Higher Frequency Wireless Channel Measurement And Modeling

For the last decade, the rapid development of wireless Internet throughout the world, facilitates and enriches people's lives greatly, and effectively eliminate the numerical gap among regions with different levels of development. At the same time, as the cornerstone of wireless Internet technology, wireless communication network is facing unprecedented opportunities and challenges. Recent researches show that adopting the high frequency radio wave in next-generation mobile communication network is feasible. Thus, the high frequency radio mobile communications technology considered as one of the key technologies of 5G, is attracting more and more attentions of a large number of researchers around the world. However, as a result of the complex propagation characteristics of the high frequency radio channel, it is not easy to make the high frequency radio wave mobility, and that is still facing with many problems, such as the large spatial propagation loss and high device cost.Based on the research background above, considering the indoor propagation scenario, this thesis carried out spatial channel measurement and modeling at high frequency band, including 23.5 GHz,28.5 GHz 42.66GHz and 45.36 GHz. In this thesis, main work is as follows.First of all, this thesis gives an overview of the wireless channel both of large-scale and small-scale propagation characteristics, and introduces three typical channel modeling methods, including ray tracing, geometry statistical and correlation matrix, and two channel detection principles, based on time domain and frequency domain, respectively. A summary about high frequency band channel modeling in recent years was listed, covering 28 GHz,38 GHz,45 GHz,60 GHz and 73 GHz.Secondly, according to existing equipment in the laboratory, adopting frequency domain channel detection methods, we improves and builds an automated channel measurement system. The system will effectively increase the dynamic range of classic frequency domain channel measurement system to 110dB by using external signal source as the spread signal source of the vector network analyzer, and the measurable spatial distance extended to 30 m at the same time. Further, the present system can complete multi-position and multi-angle spatial channel measurements under the control of program language, automatically.Finally, by analyzing the measurement data, the large-scale and small-scale spatial channel propagation characteristics of the spatial channel of typical conference room scenario were proposed. For each measuring frequency, the path loss factor and shadow fading factor of the logarithmic distance path loss model were given at both LOS (Line-of-Sight, LOS) and NLOS (Non-Line-of-Sight, NLOS) scenarios, and the parameters which can be used to describe the small-scale fading characteristics, including average delay, rms (root mean square, rms) delay, the average angle of arrival, the rms angle of arrival, delay spread and angular expansion, were listed.By measuring and analyzing the high frequency radio channels in the indoor scenario, both of large-scale and small-scale propagation characteristics, this thesis provides support to the higher frequency wireless communication technology of the next generation mobile communication system.