Blind identification method and device for number of subcarriers in optical network based on OFDM

Abstract

The invention provides a method and a device for blind identification of the number of subcarriers in an optical network based on OFDM. The method comprises the following steps of obtaining fourth-order cyclic cumulant of an optical signal at each preset frequency for each preset frequency in the power spectrum bandwidth of the received optical signal; determining a judgment threshold of the number of the subcarriers in the optical network according to the normalized value of each four-order cyclic cumulant, and obtaining the number of the fourth-order cyclic cumulants with the normalized values larger than the judgment threshold; and determining at least one numerical interval according to a preset numerical value set of the number of the subcarriers, and identifying the number of the subcarriers in the optical network according to the numerical intervals where the obtained number fall. According to the method and the device, the number of the dynamically changing subcarriers in the optical network system can be identified intelligently and quickly, and the whole blind identification process of the number of the subcarriers is independent of the transmission rate of the system andthe subcarrier modulation format, the tolerance for polarization mode dispersion, and phase noise and frequency deviation of a laser in the system is higher.

Description

technical field [0001] The present invention relates to the technical field of optical fiber communication, and more specifically, to a method and device for blindly identifying the number of subcarriers in an OFDM-based optical network. Background technique [0002] With the explosive growth of Internet and video-on-demand services, how to further improve the spectrum utilization of Internet traffic services has become an urgent problem in the field of optical communications. [0003] The traditional Wavelength Division Multiplexing (WDM) system has considerable advantages when applied to high-speed signal transmission, but due to the fixed 50GHz or 100GHz spectrum grid used in its network structure, it increasingly shows the following defects: it is difficult to adapt to 1Tbps The signal occupies the 130-180GHz optical bandwidth range; the fixed spectrum grid results in low system spectrum utilization and high transmission costs; poor adaptability to different communicatio...

AI Technical Summary

Problems solved by technology

[0003] The traditional Wavelength Division Multiplexing (WDM) system has considerable advantages when applied to high-speed signal transmission, but due to the fixed 50GHz or 100GHz spectrum grid used in its network structure, it increasingly shows the following defects: it is difficult to adapt to 1Tbps The 130-180GHz optical bandwidth range occupied by the signal; the fixed spectrum grid results in low system spectrum utilization and high transmission costs; poor adaptability to different communication types

However, it does not take into account the influence of other factors on the number of subcarriers, which will lead to inaccurate estimates of the number of subcarriers

Moreover, the process of eigendecomposing the autocorrelation matrix is ​​very complicated, and the number of subcarriers cannot be obtained quickly

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