Performance Analysis For Relay-based Device-to-Device Communication System In LTE Networks

People all the world have more expectations for mobile telecommunication technology, suchas the individuation of service, higher data transmission speed, longer duration batter life andlower transmission delay, which generates great challenges for the design of the next generationmobile communication system, such as LTE. Recently, higher spectrum efficiency and longerduration batter life are two hot subjects in academic and industrial area. Based on cellularnetwork and under control of base-station, D2D(Device-to-Device) technology is a newtechnology enabling people who are in short distance to exchange their own information directlyinstead of relaying data through base-station. Intuitively, D2D technology not only relieves theburden of cellular network and enhances spectrum efficiency or system throughput, it has thecharacteristics of low transmission delay and high energy efficiency. D2D technology is differentfrom traditional short-distance communication technology such as Bluetooth in that it is undercontrol of the cellular network. In this thesis, we focus on reliability and capacity analysis forrelay based D2D communication system in LTE networks. According to the subjects we researchon, we have the structure of this thesis as follows:The thesis firstly illustrates the history of mobile communication technology and its currentresearch status. Meanwhile, this thesis introduces the network structure and key technology ofLTE as backgrounds of our research on D2D communication system. Secondly, the thesisdescribes the concept and characteristics of D2D technology and compares it to othermachine-to-machine technology. Meanwhile, the thesis points out its benefits for cellularnetwork and draws a conclusion of the current research on this technology. Lastly, the thesisconcentrates on the author’s research on reliability and capacity analysis for relay based D2Dcommunication system, and comes up with a QoS guaranteed power control mechanism and putsforward a cross-layer design framework for D2D communication system. By theoreticaldeduction and simulation, the thesis draws a conclusion that adding relay properly does help toimprove the reliability and capacity of D2D communication system, and that longer distancebetween D2D users and lower SINR target for D2D communication prompts the use of relay, andthat the distance between D2D users can be a key factor for higher layer flow control.