Design Of Multi-user And Multi-cell Link And Test Analysis Of GFDM System Coexistence In LTE Co-simulation Platform

As the progress of 5G technical standards,it is crucial to build a system simulation platform compatible with 5G and 4G system for the next generation mobile communication.A method called link to system mapping is introduced in traditional system-level simulation to provide link quality metric.In the mapping process of link-level simulation,the complexity of new scene resulting in loss of mapping accuracy,which resulting in lack of authenticity of the system simulation.However pure software link simulation needs a longer simulation period,which can not meet the real-time scheduling requirements of system-level simulation.In order to solve these problems,this dissertation has proposed a method called hardware and software co-simulation,in which SDR equipment USRP is adopted to realize link process of baseband to radio frequency.The hardware link in this approach is used to replace the software link simulation,and system-level simulation provides system information parameters.The hardware link feedback channel quality indicators measured in real time to achieve co-simulation of system-level and link-level,which to eliminate the problem of lossing of mapping performance and timeliness problem of link-level simulation.As flexible reconfiguration of USRP-RIO,the LTE link flow is implemented and new 5G physical layer technologies is also validated.The main work of this dissertation is design the hardware link in the co-simulation platform,build the GFDM system coexistence test link and test the performance of system.The concrete work includes:First,the LTE hardware and software co-simulation platform is built.In the platform,the LTE multi-user and multi-cell hardware link is designed to meet the system simulation requirements based on the USRP-RIO device and Lab VIEW Communications software.The multi-user and multi-cell equivalent to the user interference and cell interference.Among them,9 interference controlled links of interference users are designed for inter-user interference,cell interference is designed to control the interference of 6 adjacent cells to the target cell user.The designed link is tested to verify that the it meets the needs of the co-simulation.And the link is assimilated into the co-simulation platform is tested to verify that improves the mapping precision of simulation and solves the problem of simulation timeliness.Secondly,considering the backward compatibility of co-simulation platform,the GFDM system coexistence simulation link is built to establish the theoretical foundation of test link which is the 5G new technology verification link.From the analysis of the GFDM transceiver link,the transmitter model and the receiver model.This dissertation forces on the difference between GFDM and OFDM,which is in LTE downlink,and highlights the low out of band power of GFDM which is suitable for the system coexistence.Then the effects of bandwidth,GFDM filter and roll-off factor on the system are simulated and analyzed.Third,according to the principle of simulation link,the GFDM system coexistence test link is built based on the USRP-RIO.The test work is done on the platform includes:The influence of GFDM/OFDM transmit power on LTE performance,the influence of GFDM filter roll-off factor on LTE performance,the RB allocation of GFDM/OFDM system and LTE system on the system performance.The test results show that GFDM is more suitable for LTE compatible coexistence system.Through the above aspects of the work,The multi-user and multi-cell link and GFDM system coexistence test link in hardware and software co-simulation platform is completed,and the performance of each link is analyzed through the test validation.