Cooperative Device-to-Device Communications With Caching

Device-to-Device (D2D) communications can increase the throughput of cellular networks significantly, where the interference among D2D links should be properly managed. In this paper, we propose an opportunistic cooperative D2D transmission strategy by exploiting the caching capability at the users to deal with the interference among D2D links. To increase the cooperative opportunity and improve spatial reuse gain, we divide the D2D users into clusters and cache different popular files at the users within a cluster, and then find the optimal cluster size. To maximize the network throughput, we assign different frequency bands to cooperative and non-cooperative D2D links and optimize the bandwidth partition. Simulation results demonstrate that the proposed strategy can provide 500%-600% throughput gain over existing cache-enabled D2D communications when the popularity distribution is skewed, and can provide 40%-80% gain even when the popularity distribution is uniform.