新型多速率光码分多址实现方案的研究

Study on Scheme Realizing Novel Multi-Rate Optical Code-Division Multiple-Access System

提出了一种新颖的多速率光码分多址系统的实现方案,使得光码分多址系统能够同时传输不同速率的用户信号。对系统的误码性能进行了理论分析,并讨论了在系统中加入硬件限幅器以提高系统性能的可能性。以同时传输两种不同速率信号为例,将系统与变码长光码分多址系统的误码性能进行了仿真和比较。分析表明,随着速率的增加,虽然地址码字的性能有一定下降,但其整体性能仍优于变码长的多速率的光码分多址系统。最后,设计了相应的实验,验证了码字的性能和实现多速率光码分多址系统的可能性。

A novel scheme to realize multi-rate optical code-division multiple-access system （OCDMA） is proposed, with which the OCDMA system can transmit signals with different data rates and quality at the same time. The bits error ratio （BER） of the system is analyzed theoretically, and the probability to improve the performance by using the hardware-limit is evaluated. Taking a system with two different rate signals as an example, the BERs of the proposed scheme and the multi-rate multi-length OCDMA are simulated and compared. The results show that, with the rise of transmission rate, the former system obtained a better general performance than the latter, though there appears a slight decline for the performance of the address code words for it. Finally, relevant experiments are done to verify the performance of the code and the probability of multi-rate OCDMA.