Research On D2D Communication Resource Allocation In Cellular Networks Based On F-OFDM

The International Telecommunication Union has defined three application scenarios for the fifth generation(5G)mobile communications networks:enhanced mobile broadband,massive machine type communications,ultra-reliable and low latency communications.Massive machine type communications put forward higher requirements for the frequency band utilization of the system and other communication equipment such as the base station.Due to the direct communication mode,Device-to-Device(D2D)communication has a wide application prospect in improving the frequency band utilization and reducing the pressure of the base station.In addition,facing a variety of 5G communication scenarios,many 5G candidate waveform technologies have been proposed.Using filtered orthogonal frequency division multiplexing(f-OFDM),one of the 5G candidate waveform technologies,as the waveform technology,this thesis constructs a new cellular D2D communication system model.By applying f-OFDM to the cellular network D2D communication system,it can support the simultaneous existence of cellular users with different service requirements in the system,and D2D users can reuse the resource blocks of cellular users in the system.Based on the proposed system model,the following two aspects are further studied:1)In order to improve the access number of user links in the system,this thesis proposes an D2D iterative Resource Allocation scheme Based on Hungarian algorithm(DRABH),which iteratively allocates resources for cellular users and D2D users by continuously adjusting the weight between users and resource blocks.When setting the weight between the user and the resource block,DRABH fully considers the impact of user self-interference,user interference in subband and user interference between subbands when the user uses the resource block for communication so as to ensure that the user meets the minimum communication rate and minimize the interference suffered by the user and the interference caused to other users,so that more users can be accommodated in the limited resource block for communication.The simulation results show that the resource allocation algorithm proposed in this thesis can significantly improve the number of user links in the system.2)Aiming at the one-to-one multiplexing mode between D2D users and cellular users,in order to improve the total communication capacity of users in the system,a user matching algorithm to maximize the communication system capacity is proposed.By solving the best matching between D2D users and cellular users,the reusable communication resources are selected for D2D users.When setting the intention value between cellular users and D2D users,user matching algorithm comprehensively considers the gain and interference of both sides,and finds a suitable cellular user for D2D users through multiple rounds of pairing,and reuse the resource block of the cellular user for communication.Simulation results show that the user matching algorithm proposed in this thesis can significantly improve the communication capacity of the system.