNR/SINR by up to 22.5%, 181.7%, and 343.9% compared to benchmarks employing only receive MAs, only transmit MAs, and both transmit and receive FPAs, respectively.

翻译：可移动天线（MA）是一种新兴技术，其通过局部天线移动来获得更佳的信道条件，从而提升通信性能。本文研究从配备多个MA的基站到多组单MA用户的可移动天线增强多播传输。我们的目标是通过联合优化每个收发MA的位置以及发射波束成形，最大化所有用户中的最小加权信号与干扰加噪声比（SINR）。为应对这一挑战性问题，我们首先考虑单组场景，并提出一种基于交替优化和逐次凸逼近技术的高效算法。具体而言，在优化发射或接收MA位置时，我们仅使用二阶泰勒展开为每个用户的信噪比（SNR）构建一个凹下界，与现有的两步逼近方法相比，这简化了问题求解过程。随后，所提出的设计被推广至一般的多组场景。仿真结果表明，所提算法比现有的两步逼近方法收敛更快，实现了3.4%的最大最小SNR提升。此外，与仅采用接收MA、仅采用发射MA以及同时采用收发固定位置天线（FPA）的基准方案相比，该算法可分别将最大最小SNR/SINR提升高达22.5%、181.7%和343.9%。