Performance Analysis Of Asynchronous Multicarrier D2D Communications

In recent years,along with the continuous development of mobile telecommunication technology all over the world,the wireless communication system has been developed from the first generation represented by voice business,to the fourth generation represented by high speed mobile data business.The fourth-generation has been in use on a large scale.With the growing number of mobile users,new business opportunities are brought,but with the pressure of limited spectrum and high energy consumption.Therefore,the next generation of mobile communication technology(5G)begins to be the great concern of the industry.As the key technology of future 5G,D2 D communication allows the direct communication between devices without the relay of BS,reusing cellular frequency resources.Compared with the traditional communication mode,D2 D communication can save spectrum resources,increase network capacity,reduce energy consumption of the terminal,shorten the time delay and so on.Therefore,it is important to do further research on the system-level analysis of device-to-device(D2D)node discovery in Public Safety(PS)scenario.This thesis mainly considers the system-level performance analysis of neighbor discovery in the asynchronous device-to-device(D2D)networks,assuming that the physical layer uses the OFDM technology.The performance analysis of neighbor discovery in the asynchronous device-to-device(D2D)networks can be seen as the performance analysis of asynchronous OFDM networks in a particular scenario.Firstly,we develop a detailed link-level analysis on the impact of timing misalignment in OFDM transmission.Based on the link-level analysis,we build a tractable first-order signal-to-interference-plus-noise ratio(SINR)model,which can be conveniently used in system-level studies of asynchronous device-to-device(D2D)networks.It solves the difficulty in the system-level modeling.Secondly,on the basis of the proposed SINR model,we study the system-level performance of asynchronous device-to-device(D2D)networks where the locations of devices are modeled by a PPP and an OFDM waveform is used.From the point of view of discovering device,we analyze several important statistics,including the number of decodable devices,the decoding probability of the nearest device,and system throughput.Finally,in order to reduce the loss,we compare and discuss four possible solutions including extended cyclic prefix,receiver timing advance,dynamic receiver windowing and semi-static receiver windowing.These solutions differ in complexity and may be applicable in different scenarios.