说明：  设模拟带通信号频率范围1KHz—1.1KHz，设计一个采样频率8KHz数字频谱分析系统，要求频率分辨率0.1Hz。若对信号直接用FFT进行频谱分析
(simulation based communications, with the frequency range 1KHz- 1.1KHz. Design of an 8 KHz sampling frequency digital spectrum analysis system requirements frequency resolution 0.1 Hz. If the signal directly FFT spectrum analysis)