Design Of Transmitter And Receiver Module About Radio Over Fiber Based On Generalized Frequency Division Multiplexing

With the progress of science and technology,mobile communication is also constantly updated.The fifth generation communication technology(5G)has become the focus of communication technologies.One of the alternatives in 5G is Generalized Frequency Division Multiplexing(GFDM),which has become the research focus for researchers.Due to the advantages of flexible non-rectangular filter,and small sidelobe bandwidth and high spectrum utilization,GFDM modulation technology has been used in optical fiber communication system.Based on the specific significance and the background of the research,the key technology of the Radio Over Fiber communication(ROF)and the Generalized Frequency Division Multiplexing is studied in the system,including principle of the modulation and demodulation for Generalized Frequency Division Multiplexing technique and ROF technology.Based on the advantages of GFDM technology in the ROF access system,paper focuses on the transceiver module and the related performance in the ROF system and designs an improved ROF simulation system based on the Generalized Frequency Division Multiplexing,and analyzes the link characteristics of the ROF system.Then,due to the performance of the ROF system is easily affected by the nonlinear distortion,in order to reduce the signal PAPR for Generalized Frequency Division Multiplexing,paper has a research on Selective Mapping algorithm(SLM)based on GFDM and has an analysis of PAPR and the the performance of the system on different rolloff-factor and different pulse shaping filters;at the same time,based on the GFDM selection mapping algorithm,paper has proposed Random Filtering Mapping algorithm based on GFDM(RFM)to reduce PAPR of GFDM signal,improve spectrum efficiency,and enhance the performance of the system.The main research work of paper is as follows:(1)the paper designs the terminal transceiver of the ROF system,proposes the improved GFDM transmitter and the GFDM receiver module,and studies the key technology of the ROF communication system.The paper mainly analyzes the ROF communication system based on the GFDM,introduces the improved modules and the key technologies,and makes theoretical analysis and modeling for them.Finally,the simulation results of the system are analyzed to verify the feasibility of signal transmission in the improved GFDM transceiver in the radio frequency radio system.(2)the theory of Peak to Average Power Ratio based on GFDM is introduced to reduce the common algorithm,paper studies the selected mapping algorithm based on GFDM in ROF system,in the ROF system for different optical receiving powers,different equalization methods and different roll off factor under the simulation analysis of the algorithm.Paper mainly studies the SLM-GFDM signal spectrum performance,PAPR performance and the receiver Error Vector Magnitude(EVM)performance.The simulation results show that the PAPR threshold of GFDM signal is reduced by 4dB compared with the traditional GFDM signal,which improves the transmission performance of GFDM signal and reduces the sensitivity of system to nonlinear distortion.(3)paper researches the GFDM signal on the new proposed method of random filtering mapping algorithm(RFM)to reduce the peak to average power ratio(PAPR)for GFDM signals by reducing the phase consistency of multi-carrier signal,then GFDM signal is transmitted by optical fiber of the length of 60Km and improved in single sideband modulation on ROF transmission system.Stochastic RFM algorithm is proposed in this dissertation to make GFDM signal PAPR values reduce by up to about 1dB compared to the Selected Mapping algorithm and about 5dB lower than the GFDM signal of traditional PAPR,greatly reducing the PAPR of the GFDM signal,improving the transmission performance of GFDM signal,reduceing the nonlinear distortion sensitivity of system,in addition to reduce the bit error rate of the receiving end.So the transmission system is the best choice.