Research And Implement Of Synchronization Scheme For Heterogeneous Network Of Cellular Network And D2D Network

Device to Device is a new technology which transmitting data between nodes over a direct link. Immediate gain of D2D communication underlay cellular is the capability of enhancing energy efficiency. On theother hand, more importantly, it provides a possibility to introduce a more extensive interconnected mobile communication system in the future. Synchronization is the foundation of a communication network. This paper focuses on D2D techniques based on LTE networks, aimed to research, design and implement a viable scheme that can be used in engineering practice for cell and D2D heterogeneous networks.First of all, in this paper, the heterogeneous networks are analyzed in detail. The paper analyze the sources of synchronization in this heterogeneous networks, then discuss the synchronization technology of Cell synchronization, Sync synchronization and Cell UE synchronization. After that, carry out a detailed analysis for communication synchronization scenarios that may exist in the heterogeneous network including the scenarios of double D2D terminals in different environment and the transitions between them. Based on the analysis before, the scenarios of three D2D terminals and more complex terminals are carried out.Subsequently, this synchronization scheme for the heterogeneous networks are designed. The analysis of communications scenarios shows that the communications are complex in the heterogeneous networks, and consequently, this paper design a practical synchronous state machine as synchronization scheme with state pattern. The synchronous state machine proposed in this paper include two child state machine for downlink and uplink.And each of the child machine are designed into static and dynamic.Finally, based on multithreading technique and the subject technology of D2D in LTE system, this paper finish the implementation of the synchronization scheme designed. And the communication business shows that this synchronization scheme can meet the complex synchronization requirements in heterogeneous networks.