应用于2.4GHz双向变频系统的混沌跳频频率合成器的设计

发布时间：2018-08-14 14:30

【摘要】：当今社会,通信技术已经发展的相当成熟,在扩频通信、保密通信等领域的研究和应用越来越多,要求也越来越高。同时,混沌原理在电路和通信方面的应用得到了更加广泛的关注和开发。混沌现象本身所具有的类随机性十分适合通信中的保密需要。进一步,混沌现象本身具有初始值敏感性,可以提供大量非相关、类随机的跳频序列,而得到的这些序列又是可以通过对应的混沌映射和初始值精确还原出来的。在本文中将会设计一种混沌跳频锁相环频率合成器,主要应用在2GHz的频段。主要工作原理是利用单片机计算混沌映射方程生成混沌序列,并对生成的序列进行适当的转化,使其能够符合锁相环频率合成器的控制字格式,将转换后的序列按照一定的时序要求输入到锁相环频率合成芯片中,混沌序列控制频率合成器生成混沌跳频频率。在单片机内进行混沌序列生成运算前,需要对混沌映射等式两边进行适当的按比例增大,使其能够在单片机内进行运算。按照锁相环频率合成芯片对于控制字数据格式和传输时序的要求,对运算结果进行适当处理并连同时钟信号和控制信号一起输入到芯片内。在锁相环频率合成芯片内部,根据不同的控制字进行不同频率信号的合成。输出混沌跳频频率信号的频率数值是与混沌映射方程变换后的数值完全相同的。本文后续的测试验证结果表明,利用数字元件完全能够实现生成混沌跳频频率信号的功能,并且基本性能指标也满足要求。相对于传统的模拟电路而言,该系统对外界影响具有更强的抗干扰能力。本设计生成的600组混沌跳频频率信号数据在测试过程中始终维持在混沌状态,噪声系数在2GHz中心频率范围内也能够满足要求。在扩频通信领域甚至要求更高的军事通信方面都有很好的应用前景。
[Abstract]:In today's society, communication technology has been developed quite mature, in the spread spectrum communication, secure communications and other areas of research and application, the requirements are also increasing. At the same time, the application of chaos principle in circuit and communication has been paid more attention and development. The randomness of chaos itself is very suitable for the need of security in communication. Furthermore, chaos itself is sensitive to initial values and can provide a large number of uncorrelated, quasi-random frequency hopping sequences, which can be accurately restored by corresponding chaotic maps and initial values. In this paper, a chaotic phase-hopping loop frequency synthesizer is designed, which is mainly used in the frequency band of 2GHz. The main working principle is that the chaotic sequence is generated by calculating the chaotic mapping equation of single chip computer, and the generated sequence is transformed appropriately to make it conform to the control word format of the PLL frequency synthesizer. The converted sequence is input into the PLL frequency synthesizer according to a certain time sequence requirement, and the chaotic sequence controls the frequency synthesizer to generate the chaotic frequency hopping frequency. Before the chaotic sequence generation operation is carried out in the single chip microcomputer, it is necessary to scale up the two sides of the chaotic mapping equation properly, so that it can be operated in the single chip microcomputer. According to the requirements of PLL frequency synthesis chip for the control word data format and transmission sequence, the operation results are properly processed and input to the chip along with clock signal and control signal. In the PLL frequency synthesizer, different frequency signals are synthesized according to different control words. The frequency value of the output chaotic frequency hopping signal is exactly the same as that of the chaotic mapping equation. The results of subsequent tests in this paper show that the function of generating chaotic frequency-hopping signals can be fully realized by using digital components, and the basic performance indexes can also meet the requirements. Compared with the traditional analog circuit, the system has stronger anti-interference ability to the outside world. The 600 sets of chaotic frequency hopping signal data generated by this design are always in chaotic state during the testing process, and the noise coefficient can also meet the requirements in the 2GHz center frequency range. It has a good application prospect in the field of spread spectrum communication even higher military communication.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN74

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