Research On Interference Management Technology In D2D Communication Network

Over the past decade,there has been an unprecedented increase in demand for fast data access.In order to make full use of limited frequency resources,D2 D communication is proposed as one of the key technologies supported by next-generation cellular networks.In the D2 D communication,the user equipment uses the cellular resources to send data signals to each other through the direct link,without passing through the BS.Although the D2 D communication brings increased spectral efficiency and has significant benefits to system capacity,but it causes serious interference to the cellular network due to spectrum sharing.Therefore,an effective interference coordination strategy must be designed to ensure the target performance level of cellular communications.The main contribution of this thesis is to propose two kinds of interference management strategy for D2 D communication network.First of all,this thesis proposes a D2 D cooperative transmission scheme centralized control by the base station,in this strategy we let D2 D users as a relay to assist the communication between the macro cell users and base stations,when sharing the spectrum resources of cellular user.Specifically,in the information transmission process between D2 D users,the D2 D transmitter will use superposition coding in the form of combining the received macro cell user's own signal and the information of D2 D,and transmit the combination signal to the base station and D2 D receiver in the form of multicast.Through our strategy,we can enhance the communication quality of the macro cellular user while realizing the wireless communication of the D2 D,solve the problem that some cellular user is not covered by base station in the individual area,improve the reliability of the communication link of the macro cellular user,and reduce the total power consumption of the system.The simulation results show that our cooperative communication scheme has great potential in improving macrocell coverage and mitigating the interference of D2 D communication,increasing link reliability and reducing power consumption.Secondly,we propose a distributed D2 D access and power control scheme based on location information.This scheme can relieve the excessive signaling overhead in the centralized interference management scheme and the dispatching pressure of the base station in the large-scale D2 D network.In this scheme,we firstly design a position estimation method,D2 D users can estimate the current location information of the macro cellular users in the link by analyzing the received signal.Secondly,we will establish the relationship of the energy efficiency of D2 D user,macro cellular users location information and the power of D2 D transmitter.Then,we will maximize the energy efficiency of D2 D users and ensure that the interference of macro cellular users is limited.Finally,D2 D users will get the optimal access threshold and access power.The simulation results show the correctness and effectiveness of our distributed interference management scheme.Finally,we summarize the contents of the full thesis,and the further research direction for the future.