Research On Low Complexity Interference Suppression Algorithm In Device-to-device Wireless Communication System

In 5G communication system,a lot of service and application will be carried out among users,information sharing becomes very extensive among users,huge network data traffic presents explosive growth.However,the traditional cellular system lacks a new technology to deal with this explosive growth.D2D communication technology enables users to directly communicate with each other when the distance is short,compared with the traditional cellular communication for forwarding information through a base station(BS),it can reduce mobility terminal power loss,improve system throughput and spectral efficiency,reduce the load on the base station.However,in a hybrid network of D2D communication with cellular communication,reuse of spectrum resources may cause interference between users.Therefore,effective interference management mechanism is the key to the potential advantages of D2D communication,and also the difficulty.This dissertation focuses on the interference of the traditional D2D and full-duplex relay D2D communication systems,and studies the following two aspects:resource allocation and mode selection.(1)In view of the problem that D2D users and cellular users have communication interference with the reuse of spectrum resources at the same time,the hybrid communication system model of traditional D2D communication and cellular communication is studied,and the problem of how to maximize the system throughput by rational allocation of cellular users' spectrum resources is solved.In the system model,in order to guarantee the minimum signal to noise ratio(Signal-to-Interference-plus-Noise-Ratio,SINR)of cellular users and D2D users as constraints,the above problems are decomposed into two sub problems:power control and D2D user spectrum resource allocation.First,the optimal power is allocated to all users according to the convex optimization theory.Secondly,the spectrum resource allocation problem is modeled as a assignment problem.The spectrum resource allocation scheme based on the improved Hungarian algorithm is proposed,which is based on the Hungarian algorithm,which is based on the Hungarian algorithm.The complexity of the method improves the efficiency of resource allocation for each pair of D2D users.The simulation results show that the improved algorithm can simultaneously satisfy the user service quality(Quality of Service,QoS)of the D2D communication link and cellular communication link according to the system resource situation.Compared with the traditional Hungarian algorithm,the improved algorithm has lower computational complexity and the traditional spectrum resource allocation in the case of the same complexity.In comparison,the throughput gain has an increase of 0.4dB.(2)In view of the interference of the D2D terminal as a relay in different communication modes,the heterogeneous network model of the D2D terminal cooperative communication is studied.The problem of how to effectively improve the system throughput through the rational allocation of D2D relay communication mode is solved.In the simultaneous existence of the cellular downlink and the D2D cooperative communication link,the interference and throughput of the D2D relay in the full duplex communication mode of the orthogonal channel and the full duplex communication mode of the same channel are analyzed.Because the communication mode selection algorithm of the traditional coloring theory is highly complex,and the initial algorithm is the initial algorithm.The D2D relay is colored by the throughput difference between its adjacent users in different modes.Compared with the traditional centralized algorithm such as genetic algorithm and greedy algorithm,the improved algorithm can obtain the same throughput performance and can effectively reduce the base station burden under the same complexity of the algorithm.In summary,the interference suppression scheme proposed in this paper provides a solution to the problem of complex resource allocation and high complexity of the algorithm in the hybrid network of D2D communication and has great theoretical value.