User Movements Aware Coded Caching in Small-Cell Networks

In coded caching, users cache pieces of files under a specific arrangement so that the server can satisfy their requests simultaneously in the broadcast scenario via eXclusive OR (X-OR) operation and therefore reduce the amount of transmission data. As a character of wireless communication networks, user movements, however, make the caching arrangement fruitless, which results in the disappearance of XOR opportunities. In this paper, we propose a coded caching scheme to address this problem caused by user movements. The proposed scheme divides users into groups according to their caching patterns in order that XOR coded caching messages can be reorganized when user movements happen. Transmission data volume is driven to measure the performance of the proposed scheme. Numerical results show that the proposed scheme achieves improvement on traffic offloading.