A coalitional game based interference management in cloud small cell networks

Small cells have recently emerged as an effective technology in meeting the increased demand for cellular network capacity. Cloud radio access networks (C-RANs), composed of baseband units (BBU), remote radio heads (RRH) and the optical transport network, have been introduced to harness the capacity benefits of small cells at reduced capital and operational expenses. However, dense deployment of RRHs causes severer interference among them and thus lower the spectrum efficiency. In this paper, we investigate the problem of cooperative interference management among RRHs in C-RAN based small cell networks, which are also referred to as cloud small cell networks (C-SCNs). A coalitional game in simplified-partition form, where RRHs cooperate by forming coalitions to eliminate the intra-coalition interference, is formulated. To analyze the formation of coalitions, a novel concept defection order is introduced, based on which the necessary conditions for RRHs to cooperate is derived, and a coalition formation algorithm called SOCFA is proposed as well. Simulation results show that our proposed algorithm yields a significant advantage reaching up to 28% relative to the non-cooperative scheme, in terms of aggregate system utility.