Coded Caching with Distinct Number of User Requests
Kai Huang, Xiaohong Cai, Jinbei Zhang, Zhiyong Luo · 2020
Coded caching is an effective method to reduce the traffic load on the network bottleneck link by exploiting the joint optimization of caching and transmission. In most of previous works, one user may request only one file. However, users could have distinct number of requests in practice. The number of files requested by the users may also follow different distributions. In this paper, we investigate coded caching with distinct number of user requests. We propose a decentralized coded caching transmission scheme for user requests whose number may follow an arbitrary distribution and analyze the upper bound of the transmission rate. We also derive the corresponding lower bound for any achievable scheme. We show that the gap between these two rates is within a constant factor of 12. And this result holds for any distribution on the number of user requests. For the proposed transmission scheme and a given distribution, we show that when the number of users exceeds a threshold, the transmission rate will be bounded without regard to the number of users, due to the benefit of multicast opportunities brought by coded caching. Simulation results demonstrate the superior performance of the proposed scheme.