摘要
直扩通信技术具有很强的抗干扰能力、低截获率、良好的码分多址通信能力和高保密性等优点,因此它在军事和民用通信、遥测、定位等领域得到了广泛的应用。
由于直扩信号具有上述优点,在复杂噪声中对其进行检测和参数估计是一个非常困难的课题。本文提出了应用循环谱相关技术来检测和识别直扩信号的方法。研究了直扩信号的检测和参数估计两方面内容。循环谱相关技术的分析对象是具有循环平稳性的信号,而直扩信号是利用伪随机码调制的宽带信号,具有循环平稳性。所以可以利用循环谱相关技术从复杂噪声中检测直扩信号。
在本课题中对以上方案的可行性作了深入的理论分析,提出了循环谱相关理论的两种实现算法,然后利用计算机仿真软件对该算法作了仿真研究,最后设计完成了基于DSP的硬件平台。在仿真中对直扩信号的载频和伪码速率参数进行了估计,结果和理论一致。在硬件平台上也对这两个参数的估计进行了实验,实际结果与仿真结果一致,证明该方案是可行的,与其他方法相比较,具有一定的优势。
本课题的研究,验证了循环谱技术的有效性,从而为直扩信号的检测提供了一种有效、实用的方法。
The Spread Spectrum technology has been used widely in fields such as military and civil communications, remote sensing and orientation because of its strong anti-interference, LPI, good multi-access ability and excellent secrecy.Thus it is very difficult to detect DS/SS and estimate its parameters because of its features we mentioned above. This paper presents a method that makes use of cyclic spectrum correlation technology to detect DS/SS and estimate its parameters. Cyclic spectrum correlation technology is used to analyze the cyclostationary signal. However, DS/SS has cyclic-feature, so we can use cyclic spectrum correlation technology to detect DS/SS and estimate its parameters.This paper detailedly discussed the theory of cyclic spectrum correlation technology and simulates the theory through MATLAB. In the end, the paper gives a hardware platform based on DSP to accomplish the arithmetic. Both the simulation and the experiments proved the feasibility and superiority of cyclic spectrum correlation technology.All studies in this paper proved that cyclic spectrum correlation technology is a effective and applied method for DS/SS signal detection.
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