Modeling And Evaluation Of Mmwave Wireless Cellular Networks

The development of mobile Internet and Internet of Things technology has brought new applications to the traditional cellular mobile communication.Information mobile services social network,video live broadcast,mobile cloud computing and other new business needs create the challenge on the development of cellular mobile communication networks.With the global deployment of International Mobile Telecommuncations-Advanced becoming more and more mature,the spectrum resources of IMT are facing enormous pressure and the gap between actual demand and supply of spectrum resource is growing.In order to close the gap,the standardization organizations and research community are considering the possibility to deploy IMT-2020 in millimeter wave bands.As we all know,to use a new frequency band in a communication system,there are three basic questions called WWH(Which,Whether,How)that need to be solved:Which candidate frequency band and scenario is applicable(Which problem)?Can the candidate frequency band meet the requirements of the communication system(Whether problem)?How to realize coexistence with the existing co-frequency system(How question)?Based on the 3 questions,this paper conducts in-depth research on the analysis the propagation characteristics of cellular system in mmWave,the key capability evaluation method of typical cellular system in mmWave bands,the research on the compatibility between cellular systems in mmWave and different systems,and the performance enhancement of cellular system in mmWave based on Reconfigurable Interface Surface.The main research work and innovation points of the paper mainly include the following four points:1)Channel modeling and characteristic analysis of mmWave cellular systems.In order to solve the applicability issue of mmWave cellular system(which?).The paper firstly provides candidate frequency bands suitable for millimeter-wave cellular systems by modeling the mmWave propagation model and analyzing its propagation characteristics.The corresponding test environments of mmWave cellular networks are first classified and their characteristics are summarized;then,based on different test environments,a geometric channel statistical modeling method suitable for mmWave cellular systems is carried out.The analysis method of millimeter wave channel characteristics is further proposed,and the test environment and corresponding propagation characteristics of millimeter wave wireless communication system are studied combined with the proposed four test environments.The above research proves the conclusion that mmWave has certain applicability in certaincellular system.2)Evaluation method of key capabilities of mmWave cellular networks.In order to evaluate whether the mmWave cellular networks can meet the rdemand for the IMT system(Whether problem?),this paper is based on IMT-2020 defined by thcITU-R and further study its specific evaluation scheme in mmWave cellular networks.Meanwhile,system-level simulation platform is built according to the mmWave channel characteristics and the characteristics of the mmWave cellular networks described above.Finally,based on builting system-level simulation platform,the performances of the mmWave cellular wireless mobile system in different test environments are evaluated,and the achievable performance of mmWave cellular networks are analyzed and evaluated,which lays a research foundation for mmWave cellular networks of IMT-2020.3)Analysis of Interference&Coexistence Performance of Millimeter-Wave Cellular Systems.In order to solve the coexistence problem between the cellular system and the existing co-frequency system in the millimeter wave frequency band(How problem),and avoid harmful interference to the co-frequency satellite system.This paper studies the compatibility of 26GHz and 40GHz nunWave cellular networks with the same frequency satellite earth exploration service and fixed satellite service.First,the coexistence system modeling between the millimeter-wave cellular system and the ground satellite service is carried out,and the "isolation distance" in each coexistence scenario is provided;then,the advantages brought by the combination of mmWave cellular system and AAS sidelobe suppression technology are analyzed,further evaluated the suppression ability of the system sidelobe to the same-frequency service interference by increasing the number of antenna elements.Finally,through comparing the traditional "isolation distance"scheme and the benefits and drawbacks of the scheme of increasing the number of antenna elements.It also puts forward a new coexistence scheme,which provides a technical basis for the establishment of electromagnetic compatibility specificationof mmWave cellular networks.4)the performance enhancement of cellular system in mmWave based on Reconfigurable Interface System.Based on the above results,it can be seen that,although the mm Wave cellular networks can achieve the performance indicators of the IMT-2020.However,when compared with the mid-low frequency band,there is still gap in the practicability and coexistence conditions of mmWave cellular networks in some test environments.In order to solve this problem,the research in this paper is based on RIS,it can further improve the performance and coexistence of mmWave cellular networks.This paper first introduces the applicable scenarios of RIS,and then building mathematical modeling through the mmWave cellular networks introduced by RIS and proposes channel estimation approach suitable for different scenarios.The proposed approach solves the beam tilt problem of wideband channel estimation and is superior to the existing schemes in terms of estimation error and computational complexity.The above research can effectively improve the network performance and coexistence capability of mmWave cellular networks.