Research On Key Technologies Of Wideband Wireless Channel Measurement And Modeling Under High-speed Mobile Condition

The explosive demands for mobile Internet and the rapid development of high-speed railway make it necessary to develop a wideband mobile communication system which adapts to the high-speed mobile scene. As the basic instrument of communication system development, channel model needs real data urgently for modeling or verification. Under this background, this paper studies the method and problems of wideband wireless channel measurement using LTE downlink channel to measure under high-speed mobile conditions, and utilizes the real data captured by the self-made channel sounder in the LTE trial network along the Beijing-Tianjin high-speed railway to analyze and model wideband wireless channel under the high-speed mobile conditions.Firstly, this paper briefly reviews the basic methods and principles of channel measurement and introduces general channel characteristics, the features of wideband wireless channel under high-speed mobile conditions and the basic process and general considerations of channel measurement campaign.Compared with the self-transmitting detection signal, utilizing the cellular network signal to measure channel has various advantages, such as avoiding the control of self-transmitting signal and limitation of the coverage of self-transmitted signal, etc. Thus this paper studies the basic principles of using LTE downlink signal to measure channel, analyzes its feasibility, targets of each measuring parameters as well as the access problems in live measurement and introduces the self-made channel sounding platform.Then the paper discusses the influence of non-ideal factors on channel measurement using LTE downlink signal and gives general conclusions. The non-ideal factors include timing error, frequency offset, inter-cell interference and RRU interference under the specific deployed high-speed rail network.Finally, the paper describes the channel measurement campaigns in the LTE trial network along the Beijing-Tianjin high-speed railway, and analyzes the path loss, K factor, statistical model of multipath parameters and the2x2MIMO correlation coefficients of the channel under specific station platform scene on the way.