This paper investigates the coded caching problem in a multi-access multiple-input single-output (MAMISO) network with the combinatorial topology. The considered system consists of a server containing $N$ files, $Λ$ cache nodes, and $K$ cache-less users, where each user can access a unique subset of $r$ cache nodes. The server is equipped with $L$ transmit antennas. Our objective is to design a caching scheme that simultaneously achieves a high sum Degree of Freedom (sum-DoF) and low subpacketization complexity. To address this challenge, we formulate the design of multi-antenna placement delivery arrays (MAPDA) as a $0$--$1$ knapsack problem to maximize the achievable DoF, thereby transforming the complex combinatorial caching structure into a tractable optimization framework that yields efficient cache placement and flexible delivery strategies. Theoretical and numerical analyses demonstrate that: for networks with combinatorial topologies, the proposed scheme achieves a higher sum-DoF than existing schemes. Under identical cache size constraints, the subpacketization level remains comparable to existing linear subpacketization schemes. Moreover, under specific system conditions, the proposed scheme attains the theoretical maximum sum-DoF of $\min\{L+KM/N, K\}$ while achieving further reductions subpacketization. For particular combinatorial structures, we further derive optimized constructions that achieve even higher sum-DoF with lower subpacketization. ```

翻译：本文研究了具有组合拓扑的多接入多输入单输出(MAMISO)网络中的编码缓存问题。所考虑的系统包含一个拥有$N$个文件的服务器、$Λ$个缓存节点和$K$个无缓存用户，其中每个用户可以访问$r$个缓存节点的唯一子集。服务器配备$L$根发射天线。我们的目标是设计一种能同时实现高总自由度(sum-DoF)和低子分组复杂度的缓存方案。为应对这一挑战，我们将多天线放置递送阵列(MAPDA)的设计建模为$0$--$1$背包问题以最大化可获得的DoF，从而将复杂的组合缓存结构转化为可处理的优化框架，该框架能产生高效的缓存放置和灵活的递送策略。理论与数值分析表明：对于具有组合拓扑的网络，所提方案比现有方案实现了更高的总DoF。在相同缓存容量约束下，子分组水平与现有线性子分组方案保持相当。此外，在特定系统条件下，所提方案达到了理论最大总DoF $\min\{L+KM/N, K\}$，同时实现了子分组的进一步降低。针对特定的组合结构，我们进一步推导出优化的构造方法，能以更低的子分组复杂度实现更高的总DoF。