在调频系统中人们普遍采用了一种叫做预加重和去加重措施，其中心思想是利用信号特性和噪声特性的差别来有效地对信号进行处理。-FM system in widespread use a technique called pre-emphasis and de-emphasis of measures, the central idea is to use the difference between the signal and noise characteristics to efficiently process the signals.