Transmission Design Of MIMO Based On USRP In High-speed Railway Environment

Currently,GSM-R system is the most mature wireless communication network for railway applications.Because it is responsible for the transmission of various control information and scheduling commands,its reliability has become a research project for many researchers.The existing GSM-R technology can only meet the basic network coverage requirements of the area along the railway.The multipath effect caused by the high speed of the train movement and the complex and varied terrain has directly influenced the communication quality of the system and cannot meet the demand of reliable transmission.Therefor,the GSM-R system has introduced multiple-input-multiple-output(MIMO)technology to improve the communication quality of the system.In the field of wireless communications,MIMO technology is a crucial new technology.It can significantly increase the capacity,spectrum efficiency and wireless coverage of wireless communication systems without increasing power and bandwidth,and it also other characteristics,such as,reducing deep fading and the error rate.The base station side in the GSM-R system is more suitable for using the MIMO technology to perform diversity gains on the transceiving antennas,and it is feasible to combine the operability with the reliability of the GSM-R system.This dissertation focuses on the Space Time Block Code(STBC)of MIMO technology,deeply explores the design of space-time block coding schemes,analyzes the performance of the various combined technologies at the receiving end,and derives the most excellent coding algorithms.The Matlab simulation analysis under the WINNERII channel model of the high-speed rail environment confirms the performance of the coding and decoding scheme.This dissertation adopts the software radio platform which is combined with LabVIEW+USRP-2920.The principle and structure of the hardware platform,the work flow and performance characteristic of software are introduced.Under the WINNERII channel simulating the high-speed rail environment,a 2×2 MIMO transceiver platform was set up,the program flow of the experiment sending end,the USRP running part and the receiving end was introduced,and the diversity algorithm,symbol synchronization,carrier synchronization,frame synchronization,channel estimation and merging algorithms in the experimental program are studied separately.The results verify the implementation of multi-antenna MIMO transceivers.In the end,based on the platform,different debugging methods of the system are compared.The test result shows the best modulation method and obtains that the transceiver has good performance and can meet the demands of GSM-R.