【作者】 姚海涛；

【导师】 覃团发；

【作者基本信息】 广西大学 ， 控制理论与控制工程， 2001， 硕士

【摘要】 扩频通信采用伪随机编码调制，使用比信息数据大得多的带宽。接收端使用同步的伪随机序列进行相关解调恢复出原始信息数据。因此扩频通信能在低功率谱密度下工作，具有抗干扰、抗多径衰落、多址能力强、频谱利用率高等特点。在民用移动通信、军事通信等领域都得到了广泛的应用。伪随机码性能对扩频通信至关重要。研究表明，传统的伪随机码扩频序列存在复杂度低，保密性差等缺点，并且相关特性较好的伪随机序列数目极其有限。 混沌是在非线性系统中出现的确定性的、类随机的过程。混沌系统最基本的特征是对初始条件极端敏感性，由此可以提供数量众多、相关特性优良的扩频序列。 本文研究了分别采用蔡氏电路、逻辑映射和时空混沌耦合映象格子这三种混沌系统来产生混沌扩频序列的方法，分析了产生出来的序列的特性，主要包括自相关和互相关特性等。经过分析发现采用混沌系统产生的混沌序列特性良好，可用来代替传统的扩频序列以提高扩频通信系统性能，比如系统容量等。为了验证混沌扩频序列的可行性，特此讨论了把混沌扩频序列应用于扩频通信中，特别 广西大学硕土研究生学位论文 中文摘要分析了它在AWGN信道条件下的误码性能，得出了相应的误码性能公式，构造蒙特卡罗仿真檬型，把理论计算结果与实际仿真结果进行了比较，发现二者吻合得很好，从而证明了混饨序列作为扩频序列的可行性。最后结合移动卫星通信系统模型，把混饨扩频序列实际应用于移动卫星扩频通信系统中，相应分析了它的误码性能。更多还原

【Abstract】 Spread spectrum communication uses much larger bandwidth than required by spreading original information using pseudo noise (PN) sequences. A spread spectrum receiver then uses the synchronized replica of the pseudo noise sequences to recover the original information. Due to this pseudo noise property of the spreading sequences, spread spectrum communication can work at low power spectral density and has many good characters such as anti-noise, anti-interference, anti-multipath effect, multiple access, efficient frequency usage. It has been applied widely in civil mobile communication and military communication. It is well-known that the spreading sequences generation is first step for achieving spread spectrum communication, and the auto-correlation property and cross-correlation property of the spreading sequences are very importance for spread spectrum communication. Research has showed that conventional PN has low complication and low security, et al. In addition, PN sequences with good correlation property are not many enough. Chaos is produced by deterministic nonlinear systems, its phenomena is pseudo random. Because chaotic systems exhibit sensitivity to initiaI conditions, they can generate many enough PNsequences with good correlation propertyIn this article, the methods of generating cbaotic spreadspectrum sequences by using chua’s circuit, logistics-map, andcoupled map Iattice are studied. The characters of these 8equencesare also anaIyzed such as auto-correlation property andcross-correIation property We find a fact that chaotic spreadspectrum sequences have well enough auto-correlation propertyand cross-correIation property chaotic sequences can repIaceconventional PN sequences in spread spectrum communication andimprove communication system property such as capacity In orderto exam the feasibiIity of chaotic sequences applying for real spreadspectrum teIecommunications, we anaIyze the EBR in AWGNchannel in theoretics and give BER formula. The feasibiIity ofchaotic sequences are able to be used in spread spectrumcommunication systems is proved by theoretic calculation andMonte CarIo method simulation. In the last chapter of tbe article,BER that chaotic spread spectrum sequences apply in mobilesatellite spread spectrum communication system is studied.更多还原