关于sampling

soochowren

有没有达人，介绍一下以下一些东东：
undersampling: the sampling frequency is lower than the nyquist rate,but higher than the maxium signal frequency
over sampling  : the sampling frequency is much higher thant the nyquist rate
nyquist sampling : the sampling frequency is  based on the sampling theory( two times the maximum signal frequency)
subsampling : the sampling frequency is lower thant the maximum signal frequency
baseband sampling :  the signal to be sampled is baseband  signal (i.e. signal with spectra centered around DC)
bandpass sampling  : the signal to be sampled is passband signal   

are these right?

[ 本帖最后由 soochowren 于 2008-10-10 10:55 编辑 ]

tr_coder

I believe they are correct. However, when use sub- or under-sampling, the sampling frequency still has to be at least twice of the signal bandwidth to meet the Nyquist requirement.