Abstract: A method for recovering an OTUk frame includes: receiving an optical signal sent by using a method of multi-lane distribution from the OTUk frame to an interface of an optical module; converting the optical signal into an electrical signal, performing electrical equalization and demodulation on the electrical signal, and recovering multi-lane data from the demodulated signal; aligning and rearranging the data on each lane, according to a lane sequence identifier included in an overhead frame header of the data on each lane; and recovering the OTUk frame according to the aligned and rearranged data. According to the present invention, lane rearrangement is performed by detecting the lane sequence identifier, and the recovery of the OTUk frame is achieved. Therefore, a training sequence overhead does not need to be additionally introduced, and the influence on the system performance is avoided.

Abstract: A method for carrier frequency recovery in an optical coherent transmission system is provided in which at least one kind of equalization of a received signal is performed in frequency domain, the method comprising: performing a frequency offset compensation in frequency domain on a received signal according to an estimated value of the frequency offset; obtaining the signal with the frequency offset compensated. Further, an optical coherent receiver is provided comprising: an equalization unit, adapted to perform at least one kind of optical distortion compensation of a received signal in frequency domain; a frequency offset compensation unit, adapted to perform the frequency offset compensation in frequency domain on a received signal according to an estimated value of the frequency offset to obtain the signal with frequency offset compensated.

Abstract: Embodiments of the present invention disclose an electronic equalization and electronic depolarization method, a receiving end equipment, and a communication system. According to the embodiments of the present invention, parameters required by electronic equalization and electronic depolarization are calculated by detecting a Synchronization Sequence (SS) in a received signal, and then the electronic equalization and the electronic depolarization are performed on the received signal in a frequency domain by utilizing the parameters, so as to solve a problem of the electronic equalization and the electronic depolarization in a Polarization Division Multiplexing (PDM) Orthogonal Frequency Division Multiplexing (OFDM) system. Furthermore, the realization complexity of the electronic equalization and the electronic depolarization performed in the frequency domain is greatly reduced relative to the electronic equalization and the electronic depolarization performed in a time domain.

Abstract: The invention relates to a receiver for a quadrature-modulated signal, which can be divided into an inphase signal (I) and a quadrature signal (Q). The inphase signal (I) is fed to first and third equalizers (EZ1, EZ3), and the quadrature signal (Q) is fed to second and fourth equalizers (EZ2, EZ4), wherein the first and second equalizers (EZ1, EZ2) each perform a first equalization of the respective signal. An output of the first equalizer (EZ1) is connected to a second input of the fourth equalizer (EZ4), which, by means of a second equalization of the quadrature signal (Q), transmits an equalized quadrature signal (Q2) as a function of the previously fed equalized inphase signal (II) of the first equalizer (EZ1).