低通和带通信号采样的频谱混叠分析

Analysis on Frequency Aliasing in the Sampling of Lowpass and Bandpass Signals

对带通信号的采样和重建进行了理论分析 ,结果表明 ,如果用信号的 2倍带宽频率进行采样 ,会产生频谱混叠 ,且当信号的最高和最低频率分量中含有冲激函数时 ,采样之后的信号不能精确重建原信号 ,当信号的最高和最低频率分量为有限值时 ,仍然能精确重建原信号 .研究还表明 ,低通信号的

A theory analysis on the sampling and reconstruction of bandpass signal was presented. It indicates that the original signal can be uniquely reconstructed if sampling frequency is 2 times the signal band-width and there is no δ function in the frequency border. Conversely, the original signal can not be reconstructed if there is δ function in the frequency border. The similar problem encountered in the sampling on lowpass signal with Nyquist rate is only the special case of the bandpass signal sampling.