Architecture Of Software Defined System And Radio Resource Management For LTE D2D System

Device to Device is a new technology which transmitting data between nodes over a direct link. In the scenarios where D2D is deployed, the links are usually short-distant with high channel quality, which are proper for services that require high data rate, low latency and low transmitting power. By introducing D2D network as a heterogeneous network, the performance of coverage and local applications for LTE system can be improved.The paper discuss the architecture of the heterogeneous network and the approaches to reuse the radio resources. In this paper, the D2D network will be self-organizing without assistance from the cellular, and the uplink resource of cellular is reused by D2D nodes. In the D2D network, statistical time division multiplexing is used for resource competition. A D2D wireless protocol stack is designed, which includes RLC, RRC, MAC and PHY. The transmitting technology for PHY is specifically illustrated.A detail architecture design for implementing the D2D protocol stack on software defined radio platform is discussed. First the paper analyze the functionalities of the protocol entities. Hence the protocol entities are converted to independent modules. To guarantee the real time signal processing, the stack is based on a message driven model. After demonstrating details of each module, the internal message design is specified, by which the interactions among different modules are also discussed. By running real world application, the architecture is proved to be able to carry high-rate data services and can meet the expectation of building D2D network.