Capacity Optimization of Full Duplex Architectures in D2D Systems underlaying Cellular Networks

Abstract

Abstract -Cisco has predicted that by 2020 nearly 50 billion mobile devices will be connected to the wireless network, which will put significant pressure on capacity improvement. Hence one of the main feature of a 5G network is to enhance the spectral efficiency to meet the ever increasing demand of larger wireless data traffic volume. Full duplex (FD) transceivers have the potential to double the spectral efficiency of a wireless system if considerable amount of self interference cancellation is achieved. Unlike Half Duplex (HD) systems, where transmission and reception of a signal takes place on a different frequency band or time slot, full duplex systems are capable of transmitting and receiving simultaneously in the same band and time slot which can improve the overall spectral efficiency of the system. However, in a multi user scenario the co-channel interference is the main limiting factor in deploying FD communication. Therefore in order to draw legitimate conclusions about the throughput gains, in a FD system, multi-user scenarios needs to be studied.In my work I have proposed radio resource allocation problem for full duplex device-to-device (D2D) communication under laying cellular network. Unlike previous works, a new FD-D2D system framework has been proposed for the wireless cellular network, in which D2D users operate at full duplex. We consider different scenarios of resource allocation between uplink frequency resources of cellular users which are shared by the FD-D2D pairs. A greedy iterative algorithm is proposed which maximizes the rate of the system, while meeting the minimum rate requirements of the cellular users. The FD-D2D users switch from FD mode to HD mode if the system interference is high. Simulation results show that in perfect self interference cancellation (SIC), the proposed scheme gives considerable spectral efficiency gains. However a trade off is achieved between maximum system capacity and number of operating users in the system.