Optical code division multiplexing based sending and receiving methods and devices thereof for realizing integration of three networks

The invention discloses optical code division multiplexing based sending and receiving methods and devices thereof for realizing integration of three networks. The sending device comprises a light source, a rate unifier, a 1:3 optical splitter, three light modulators, three multipliers, three OCDMA (optical code division multiple access) encoders and an optical coupler; and the receiving device comprises a wavelength division multiplexer, three OCDMA decoders, three photoelectric detectors, three threshold value discriminators and three bit discriminators. According to the methods and the devices, the rate unifier is adopted for matching a rate with a unipolar address code, so that a multi-rate transmission characteristic is realized by using a constant code length; and compared with a traditional variable code length, the invention has the advantages of simple structure, low system cost, easiness in implementation, random asynchronous access, channel sharing of multiple users, high safety of a physical layer and the like, can support transparent transmission of a multi-rate protocol according to different business requirements, and has the characteristics of simple structure, low power consumption and the like.