OCDMA系统中多码长地址码的设计及性能研究

为了满足光码分多址系统中不同用户能够获得不同发送速率的需求,根据所需地址码的容量和码重,通过MATLAB编程,设计出没有重复数字的间隔集,得到具有理想相关性的多码长地址码。根据该地址码的构造特点推导计算出该地址码的误比特率,并绘制出误比特率随同步用户数变化图。设计并仿真了多速率光码分多址系统,分析了误比特率和系统性能。结果表明,该多码长地址码具有良好的相关性和误比特率性能,能够满足各种速率需求的用户。通过系统编解码后能够理想地恢复出原始信号,得到优良的眼图。此研究对光码分多址多速率系统的进一步发展是有帮助的。

Design and performance of multi-length address codes in an OCDMA system

In order to meet the demand that different users sent at different rates in an optical code division multiple access (OCDMA) system,the interval-set with no repetitive data was designed based on MATLAB and the multi-length address codes with ideal correlation was obtained. The code family will be obtained corresponding to the given code weight and corresponding capacity. The formula of bit error rate (BER) was derived based on the characteristics of the codes and BER diagram with the change of user numbers was given. The multi-rate OCDMA system was designed and simulated. The bit error rate and system performance were analyzed. The results show that the codes have the good correlation and good performance of BER. The system can meet the needs of users at different rates. The original sign can be restored after decoding and the excellent eye diagrams can be obtained. The results are helpful for the development of multi-rate OCDMA systems.