A Guard Zone Based Scalable Mode Selection Scheme in D2D Underlaid Cellular Networks

摘要

Underlaying the cellular networks, Device to Device (D2D) communicationbrings the possibility to significantly improve the spectral efficiency incellular networks and offload the traffic relayed by the base station. However,it creates new challenge for interference management as well. In this paper, weconsider the multi-cell D2D underlaid cellular network in which many D2D linksreuse the uplink resource simultaneously. The infeasibility of interferencecancellation/alignment motivates us to force the D2D users near the basestations to work in cellular mode. Based on that, we present a distributed andscalable mode selection scheme based on guard zone to make a good tradeoffbetween decreasing interference penalty to base stations and improving spectrumutilization. With the help of stochastic geometry, we develop an analyticallytractable framework to analyze the interference and then throughput for the twokinds of users in the considered scenario. The results obtained by theframework reveal that enabling D2D communication does improve the per userthroughput and that a proper guard zone can further significantly increase theaverage throughput of both kinds of users. Thanks to the tractability of ourmodel, the optimal guard zone, which is the key parameter in our scheme, can beefficiently obtained by finding the root of the first order derivative of thethroughput expression. Through extensive numerical analysis, we show insightsof the system and give some guidelines in system design aspect.