Contrarily, if the frequency bandwidthofsignal is finite, the time length of signal will be infinite when sampling in frequency domain, the time folding phenomenon will certainly happen.
反之，若信号的频带宽度有限，当进行频域抽样时，时域必然发生混叠。
2
Since there is an inherent trade-off between the amount of available bandwidth and the distance that a signal can travel, the more bandwidth is available, the farther a signal can travel.
By analyzing local properties of the signal, the application could, for instance, sharpen frames of video, or look for redundant information that can be removed to save memory or bandwidth.