混沌序列 OCDMA 系统性能分析

摘要

In this paper,a unipolar channel-based OCDMA system that can use bipolar sequences is introduced and a method for constructing bipolar chaotic sequences with good correlation property by using the 3rd-order Chebyshev mapping described. With the bipolar chaotic sequences applied to the above-mentioned OCDMA system,its performance is analyzed.Under the condition of complete asynchronization,the expressions for SNR and BER are derived and the BER curves varying with the number of users simulated and compared with the similar systems based on the Gold sequences.The results indicate that with the same number of users,those systems that are based on the chaotic sequences have lower BER.%介绍了一种可以使用双极性序列的单极性信道 OCDMA(光码分多址)系统，阐述了利用三阶 Chebyshev 映射构造具有良好相关性的双极性混沌序列的方法，并将双极性混沌序列应用到上述单极性信道 OCDMA 系统中。对系统性能进行了分析，在完全异步的情况下，推导了信噪比和误码率的表达式，仿真了误码率随用户数变化的曲线，与使用 Gold 序列的相同系统进行了比较，结果表明：在相同用户数的情况下，使用混沌序列时具有较低的误码率。