Cache Hit Ratio Maximization in Device-to-Device Communications Overlaying Cellular Networks

This paper investigates the content placement problem to maximize the cache hit ratio in device-to-device(D2 D) communications overlaying cellular networks. We consider offloading contents by users themselves, D2 D communications and multicast, and we analyze the relationship between these offloading methods and the cache hit ratio. Based on this relationship, we formulate the content placement optimization as a cache hit ratio maximization problem, and propose a heuristic algorithm to solve it. Numerical results demonstrate that the proposed scheme can outperform existing schemes in terms of the cache hit ratio.