Research On Interference Suppression Method Of D2D Communication Technology

The proposal of 5th-generation mobile communication(5G)marks the arrival of the era of intelligent communication.The Gps-scale network speed and abundant terminal services brought by wireless communication make our lives convenient,but at the same time,it is undoubtedly a great challenge for the limited and scarce spectrum resources.In addition to spreading spectrum,more people focus on improving the spectrum utilization.D2 D communication technology(Device-to-Device),Orthogonal Frequency Division Multiplexing(OFDM),Multiple-Input Multiple-Output(MIMO)and Cognitive Radio(CR)can improve resource utilization and users' experience.D2D(Device-to-Device)communication technology is one of the key technology in 5G,and it is also the focus of research in recent years.In heterogeneous networks,D2 D communication technology based on multiplexing mode can make terminal devices communicate directly.It not only improves resource utilization,but also enlarges cell capacity.At the same time,that would make some interference between cellular users and D2 D users.In recent years,the research on the suppression of the interference in D2 D communication is the focus of D2 D communication technology.It mainly seeks breakthroughs in three aspects: communication mode selection,resource allocation and power control.Cognitive Radio(CR)technology can sense the unoccupied spectrum of the surrounding channel based on the moment and effectiveness,it also screens and manages the free spectrum,and distributes the free spectrum to the secondary users.It can also ensure the continuity of communication to achieve spectrum sharing.Therefore,the combination of D2 D communication and CR technology can greatly improve capacity of cell.In this thesis,a heuristic algorithm,named QoS-Based Allocation Algorithms for D2 D Communication Resources(QBA),is proposed.In the allocation step,D2 D users' priority is introduced as the basis of resource allocation order.The allocation order is from high to low based on D2 D user priority.D2 D users with higher the priority would have the higher the transmission rate and need the fewer resource blocks(RB)to meet the rate requirements.This thesis also proposes a mode of communication,namely cognitive D2 D communication mode in heterogeneous networks,and proposes a power control scheme based on this mode.By using CR technology to sense the "holes" in the surrounding spectrum,and introducing bidding mechanism to mark the "holes" in the spectrum,D2 D users tend to reduce their transmission power to maximize their ability to pay,thus reducing the interference in the system and achieving maximum benefits.