Device and method for locking demodulator phase in differential phase shift keying (DPSK) receiver

Abstract

The invention provides a device and a method for locking a demodulator phase in a differential phase shift keying (DPSK) receiver. The device comprises a demodulator, a balance receiver, a multiplier and a demodulator control unit, wherein the demodulator is used for transmitting a DPSK optical signal to the balance receiver after adjusting the DPSK optical signal; the balance receiver is used for converting the demodulated optical signal into electrical signals by two photoelectric detectors, respectively separating one part of monitoring signals from two paths of electrical signals, transmitting the electrical signals to the multiplier and outputting the other part of monitoring signals after carrying out differential amplification; the multiplier is used for carrying out multiplication operation on the two paths of monitoring signals transmitted by the balance receiver and transmitting an operation result to the demodulator control unit; and the demodulator control unit monitors a feedback signal output by the multiplier and guides the phase adjusting direction of the demodulator according to the feedback signal. The invention directly realizes the mergence of the rough adjustment and the fine adjustment of the demodulator phase in the DPSK receiver and greatly optimizes the control scheme of the DPSK receiver.

Description

technical field [0001] The invention relates to the technical field of optical communication, in particular to a device and method for phase locking of a demodulator in a DPSK receiver. Background technique [0002] Differential Phase Shift Keying (DPSK) modulation codes are superior to traditional codes based on intensity modulation, and have been widely researched and applied in high-speed, long-distance optical transmission. Phase modulation technology includes two methods of coherent demodulation and self-coherent detection to realize signal reception. Among them, the implementation of coherent demodulation is more complicated, and the self-coherent detection method is relatively simple. The delay-interferometer (Delay-interferometer, DLI) is used as the demodulator (Demodulator), and then the balanced receiver (Balanced Receiver, BR) is used to realize the signal. recovery, such as figure 1 shown. The phase of the DPSK system demodulator has a significant impact on s...

AI Technical Summary

Problems solved by technology

However, the specific implementation and software algorithm of phase locking based on error code information before error correction is relatively complex, and coordination with other optimal adjustment controls needs to be considered

[0006] Therefore, it is necessary to find a way to overcome the costly problem caused by the phase offset of the demodulator in the DPSK receiver with a relatively simple technical solution

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