Research On Interference Coordination For Device-to-device Communication Underlaying Cellular Networks

Device-to-device (D2D) communication is a technique that can realize direct communication by sharing cellular resource in existing cellular network. It can keep the backward compatibility of the original cellular network without significantly changing the access technology of the cellular terminal. However, D2D transmissions will cause interference to the primary cellular network when radio resources are shared by them. Without effectively dealing with the inference, D2D communication not only can not improve the performance of the system, but also will degrade the performance of the original cellular system. Interference brought by D2D communication has become one of the major challenges faced by D2D technology.In view of this co-channel interference, many scholars have proposed some interference coordination schemes focusing on ensuring the connectivity of D2D link and cellular link without effectively solving the problem of cellular link quality dropping caused by the co-channel interference, and these scheme can’t modify the transmission power according to the need of D2D user or the situation of resource reusing. Besides, there is no real-time power compensation for users due to limited power increment, so when cellular link interference caused by D2D link exceeds a certain threshold, the system will reject the accessing of D2D link, resulting the decline of access probability.Considering the existing shortages, this paper presents a complete compensation scheme which minimizes the power increment. And we propose a selective power compensation scheme based on the channel quality indicator (Channel Quality Indicator, CQI) defined in LTE system, to improve the complete compensation scheme and combines Both two schemes can increase the probability of D2D user permitted to access the network greatly in the condition of ensuring the communication quality of the original cellular user, meanwhile, it can meet the communication needs of D2D users and enhance the system spectrum utilization.This paper will delve into the problem that how to reduce the inference between cellular and D2D users in the worst case that the cellular resources are used in a non-orthogonal mode. The proposed interference management strategies are also proved to be rational and effective by simulating. This work provides a good idea in the field of interference management of D2D communication and a strong theoretical support for the application of D2D technology in the future mobile communication system.