🤖 AI Summary
This work proposes a general graph-based transmission design framework for multi-access coded caching systems under arbitrary user-cache access topologies, reformulating the coded multicast problem as a conflict graph coloring task. For the first time, graph neural networks are leveraged to achieve low-complexity near-optimal solutions, and the index coding duality bound is extended to arbitrary access structures. The proposed learning-based scheme achieves transmission loads close to those of the DSatur greedy algorithm and the theoretical duality bound, while substantially reducing computational overhead, thereby demonstrating strong scalability and adaptability in large-scale and heterogeneous network topologies.
📝 Abstract
This paper studies the multi-access coded caching (MACC) problem under arbitrary user-cache access topologies, extending existing models that rely on highly structured and combinatorially designed connectivity. We consider a MACC system consisting of a single server, multiple cache nodes, and multiple user nodes. Each user can access an arbitrary subset of cache nodes to retrieve cached content. The objective is to design a general and low-complexity delivery scheme under fixed cache placement for arbitrary access topologies. We propose a universal graph-based framework for modeling the MACC delivery problem, where decoding conflicts among requested packets are captured by a conflict graph and the delivery design is reduced to a graph coloring problem. In this formulation, a lower transmission load corresponds to using fewer colors. The classical greedy coloring algorithm DSatur achieves a transmission load close to the index-coding converse bound, providing a tight benchmark, but its computational complexity becomes prohibitive for large-scale graphs. To overcome this limitation, we develop a learning-based framework using graph neural networks that efficiently constructs near-optimal coded multicast transmissions and generalizes across diverse access topologies and varying numbers of users. In addition, we extend the index-coding converse bound for uncoded cache placement to arbitrary access topologies and propose a low-complexity greedy approximation. Numerical results demonstrate that the proposed learning-based scheme achieves transmission loads close to those of DSatur and the converse bound while significantly reducing computational time.