机场频谱监测相关技术仿真分析

Simulation analysis of airfield spectrum monitoring technology

针对军用机场通信导航设备较多、信号环境复杂而接收设备无法区分敌我信号的问题,提出两种频谱监测方法来解决这一问题。首先采用搜索式超外差接收机测频法对接收信号进行仿真分析,通过改变系统的扫描速度和搜索频率窗口的大小来观察其对系统频率分辨力的影响,经过仿真发现采用慢速扫描时输出信号的波形与原信号波形基本保持不变;当输入信号流密度小于105时,系统分辨力都可以达到60%以上,但搜索频率窗口越小,系统分辨力越强。同时采用频率变换法对同时接收的多种信号进行测频,该方法能够进行分辨,但如果系统的测频时间低于5μs时,则系统的频率分辨力低于1 MHz。两种方法都能够对机场复杂信号进行分辨,但两种方法各有利弊,可根据机场实际需求选择频谱监测的方法。

Aiming at the problem that there are many communication and navigation devices in military airfields and the signal environment is complex, the receiving devices cannot distinguish between enemy and us signals, two spectrum monitoring methods are proposed to solve this problem. Firstly, the frequency measurement method of the search superheterodyne receiver is used to simulate and analyze the received signal, and its influence on the frequency resolution of the system is observed by changing the scanning speed of the system and the size of the search frequency window. Through simulation, it is found that the waveform of the output signal is basically unchanged from the original waveform when the slow scanning is adopted. When the input signal flow density is less than 10~5, the resolution of the system can reach more than 60%, but the smaller the search frequency window is, the stronger the resolution of the system will be. At the same time, frequency conversion method is used to measure the frequency of multiple signals received at the same time. This method can be used to resolve, but if the frequency measurement time of the system is less than 5 μs, the frequency resolution of the system is less than 1 MHz. Both methods can resolve complex signals of airports, but both methods have their own advantages and disadvantages. The spectrum monitoring method can be selected according to the actual needs of airports.