Performmance Analysis Of Communication System And Study On Resource Allocation Algorithms In FeD2D

With the popularization of low-cost wearables and IoT devices,it is a hot research that connecting such devices into the network and managing them effectively in the 5th Generation mobile communication technology(5G)standardization currently.The characters of these devices are limited bandwidth,low complexity,low cost,and high energy saving requirements.The 3rd Generation Partnership Project(3GPP)standardization work group carries out research on Further Enhancements to LTE Device to Device(FeD2D).The technology aims to enable relay communication between wearable devices or IoT devices and base stations by using traditional cellular users.In this work,some researches on FeD2D communication technologies and some system level simulations of sidelink communication are realized.In addition,the system performance is improved in two aspects of link adaptation and power control scheme.Under the condition of limited spectrum resources,massive connections put forward higher requirements for system resource scheduling.Resource reuse is an effective method to improve resource utilization.However,when multiple communication links occupy the same time-frequency resources,they will generate co-channel interference with each other.To address this problem,this paper proposes two resource allocation algorithms firstly.A minimum interference distance,dmin,that maximizes the system reception success rate is obtained through analysis and calculations.The same resources can be reused by interference link and communication link when the distance between the interferer and the receiver is greater than the value above.Based on dmin,a resource allocation algorithm based on collision avoidance and a resource allocation algorithm based on user grouping are proposed,both to improve system performance by reducing the probability of resource collisions.Further,considering the shortcomings of scheduling by base station,generating delay and a large amount of signaling overhead,this paper proposes a resource allocation algorithm based on link feedback.First,the pilot signal is transmitted by the transmitter autonomously,and received and demodulated by the receiver.Then the receiver feeds the results back to the transmitter.Finally,the transmitter makes a decision to cancel the communication qualification of the partial links.In this work,the scenario that the remote UEs are IoT devices is imodeled and simulated in system level.Firstly,simulation analysis of the random assignment algorithm based on communication protocol is realized.Then,it turns to the simulation analyses of the proposed three algorithms.By comparing users' average throughputs and average energy efficiencies under the different resource allocation algorithms,it is shown that the proposed algorithms can improve the system performance effectively.