监测接收机中突发信号检测及AGC电路设计与实现
发布时间：2018-12-24 14:36
【摘要】：当今无线电通信技术的发展日新月异,其应用范围也越来越广,随之而来的问题是各行各业对无线电频谱资源的需求急速增长,同时也使得无线电通信环境日趋复杂。这种情况下对无线电频谱资源的监测管理势在必行,监测接收机作为频谱监测管理的核心设备,它对净化电磁环境、提高无线电频谱利用率具有不可替代的作用。随着世界各国对于频谱监测管理工作的重视程度越来越高,监测接收机的研制也有了长足进步,对于监测接收机的性能要求也越来越高。本文基于接收机动态范围这一指标设计并在FPGA上实现了自动增益控制系统;基于如今突发通信机制的广泛应用,设计并在FPGA上实现了针对突发信号的突发信号检测器。本文首先对自动增益控制理论进行了深入研究,然后结合本监测接收机系统设计实现了自动增益控制系统。本文设计实现的自动增益控制系统包含射频增益控制和基带增益控制两个部分。本接收机系统采用的射频前端只提供了可变增益放大器却没有提供自动增益控制功能,为了充分利用射频前端,有效提高系统动态范围,采用直接计算和定步长相结合的方法在FPGA中设计实现了射频增益控制系统。同时由于本接收机基带带宽可变且变化范围大,不同带宽下基带信号的幅度变动较大,针对这一特点本文采用误差积分法设计实现了速度三档可调、可适应多种基带带宽的基带自动增益控制系统。针对突发通信越来越多的情况,本文在对突发信号检测算法进行深入研究之后,在FPGA中设计实现了适合本接收机系统的突发信号检测器。该检测器基于双滑动窗口法,采用双门限设置,高门限与最大值检测电路相结合检测突发信号的起始位置,低门限与最小值检测电路相结合检测突发信号的结束位置。本文设计的基于双滑动窗口法的突发信号检测器检测具有以下特点:门限可调、在中频60MHz采样率下可检测的信号时长最小40?s且对突发信号起止位置的判断精度能够达到4?s,这对监测接收机实现精确授时和GPS定位有直接帮助。
[Abstract]:Nowadays, with the rapid development of radio communication technology, its application scope is becoming more and more extensive. The following problems are the rapid growth of the demand for radio spectrum resources in various industries, and at the same time, the radio communication environment is becoming more and more complex. In this case, it is imperative to monitor and manage the radio spectrum resources. As the core equipment of spectrum monitoring and management, the monitoring receiver plays an irreplaceable role in purifying the electromagnetic environment and improving the radio spectrum efficiency. As more and more attention has been paid to spectrum monitoring and management in the world, the development of monitoring receivers has made great progress, and the performance requirements of monitoring receivers have become increasingly high. Based on the dynamic range of receiver, an automatic gain control system is designed and implemented on FPGA, and a burst signal detector for burst signal is designed and implemented on FPGA based on the wide application of burst communication mechanism. In this paper, the theory of automatic gain control is studied deeply, and then the automatic gain control system is designed and implemented in combination with the monitoring receiver system. The automatic gain control system designed in this paper consists of RF gain control and baseband gain control. The RF front end used in this receiver only provides variable gain amplifier but not automatic gain control function. In order to make full use of RF front end, the dynamic range of the system is improved effectively. The RF gain control system is designed and implemented in FPGA by the combination of direct calculation and fixed step size. At the same time, because the baseband bandwidth of the receiver is variable and the range of variation is large, the amplitude of the baseband signal varies greatly under different bandwidth. In view of this characteristic, the error integral method is used to design and realize the three-step adjustable speed. Baseband automatic gain control system can adapt to various baseband bandwidth. In view of more and more burst-mode communication, the burst signal detector is designed and implemented in FPGA after the research of burst signal detection algorithm. The detector is based on the double sliding window method, which uses double threshold setting, high threshold and maximum detection circuit to detect the starting position of burst signal, and low threshold and minimum detection circuit to detect the end position of burst signal. In this paper, the detection of burst signal based on double sliding window method has the following characteristics: the threshold is adjustable, At if 60MHz sampling rate, the minimum time length of the detected signal is 40 s and the accuracy of judging the starting and ending position of the burst signal can reach 4 s, which is of direct help to the precise timing and GPS positioning of the monitoring receiver.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN851
，
本文编号：2390754
[Abstract]:Nowadays, with the rapid development of radio communication technology, its application scope is becoming more and more extensive. The following problems are the rapid growth of the demand for radio spectrum resources in various industries, and at the same time, the radio communication environment is becoming more and more complex. In this case, it is imperative to monitor and manage the radio spectrum resources. As the core equipment of spectrum monitoring and management, the monitoring receiver plays an irreplaceable role in purifying the electromagnetic environment and improving the radio spectrum efficiency. As more and more attention has been paid to spectrum monitoring and management in the world, the development of monitoring receivers has made great progress, and the performance requirements of monitoring receivers have become increasingly high. Based on the dynamic range of receiver, an automatic gain control system is designed and implemented on FPGA, and a burst signal detector for burst signal is designed and implemented on FPGA based on the wide application of burst communication mechanism. In this paper, the theory of automatic gain control is studied deeply, and then the automatic gain control system is designed and implemented in combination with the monitoring receiver system. The automatic gain control system designed in this paper consists of RF gain control and baseband gain control. The RF front end used in this receiver only provides variable gain amplifier but not automatic gain control function. In order to make full use of RF front end, the dynamic range of the system is improved effectively. The RF gain control system is designed and implemented in FPGA by the combination of direct calculation and fixed step size. At the same time, because the baseband bandwidth of the receiver is variable and the range of variation is large, the amplitude of the baseband signal varies greatly under different bandwidth. In view of this characteristic, the error integral method is used to design and realize the three-step adjustable speed. Baseband automatic gain control system can adapt to various baseband bandwidth. In view of more and more burst-mode communication, the burst signal detector is designed and implemented in FPGA after the research of burst signal detection algorithm. The detector is based on the double sliding window method, which uses double threshold setting, high threshold and maximum detection circuit to detect the starting position of burst signal, and low threshold and minimum detection circuit to detect the end position of burst signal. In this paper, the detection of burst signal based on double sliding window method has the following characteristics: the threshold is adjustable, At if 60MHz sampling rate, the minimum time length of the detected signal is 40 s and the accuracy of judging the starting and ending position of the burst signal can reach 4 s, which is of direct help to the precise timing and GPS positioning of the monitoring receiver.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN851
，
本文编号：2390754
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