A Novel Parallel Interference Suppressing System in Optical Code Division Multiple Access Communication with Optical Hard Limiter Based on Maximum Value Decision
基于最大值判决及光硬限幅器的光码分多址并行干扰抑制系统

Aiming at multi-user interference that exists in optical code division multiple access(OCDMA) system,a novel parallel interference suppressing system is presented,which adopts an optical hard limiter and maximum value decision.It avoids no optical pulse existing while bit 0 is transmitted by adopting a spread spectrum code and its shift as the address codes of bit 0 and bit 1,respectively; placing an optical hard-limiter before correlator in receiver,and using maximum decision instead of threshold decision to decrease error-decision happening.The fundamental of the system is stated,optical orthogonal codes is applied as address codes;PIN opto-electro detector is used,the bit error probability of the novel system is derived and analyzed.Simulations based on the expression are done.The results show that the bit error performance of the novel system can be ten orders better than that of conventional system,two orders better than conventional parallel interference suppressing system while signal photon arrival rate is 25.