Analysis and Scheduling for Cooperative Content Delivery in 5G Heterogeneous Networks

In 5G mobile communications, caching popular media contents is considered as a promising solution to mitigate the network congestion pressure. In this paper, we design a heterogeneous network model including base station (BS), small cells (SCs) and device-to-device (D2D) pairs, which are all portions of 5G networks. In addition, we analyze the performance of cache-based content delivery in this network. With the mutually independent Possion Point Process (PPP), we first provide the user request hitting probability analysis and theoretical expectation expression in the heterogeneous network. Subsequently, We further propose a novel resource selection and scheduling algorithm for the three-tier heterogeneous network, i.e., the optimal transmission links selecting and scheduling strategy (OTLSSS), satisfying both signal to interference plus noise ratio (SINR) and maximizing the efficiency of user request hitting ratio in the actual environment based on coloring diagram theory. Numerical results reveal that the theoretical results are consistent with the simulation results with Zipf-distribution caching scheme, meanwhile, the proposed scheduling algorithm has a satisfying performance compared with the theoretical limit and the state of the art.