The Research On Some Key Issues In Optical Access Network Based On Optical GFDM Network

The development of future typical business and application scenarios as online classroom, live online, ultra-high-definition video and smart transportation continue to drive the development of mobile communication research, which the research of physical layer 5G signal modulation technology is one of the highlights. GFDM technology, as one of the physical layer alternative modulation techniques of the fifth generation mobile communication, has the following advantages: Firstly, the spectrum of the GFDM signal has an extremely low out-of-band leakage which can reduce the interference between adjacent wideband GFDM signals for the use of the flexibility of the pulse shaping filter. Secondly, the subcarriers of the GFDM signal are no longer orthogonal, therefore the GFDM is not insensitive to frequency offset and phase noise. In addition, cyclic prefix is added in in each GFDM block rather than in each GFDM symbol, which improve the utilization rate of resource. Finally, we can reduce the peak-to-average power ratio (PAPR) of the GFDM signal by designing the appropriate pulse shaping filter. Therefore, in this paper, the application of GFDM in optical access network, the following research work. Therefore,based on the application of GFDM in optical access network, carry out the following research work.The theory of modulation and demodulation of GFDM is firstly researched. Besides, In addition, the technology of optical access network is also researched,including optical access technology, radio over fiber technology as well as modulating and demodulating technology of optical carrier RF signal.Based on the theoretical research of GFDM and optical access network technology, the transmission performance of single-user broadband GFDM optical access system based on direct detection is studied,and the transmission law and transmission performance of GFDM in optical access system are also explored. Verify the feasibility of GFDM signal transmission in optical access network system.In order to further study the spectrum structure of GFDM signal, a fast side-lobe attenuation with very low out-of-band leakage to reduce the adjacent broadband GFDM signal interference, we further carry out the following research work: Based on the study of the transmission performance of single-user broadband GFDM optical access system with direct detection and affirm the feasibility of this transmission system, we further studies that to what extent the laser linewidth, transmit power,extinction ratio of optical modulator, received optical power and pulse shaping have an influence on the transmission performance of the multi-user broadband GFDM optical access system with direct detection of SSB modulation. The simulation results show that the optical access network based on optical GFDM signal has good transmission performance and applying feasibility.