| Due to the rapid development of wireless communication technology,the 5th generation(5G)mobile communication network has been commercially deployed in many parts of the world and widely used in all walks of life.Opportunities and development are accompanied by challenges.The exponential growth of the number of intelligent terminal users has already made the limited spectrum resources more scarce.Therefore,along with the improvement of hardware production and development level,the former non-orthogonal multiple access(NOMA)technology has gradually been refocused by academia and industry,becoming a research hotspot and is expected to be implemented from theory.In the fourth generation(4G)wireless mobile communication system,orthogonal frequency division multiple access(OFDMA)technology,as one of the typical orthogonal multiple access(OMA)technologies,has been unable to meet the future large-scale machine communication(m MTC)application scenarios.In contrast,NOMA allows multiple users to share the same spectrum resources,greatly improving the spectrum utilization and system capacity,and can meet the data rate requirements of5 G network level and user experience level at the same time.Non-orthogonal multiple access based on power domain multiplexing(PD-NOMA)and non-orthogonal multiple access based on code domain multiplexing(CD-NOMA)are considered as the two most important candidate technologies for multiple access in 5G mobile communication systems.This paper first introduces two typical NOMA technology studies,including PDNOMA and Sparse Code Division Multiple Access(SCMA),analyzes the key technical principles of each technology,and provides relevant single carrier NOMA system link simulations.Then,regarding the various human and environmental interferences that NOMA technology may face when widely applied in various complex and ever-changing scenarios in the future,this article introduces several different types of typical strong interferences,and also demonstrates typical interference detection and suppression technologies proposed for strong interferences.The above interference detection and suppression algorithms are simulated based on the SCMA system.Finally,in order to improve the effectiveness and reliability of communication in the NOMA system and enable users to improve their ability to suppress interference while enjoying service,an algorithm improvement was made for interference elimination in the PD-NOMA system.The simulation results obtained show that the improved algorithm is more suitable for single carrier NOMA systems in interference environments. |
