noise power spectrum

例句：

1. 1.The noise power spectrum of the signal is measured to determine its frequency content.
   信号的噪声功率谱被测量以确定其频率内容。
2. 2. The noise power spectrum shows that the system is operating at a high level of noise.
   噪声功率谱显示系统处于高噪声水平运行。
3. 3. The noise power spectrum is used to analyze the performance of the communication system.
   噪声功率谱用于分析通信系统的性能。