Spectral arrangement and other topics in first-order bandpass sampling theory

A problem of first-order bandpass sampling is that the indifferent disposit ion of the baseband spectrum may cause inconvenience in practical applicati ons. To overcome it, we modify the first-order bandpass sampling theory acc ording to the spectral arrangement of the sampled signal. We consider two s ituations on the arrangement of the shifted replicas of the bandpass signal spectrum: the normal and the inverse placement of the spectrum. The positi ve spectrum of the bandpass signal is placed in the lowest positive part of the sampled signal in the normal placement situation and in the lowest neg ative part in the inverse situation. The sampling frequencies are formulate d in a cluster of lower and upper bounds in both situations, and robust sam pling frequencies are given, Topics of the modified theory related to appli cations are addressed.