Design And Implementation Verification Of D2D Radio Resource Management Scheme In Heterogeneous Cellular And D2D Networks

With the increasing demand driven by growing wireless local services, bearing pressure of cellular networks is becoming more and more serious.3GPP proposes to introduce the Device-to-Device (D2D) technology into cellular networks, by which adjacent devices can exchange information directly. In this way, it will divert part of the local traffic from the base station, enhance network capacity and resource utilization, support public safety emergency communication environment. But with D2D technology introduction, the problem of global network interference and scheduling policy will become more complicated than ever. Proper designs of coexistence mode and radio resource management (RRM) schemes are essential for effective integration of these two communication methods.This thesis presents a solution of D2D RRM in heterogeneous network, accomplishes the scheme designs of the interference sensing and coordination, power control, resource allocation, link adaptation mecha-nism and D2D data communication procedure in LTE/D2D networks. The implementation and verification are carried out based on the relevant hardware platform at last.The main works and highlights of the thesis are the following:Firstly, after the compare of different resource reuse plans, D2D control methods and interference patterns in coexistence network, a cognitive and little network-assisted D2D distributed RRM framework is proposed. With this framework, it can support D2D RRM both within and without cellular environment.Secondly, D2D distributed interference sensing and coordination schemes are studied and designed. They are composed of three specific methods, including an interference avoidance method based on power measurement for Cellular-to-D2D (C2D) interference, an interference tracing method based on the maximum cellular traffic loss settings for D2D-to-Cellular (D2C) interference and a synchronous slotted collision avoidance (SSCA) scheme based on D2D common control channels for D2D intra-interference. According to SSCA, the corresponding D2D data transmission procedure under LTE networks is designed.Thirdly, the hybrid resource utilization schemes based on sensing and coordination are presented, including the following methods. One is the specific D2D HARQ and AMC joint link adaption method. The other is a hybrid resource selection method using resource fragment and SINR prediction, which can reuse serveral cellular user resources at the same time without causing harmful influence to cellular users.Fourthly, based on D2D RRM schemes designed above, a LTE-D2D hardware platform is implemented. Under the current LTE network, D2D devices are successfully networking along with LTE commercial terminals. The verification results figured out that distributed D2D RRM schemes proposed in this thesis would effectively control the C2D interference according to the loss threshold setting. The shared resource utilization opportunity could also be found and be made good use of to provide high proximity transmission speed. When the resource reuse conditions were met, D2D links would automatically share these resources with cellular links to achieve greatly enhancement of spectral efficiency compared with that in single type network. With some expansion, it could also support the seamless handover between within and without cellular coverage, D2D relay functions.