Frequency deviation self-adaptive precise compensation system and frequency deviation self-adaptive precise compensation method in coherence optical communication

Abstract

The invention discloses a frequency deviation self-adaptive precise compensation system and a frequency deviation self-adaptive precise compensation method in coherence optical communication, which relate to the field of the frequency deviation compensation in the coherence optical communication. The method comprises the following steps of adopting a tunable light source as a local oscillator receiving light source, outputting local oscillator light with a designated wavelength, utilizing the local oscillator light to conduct coherence reception and low-pass filter with a transmission signal, conducting digital sampling on the filtered signal, and solving the energy of the sampled signal by utilizing a numerical algorithm; recording an energy value corresponding to the wavelength, completing one-time scanning, simultaneously changing the wavelength value and repeating the previous steps to obtain a wavelength-energy scanning curve, and determining an initial wavelength of the transmission signal according to a position of an extreme value point on the curve; and dynamically adjusting the local oscillator wavelength value by self-adaptively detecting the energy value under the condition of the initial wavelength, so that the frequency difference value is minimized. According to the system and the method, the precise compensation of a frequency deviation value in the coherence reception is completed through wavelength scanning of the light source, determination of the extreme value and the self-adaptive tracking process, so that the performance of the entire coherence receiving system is improved.

Description

technical field [0001] The invention relates to the field of frequency offset compensation in coherent optical communication, in particular to a system and method for self-adaptive and precise compensation of frequency offset in coherent optical communication. Background technique [0002] In order to meet the high-speed and large-capacity communication requirements, coherent receiving technology in optical communication has been more and more widely used. Compared with direct reception, the amplitude and phase information of the transmission signal can be demodulated in coherent reception, thereby realizing the demodulation of high-order modulation, so various transmission schemes with high spectral efficiency have been applied. Typically, the final signal obtained after coherent reception is: Where: A(t) is the transmission signal amplitude information, ω 0 is the carrier frequency of the transmitted signal, is the phase of the transmitted signal, B is the amplitude o...

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Problems solved by technology

Therefore, the carrier frequency determined by the spectrometer may deviate from the actual value beyond the estimated range, resulting in an excessive frequency deviation value after coherent reception, which reduces the performance of the carrier recovery algorithm and ultimately reduces the system performance

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