Research On The Key Technology Of F-OFDM In 5G Mobile Communication System

The 5th generation mobile communication system faces the challenge of complex and diverse business scenarios.The OFDM(Orthogonal Frequency Division Multiplexing)system has the advantages of easy combination and high spectral resource efficiency and is widely used in 4G,but some defects inherent in orthogonal frequency division multiplexing make it difficult to meet future 5G communication requirements.The new air interface technology must be able to adapt to the needs of complex and diverse business scenarios.Based on the research of OFDM technology in 4G mobile communication,this paper analyzes and compares several new air interface technologies,and gives an optimized F-OFDM(Filtered-OFDM)system based on new waveforms.First of all,the theoretical basis of F-OFDM technology is studied,including the analysis and study of the basic principles of OFDM technology and the analysis of wireless channel characteristics and channel models.Based on this,the basic idea of F-OFDM and its advantages of F-OFDM system are introduced.Secondly,the basic principle of F-OFDM system is expounded.Based on the theory of OFDM coding in 4G,the design and implementation of F-OFDM system is studied.In the new system,the carrier frequency band of the OFDM system is divided into different sub-bands that can support multiple types of services.Each sub-band will be configured with appropriate parameters according to the actual needs of the scenario,and the filter with better performance is added to each sub-band to weak the out-of-band frequency spectrum leakage of each sub-band.The sub-band filter is generated using a window function method that is easy to implement and has good filtering performance,and uses a low-complexity frequency domain filter,which greatly improves the time efficiency of the filtering operation of the F-OFDM system.Then the performance of the F-OFDM system is analyzed through simulation.The results show that the F-OFDM system has the characteristics of flexible resource configuration,good asynchronous performance and high spectrum utilization,which can better meet the requirements of diverse services and meet future communication needs.Finally,the problem of high PAPR(Peak to Average Power Ratio)in OFDM system is optimized in the F-OFDM system.The first is to study and analyze several classic algorithm to reduce the peak-to-average ratio and to analyze and compare the advantages and disadvantages of various algorithms.Then a scheme to suppress the signal PAPR of F-OFDM systems is presented,which effectively reduces the requirements of components in the system.It can be seen from the simulation curve that this method is a very effective scheme to reduce the PAPR of F-OFDM system.