Research On Collaborative Incentive Mechanism In D2D Communication

Owing to the proliferation and popularity of smart mobile devices,the mobile data traffic is increasing at an unprecedented speed.Cellular networks are forced to transfer from connection-oriented end-to-end communication to content-centric communication,facing many challenges like resources constraints and limited capacity.Therefore,novel wireless communication paradigm are urgently needed to meet these challenges.Device-to-Device(D2D)communications,as one of the key technology in the 5th Generation Mobile Communication(5G),has been proposed and considered as one promising approach to solve the radio spectrum shortages and oflfload the data traffic in the future networks.D2D communications benefits from the fact that two user equipments in proximity of one another can establish a direct communication link to share contents,which offload the traffic of the base station.In future networks,the base station may send one frequently requested media file to the user equipment who can spread the contents to other interested users via D2D model.Hence,energy efficiency and spectral efficiency can be improved,data traffic in the base station can be offloaded,and cellular coverage can be extended.To achieve these goals,many researchers have focused on the D2D performance optimization,while much less effort has been put on investigating how to motivate the users to participate and cooperate in the D2D content sharing.In reality,if most of the users are unwilling to share their contents via D2D communication,the base station will still have to provide the contents via the cellular downlinks.This thesis aims to design collaborative incentive mechanisms to encourage mobile users in D2D content sharing to alleviate the cellular network resources shortages and data traffic pressure.The Principle-Agent theory(model)from the economics is introduced to model the problem of the cooperative incentive design in D2D communications.In the D2D content sharing,the base station(BS)acts as the principal and the user who is the content provider serves as the agent to send the contents to the requester via D2D communication.Two types of information asymmetry between BS and content provider are studied and two collaboration incentive mechanisms,which are based on the signaling model and performance-related model,namely the SCSI(Signaling-based Content Sharing Scheme)mechanism and PRCSI(Performance-Related Content Sharing Incentive)mechanism are designed to encourage the content providers to participate in the D2D content sharing accordingly.In SCSI,optimal strategy for each content provider is derived to maximize their utility(monetary profit)while guaranteeing a non-negative utility for the BS.And in PRCSI,a performance-related reward is signed in the contract to motivate the content provider to put more "effort",by the way,solving the Hidden-Action problem.In both SCSI and PRCSI collaboration incentive mechanisms,the agent and the principal choose the optimal action,by which they can reach the Nash equilibrium.Simulation results show that the SCSI and PRCSI can motivate the content provider well and increase the data rate and the utility of agents and principal.Thus,the spectral efficiency and data rate will be greatly improved.