A Spectral Efficiency Guaranteed Caching Scheme in Small Cell Networks

Abstract

Small cell network is a promising approach to improve network capacity due to the high link quality and spectrum utility efficiency. Nevertheless, the bandwidth enjoyed by small cell networks is limited by the wireless backhaul capacity and the serious interference from neighbor cells. The backhaul resource needed can be reduced by caching in small cell base stations (SBSs). On the other hand, the inter-cell interference can be mitigated by Coordinated Multi-Point-Joint Transmission (CoMP-JT) which allows multiple SBSs transmit concurrently. Unfortunately, CoMP-JT requires more backhaul resources and caching capacity. This paper jointly considers the transmission mode selection and the caching scheme to minimize wireless backhaul resources consumption. Different from existing works, our work identifies the optimal caching placement while satisfying the spectral efficiency. Our simulation results show that our proposed caching scheme can effectively reduce the backhaul resources consumption.