Research On Power Control Algorithm In D2D Communication System

With the rapid development of modern mobile communication technology,various communication technologies have emerged,which has entered the era of information technology,but with it comes the challenges faced by limited resources.In order to solve the requirements of equipment for a large amount of spectrum resources during communication process,device-to-device(D2D)technology has gradually become a hot research technology.It is mainly used to realize communication without the base station for forwarding information.This technology can greatly improve the communication speed and spectrum utilization rate of neighboring users.The main content of this paper is the research of power control algorithm in D2 D communication system.While ensuring the normal communication of cellular users,D2 D communication users are introduced into cellular communication network.This paper selects uplink resources for communication,because multiplexing uplink resources mainly produces interference to the base station,and because the location of the base station is relatively stable,power control method can be used to adjust and optimize it to reduce interference.However,when multiplexing downlink resources,it mainly interferes with the receiving end of communication users,and because the receiving end of users is usually a mobile end with relatively unstable position,it is difficult to control its power.Therefore,this paper mainly adopts uplink multiplexing resources with relatively stable position and easy power control,and this paper adopts one to many and many to many allocation methods,and then puts forward two power control schemes.1.Aiming at the situation that one pair of D2 D users reuse multiple pairs of cellular users in single cell communication network,an improved two-factor joint power control scheme is proposed by adopting one-to-many communication mode.The scheme adopts the joint power control method,calculates the path loss according to the distance relationship between the user and the base station,introduces the dynamic power compensation parameters,and then analyzes the user’s power.Thus,the problem of co-frequency interference in the communication system can be reduced,and the throughput and signal-to-noise ratio of the system can be improved.2.Aiming at the situation that multiple pairs of D2 D users reuse multiple pairs of cellular users in single cell communication,a non-cooperative game D2 D joint power control and resource allocation algorithm is proposed.In this scheme,the cost factor is introduced into the communication system to determine the utility function.Through the power control of D2 D communication link and combined with the resource allocation algorithm,The optimal response function of D2 D users participating in the game is obtained.The equilibrium in the game is analyzed in this paper,and the existence and uniqueness of Nash equilibrium are determined.It is proved that the strategy selected by this model can achieve stability.On the premise of ensuring communication quality,system selection has higher fairness and reduces system delay.The simulation results show that the two power control schemes proposed in this paper under one-to-many and many-to-many communication modes can improve the throughput and signal-to-noise ratio of the system,improve the fairness of the system and improve the performance of the system on the premise of ensuring the communication quality of the system.