Recovering the spectrum of a narrow-band process from syncopated samples

A nonuniform sampling strategy, phase quadrature sampling, in which a process of bandwith B is sampled at rate B in each of two channels where the two channels are pi/2 out of phase at frequency B is described. Phase quadrature sampling is a special case of sampling, where the phase between channels is fixed but arbitrary. A simple method for recovering the spectrum of the input process from syncopated samples is derived. The derivation indicates what values of phase between channels result in lossless sampling.