Interference Coexistence Study Of IMT-2020 System And ISS/EESS System

On 26-30 October 2015,the Radiocommunication Assembly(RA)held in Geneva,Switzerland,the ITU Radiocommunication Sector(ITU-R)formally identified the legal name of 5G as "IMT-2020".Similar to the previous mobile communications in the past,apart from the urgent need of evolution and innovation of communication technologies,as an important carrier of information,spectrum resources are irreplaceable core resources of great strategic importance and are also very important for the development of IMT-2020.According to ITU-R prediction,the IMT-2020 system will require more than 1000 MHz of spectrum by 2020.Due to the limited available spectrum in the existing low-band part,high-band resources need to be extended to meet the ultra-high speed and ultra-high capacity service requirements of the IMT-2020 system.At the World Radiocommunication Conference(WRC-15)conference in 2015,the WRC-19 1.13 issue was decided to conduct a compatibility study of the IMT-2020 system with existing services in 11 candidate bands in the frequency band 24.25-86 GHz for IMT-2020 In high-frequency spectrum search resources.This thesis is selected in the major project of national science and technology "IMT-2020 candidate band analysis and evaluation".The paper studies the coexistence of interference between IMT-2020 system and other services to determine the feasibility of deploying IMT-2020 system in high frequency band.The main consideration is the existing space services in the 24.25-27.5 GHz and 37-43.5 GHz bands,including Inter-satellite Service(ISS)and Earth Exploration Satellite Service(EESS).In this dissertation,IMT-2020 system,ISS and EESS are briefly introduced.According to ITU and 3GPP standards and Recommendations,the system parameters,propagation models,antenna models and interference protection criteria that need to be referenced in interference coexistence research are proposed.The co-existence of interference between systems provides a theoretical basis.In view of the coexistence of interference between IMT-2020 system and ISS,this dissertation uses the deterministic analysis method to get the interference value of IMT-2020 base station to ISS relay satellite in 24.25～27.5GHz band.And the system-level simulation method is used to analyze the IMT-2020 base station’s aggregate interference to ISS relay satellites.The theoretical analysis and simulation results show that the IMT-2020 base station’s aggregate interference to the ISS relay satellite receiver is less than the maximum interference value it can tolerate.Therefore,IMT-2020 will not interfere with ISS in this band of 24.25～27.5GHz.In view of the coexistence of interference between IMT-2020 system and EESS,this dissertation obtains the interference value of EESS(space-to-Earth)to IMT-2020 base station at 24.25～27.5GHz using deterministic analysis method and the interference value in 37～43.5GHz band Under the EESS(Earth-to-space)interference value to IMT-2020 base station,the analysis results show that EESS(space-to-Earth)will not cause interference to IMT-2020 base station,and EESS(Earth-to-space)will interfere with IMT-2020 base stations and provide the extra isolation required.Then the system-level simulation method is used to analyze the aggregate interference of IMT-2020 base stations to EESS(space-to-Earth)earth stations at 24.25～27.5 GHz and the IMT-2020 base stations to EESS receivers(ground to earth)at 37～43.5 GHz.Simulation results show that IMT-2020 base stations have a small probability of impact on EESS(Earth-to-space)earth stations with a small probability of aggregate interference to EESS(Earth-to-space)earth stations,and give corresponding interference avoidance suggestions.while the IMT-2020 base station will not interfere with the EESS(Earth-to-space)altitude receiver.