Research On Self-organizing Network And Ambient Backscatter Of Mobile Communication System

Mobile communications have gradually entered the 5G era.The coexistence of multiple access technologies such as 2G/3G/4G/5G/Wi Fi and heterogeneous networks(macro cell,micro cell,femto cell,5G small cell)has greatly increased network complexity.The existing cellular mobile network has a sharp increase in the difficulty of deployment,operation and maintenance and optimization.Therefore,strengthening the automation of network operation and maintenance,improving operation and maintenance efficiency,and reducing operation costs are urgent needs of operators.Self-Organizing Network(SON)technology uses advanced optimization algorithms to simplify network deployment and reduce manual intervention,thereby improving operation and maintenance efficiency and reducing operating costs.This dissertation discusses the related research progress and engineering application status of SON technology,and tracks and summarizes the research progress of SON technology and the application status and requirements of SON engineering by important international project agencies or standardization organizations.And on this basis,research has been conducted on how to effectively use SON technology on mobile communication networks.Uplink coverage of 5G is severely limited,making 5G network deployments face huge cost pressures.Aiming at the new technology of dynamic spectrum sharing,the development of 4G/5G spectrum dynamic sharing experimental research is of great significance for improving the spectrum utilization of mobile communication systems and saving 5G network investment.With the help of major international projects on the Belt and Road,to address the challenges of 5G network deployment and the trial network opportunities introduced by new 5G technologies,we have established a 4G/5G trial network environment to conduct dynamic spectrum sharing methods under the coexistence of 4G/5G networks research and experimental verification,related research has great significance and engineering value for the current 5G network deployment.In the process of research on wireless sensor network of self-organization technology,it is found that energy efficiency and power supply problems are always a basic bottleneck problem to be solved in wireless sensor networks.The direction of backscatter technology for communication has been tracked and studied.As a very promising technology for low-energy communication systems,environmental backscatter technology combines the convenience of wireless and the low energy consumption characteristics of green communication,and is a wireless technology with great commercial value and potential.The main research contents and results are as follows:(1)To address the current challenges faced by LTE cellular mobile networks in network deployment,operation and maintenance,and optimization,the research has investigated the relevant progress and engineering applications of mobile communication network optimization technologies including SON technology,and explained its basic principles and key technology and main algorithms.(2)Focus on the dynamic spectrum sharing(DSS)algorithm of SON,using the 4G/5G trial network environment to study 4G/5G supplementary uplink and dynamic spectrum sharing methods.Designed the PRB allocation principle for 4G/5G spectrum resource sharing(4G/5G resource allocation principle of dynamic spectrum sharing),and evaluated the network uplink rate gain obtained after enabling 4G/5G dynamic frequency sharing,the key performance indicators of the existing 4G network,and the influence of the uplink interference level of the 4G network.It can be seen from the experimental results that when dynamic frequency sharing takes effect,an average 2.43 times uplink rate gain can be obtained,and the interference effect on the 4G network is relatively small,and it does not cause obvious disadvantages to the perception of the existing 4G network users and the performance of the 4G network,and the effectiveness of the proposed PRB allocation principle is verified.(3)For the first time,backscatter technology was introduced into the wireless communication system of high-speed rail senario,and a Backscatter Aided Wireless Transmission(BAWT)scheme was proposed to reduce signal penetration loss and improve channel estimation performance.And for BAWT and the traditional direct wireless transmission scheme(DWT)we conduct the transceiver design,including channel estimation and signal detection.In terms of channel estimation,by comparing BAWT and DWT transmission schemes,the accuracy of BAWT scheme channel estimation is better than that of DWT scheme.In terms of signal detection,the BAWT scheme is better than the relay technology and the DWT scheme overall.Compared with the existing direct transmission and relay technology of high-speed rail wireless communication,the use of ambient backscatter technology can improve the performance of the existing wireless communication system in the high-speed rail scenario.For the ambient backscatter communication in the wide area environment,the link budget calculation methods of the environmental backscatter in the high-speed rail scene is proposed,and the feasibility of the BAWT solution in the wide area environment is demonstrated from the link budget perspective.(4)The lower and upper bound of the channel capacity of the Ambient Backscatter Assisted Wireless Transmission(BAWT)scheme are derived.Through theoretical analysis and simulation verification,the BAWT channel capacity is higher than the DWT channel capacity under the same SNR,and the BAWT scheme can achieve a significant increase in channel capacity.In addition,when the BAWT scheme increases the channel variance it can obtain a higher data transmission rate than the traditional DWT scheme.