METHOD FOR CONSTRUCTING MODE DIVISION MULTIPLEXING OPTICAL FIBRE COMMUNICATION SYSTEM, AND CONSTRUCTED OPTICAL FIBRE COMMUNICATION SYSTEM

摘要

The present invention relates to a method for constructing a mode division multiplexing optical fibre communication system, the method comprising the following content: converting, at a transmitting end, a multi-path input optical signal into an optical propagation mode supported by a ring core optical fibre with a gradually changing refraction index, and injecting same, after being multiplexed by a mode multiplexer, into the ring core optical fibre with the gradually changing refraction index for transmission; firstly, separating, at a receiving end, different mode groups of optical signals by means of a mode demultiplexer; for the separation of modes within a mode group, carrying out processing by means of multi-path reception and based on a digital signal processing method with multiple input multiple output equalization; and for the separation of modes within a base mode group and a high-order mode group, respectively using a digital signal processing algorithm with 2x2 and 4x4 multiple input multiple output equalization to carry out recovery processing. According to the method of the present invention, when a mode group is increased to expand a communication capacity, only optical receivers and digital signal processing modules based on 4x4 multiple input multiple output equalization need to be repeatedly increased. Compared with the prior art, the present invention has the characteristics of low complexity, high expandability and easy upgrade.