Research Of Signal Transmission And Processing In Photonic Multi-antenna System

Antenna array system has been widely deployed in commercial and military applications.However,with the limitation of "electronics bottleneck",a wide-bandwidth,multi-function and high-resolution antenna array system is difficult to realize.Due to the advantages of wide bandwidth,small size,low loss and anti-electromagnetic interference,microwave photonics has become an enabling technology in the antenna array system.Based on microwave photonics,broadband signal transmission with stable phase,channelized receiver and phased-array antennas based beamforming have been studied in this thesis.First,a method that can simultaneously achieve the phase stabilized of time and frequency between central office and remote antenna array is discussed,which can meet different precision requirements in stabilized-phase transmission of time and frequency signal.To handle the broadband signal processing with the limitation of analog-to-digital converters(ADC),it is essential to provide a way to channelize broadband signal spectrum with proper widths.The channelized receiver(a specialized class of pre-processor)is employed to slice one broadband RF channel into different narrowband sub-channels.Second,a broadband photonics-assisted channelization scheme with double channelized efficiency and optical carrier power suppression(OCS)is proposed for instantaneous RF spectrum analysis.In this scheme,optical carriers with only half of the number of sub-channels are needed.So,it has low cost and complex.Third,for the typical application of antenna array system in civilian field,a centralized beamforming control system with phased array antennas(PAAs)by using optical true time delay pool(OTTD-P)is proposed.In this scheme,all complex functions of beam steering for BSs have been concentrated in one “place”.The key contributions of this thesis are summarized as follows: 1.By using pre-designed OTTD-Ps,a centralized beamforming control system isproposed for multiple base stations(BSs)of wireless communication with PAAs.2.A double-efficiency photonics-assisted channelization scheme with optical carrierpower suppression(OCS)is proposed for the first time.Based on the well-designedspectrum relationships,double channelized efficiency can be obtained.3.Based on wavelength division multiplexing(WDM)technology,a method that canachieve the phase stabilized of time and frequency between central office andremote antenna array simultaneously is proposed.