Abstract: The method includes: splitting an optical carrier into two or more sets of optical sub-carriers at a receiving end; respectively performing optical PDM on each set of the optical sub-carriers to obtain two sets of to-be-demodulated optical signals; and extracting a part of signals from each set of the to-be-demodulated signals to calculate features characterizing polarization states, controlling feedback signals according to the features, and correspondingly adjusting a polarization state of each set of the optical sub-carriers. With the device combining optical division into two or more sets of sub-carriers with optical PDM, an optical carrier signal can be split in an optical modulation format into four or more sets of signals for processing, and delay interference can be performed directly on an optical wave by using Differential Quadrature Phase Shifted Keying (DQPSK) demodulators to obtain by detection output signals.

Abstract: A method, device, system for realizing polarization mode dispersion (PMD) compensation are provided. The method for realizing PMD compensation includes: de-multiplexing a polarization-multiplexed optical signal, to obtain a first polarization light and a second polarization light; and joint-equalizing the first polarization light and the second polarization light, to obtain a first equalization signal and a second equalization signal. Since the polarization-multiplexed optical signal is de-multiplexed and then joint-equalized, not only the intra-channel symbol interference but also the inter-channel symbol interference during transmission of the polarization-multiplexed optical signal is eliminated, so as to realize the PMD compensation.

Abstract: In the field of communication and transmission, a method and a device for receiving an OPFDM-DQPSK signal are provided. The device includes a power splitter, adapted to split the OPFDM-DQPSK signal into two beams of signals; a polarization beam splitter (PBS), adapted to splitting one of the two beams of signals into a first signal and a second signal; a demultiplexer (Demux), adapted to demultiplex the other beam of signal to obtain a third signal and a fourth signal; two delayers, adapted to delay the third signal and the fourth signal respectively; a first frequency-mixing receiving module, adapted to perform frequency-mixing receiving on the first signal and the delayed third signal; a second frequency-mixing receiving module, adapted to perform frequency-mixing receiving on the second signal and the delayed fourth signal; and a decision recovery module, adapted to recover four logical sequences by performing decision on the four electrical signals.