Method and system for receiving orthogonal mode division multiplexing signal

Abstract

The invention discloses a method for receiving an orthogonal mode division multiplexing signal. The method comprises the following steps: for a transmitted orthogonal multiplexing signal, firstly, suppressing dispersion among modules and eliminating time delay among different signals, secondly, separating signal light in each orthogonal mode, then receiving the separated light signals in differentmodes, and performing digital signal processing on the received signals by adopting an MIMO technology. According to the invention, the transmission capacity and the transmission distance of the system can be effectively improved; the receiving flexibility can be improved by using a coherent receiving method, the sensitivity of a receiving system can be greatly improved by using a heterodyne detection mode, and a very good effect of suppressing background noise is achieved; according to the coherent receiving technology, coherent mixing of the signal light and the local oscillator light on the photosensitive surface of the detector can be utilized to convert the received signal frequency from the 1014Hz optical signal field to the 108-109Hz electric signal field, and the complexity of digital signal processing can be reduced.

Description

technical field [0001] The present invention relates to the field of communication technology, in particular to a method and system for receiving an orthogonal mode division multiplexing signal. Background technique [0002] With the rapid development of Internet of Things, 4K high-definition video, cloud data, virtual reality technology (VR) and other services, and the coming 5G era, people's demand for network bandwidth continues to grow. After the use of a series of multiplexing technologies such as wavelength division multiplexing (WDM), frequency division multiplexing (FDM), time division multiplexing (TDM), and polarization multiplexing (PDM), the transmission capacity of single-mode optical fiber communication systems has continued to increase. approaching the Shannon limit. Against this background, the researchers focused on untapped dimensions in optical fibers. Space Division Multiplexing (SDM) technology utilizes a relatively large number of modes carried by few...

AI Technical Summary

Problems solved by technology

Under ideal conditions, any two modes transmitted in a few-mode fiber satisfy orthogonality, but under actual conditions, due to flaws in the preparation of the few-mode fiber, there will be stretching and twisting during use. It will lead to the superposition of the mode fields between the modes in the few-mode fiber, thus destroying the orthogonality between the modes transmitted in the few-mode fiber, and finally causing the coupling between the modes, which not only damages the transmission signal, And limit the transmission bandwidth

At the same time, in the MDM system, since the mode multiplexer and demultiplexer will couple the light of each mode, the differential group delay between the modes and the transmission loss of the optical fiber will cause problems such as the crosstalk between the modes, and the signal will be distorted.

Although the method of physical channel optimization can effectively suppress the nonlinear damage of the channel, the nonlinearity between the signal modes at the receiving end cannot be completely eliminated, especially in the case of intermodal crosstalk, the nonlinear effect between the modes is very serious

[0003] Orthogonal mode division multiplexing signals can effectively solve the aforementioned problems, but how to quickly and effectively generate orthogonal mode multiplexing signals, as well as the research on the reception and demodulation based on this kind of orthogonal mode division multiplexing signals are relatively vacant. Can be effectively used in the actual communication process

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