Mode Selection And Interference Management Of Device-to-Device Communication Underlaying Heterogeneous Networks

With the rapid increase of the portable terminal equipments and the development of video,voice and other multimedia services, increasing demand for bandwidth wireless communication and limited wireless network resources has become a major contradiction.How to improve the utilization of limited spectrum is an important research direction.D2 D communication is a new technology which allows the proximity user terminals communicate directly. Due to its advantages of improving spectral efficiency, reducing transmission delay, power consumption of the mobile terminal and the load of the base station, D2 D communication becomes the focus in recent years. Despite the advantages,when D2 D communication is introduced into a network system, D2 D users might cause interference to the original user, while the original user will also affect the communication of D2 D communication users. In this paper, we study the mode selection and interference management, so as to minimize interference between the D2 D users and the system,maximizing the advantages of D2 D communication technology.Firstly, we made some research about D2 D communication in wireless local area networks,WLAN is able to provide high data rate with low cost. As WLAN coverage is small, users are close to each other. D2 D communication can applied in this area, and network performance will be further improved. Accordingly, we propose D2 D communication system and modes in WLAN network. And make a brief analysis of D2 D interference under WLAN.Secondly, this paper has a deep study about D2 D communication mode selection and interference management underlaying heterogeneous network. Heterogeneous networks refers to the networks consisting of LTE cellular network and IEEE 802.11 n WLAN. For mode selection, firstly, we propose a new D2 D communication mode, therefore D2 D communication in heterogeneous network has five alternative modes: LTE cellular network-traditional mode, LTE cellular networks-reuse mode, LTE cellular network-dedicated mode, WLAN- traditional mode and WLAN-dedicated mode. To make users work in the best D2 D mode to maximize system performance, we choose LTE cellular network or WLAN based on user's WLAN access need and the user terminal's location, multi-homing users are also considered. Finally, we select D2 D communication mode to maximize spectral efficiency. For interference management issue in heterogeneous networks, this paper analyzes the three-tier interference D2 D suffered in heterogeneous networks, and propose a spectral queue interference management algorithm, in case of abundant resources and lack of resources.Finally, we also set up a heterogeneous network simulation platform based on LTE cellular networks and IEEE 802.11 n WLAN,with D2 D module introduced. Simulation results show that the mode selection algorithm and interference management algorithm we propose can improve spectral efficiency and system performance.