Research On Communication Technology Of Filtered Multitone Modulation

It is well known that wireless and broadband technology is a hot research topic in today's communication industry and even the whole information industry.With the rapid development of Internet services,users have higher requirements for network throughput and mobility.Wireless communication plays an important role in it.However,the communication environment of wireless communication is a communication environment that changes with time,environment and other external factors,so it still faces many challenges.In the digital transmission system,with the continuous improvement of data rate,the existence of inter-symbol interference(ISI)greatly limits the performance of single carrier system due to the delay expansion and the limitation of channel bandwidth,and becomes an obstacle to improve the data transmission rate.Multicarrier transmission technology is an effective way to overcome ISI.Multicarrier technology can be divided into two categories according to its subcarrier spectrum: one is the non-overlapping mode of subchannel bands represented by Filtered Multitone Mdulation(FMT),the other is the overlapping mode of subchannels represented by OFDM.OFDM technology originated in the mid-1950 s and has been widely studied for its anti-multipath interference advantages.Even so,OFDM technology has many shortcomings,such as weak resistance to frequency offset and phase noise;secondly,in order to maintain the orthogonality of subchannels and combat multipath interference,it is necessary to insert cyclic prefix and virtual carrier,which reduces the spectrum utilization of the system and improves the complexity of system implementation.Compared with OFDM,Filtered Multitone(FMT)Modulation technology is a relatively new technology.It also has good anti-multipath effect.Unlike OFDM,FMT uses filter banks in frequency domain to make each sub-channel not overlap with each other and has high spectral constraints,so that the sub-carriers remain strictly orthogonal.Therefore,the system overcomes FMT system's sensitivity to frequency offset.Shortcomings.It is also one of the standards of VDSL technology,so it has broad application prospects in future wireless communications.This paper mainly studies the basic principle and implementation of FMT technology,focusing on the prototype filter design and filter bank polyphase decomposition,PAPR issues.Firstly,the development of FMT and OFDM technology is described,then the basic principles and implementation models of FMT and OFDM are analyzed,and the subchannel partition mode,system structure,performance and complexity are compared.Secondly,we focus on the efficient implementation of FMT system,including the design of prototype filters and filter banks,and build a complete FMT system for simulation and verification.Finally,the PAPR problem of FMT system is studied,and its PAPR distribution is simulated and compared with that of OFDM system.Finally,a method of improving the PAPR performance of FMT system by using the limiting method and selective mapping method is proposed,and the optimization results are simulated.