Research And Implementation Of Wireless Channel Emulation Method For Virtual Drive Test

With the rapid development of wireless communication technology,the applications of wireless communication network are becoming more and more diversified.The wireless communication technology is not only limited to apply in the traditional public networks,but also rapidly developed to apply in some private networks for industry-specific applications.Especially the upcoming fifth-generation mobile communication(5G),which is characterized by high reliability,low delay,and low power consumption,will bring qualitative changes to the industry and create a new network world by Internet of Everything.Under the diversified network the number of new types of terminals has appeared and increased dramatically,which greatly increases the drive test requirements during network construction,and also brings a large number of terminal performance testing work.The traditional drive test method is time-consuming,inefficient,and cost-intensive,which is difficult to meet the huge drive test business needs.The semi-physical emulation test in laboratory based on the standard statistical channel model is relatively simple,and more mathematical assumptions are used.Thus it has some differences to the real channel scenario,which makes it difficult to present the influence of the wireless channel on the propagation performance of the wireless communication system.Because of the shortcomings of the traditional drive test method and the semi-physical emulation method based on the standard model,this paper proposes a wireless channel emulation method for virtual drive test,establishes a virtual drive test system in the laboratory,and achieves the test verification.The scheme obtains the characterized parameters of wireless channel by processing the real drive test data,and realizes the wireless channel reproduction with the wireless channel emulator,thereby reproducing the field test environment in the laboratory,thus to replace part of real drive test work.This solution can significantly improve test efficiency,shorten terminal time to market,speed up network deployment and optimization,and reduce costs of network construction and maintenance.The main work and innovations of this paper are as follows:(1)Based on the measured data,the characteristics of wireless channel is investigated.The influence mechanism of path loss,shadow fading,small-scale fading,noise and interference,MIMO channel correlation on the performance of wireless communication system is analyzed,and the emulation method of wireless channel characteristics suitable for hardware is proposed;(2)The recording method of wireless channel characteristic parameters applicable to the virtual drive test is studied,the drive test system which can reflect the characteristics of the field channel to the greatest extent is designed,and the problems existing in the test process and the corresponding reasonable solutions are studied;(3)A virtual drive test system is established in the laboratory.By comparing the wireless channel characteristic parameters and QoS test indicators obtained by both the virtual drive test and the real drive test,the virtual drive test scheme and the drive test system proposed in this paper are verified to be effective.The scheme supports a application method with reference value for the virtual drive test in various scenarios.