Stokes space coherent light modulation format recognition method based on self-adaptive non-iterative clustering

Abstract

The invention provides a coherent light modulation format recognition method based on self-adaptive non-iterative clustering; the method comprises the following steps: according to distribution of thesignals on the least squares plane of a stokes space, two simple parameter establishing decision graphs are constructed for clustering center selection; meanwhile, according to the conditions of different modulation formats and signal-to-noise ratios, a decision threshold value of the clustering center on the decision graphs is adaptively selected; therefore, higher recognition precision is achieved. The method has the advantage that the Stokes space modulation method is insensitive to large-phase noise and polarization crosstalk of a coherent light receiver; meanwhile, the limitation that the algorithm is low in high-order modulation format recognition precision and high in complexity is broken through; relatively high recognition accuracy of the high-order modulation format under the low signal-to-noise ratio is achieved; iterative calculation is not needed; and the recognition method is relatively low in complexity.

Description

technical field [0001] The present invention relates to the research field of coherent optical communication systems, and more particularly relates to a Stokes spatial coherent optical modulation format identification method based on adaptive non-iterative clustering. Background technique [0002] To improve spectral efficiency and guarantee the quality of communication services, cognitive optical networks (CON) with variable-bandwidth transceivers are considered to be one of the main options for next-generation optical fiber communication networks. The transmitter of CON can adaptively select the modulation format of the signal according to the dynamic network environment and the needs of users. Therefore, it is necessary for the coherent optical receiver to have the function of identifying the modulation format, so that the subsequent digital signal processing algorithms related to the modulation format (such as adaptive equalization, carrier phase recovery algorithm, etc....

AI Technical Summary

Problems solved by technology

[0003] However, the existing Stokes space modulation format identification method still has high computational complexity (such as iterative calculation, etc.)

And because high-order modulation signals (such as 16QAM, 32QAM, 64QAM, etc.) have a large number of mapping points in the Stokes space and the distribution is relatively dense, it is difficult for this type of algorithm to achieve high-precision identification of high-order modulation formats

Therefore, how to design a Stokes spatial modulation format recognition method with low computational complexity and can recognize high-order modulation formats is still a challenge

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