Research On The Coexistence Interference Between NB-IoT And LTE&5G Systems

With the coming of the Internet of Everything,more and more technology of Narrow Band Internet of Things(NB-IoT)is used in everyday life.Since the introduction of NB-IoT technology in 3GPP Release 13,NB-IoT has developed rapidly,bringing a better coverage experience for communication between objects and objects,or people and obj ects.NB-IoT is part of the LTE evolution roadmap and can be deployed directly in the existing LTE network spectrum,working in adjacent frequency bands.Due to the undesirable characteristics of the transmitting filter and the receiving filter,interference occurs between wireless communication systems in the same or adj acent frequency bands,which in turn affects the service quality of the communication system.Therefore,how to carry out fr-equency planning is the primary consideration in LTE NB-IoT deployment.With the unification of 5G standards and commercialization,NB-IoT has used its ubiquitous coverage capability to lay a solid foundation for 5G NB-IoT.5G will inevitably bring new capabilities to NB-IoT in the future.Therefore,research work on interference coexistence and spectrum compatibility between NB-IoT system and 5G system is also urgently needed.This paper makes a qualitative analysis of the coexistence interference between systems firstly,and then builds a simulation platform for quantitative calculation.Based on deterministic analysis and system simulation methods,the interference coexistence problem of NB-IoT systems in middle and low frequency bands is studied in detail.Firstly,for the coexistence problem of two NB-IoT systems around 900MHz,a symmetric bandwidth interference model is proposed,and the performance loss of the system under different protection intervals is analyzed.This thesis gives an proposal on the network deployment and provides technical support for the NB-IoT system's frequency planning in low frequency band.Then,for the coexistence problem of NB-IoT system and LTE system around 2GHz,an equivalent interference model is proposed.The degree of interference between the systems is analyzed under different scheduling modes.This thesis evaluates whether the two systems can coexist in adj acent frequency and provides a theoretical basis for the construction and deployment of the LTE NB-IoT.Finally,for the coexistence problem of NB-IoT system and 5G system around 3.5GHz,a 5G-iot interference resear-ch model is proposed,and the interference between systems is analyzed under the scenario of Massive MIMO.This thesis gives the additional isolation required for the coexistence of the two systems,and lays the foundation for the promotion of 5G NB-IoT frequency band planning.