Service Delay Minimization-Based Joint Clustering and Content Placement Algorithm for Cellular D2D Communication Systems

The rapidly increasing content fetching requirements pose challenges to the transmission performance of traditional cellular system. Due to the limited transmission performance of cellular links and the caching capabilities of the base stations (BSs), it is highly difficult to achieve the quality of service (QoS) requirements of multi-user content requests. In this paper, a joint user association and content placement algorithm is proposed for cellular device-to-device (D2D) communication network. Assuming that multiple users located in a specific area may have content requests for the same content, a clustering and content placement mechanism is presented in order to achieve efficient content acquisition. A joint clustering and content placement optimization model is formulated to minimize total user service delay, which can be solved by Lagrange partial relaxation, iterative algorithm and Kuhn-Munkres algorithm, and the joint clustering and content placement strategies can be obtained. Finally, the effectiveness of the proposed algorithm is verified by MATLAB simulation.