KEYWORDS: Optical communications, Optical coherence, Telecommunications, Optical transmission, Signal attenuation, Dispersion, Digital signal processing, Complex systems, Frequency response, Receivers
High-speed coherent optical communication systems can effectively solve the current problems of transmission capacity and transmission distance in the field of communication, and have become an important research direction in optical communication. The optical signals generated by lasers are composed of different frequency components, which have different transmission speeds in optical fibers, causing dispersion effects. Dispersion causes inter-code crosstalk, which has an impact on coherent demodulation and threshold judgments at the receiving end. Dispersion has a constraining effect on the performance of high-speed coherent optical communication systems, and the development of optical communication requires the study of equalization methods to solve the dispersion problem. In this paper, we examine the dispersion problems and the corresponding solutions in coherent optical communication by reviewing various domestic and foreign literature, focusing on the classical optical communication dispersion equalization technique and analyzing the phenomenon of limited dispersion equalization effect due to the constant modal value of the classical technique tapping coefficient. We study and design the dispersion equalizer CMGD-FIR based on the momentum gradient descent optimization algorithm, which exponentially weights the average optimized gradient and corrects the deviation at each update iteration. Simulation results show that this technique can quickly update the tap weights close to the minimum value and improve the convergence speed while ensuring the dispersion equalization effect.
The oscillator is the core module of the radio frequency receiving front-end, which directly determines the signal processing capability of the communication system. Optoelectronic Oscillator (OEO) technology has become the main research direction to solve the indicators of improving phase noise and frequency tuning range of RF receiving front-end. In order to better solve the problem of RF reception, this paper studies the coupled opto-electronic oscillator, discusses its application in 5G communication systems, and discusses the voltage-controlled tunable fiber Fabry-Perot Coupled Optoelectronic Oscillator (FFP-COEO); Phase noise phase and frequency tuning model, the oscillator controls the cavity length of the Fabry-Perot cavity by voltage, and the starting frequency can be adjusted. The experimental results show that the oscillator can increase the secondary mode-locked loop by improving the filtering performance of the optical loop, further optimize the phase noise of the system, and improve the side mode suppression ratio and output power.
The processing quality of optical communication devices will affect the performance of the equipment. Therefore, it is necessary to carry out strict inspection on optical communication devices, and they can only leave the factory after passing the test. Judging from the current detection methods, the detection of optical communication devices mainly adopts manual detection methods, resulting in low detection efficiency and subjective influence on the detection results. Aiming at the problems existing in the detection of optical communication devices, this paper studies the defect detection technology of optical communication devices based on machine vision. This paper analyzes the main inspection items and indicators of optical communication devices, the composition of the inspection system and the main module structure, studies different template pairing methods, and designs the corresponding defect detection algorithm according to the imaging characteristics of components and bases on the product. The experimental results show that the components can be successfully matched under different conditions. The detection technology studied in this paper has a low rate of missed detection and false detection and has good defect detection stability and accuracy.
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