This paper considers wireless device-to-device (D2D) coded caching in a multiaccess network, where the users communicate with each other and each user can access multiple cache nodes. Access topologies derived from two combinatorial designs known as the $t$-design and $t$-group divisible design ($t$-GDD), referred to as the $t$-design and $t$-GDD topologies respectively, which subsume a few other known topologies, have been studied for the multiaccess coded caching (MACC) network by Cheng \textit{et al.} in \cite{MACC_des}. These access topologies are extended to a multiaccess D2D coded caching (MADCC) network and novel MADCC schemes are proposed. MADCC network has been studied so far only for the cyclic wrap-around topology. Apart from the proposed novel MADCC schemes, MADCC schemes are also derived from the existing MACC schemes in \cite{MACC_des}. To compare the performance of different MADCC schemes, the metrics of load per user and subpacketization level are used while keeping the number of caches and cache memory size same. The proposed MADCC scheme with $t$-design topology performs better in terms of subpacketization level while achieving the same load per user compared to the MADCC scheme derived from the MACC scheme with $t$-design topology in \cite{MACC_des}. The proposed MADCC scheme with $t$-GDD topology performs better in terms of load per user while achieving the same subpacketization level compared to the MADCC scheme derived from the MACC scheme with $t$-GDD topology in \cite{MACC_des} in some cases. Compared to the existing MADCC scheme with cyclic wrap-around topology, the proposed MADCC scheme with $t$-design topology performs better in terms of load per user, and the proposed MADCC scheme with $t$-GDD topology performs better in terms of subpacketization level at the expense of an increase in load per user.

翻译：本文研究多址网络中的无线设备到设备（D2D）编码缓存问题，其中用户间相互通信且每个用户可接入多个缓存节点。Cheng等人在文献\cite{MACC_des}中针对多址编码缓存（MACC）网络研究了基于两种组合设计（即$t$-设计和$t$-群可除设计（$t$-GDD））衍生的接入拓扑（分别称为$t$-设计拓扑和$t$-GDD拓扑），这些拓扑涵盖若干其他已知拓扑。本文将此类接入拓扑扩展至多址D2D编码缓存（MADCC）网络，并提出新型MADCC方案。目前MADCC网络仅针对循环环绕拓扑开展过研究。除提出的新型MADCC方案外，本文还从文献\cite{MACC_des}中现有MACC方案推导出MADCC方案。为比较不同MADCC方案的性能，在保持缓存节点数量和缓存容量不变的条件下，采用单用户负载和子分组化层级作为评估指标。与文献\cite{MACC_des}中基于$t$-设计拓扑的MACC方案推导的MADCC方案相比，所提出的$t$-设计拓扑MADCC方案在实现相同单用户负载的同时，具有更优的子分组化层级性能。在某些情况下，与文献\cite{MACC_des}中基于$t$-GDD拓扑的MACC方案推导的MADCC方案相比，所提出的$t$-GDD拓扑MADCC方案在保持相同子分组化层级的同时，实现了更优的单用户负载性能。相较于现有循环环绕拓扑MADCC方案，所提出的$t$-设计拓扑MADCC方案在单用户负载指标上表现更优，而$t$-GDD拓扑MADCC方案则以单用户负载的增加为代价，在子分组化层级指标上具有更优性能。