Research On Instantaneous Microwave Frequency Measurement And Optical Performance Monitoring Techniques

The development of information technology has promoted the demand for microwave communication and fiber optical communication in modern society.During the last decade,research based on the communication engineering field has provided more advanced technical support for the construction and maintenance of next-generation networks.In this thesis,instantaneous microwave frequency measurement(IMFM)and optical performance monitoring(OPM)techniques in the communication engineering field are deeply studied.IMFM can quickly measure the frequency of unknown microwave signals in a short time.OPM can effectively complete the monitoring and compensation of optical impairments in optical networks.Both techniques provide the necessary protection for the normal operation of the communication network.In this thesis,the research status and development trends of these two techniques are discussed in detail,and then systematic research is carried out according to the relevant fields involved.Finally,two kinds of schemes for IMFM and OPM are proposed innovatively for the whole research.In the first scheme,this thesis proposes IMFM technique based on power monitoring.According to the mapping relationship between frequency and amplitude of monotonous change,the technique uses a phase modulator(PM)and a Mach-Zehnder modulator(MZM)to obtain an amplitude comparison function(ACF)by monitoring the output power ratio of two modulated signals,so that the frequency of the unknown microwave signal can be measured.According to analysis and research,the scheme is simple in structure and can quickly and accurately measure the frequency of unknown microwave signal.The measurement range can reach 0.5-53 GHz and the measurement error is less than ± 200 MHz.In addition,this thesis further analyzes and optimizes the frequency range and frequency accuracy.The proposed scheme can effectively measure the frequency of the microwave signal,and has the advantages of high reliability,low cost and wide application range.In the second scheme,this thesis proposes OPM technique based on the cross-phase modulation effect.The technique uses a ratio of optical power of a particular spectrum in the cross-phase modulation effect to achieve monitoring of multiple optical impairments.This thesis analyzes the influence of optical impairments on the spectrum in the OPM scheme and verifies that it is suitable for a variety of signal formats.According to analysis and research,the scheme can realize the simultaneous monitoring of optical signal-to-noise ratio(OSNR)and chromatic dispersion(CD).The monitoring range of OSNR can reach 0-40 d B,and the CD monitoring range can reach 0-120 ps/nm.The scheme is also insensitive to changes in the differential group delay(DGD).Finally,the influence of different device parameters on the monitoring in the system is studied to verify that the designed scheme has good monitoring accuracy and rationality.Both of the schemes mentioned in this thesis can achieve promising results.In the future,the application of the two will play an increasingly important role in the communication engineering field,and at the same time promote the common development of microwave communication and fiber optical communication.