Research on noise optimization methods in passive optical network based on OCDMA

Optical code division multiple access (OCDMA) is a preferable candidate technology for the next-generation passive optical network (PON) because of its distinct advantages such as asynchronous multiple access, flexible bandwidth assignment and its simplicity to provide access and routing operations in a common channel without switch. The key technique and the pending main problem for OCDMA-PON are presented. The methods of resolving the near-far effect are introduced through missing chip detection or power-leaving. Three solutions of improving noise margin are investigated, which are threshold technique, forward error correction and differential phase-shift keying. And their recent development is summarized.