2022/12/24 by K. K. Krishnan Namboodiri, Namboodiri, K. K. Krishnan, B. Sundar Rajan +1
Computer Science · #Advanced Data Storage Technologies #Caching and Content Delivery #Cooperative Communication and Network Coding #FOS: Computer and information sciences #Information Theory (cs.IT)
paper · doi:10.48550/arxiv.2212.12686
openalex publication_date 2022/12/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
This work considers the combinatorial multi-access coded caching problem introduced in the recent work by Muralidhar et al. [P. N. Muralidhar, D. Katyal, and B. S. Rajan, ``Maddah-Ali-Niesen scheme for multi-access coded caching,'' in IEEE Inf. Theory Workshop (ITW), 2021] The problem setting consists of a central server having a library of N files and C caches each with capacity M. Each user in the system can access a unique set of r N/C. For a lower memory regime, we present another scheme with coded placement, which outperforms the optimal scheme under uncoded placement if the number of files is no more than the number of users. Further, we derive an information-theoretic lower bound on the optimal rate-memory trade-off of the combinatorial multi-access coded caching scheme. In addition, using the derived lower bound, we show that the first scheme is optimal in the higher memory regime, and the second scheme is optimal if N≤ \binomCr. Finally, we show that the performance of the first scheme is within a constant factor of the optimal performance, when r=2.