Track circuit frequency-shift signal is used to control the train operation, and the parameter detection should achieve high frequency resolution requirements. According to the sampling theorem knowledge, we know that it needs longer sampling time, which can not meet the real-time requirement of test instrumentation. In order to attain high frequency resolution in a relatively short period of sampling time, the paper analysed the spectrum characteristics of the frequency-shift signaling in the two formats track circuit, the domestic 18kinds of information and ZPW-2000, and then put forward a new method to test the parameters of frequency-shift signaling using CZT and time-domain measurement. At last, we compiled CZT algorithm in the MATLAB environment. The simulation results show that the method can effectively improve frequency resolution, and meet the technical indexes requirements while shortens sampling time. This algorithm research has a great practical application prospect in the design of tester about frequency-shift signaling parameters.%轨道电路移频信号是用来控制列车的行驶状态,对其参数的检测需要达到较高的频率分辨率,根据采样定理知识可知,检测需要较长的采样时间,而这不能满足测试仪表的实时性要求.为了解决在较短的采样时间内达到较高的频率分辨率问题,分析了国产18信息和ZPW-2000型两种制式移频轨道电路的移频信号的频谱特点,提出了采用CZT线性调频Z变换和时域测量相结合的方法检测移频信号的参数.在MATLAB环境下编写CZT算法进行仿真,仿真结果表明,能有效提高频率分辨率,满足技术指标要求的同时缩短了采样时间.在移频信号参数测试仪的设计中有着很大的实际应用前景.
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