| Optical code-division multiple-access(OCDMA)communication system , adopting the concept from the wireless mobile system., has arose intensive interest for its many merits: Efficient use of the huge bandwidth of the fiber, asynchronous and flexible access, high security, etc. All of these advantages make OCDMA very competitive in high-security-requirement communication system, especially in the military communication.But OCDMA codes is unipolar, and its relativity is not good, aggravating MUI and confining the number of users; So the design of OCDMA codes with good relativity becomes a crucial technology which should be solved urgently. OCDMA encodes and decodes in two-dimension(time,wavelength) even in three-dimension(space), making the system very safe. Meanwhile, it makes the design of OADM very difficult,resulting the slow development of the OCDMA network. With the developmet of the economic and the improvement of the live, broad network access will become very competitive in the market. As the candidate to the solution of FTTH,Passive Optical Network(PON) has been deployed by the network supplier all of the world. Based on the OCDMA technology ,OCDMA-PON will also be very attractive. Now ,OCDMA technology is still in its primary stage. Many theories have not been solved very well, and some critical technologies are still in the probing period. But what makes us happy is that OCDMA has made great progress in the recent years.My paper focuses on the fields as following:1. summarize and compare the exiting codes and their encoding/decoding principle according to the theoretical analysis and simulation2. based on Arrayed Waveguide Gratings (AWG) and two-dimensional time-wavelength code, design and simulate the Optical code-division multiple access (OCDMA) add-drop multiplexer (ADM)3. based on the exiting OCDMA-PON tech., propose several different schemes which can make the system very compact... |
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