Study On60GHz Transmission Technologies And Microwave Signal Photonic Processing Technologies In RoF Systems

The RoF technology which integrates the advantages of both the optical fibertransmission technology and the wireless access technology will play an important rolein future broadband wireless access networks. Several important transmission andaccess technologies in60GHz RoF systems as well as some microwave signal photonicprocessing technologies base on the RoF schemes are studied in this paper.In the transmission and access technology part, the low-cost full-duplextransmission method for60GHz RoF systems is first studied and a novel low-costfull-duplex transmission scheme based on optical LO carrier remote distribution for60GHz RoF systems is proposed and experimentally verified. In the experiment,full-duplex RoF signals at the bit rate of622Mb/s are successfully transmitted through20km SMF link and50cm wireless channel at the error-free state. Then according topresent researching trends, the integration architecture of60GHz RoF and wired accesstechnologies is studied subsequently, and a broadband access scheme which integratesthe advantages of both the RoF and the WDM-PON technologies and merges wired andwireless services is proposed and experimentally verified. In the experiment, the RoFand baseband signals both at the bit rate of1.25b/s are successfully distributed through40km SMF link at the error-free state. The photonic generation and transmissionmethods of60GHz-band vector signals are also studied in this part and a novel photonicgeneration scheme based on optical vector signal down-conversion is proposed and andexperimentally verified. In the experiment, the64GHz-band8QAM and4QAM vectorsignals both at the data rate of622M symbols/s which are generated with two differentmodulation methods respectively are successfully distributed through50km SMF linkand5m wireless channel at the error-free state.In the RoF based microwave photonic processing part, the microwave photonicamplification and filtering technologies which will be widely used are mainly discussed.A microwave photonic amplification scheme which takes advantage of the broadbandgain of EDFA is first studied, and a detail model of the amplification principle is givenwhich is then experimentally verified. Stable broadband gain of about17dB for themicrowave signals from10MHz to10GHz is obtained in the experiment. As to the microwave photonic filtering, the intrinsic relationship between the system parametersand the frequency response of the incoherent MPF is studied and a novel designingmethod for incoherent MPF based on basic filtering cell recombination is proposed. Theproposed method is then experimentally verified with a practical designing example,and the frequency response of the MPF measured in the experiment accords with thetheoretically designing result well.In a word, several important transmission and access technologies in60GHz RoFsystems as well as some RoF based microwave signal photonic processing technologiesare theoretically and experimentally studied in this paper. The correspondingachievements will have some value in related fields such broadband access networks,high frequency radar systems and satellite communication systems.